Mediation analysis methods used in observational research: a scoping review and recommendations

Kidney function decline mediates the adverse effects of per- and poly-fluoroalkyl substances (PFAS) on uric acid levels and hyperuricemia risk

Previous studies indicated per- and poly-fluoroalkyl substances (PFAS) were related to uric acid and hyperuricemia risk, but evidence for the exposure-response (E-R) curves and combined effect of PFAS mixture is limited. Moreover, the potential mediation effect of kidney function was not assessed. Hence, we conducted a national cross-sectional study involving 13,979 US adults in NHANES 2003-2018 to examine the associations of serum PFAS with uric acid and hyperuricemia risk, and the mediation effects of kidney function. Generalized linear models and E-R curves showed positive associations of individual PFAS with uric acid and hyperuricemia risk, and nearly linear E-R curves indicated no safe threshold for PFAS. Weighted quantile sum regression found positive associations of PFAS mixture with uric acid and hyperuricemia risk, and PFOA was the dominant contributor to the adverse effect of PFAS on uric acid and hyperuricemia risk. Causal mediation analysis indicated significant mediation effects of kidney function decline in the associations of PFAS with uric acid and hyperuricemia risk, with the mediated proportion ranging from 19 % to 57 %. Our findings suggested that PFAS, especially PFOA, may cause increased uric acid and hyperuricemia risk increase even at low levels, and kidney function decline plays a crucial mediation effect.

Periodontitis and hypertension are linked through systemic inflammation: A 5-year longitudinal study

AIM

To investigate the associations between periodontitis and hypertension and potential mediation via systemic inflammation through a 5-year longitudinal study.

MATERIALS AND METHODS

The severity and extent of periodontitis were determined using probing depth (PD). Oral hygiene was assessed using plaque scores. The associations between periodontal variables and 5-year blood pressure changes or incident hypertension were analysed using linear or Poisson regression, adjusting for potential confounders. Mediation analysis of two systemic inflammatory biomarkers, namely white blood cell count (WBC) and C-reactive protein (CRP) levels, was performed.

RESULTS

The study population included 901 hypertension-free participants, aged 50-73 years. Greater mean PD, higher percentage of sites with PD ≥ 6 mm and poor oral hygiene were associated with elevated systolic blood pressure and increased hypertension risk (relative risks = 1.17 [95% confidence interval [CI]: 1.02-1.34], 1.13 [95% CI: 1.02-1.26] and 1.08 [95% CI: 1.03-1.13], respectively). Periodontitis and poor oral hygiene were associated with higher WBC and CRP levels (p < .05), which, in turn, were associated with increased hypertension risk (p < .05). WBC and CRP jointly mediated 14.1%-26.9% of the associations between periodontal variables and incident hypertension.

CONCLUSIONS

Periodontitis and poor oral hygiene were associated with increased hypertension risk, and systemic inflammation was, in part, a mediator of these associations.

Associations between metabolic obesity phenotypes and pathological characteristics of papillary thyroid cancer

BACKGROUND

The association between obesity, metabolic dysregulation, and the aggressive pathological traits of papillary thyroid carcinoma (PTC) continues to be a contentious issue. To date, no investigations have examined the impact of metabolic status on the malignant pathological features of PTC in relation to obesity.

METHODS

This research involved 855 adult PTC patients from Shandong Provincial Hospital, classified into four groups based on metabolic and obesity status: metabolically healthy nonobese (MHNO), metabolically unhealthy nonobese (MUNO), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO). We employed logistic regression to investigate the relationship between these metabolic obesity phenotypes and PTC's pathological characteristics. Mediation analysis was also performed to determine metabolic abnormalities' mediating role in the nexus between obesity and these characteristics.

RESULTS

Relative to MHNO individuals, the MUO group was significantly associated with an elevated risk of larger tumor sizes and a greater number of tumor foci in PTC. Mediation analysis indicated that obesity directly influences tumor size, whereas its effect on tumor multifocality is mediated through metabolic dysfunctions. Specifically, HDL-C levels were notably associated with tumor multifocality within obese subjects, serving as a mediator in obesity's impact on this trait.

CONCLUSION

The concurrent presence of obesity and metabolic dysregulation is often connected to more aggressive pathological features in PTC. The mediation analysis suggests obesity directly affects tumor size and indirectly influences tumor multifocality via low HDL-C levels.

Associations of preoperative anaemia with healthcare resource use and outcomes after colorectal surgery: a population-based cohort study

BACKGROUND

Preoperative anaemia is common in patient undergoing colorectal surgery. Understanding the population-level costs of preoperative anaemia will inform development and evaluation of anaemia management at health system levels.

METHODS

This was a population-based cohort study using linked, routinely collected data, including residents from Ontario, Canada, aged ≥18 yr who underwent an elective colorectal resection between 2012 and 2022. Primary exposure was preoperative anaemia (haemoglobin <130 g L-1 in males; <120 g L-1 in females). Primary outcome was 30-day costs in 2022 Canadian dollars (CAD), from the perspective of a publicly funded healthcare system. Secondary outcomes included red blood cell transfusion, major adverse events (MAEs), length of stay (LOS), days alive at home (DAH), and readmissions.

RESULTS

We included 54,286 patients, with mean 65.3 (range 18-102) years of age and 49.0% females, among which 21 264 (39.2%) had preoperative anaemia. There was an absolute adjusted cost increase of $2671 per person at 30 days after surgery attributable to preoperative anaemia (ratio of means [RoM] 1.05, 95% confidence interval [CI] 1.04-1.06). Compared with the control group, 30-day risks of transfusion (odds ratio [OR] 4.34, 95% CI 4.04-4.66), MAEs (OR 1.14, 95% CI 1.03-1.27), LOS (RoM 1.08, 95% CI 1.07-1.10), and readmissions (OR 1.16, 95% CI 1.08-1.24) were higher in the anaemia group, with reduced DAH (RoM 0.95, 95% CI 0.95-0.96).

CONCLUSIONS

Approximately $2671 CAD per person in 30-day health system costs are attributable to preoperative anaemia after colorectal surgery in Ontario, Canada.

Rethinking ketamine as a panacea: adverse effects on oxygenation and postoperative outcomes

Ketamine is receiving renewed interest in perioperative medicine as an anaesthetic adjunct and a treatment for chronic conditions, including depression. Ketamine's complex pharmacologic profile results not only in several desirable effects, such as anaesthesia and analgesia, but also multiple adverse effects affecting the central nervous, cardiovascular, and respiratory systems. In addition to defining patient-centred outcomes in future clinical studies on the perioperative uses of ketamine, careful monitoring for its numerous adverse effects will be paramount.

Residential greenness and lower breast and prostate cancer incidence: Evidence from a retrospective cohort study of 977,644 participants from Israel

BACKGROUND

There is limited evidence on the associations between residential greenness and cancer incidence in longitudinal studies.

OBJECTIVES

The aim of the study was to evaluate the associations between weighted mean residential greenness exposure and cancer incidence.

METHODS

This is a registry based retrospective cohort study of 977,644 participants. The residential greenness exposure was estimated for every participant, as the weighted mean residential greenness exposure. This was based on the mean Normalized Difference Vegetation Index (NDVI) in the residential small geographic area and the duration of the residence in this area. Cancer incidence cases included consecutive newly diagnosed cases of primary cancer. Analyses were conducted for all cancer sites, lung cancer, bladder cancer, breast cancer, prostate cancer and melanoma-skin cancer. Cox regression models were used to evaluate the crude and adjusted associations (hazards ratios (HR) and its 95 % confidence intervals (CIs)) between tertiles of residential greenness and cancer incidence. Further adjusted models to nitrogen oxides (NOx) were estimated.

RESULTS

After adjustment to covariates, exposure to the highest tertile of residential greenness, compared to the lowest, were associated with lower risk for all cancer sites (HR = 0.88, 95 % CI: 0.86-0.90), breast cancer (HR = 0.85, 95 % CI: 0.80-0.89) and prostate cancer (HR = 0.85, 95 % CI: 0.79-0.91). In addition, lower risk were observed for the middle tertile of exposure and all cancer sites (HR = 0.88, 95 % CI: 0.86-0.90), breast cancer (HR = 0.88, 95 % CI: 0.84-0.92) and prostate cancer (HR = 0.83, 95 % CI: 0.79-0.89). There was no evidence for mediation by air pollution (NOx).

DISCUSSION

Residential greenness demonstrated beneficial associations with lower risk for all cancers, breast and prostate cancers. If our observations will be replicated, it may present a useful avenue for public-health intervention to reduce cancer burden through the provision of greenness exposure.

Systolic blood pressure as a critical mediator in the association between adult height and 25-year risk of stroke

BACKGROUND

Adult height is associated with the risk of stroke. However, the underlying mechanism remains unclear. We explored the mediating role of metabolic factors in the association between adult height and stroke incidence.

METHODS

We used data from 3306 community-dwelling participants with complete information on adult height, metabolic factors, and 25-year cardiovascular outcomes. Participants were classified into three adult height groups based on sex-specific height quartiles: short (Q1), average (Q2-Q3), and tall (Q4). The primary endpoint was the occurrence of cardiovascular disease, including coronary artery disease and stroke.

RESULTS

Taller adult height was associated with a lower risk of stroke. Compared with the short group the risk of stroke reduced with taller height with a hazard ratio (HR) of 0.68 in the average group (95% confidence interval [CI]: 0.50-0.93), and 0.45 in the tall group (95% CI: 0.31-0.65). Low systolic blood pressure was considered as a protective mediator in the effect of adult height on the risk of stroke in the average (HR: 0.86; 95% CI: 0.82-0.93) and the tall group (HR: 0.85; 95% CI: 0.78-0.91). Systolic blood pressure significantly contributed to height-related stroke risk (proportion mediated: 0.41; 95% CI: 0.19-1.56).

CONCLUSIONS

This study found an inverse association between adult height and stroke risk, which is partly driven by lower systolic blood pressure. These findings highlight the importance of systolic blood pressure management as a potential preventive strategy against stroke.

Chewing difficulties mediated association between edentulism and depressive symptoms among middle aged and older population

BACKGROUND

Depression is a major health condition among the aging population. Previous studies indicated that edentulism was a risk factor for depression. The link between edentulism and depression has not been fully clarified.

OBJECTIVES

This study aimed to estimate whether chewing difficulties play a mediating role in the association between edentulism and depression among middle-aged and older populations with national cross-sectional data.

METHODS

Data were obtained from the latest fourth wave of the China Health and Retirement Longitudinal Study (CHARLS). The outcome variable was set as depression, which was measured by the Center for Epidemiologic Studies Depression Scale (CES-D-10). Independent and mediated variables were separately set as self-assessed edentulism and chewing difficulties. The nearest neighbour propensity score matching (PSM) method was used to construct a matching group to balance the basic characteristics of individuals with and without edentulism with minimised bias in the estimation. Causal mediation analysis was performed to estimate the degree of contribution of chewing difficulties to the association between edentulism and depression. Several sensitivity analyses were performed to evaluate the robustness of the primary result.

RESULTS

A total of 15 853 individuals remained for analysis. After PSM, 809 individuals with edentulism and 2628 without edentulism remained for analysis. Among the matched individuals, the mean age was 66.3 ± 9.2 years, 58.5% were female, 78.8% lived in rural areas, 23.5% had edentulism, 51.1% had depressive symptoms, and 50.1% had chewing difficulties. Logistic regression results showed that a higher incidence of edentulism was associated with a higher rate of depression (OR: 1.39, 95% CI: 1.19-1.63) in the matching group. Causal mediation analysis results indicated that the average mediation effect of chewing difficulties on the association between edentulism and depression was 0.010 (95% CI: 0.005-0.015), and the average direct effect was 0.072 (95% CI: 0.036-0.11). The mediation proportion of chewing difficulties was 11.7% (95% CI: 0.079-0.21).

CONCLUSION

A higher prevalence of edentulism was associated with a higher rate of depression among middle-aged and elderly populations. Chewing difficulties moderately mediated the association between edentulism and depression. Fundamental oral function should not be neglected to improve mental health among the aging population.

Temporal relationship between inflammation and metabolic disorders and their impact on cancer risk

Background

Inflammation and metabolic disorders are closely associated with cancer. Whether inflammation leads to metabolic disorders or vice versa during cancer initiation remains unclear. In this study, we explored this temporal relationship and the co-exposure effect on cancer risk.

Methods

This prospective study had two phases. Initially, we examined the temporal relationship between inflammation (high-sensitivity C-reactive protein (CRP)) and metabolic disorders (metabolic syndrome severity Z-score (MetS-Z)) using a 3.98-year survey and cross-lagged analysis. Subsequently, we assessed the connection of co-exposure to inflammation and metabolic disorders, and the risks of overall cancer, as well as specific obesity-related, non-obesity-related, digestive system, lung, and other cancers using an 11.04-year survey and Cox proportional hazard models.

Results

The cross-lagged analysis revealed that the path coefficient from baseline CRP to follow-up MetS-Z (β2 = 0.032; 95% confidence interval (CI) = 0.026, 0.046) was more significant than the path coefficient from baseline MetS-Z to follow-up CRP (β1 = 0.009; 95% CI = -0.001, 0.019). During the follow-up, 2304 cases of cancer occurred. Compared with the risk of cancer of patients with low average cumulative CRP and MetS-Z, patients with high value had a significantly increased risk (hazard ratio = 1.54, 95% CI = 1.30, 1.83). The mediation analysis showed that MetS-Z mediated the association between CRP levels and overall cancer (12.67%), digestive system cancer (10.16%), and obesity-related cancer risk (13.87%).

Conclusions

Inflammation had a greater impact on metabolic disorders than vice versa. Co-exposure to inflammation and metabolic disorders significantly increased the risk of cancer, particularly digestive system and obesity-related cancers.

Registration

Chinese Clinical Trial Registry: ChiCTR-TNRC-11001489.

Metabolic disorders mediate the relation of miscarriage with cardiovascular diseases

AIMS

The extent to which the contribution of pregnancy loss to cardiovascular diseases (CVDs) can be explained by metabolic disorders is poorly elucidated but holds insights for reducing long-term cardiovascular risk. The aim of this study is to investigate the mediating effects of hypertension, diabetes mellitus (DM), and lipoprotein metabolism disorders on the association of miscarriage and stillbirth with coronary heart disease (CHD), stroke, heart failure, atrial fibrillation, and composite outcomes.

METHODS AND RESULTS

A total of 163 283 ever-gravid women (age 55.3 ± 7.9 years) from the UK Biobank cohort without established metabolic disorders and CVDs were included and followed from 2007 to 2010 baseline until December 2020. Causal mediation analyses were used to estimate the proportion mediated. Hypertension mediated 11.1% (95% confidence interval, 3.7-18.5%) of the association between a history of miscarriage and incident CHD. Approximately, 9.5% (4.1-14.8%) of the effect of recurrent miscarriages on incident CHD was via hypertension, 8.4% (2.5-14.3%) of the effect was via lipoprotein metabolism disorders, 1.7% (0.5-2.9%) of the effect was via DM, and 10.7% (0.2-21.1%) of the effect of recurrent miscarriages on incident stroke was via hypertension. Hypertension mediated the largest proportion of effect for the atherosclerotic cardiovascular event (15.5% for a history of miscarriage and 9.4% for recurrent miscarriages), followed by lipoprotein metabolism disorders and DM.

CONCLUSION

Hypertension, DM, and lipoprotein metabolism disorders mediated the association between miscarriage and various cardiovascular outcomes in later life. In particular, hypertension mediated a large proportion of the relationship between miscarriage and atherosclerotic CVD.

The influence of perceived teacher support on online English learning engagement among Chinese university students: a cross-sectional study on the mediating effects of self-regulation

Objectives

This study examines the association between perceived teacher support and self-regulation in learning, and their combined relationship with online English learning engagement among university students in China. The objective is to uncover the underlying mechanisms of this relationship, with a particular focus on the role of self-regulation in learning as a mediator.

Methods

The study involved 1,361 university students from Southwest China, predominantly female (73.84%) with an average age of 18.94 years (SD = 1.07). Refined measurement tools were employed to assess perceived teacher support, online English learning engagement, and self-regulation in learning.

Results

The findings indicate that components of self-regulation, such as goal setting, environmental structuring, and time management, act as full mediators in the relationship between perceived teacher support and online English learning engagement.

Conclusion

This research underscores the importance of self-regulation in learning in linking perceived teacher support with online English learning engagement. The insights gained are crucial for enhancing teaching strategies in online English language education.

Quality of life, household income, and dietary habits are associated with the risk of sarcopenia among the Chinese elderly

BACKGROUND

Health-related quality of life (HRQoL), which can be influenced by various aspects, especially socioeconomic status and lifestyle, has been identified as an important predictor of the prognosis of older adults. Dietary habit, a major part of lifestyle, can affect the nutritional status, which is closely correlated with the development of geriatric syndromes in the elderly.

AIMS

The aim of the study was to examine the association of HRQoL, socioeconomic status, and lifestyle with the risk and severity of sarcopenia, a geriatric syndrome characterized by progressive loss of skeletal muscle mass, strength and function.

METHODS

A cross-sectional retrospective study with 2877 participants aged ≥65 years was performed. HRQoL was assessed using EuroQoL Five Dimensions questionnaire. Socioeconomic status was assessed by the educational attainment, occupation, and household income. Lifestyle was assessed using 12 items closely related to Chinese living habits. The information of daily dietary habits including tea, alcohol, type of diet, and volume of drinking water were collected. The associations of HRQoL, socioeconomic status, and lifestyle with the risk of sarcopenia were examined by multivariate regression logistical analysis. The potential causal role of age, body mass index, and waist circumference in the effect of HRQoL on sarcopenia risk was analyzed by causal mediation analysis.

RESULTS

High HRQoL [adjusted odds ratio (OR) =0.85, 95% confidence interval (CI) =0.69-0.95, P=0.034] and household income levels (adjusted OR =0.74, 95% CI =0.57-0.95, P=0.019) were inversely associated with the risk of sarcopenia. Meanwhile, more consumption of spicy food (adjusted OR =1.34, 95% CI =1.09-1.81, P =0.037) and occasionally drinking (adjusted OR =1.46, 95% CI =1.07-2.00, P =0.016, as compared to those never drinking) were associated with higher risk of sarcopenia, while skipping breakfast occasionally (adjusted OR =0.37, 95% CI =0.21-0.64, P <0.001, as compared to those eating breakfast every day) and less consumption of salt (adjusted OR =0.71, 95% CI =0.52-0.96, P =0.026, as compared to those consuming high amount of salt) were associated with lower risk of sarcopenia. Further causal mediation analysis aimed to explore how much age, body mass index, and waist circumference might explain the effect of HRQoL on the risk of sarcopenia showed that the estimated proportion that mediated the effect of HRQoL on the risk of sarcopenia by age was 28.0%.

CONCLUSIONS

In summary, our findings demonstrate that low levels of HRQoL and household income, more intake of salt and spicy food, and occasional intake of alcohol are correlated with higher risk of sarcopenia, while skipping breakfast occasionally is associated with lower risk of sarcopenia in a Chinese population of older adults.

A nested case-control study of serum zinc and incident diabetes among Chinese adults: Effect modifications and mediation analysis

Although numerous evidences suggest that zinc may have a beneficial impact on preventing and treating diabetes, findings from the population studies are inconclusive. To address this gap, we conducted a nested case-control study, employing restricted cubic splines and a conditional logistic regression model to explore the association between serum zinc levels and the risk of diabetes. We also assessed potential effect modifications through stratified analyses and examined the mediating effects of metabolic indicators using a multiclass mediation effect model. We measured baseline serum zinc concentrations using Inductively Coupled Plasma Mass Spectrometry in a cohort of 2156 participants, including 1078 individuals with diabetes and 1078 matched controls. Our findings revealed a 51 % increased risk of diabetes when comparing the highest quartile (Q4) to the lowest quartile (Q1) of serum zinc levels (Odds Ratio [95 % Confidence Interval]: 1.51 [1.09, 2.09]). There was a positive linear dose-response relationship between serum zinc and diabetes risk (P overall ≤0.01, P nonlinear = 0.20). Effect modifications were evident between serum zinc and factors such as educational attainment, body mass index, alcohol index, family history of diabetes, history of hypertension, coronary heart disease, and stroke, all of which influenced the risk of diabetes (all P-interaction <0.05). Moreover, our study identified significant indirect effects of triglycerides levels on diabetes risk for participants in the third (Q3) and fourth (Q4) quartiles of serum zinc, with mediation proportions of 19.23 % and 19.28 %, respectively. A significant indirect effect of alanine aminotransferase on diabetes risk was found for those in the Q4 of serum zinc, with a mediation proportion of 12.05 %. Considering these findings, it is advisable to conduct testing for serum zinc level and exercise caution when considering zinc supplementation. Furthermore, our results emphasized the necessity for additional validation through large-sample prospective population studies and experimental research.

Social determinants of health and incident postoperative delirium: Exploring key relationships in the SAGES study

BACKGROUND

Examining the associations of social determinants of health (SDOH) with postoperative delirium in older adults will broaden our understanding of this potentially devastating condition. We explored the association between SDOH factors and incident postoperative delirium.

METHODS

A retrospective study of a prospective cohort of patients enrolled from June 18, 2010, to August 8, 2013, across two academic medical centers in Boston, Massachusetts. Overall, 560 older adults age ≥70 years undergoing major elective non-cardiac surgery were included in this analysis. Exposure variables included income, lack of private insurance, and neighborhood disadvantage. Our main outcome was incident postoperative delirium, measured using the Confusion Assessment Method long form.

RESULTS

Older age (odds ratio, OR: 1.01, 95% confidence interval, CI: 1.00, 1.02), income <20,000 a year (OR: 1.12, 95% CI: 1.00, 1.26), lack of private insurance (OR: 1.19, 95% CI: 1.04, 1.38), higher depressive symptomatology (OR: 1.02, 95% CI: 1.01, 1.04), and the Area Deprivation Index (OR: 1.02, 95% CI: 1.01, 1.04) were significantly associated with increased risk of postoperative delirium in bivariable analyses. In a multivariable model, explaining 27% of the variance in postoperative delirium, significant independent variables were older age (OR 1.01, 95% CI 1.00, 1.02), lack of private insurance (OR 1.18, 95% CI 1.02, 1.36), and depressive symptoms (OR 1.02, 95% CI 1.00, 1.03). Household income was no longer a significant independent predictor of delirium in the multivariable model (OR:1.02, 95% CI: 0.90, 1.15). The type of medical insurance significantly mediated the association between household income and incident delirium.

CONCLUSIONS

Lack of private insurance, a social determinant of health reflecting socioeconomic status, emerged as a novel and important independent risk factor for delirium. Future efforts should consider targeting SDOH factors to prevent postoperative delirium in older adults.

Mediating pathways that link adverse childhood experiences with cardiovascular disease

OBJECTIVES

There is uncertainty about which factors mediate the association between adverse childhood experiences (ACEs) and cardiovascular disease (CVD). This could inform secondary prevention targets.

STUDY DESIGN

Mediation analysis of a prospective cohort study.

METHODS

English Longitudinal Study of Ageing (ELSA) wave 3 data (2006/7) were used to measure retrospective exposure to 12 individual ACEs and waves 2 to 4 (2004/5 to 2008/9) data to measure current exposure to potential mediators [smoking, physical activity, alcohol consumption, body mass index, depression, and C-reactive protein (CRP)]. Waves 4 to 9 ELSA data (2008/9 to 2018/19) were used to measure incident CVD. Cumulative ACE exposure was categorised into experiencing 0, 1 to 3, or ≥4 individual ACEs. Associations were tested between ACE categories, potential mediators, and incident CVD, to inform which variables were analysed in causal mediation models.

RESULTS

The analytical cohort consisted of 4547 participants (56% women), with a mean age of 64 years (standard deviation = 9 years). At least one ACE had been experienced by 45% of the cohort, and 24% developed incident CVD over a median follow-up period of 9.7 years (interquartile range: 5.3-11.4 years). After adjusting for potential confounders, experiencing ≥4 ACEs compared with none was associated with incident CVD [odds ratio (OR): 1.55; 95% confidence interval (CI): 1.10, 2.17], and the association of one to three ACEs compared with none was non-significant (OR: 1.08; 95% CI: 0.93, 1.24). There were two statistically significant mediators of the association between ≥4 ACEs and incident CVD: CRP and depression, which accounted for 10.7% and 10.8% of the association, respectively.

CONCLUSIONS

Inflammation and depression partially mediated the association between ACEs and CVD. Targeting these factors may reduce the future incidence of CVD.

The Link between the Nature of the Human-Companion Animal Relationship and Well-Being Outcomes in Companion Animal Owners

Research into the impact of companion animals on well-being has been both extensive and inconclusive, with studies finding both positive and negative relationships. The present research explored three previously unexamined relationship science concepts that may help clarify whether companion animals provide well-being benefits: self-expansion (the process of adding positive content to the self through incorporating new resources and perspectives into one's identity or engaging in novel, exciting activities), perceived pet responsiveness, and perceived pet insensitivity; as well as attachment. We focused on dog and cat owners' depression, anxiety, positive and negative affect, and loneliness through an online survey with a large sample population (N = 1359). We found that perceived pet insensitivity is a significant positive predictor of depression, anxiety, negative affect, and loneliness; that attachment is a significant positive predictor of depression, anxiety, and loneliness, and a significant negative predictor of positive affect; and that self-expansion is a significant positive predictor of positive affect, and a significant negative predictor of loneliness. Loneliness emerged as a mediator in the relationship between perceived pet insensitivity, attachment, self-expansion, and all mental well-being outcome variables. These findings indicate that perceived pet insensitivity, attachment, and self-expansion may play an important yet neglected role in well-being outcomes.

Is the long-term poor prognosis of acute myocardial infarction in patients with mental illness mediated through their poor adherence with recommended healthcare?

BACKGROUND

Compared with patients without evidence of psychiatric symptoms, those with mental disorders experience reduced adherence with recommended healthcare and poorer clinical outcomes. This study aimed to evaluate whether the worse prognosis of patients with mental disorders after experiencing acute myocardial infarction could be fully or partially mediated by their reduced adherence to recommended healthcare.

METHODS

In this retrospective cohort population-based study, 103 389 residents in the Italian Lombardy Region who experienced acute myocardial infarction in 2007-19 were identified. Among them, 1549 patients with severe mental illness (SMI) were matched with five cohort members without evidence of mental disorders (references). Recommended healthcare (cardiac medicaments and selected outpatient services) was evaluated in the year after the date of index hospital discharge. The first occurrences of cardiovascular (CV) hospital admissions and any-cause-death were considered as endpoints. Mediation analysis was performed to investigate whether post-discharge use of recommended healthcare may be considered a mediator of the relationship between healthcare exposure and endpoints occurrence.

RESULTS

Compared with references, patients with SMI had lower adherence with recommended healthcare and adjusted risk excesses of 39% and 73% for CV hospitalizations and all-cause mortality. Mediation analysis showed that 4.1% and 11.3% of, respectively, CV hospitalizations and deaths occurred among psychiatric patients was mediated by their worse adherence to specific healthcare.

CONCLUSION

The reduced use of recommended outpatient healthcare by patients with SMI had only a marginal effect on their worse prognosis. Other key factors mediating the prognostic gap between patients with and without mental disorders should be investigated.

Short sleep time may be the main reason for irregular breakfast to cause overweight-a cross-sectional study

Introduction

In recent years, the relationship between circadian rhythm and overweight and obesity has attracted the attention of many scholars.

Methods

To evaluate association between the duration of sleep and the regularity of breakfast and overweight. A total of 1,178 students from Qingdao University were selected by stratified cluster sampling. There were 601 males (24.69 ± 0.80 years old) and 569 females (24.54 ± 0.70 years old). We used body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) to define overweight levels. Chi-square test, Pearson correlation test, and logistic regression were applied to test association among overweight, sleep duration, sleep onset time, and breakfast regularity. Pittsburgh sleep quality index was used to assess the overall sleep quality of the study subjects. Mediation effect and Sobel test were used to analyze the effect of sleep duration on breakfast regularity and overweight.

Results

Only 34.1% of the population ate breakfast every day, and eating breakfast 1-3 times per week was associated with a higher risk of overweight (BMI: OR = 2.183, 95%CI: 1.369,3,481; WC: OR = 2.101, 95%CI: 1.232,3,583; WHR: OR = 2.108, 95%CI: 1.331,3,337). The effects of all types of Usual Breakfast Consumption Frequency on overweight were fully mediated by sleep duration (p < 0.05). In particular, the subjects exercised outdoors more than five times per week slept longer (p < 0.05).

Conclusion

Short sleep duration may be the main reason for irregular breakfast leading to overweight. Adequate outdoor exercise is essential for weight maintenance.

Influence of mental health service provision on the perceived quality of life among psychiatric outpatients: associations and mediating factors

Objective

To investigate the relationship between perceived mental health service provision and quality of life (QoL) as perceived by patients in psychiatric outpatient care.

Methods

A total of 373 adult patients registered at 15 psychiatric outpatient clinics in three regions in central and southern Sweden were included in the study. Survey data were collected using a questionnaire on mental health service provision, symptom severity, recovery, clinical diagnosis, sociodemographics (serving as independent variables) and QoL (serving as the dependent variable). Three aspects of mental health service provision were used: patients’ perceived quality of care, perceived staff-patient interaction, and patient reported psychiatric treatments. Structural equation modelling was used to model the relationship among the variables.

Results

Variables in mental health service provision showed few direct associations with patients’ perceived QoL. Instead, the associations of mental health service provision on QoL were mainly mediated through symptom severity and recovery. These relationships were retained after adjusting for sociodemographic variables and clinical diagnoses. The final model achieved excellent goodness of fit (χ2 = 49.502, p = 0.230, RMSEA = 0.020, CFI = 0.997 and a SRMR = 0.024).

Conclusion

This study shows that mental health service provision is associated with patients’ perceived QoL; however, this association is mostly indirect and mediated by reduced symptom severity and increased recovery. This finding can help inform the design of future interventions to enhance service provision to improve patients’ QoL.

The associations between social determinants of health, mental health, substance-use and recidivism: a ten-year retrospective cohort analysis of women who completed the connections programme in Australia

BACKGROUND

Women with substance-use issues are overrepresented in prison. Research on women's recidivism often focuses on offending behaviour rather than the health and social circumstances women are experiencing when reimprisonment occurs. This study examines the relationship between social determinants of health (SDOH), mental health, substance-use and recidivism among women exiting prison with histories of substance-use.

METHODS

A retrospective cohort study of women exiting prison who completed the transitional support programme "Connections" between 2008 and 2018. Recidivism was measured up to two years post-release. Women's support needs were measured at baseline (4 weeks pre-release) and follow-up (four weeks post-release). Ongoing needs in relation to well-established SDOH were calculated if: (1) at baseline women were identified as having a re-entry need with housing, employment, finances, education, domestic violence, child-custody and social support and (2) at follow-up women reported still needing help in that area. Women's self-reported substance-use and mental health since release were captured at follow-up. Descriptive statistics were calculated for all measures. Associations between SDOH, mental health, substance-use and recidivism were estimated by multiple logistic regression, adjusting for potential confounders. We also evaluated the mediating effects of mental health on the relationship between SDOH and substance-use.

RESULTS

Substance-use was associated with increased odds of recidivism (adjusted odds ratio (AOR) 1.8, 95% confidence interval (CI) 1.1-2.9; p = 0.02). Poor mental health (AOR 2.9, 95% CI 1.9-4.6; p =  < 0.01), ongoing social support (AOR 3.0, 95% CI 1.9-5.0; p =  < 0.01), child-custody (AOR 1.9, 95% CI 1.0-3.3 p = 0.04), financial (AOR 2.0, 95% CI 1.3-3.2; p =  < 0.01) and housing (AOR 1.8, 95% CI 1.1-2.9; p = 0.02) needs were individually associated with increased odds of substance-use. Mediation analysis found mental health fully mediated the effects of ongoing housing (beta efficiency (b) = - 033, standard error (SE) 0.01; p = 0.05), financial (b = 0.15, SE 0.07; p = 0.05), child-custody (b = 0.18, SE 0.01; p = 0.05) and social support (b = 0.36, SE 0.1; p = 0.05) needs onto substance-use, and partially mediated the effects of domestic violence (b = 0.57, SE 0.23; p = 0.05) onto substance-use.

CONCLUSION

This study underscores the critical importance of addressing the interplay between SDOH, mental health, substance-use and recidivism. An approach that targets SDOH holds the potential for reducing mental distress and substance-use, and related recidivism.

Revealing subgroup-specific mechanisms of change via moderated mediation: A meditation intervention example

OBJECTIVE

Effective psychosocial interventions exist for numerous mental health conditions. However, despite decades of research, limited progress has been made in clarifying the mechanisms that account for their beneficial effects. We know that many treatments work, but we know relatively little about why they work. Mechanisms of change may be obscured due to prior research collapsing across heterogeneous subgroups of patients with differing underlying mechanisms of response. Studies identifying baseline individual characteristics that predict differential response (i.e., moderation) may inform research on why (i.e., mediation) a particular subgroup has better outcomes to an intervention via tests of moderated mediation.

METHOD

In a recent randomized controlled trial comparing a 4-week meditation app with a control condition in school system employees (N = 662), we previously developed a "Personalized Advantage Index" (PAI) using baseline characteristics, which identified a subgroup of individuals who derived relatively greater benefit from meditation training. Here, we tested whether the effect of mindfulness acquisition in mediating group differences in outcome was moderated by PAI scores.

RESULTS

A significant index of moderated mediation (IMM = 1.22, 95% CI [0.30, 2.33]) revealed that the effect of mindfulness acquisition in mediating group differences in outcome was only significant among those individuals with PAI scores predicting relatively greater benefit from the meditation app.

CONCLUSIONS

Subgroups of individuals may differ meaningfully in the mechanisms that mediate their response to an intervention. Considering subgroup-specific mediators may accelerate progress on clarifying mechanisms of change underlying psychosocial interventions and may help inform which specific interventions are most beneficial for whom. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Delirium During Critical Illness and Subsequent Change of Treatment in Patients With Cancer: A Mediation Analysis

OBJECTIVES

To assess whether delirium during ICU stay is associated with subsequent change in treatment of cancer after discharge.

DESIGN

Retrospective cohort study.

SETTING

A 50-bed ICU in a dedicated cancer center.

PATIENTS

Patients greater than or equal to 18 years old with a previous proposal of cancer treatment (chemotherapy, target therapy, hormone therapy, immunotherapy, radiotherapy, oncologic surgery, and bone marrow transplantation).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We considered delirium present if Confusion Assessment Method for the ICU was positive. We assessed the association between delirium and modification of the treatment after discharge. We also performed a mediation analysis to assess both the direct and indirect (i.e., mediated by the development of functional dependence after discharge) of delirium on modification of cancer treatment and whether the modification of cancer treatment was associated with mortality at 1 year. We included 1,134 patients, of whom, 189 (16.7%) had delirium. Delirium was associated with the change in cancer treatment (adjusted odds ratio [OR], 3.80; 95% CI, 2.72-5.35). The association between delirium in ICU and change of treatment was both direct and mediated by the development of functional dependence after discharge. The proportion of the total effect of delirium on change of treatment mediated by the development of functional dependence after discharge was 33.0% (95% CI, 21.7-46.0%). Change in treatment was associated with increased mortality at 1 year (adjusted OR, 2.68; 95% CI, 2.01-3.60).

CONCLUSIONS

Patients who had delirium during ICU stay had a higher rate of modification of cancer treatment after discharge. The effect of delirium on change in cancer treatment was only partially mediated by the development of functional dependence after discharge. Change in cancer treatment was associated with increased 1-year mortality.

COVID-19 vaccination effectiveness in the population of Friuli Venezia Giulia, North-East Italy. Control of bias associated with divergent compliance to policies in a test-negative case-control study

BACKGROUND

Vaccine effectiveness (VE) studies consolidate knowledge of real-world effectiveness in different contexts. However, methodological issues may undermine their conclusions: to assess the VE against COVID-19 within the Italian population, a specific threat to validity is related to the consequences of divergent compliance to the Green Pass policy.

METHODS

To address this challenge we conducted a test negative case-control (TNCC) study and multiple sensitivity analysis among residents aged ≥ 12 in Friuli Venezia Giulia Region (FVG), North-east Italy, from February 1, 2021 to March 31, 2022. Information regarding 211,437 cases of COVID-19 infection and 845,748 matched controls was obtained from the regional computerized health database. The investigation considered: COVID-19 infection, hospitalization, and death. Multiple conditional logistic regressions adjusted for covariates were performed and VE was estimated as (1-OR COVID-19vaccinated vs. unvaccinated)x100. Mediation analyses were carried out to offset potential collider variables, particularly, the number of swabs performed after the introduction of pandemic restrictions.

RESULTS

Full-cycle VE against infection decreased from 96% (95% CI: 96, 97) in the Alpha period to 43% (95% CI: 42, 45) in the Omicron period. Booster dose raised the protection in Omicron period to 67% (95% CI: 66, 67). Against the evasive Omicron variant, the protection of the booster dose was 87% (95% CI: 83, 90) for hospitalization and 90% (95% CI: 82, 95) for death. The number of swabs performed was included as a covariate in the adjustments, and the mediation analysis confirmed that it was a strong mediator between vaccination and COVID-19-related outcomes.

CONCLUSIONS

The study suggests that, under similar TNCC settings, mediation analysis and adjustment for number of diagnostic tests should be included, as an effective approach to the challenge of differential testing behavior that may determine substantial selection bias. This correction allowed us to align with results from other studies that show how full-cycle VE against infection was initially high but decreased over time by variant circulation, counterbalanced by booster dose that raised protection across variants and outcome severity.

Mediation analysis of mental health characteristics linking social needs to life satisfaction among immigrants

Background

Life satisfaction contributes to improved long and healthy lives, enhanced biological function, better mental health, and decreased mortality risks. Social needs (e.g., food security, employment, healthcare utilization) are important determinants of mental health and life satisfaction among immigrants. However, there is limited literature on how social needs influence mental health, which, in turn, affects life satisfaction among immigrants. We examined whether mental health influences the mechanisms of the relationship between social needs and life satisfaction among immigrants.

Methods

We used the 2021 cross-sectional National Health Interview Survey data on U.S. immigrants (n = 4320) aged ≥18 years. We conducted weighted mediation analyses with multiple linear regression. Life satisfaction (scores 0-10; ≥1 as higher life satisfaction) was the dependent variable; independent variables were food security, employment, and healthcare utilization; and the mediator, serious psychological distress (SPD: scores 0-24; ≥1 as higher SPD).

Results

The total effect (not accounting for SPD) of food insecurity (vs. secure) on life satisfaction was negative (β = -0.61, p < 0.001); the direct effect (after accounting for SPD) was not statistically significant (β = -0.21, p = 0.153), while the indirect effect (food insecurity's effect explained by SPD) was negative (β = -0.40, p < 0.001). The total (β = 0.32, p < 0.001), direct (β = 0.24, p = 0.004), and indirect (β = 0.09, p = 0.006) effects of being employed (vs. unemployed) on life satisfaction were positive. The total (β = -0.12, p = 0.116) and direct (β = -0.03, p = 0.683) effects of healthcare utilization within the past year (vs. more than a year) on life satisfaction were not statistically significant, whereas the indirect effect was negative (β = -0.09, p < 0.001).

Conclusions

SPD mediates the effect of food security, healthcare utilization, and employment on life satisfaction, suggesting the need to improve social needs and mental health among immigrants.

Attention-deficit/hyperactivity disorder symptoms and subsequent cardiometabolic disorders in adults: investigating underlying mechanisms using a longitudinal twin study

BACKGROUND

Emerging research suggests that attention-deficit/hyperactivity disorder (ADHD) increases the risk for cardiovascular (CVDs) and metabolic disorders (i.e., cardiometabolic disorders) in adulthood. Yet, available studies are scarce and have mainly been focused on individuals receiving clinical ADHD diagnoses. We aimed to investigate the prospective associations of ADHD symptoms in young and mid-adulthood with subsequent cardiometabolic disorders and the underlying mechanisms.

METHODS

We studied 10,394 twins from the Swedish Twin Registry (STR), born between 1958 and 1985 without previous medical history of cardiometabolic disorders. They provided self-assessment of ADHD symptoms (score range 0-36) via a validated, DSM-IV-based scale in a web-based questionnaire/telephone interview within the Study of Twin Adults: Genes and Environment (STAGE), in 2005-2006 (aged 19-47 years), and were followed until the end of 2018 (33-59 years) to identify incident clinical diagnoses/medication prescriptions for cardiometabolic disorders acquired from Swedish national registers. We used Cox regression models to investigate the associations between ADHD symptoms score and cardiometabolic outcomes, with and without adjustment for relevant covariates, and a co-twin control design to study familial confounding.

RESULTS

A one-unit increase in the level of ADHD symptoms was associated with a 2% increase in the rate of CVDs (hazard ratio [HR] = 1.02, 95% confidence interval 1.01-1.04) and a 3% increase in the rate of metabolic disorders (HR = 1.03, 1.02-1.05), after adjusting for birth year and sex. The associations were no longer significant after adjusting for educational attainment, lifestyle factors, and comorbid psychiatric disorders. The associations remained significant after adjusting for familial factors shared by dizygotic twin pairs but became nonsignificant after adjusting for factors shared by monozygotic twin pairs. However, the strength of the associations attenuated significantly in monozygotic twins compared to dizygotic twins for CVDs only, suggesting genetic confounding.

CONCLUSIONS

ADHD symptom score is associated with a higher risk for cardiometabolic disorders, which may be explained by lower educational attainment, adverse lifestyle factors, and psychiatric comorbidities. Moreover, the associations appear to be partly confounded by shared genetic factors, especially for CVDs. Further research is needed to investigate the identified associations at the level of individual cardiometabolic disorders and to follow-up participants until a more advanced older age.

The complex role of air pollution on the association between greenness and respiratory mortality: Insight from a large cohort, 2009-2020

BACKGROUND

Although emerging studies have illuminated the protective association between greenness and respiratory mortality, efforts to quantify the potentially complex role of air pollution in the causal pathway are still limited. We aimed to examine the potential roles of air pollution in the causal pathway between greenness and respiratory mortality in China.

METHODS

We used data from a community-based prospective cohort of 654,115 participants in southern China (Jan 2009-Dec 2020). We evaluated the greenness exposure as a three-year moving average Normalized Difference Vegetation Index (NDVI) within the 500 m buffer around the residence. Cox proportional hazards model was applied to estimate the association between greenness and respiratory mortality. Causal mediation analysis combined with a four-way dimensional decomposition method was utilized to simultaneously quantify the interaction and mediation role of air pollution including PM2.5, PM10, or NO2 on the greenness-respiratory mortality relationship.

FINDINGS

We observed 6954 respiratory deaths during 12 years of follow-up. Increasing NDVI level from the lowest to the highest quartile is associated with a 19 % (95%CI: 13-25 %) reduction in the respiratory mortality risk. For the total protective effect, the proportion attributable to the overall negative interaction between greenness and air pollution (PM2.5, PM10, or NO2) was 2.2 % (1.7-3.2 %), 3.5 % (0.4-3.7 %), or 25.0 % (22.8-27.1 %), respectively. Simultaneously, we estimated 25.5 % (20.1-32.0 %), 49.5 % (32.5-71.9 %), or 1.0 % (0.8-1.2 %) of the total protective association was mediated through a reduction in PM2.5, PM10, or NO2, respectively.

INTERPRETATION

Increased greenness exposure mitigated respiratory mortality through both the antagonistic interaction and mediation pathway of air pollution (PM2.5, PM10, or NO2).

Mediating effect of body fat percentage in the association between ambient particulate matter exposure and hypertension: a subset analysis of China hypertension survey

BACKGROUND

Hypertension caused by air pollution exposure is a growing concern in China. The association between air pollutant exposure and hypertension has been found to be potentiated by obesity, however, little is known about the processes mediating this association. This study investigated the association between fine particulate matter (aerodynamic equivalent diameter ≤ 2.5 microns, PM2.5) exposure and the prevalence of hypertension in a representative population in southern China and tested whether obesity mediated this association.

METHODS

A total of 14,308 adults from 48 communities/villages in southern China were selected from January 2015 to December 2015 using a stratified multistage random sampling method. Hourly PM2.5 measurements were collected from the China National Environmental Monitoring Centre. Restricted cubic splines were used to analyze the nonlinear dose-response relationship between PM2.5 exposure and hypertension risk. The mediating effect mechanism of obesity on PM2.5-associated hypertension was tested in a causal inference framework following the approach proposed by Imai and Keele.

RESULTS

A total of 20.7% (2966/14,308) of participants in the present study were diagnosed with hypertension. Nonlinear exposure-response analysis revealed that exposure to an annual mean PM2.5 concentration above 41.8 µg/m3 was associated with increased hypertension risk at an incremental gradient. 9.1% of the hypertension burden could be attributed to exposure to elevated annual average concentrations of PM2.5. It is noteworthy that an increased body fat percentage positively mediated 59.3% of the association between PM2.5 exposure and hypertension risk, whereas body mass index mediated 34.3% of this association.

CONCLUSIONS

This study suggests that a significant portion of the estimated effect of exposure to PM2.5 on the risk of hypertension appears to be attributed to its effect on alterations in body composition and the development of obesity. These findings could inform intersectoral actions in future studies to protect populations with excessive fine particle exposure from developing hypertension.

The association between renal hyperfiltration and mortality is not mediated by diabetes mellitus

BACKGROUND

Renal hyperfiltration (RHF), recently established as a risk factor for mortality, is linked to current and subsequent diabetes mellitus (DM). DM could be seen as a mediator in the pathway between RHF and mortality. However, the mediating role of DM in the relationship between RHF and mortality is unclear.

METHODS AND RESULTS

Based on a cohort of 2682 Finnish men from the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) followed-up for 35 years, we evaluated the association between RHF and mortality, with DM as a mediator, following two methods: a classic mediation analysis approach, using Cox regression, and a counterfactual framework for mediation analysis, using g-computation, Cox regression, and logistic regression. RHF is associated with an increased risk of mortality. This association was not mediated by DM. Under a counterfactual framework and on a hazard ratio scale, RHF association with mortality had a total effect of 1.54 (95% confidence interval, 1.26-1.98) and a controlled direct effect of 1.66 (1.34-2.16).

CONCLUSION

An association between RHF and mortality risk, independent of DM, was established. RHF should be considered, managed, and followed-up as a mortality-associated condition, regardless of the status of DM. We suggest clinicians to consider including RHF screening in routine clinical care, especially diabetic care.

Applying the Global Leadership Initiative on Malnutrition criteria in patients admitted with SARS-CoV-2 infection using computed tomography imaging

BACKGROUND

Patients with low muscle mass and acute SARS-CoV-2 infection meet the Global Leadership Initiative on Malnutrition (GLIM) etiologic and phenotypic criteria to diagnose malnutrition, respectively. However, available cut-points to classify individuals with low muscle mass are not straightforward. Using computed tomography (CT) to determine low muscularity, we assessed the prevalence of malnutrition using the GLIM framework and associations with clinical outcomes.

METHODS

A retrospective cohort was conducted gathering patient data from various clinical resources. Patients admitted to the COVID-19 unit (March 2020 to June 2020) with appropriate/evaluable CT studies (chest or abdomen/pelvis) within the first 5 days of admission were considered eligible. Sex- and vertebral-specific skeletal muscle indices (SMI; cm2 /m2 ) from healthy controls were used to determine low muscle mass. Injury-adjusted SMI were derived, extrapolated from cancer cut-points and explored. Descriptive statistics and mediation analyses were completed.

RESULTS

Patients (n = 141) were 58.2 years of age and racially diverse. Obesity (46%), diabetes (40%), and cardiovascular disease (68%) were prevalent. Using healthy controls and injury-adjusted SMI, malnutrition prevalence was 26% (n = 36/141) and 50% (n = 71/141), respectively. Mediation analyses demonstrated a significant reduction in the effect of malnutrition on outcomes in the presence of Acute Physiology and Chronic Health Evaluation II, supporting the mediating effects of severity of illness intensive care unit (ICU) admission, ICU length of stay, mechanical ventilation, complex respiratory support, discharge status (all P values = 0.03), and 28-day mortality (P = 0.04).

CONCLUSIONS

Future studies involving the GLIM criteria should consider these collective findings in their design, analyses, and implementation.

β-Aminoisobutyric Acid Relates to Favorable Glucose Metabolism through Adiponectin in Adults with Obesity Independent of Prediabetes

β-Aminoisobutyric acid (BAIBA) is secreted by skeletal muscle and promotes insulin sensitivity, fat oxidation, and anti-inflammation. While BAIBA is purportedly lower in individuals with obesity, no work has examined if prediabetes (PD) differentially impacts BAIBA concentrations in people with obesity. Methods. Adults were classified as normal glucose tolerant (NGT; n = 22 (20F); 48.0 ± 2.4 yrs; 36.9 ± 1.2 kg/m2) or PD (n = 23 (18F); 54.2 ± 1.6 yrs; 38.4 ± 1.2 kg/m2) based on ADA criteria. A 180-minute 75 g OGTT was used to estimate fasting (HOMA-IR (liver)) and postprandial (Matsuda index (muscle)) insulin sensitivity as well as β-cell function (disposition index (DI), glucose-stimulated insulin secretion adjusted for insulin sensitivity). Body composition and fasting measures of BAIBA, fat oxidation (indirect calorimetry), and adipokines were determined. Results. NGT and PD had similar BAIBA concentrations (1.4 ± 0.1 vs. 1.2 ± 0.1 μM, P = 0.23) and fat oxidation (P = 0.31), despite NGT having lower fasting (92.2 ± 1.2 vs. 104.1 ± 3.2 mg/dL, P = 0.002) and tAUC180min glucose (P < 0.001) compared to PD. Moreover, NGT had higher postprandial insulin sensitivity (P = 0.01) and higher total phase DIliver (P = 0.003) and DImuscle (P = 0.001). Increased BAIBA was associated with adiponectin (r = 0.37, P = 0.02), adiponectin/leptin ratio (r = 0.39, P = 0.01), and lower glucose and insulin at 180 minutes (r = -0.31, P = 0.03 and r = -0.39, P = 0.03, respectively). Adiponectin also correlated with lower glucose at 180 minutes (r = -0.45, P = 0.005), and mediation analysis showed that BAIBA was no longer a significant predictor of glucose at 180 minutes after controlling for adiponectin (P = 0.08). Conclusion. While BAIBA did not differ between NGT and PD, higher BAIBA is related to favorable glucose metabolism, possibly through an adiponectin-related mechanism. Additional work is required to understand how exercise and/or diet impact BAIBA in relation to type 2 diabetes risk.

Prognostic Value of Left Ventricular 18 F-Florbetapir Uptake in Systemic Light-Chain Amyloidosis

Background

Myocardial immunoglobulin light-chain (AL) amyloid deposits trigger heart failure, cardiomyocyte stretch and myocardial injury, leading to adverse cardiac outcomes. Positron emission tomography/computed tomography (PET/CT) with 18 F-florbetapir, a novel amyloid-targeting radiotracer, can quantify left ventricular (LV) amyloid burden, but its prognostic value is not known. Therefore, we aimed to evaluate the prognostic value of LV amyloid burden quantified by 18 F-florbetapir PET/CT and to identify mechanistic pathways mediating its association with outcomes.

Methods

Eighty-one participants with newly-diagnosed systemic AL amyloidosis were prospectively enrolled and underwent 18 F-florbetapir PET/CT. LV amyloid burden was quantified using 18 F-florbetapir LV percent injected dose (%ID). Mayo AL stage was determined using troponin T, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and difference between involved and uninvolved free light chain levels. Major adverse cardiac events (MACE) were defined as all-cause death, heart failure hospitalization, or cardiac transplantation within 12 months.

Results

Among participants (median age 61 years, 57% males), 36% experienced MACE. Incidence of MACE increased across tertiles of LV amyloid burden from 7% to 63% (p<0.001). LV amyloid burden was significantly associated with MACE in univariable analysis (hazard ratio 1.45, 95% confidence interval 1.15-1.82, p=0.002). However, this association became non-significant in multivariable analyses adjusted for Mayo AL stage. Mediation analysis showed that the association between 18 F-florbetapir LV %ID and MACE was primarily mediated by NT-proBNP (p<0.001), a marker of cardiomyocyte stretch and component of Mayo AL stage.

Conclusion

In this first study to link cardiac 18 F-florbetapir uptake to subsequent outcomes, LV amyloid burden estimated by LV %ID predicted MACE in AL amyloidosis. But this effect was not independent of Mayo AL stage. LV amyloid burden was associated with MACE primarily via NT-pro-BNP, a marker of cardiomyocyte stretch and component of Mayo AL stage. These findings provide novel insights into the mechanism through which myocardial AL amyloid leads to MACE.

Clinical Perspective

In systemic light-chain (AL) amyloidosis, cardiac involvement is the key determinant of adverse outcomes. Usually, prognosis is based on the Mayo AL stage, determined by troponin T, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and the difference between involved and uninvolved immunoglobulin free light chain levels (dFLC). Cardiac amyloid burden is not considered in this staging. In the present study, we used the amyloid-specific radiotracer 18 F-florbetapir to quantify left ventricular (LV) amyloid burden in 81 participants with newly-diagnosed AL amyloidosis and evaluated its prognostic value on major adverse outcomes (MACE: all-cause death, heart failure hospitalization, or cardiac transplantation within 12 months). We found that higher LV amyloid burden by 18 F-florbetapir positron emission tomography/computed tomography (PET/CT) was strongly associated with MACE. However, this association became non-significant after adjustment for the Mayo AL stage. Mediation analysis offered novel pathophysiological insights, implying that LV amyloid burden leads to MACE predominantly through cardiomyocyte stretch and light chain toxicity (by NT-proBNP), rather than through myocardial injury (by troponin T), also considering the severity of plasma cell dyscrasia (by dFLC). This mediation by NT-proBNP may explain why the association with outcomes was non-significant with adjustment for Mayo AL stage. Together, these results establish quantitative 18 F-florbetapir PET/CT as a valid method to predict adverse outcomes in AL amyloidosis. These results support the use of 18 F-florbetapir PET/CT to measure the effects of novel fibril-depleting therapies, in addition to plasma cell therapy, to improve outcomes in systemic AL amyloidosis.

Bone safety of dual-release hydrocortisone in patients with autoimmune primary adrenal insufficiency

Background

Conventional glucocorticoids (C-GC) replacement regimens have a detrimental effect on skeletal health in patients with adrenal insufficiency (AI), ultimately leading to an increased fracture risk. The novel dual-release hydrocortisone (DR-HC) formulations are characterized by a more favourable safety profile on various clinical endpoints. Data comparing the impact of C-GC and DR-HC on bone, however, are scarce.

Methods

Twenty-seven patients with autoimmune primary AI (PAI; 13 treated with C-GC and 14 treated with DR-HC) were evaluated to compare bone-related parameters between the two treatment groups.

Results

No significant differences between the two treatments groups were observed with respect to bone turnover markers. Patients treated with C-GC showed a lower bone mineral density (BMD) at lumbar spine (LS; 0.791 ± 0.195 vs. 0.942 ± 0.124 g/cm2, p=0.025) and at femoral neck (FN; 0.633 ± 0.114 vs. 0.716 ± 0.088 g/cm2, p=0.045). Moreover, they were characterized by a lower trabecular bone score (TBS; 1.236 ± 0.035 vs. 1.383 ± 0.030, p=0.004) and by a higher mean number of vertebral fractures per patient (0.75 vs. 0 fractures, p=0.002). TBS was the best predictor of fracture risk, with a pseudo-R2 of 0.593; moreover, at mediation analysis, it was able to fully explain the observed detrimental effect of C-GC, compared to DR-HC, on fracture risk.

Conclusions

These results suggest that DR-HC is associated with less bone-related complications compared to C-GC in patients with PAI. Moreover, TBS seems to play a pivotal role in the mediation of the relationship between glucocorticoid treatment regimens and fracture risk.

Neighborhood Factors, Individual Stressors, and Cardiovascular Health Among Black and White Adults in the US: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

Importance

Chronic stress has been posited to contribute to racial disparities in cardiovascular health. Investigation of whether neighborhood- and individual-level stressors mediate this disparity is needed.

Objective

To examine whether racial differences in ideal cardiovascular health (ICH) are attenuated by experiences with neighborhood- and individual-level stressors within a racially and geographically diverse population sample.

Design, Setting, and Participants

This cross-sectional study examined data from 7720 participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study who completed the second in-home visit (2013-2016). The REGARDS study is a population-based, longitudinal study of 30 239 non-Hispanic Black and non-Hispanic White adults aged 45 years or older at baseline (2003-2007). Data for the present study were analyzed from June to July 2021 and in March 2022.

Exposures

Neighborhood physical environment (eg, excessive noise, violence; scored from 7-28, with higher scores indicating more problems), neighborhood safety (scored as very safe, safe, or not safe), neighborhood social cohesion (eg, shared values; scored from 5-25, with higher scores indicating higher cohesion), perceived stress (eg, coping; scored from 0-16, with higher scores indicating greater perceived stress), and the experience of discrimination (yes or no).

Main Outcomes and Measures

Ideal cardiovascular health (ICH), measured as a composite of 4 health behaviors (cigarette smoking, diet, physical activity, body mass index) and 3 health factors (blood pressure, cholesterol, and glucose levels).

Results

The sample included 7720 participants (mean [SD] age, 71.9 [8.3] years; 4390 women [56.9%]; 2074 Black participants [26.9%]; and 5646 White participants [73.1%]). Black participants compared with White participants reported higher perceived stress (mean [SD] score, 3.2 [2.8] vs 2.8 [2.7]) and more often reported discrimination (77.0% vs 24.0%). Black participants also reported poorer neighborhood physical environment (mean [SD] score, 11.2 [3.8] vs 9.8 [2.9]) and social cohesion (mean [SD] score, 15.5 [2.0] vs 15.7 [1.9]) and more often reported their neighborhoods were unsafe (54.7% vs 24.3%). The odds of having a high total ICH score (ie, closer to ideal) were lower for Black adults compared with White adults, both overall (adjusted odds ratio [AOR], 0.53; 95% CI, 0.45-0.61) and by gender (men: AOR, 0.73 [95% CI, 0.57-0.93]; women: AOR, 0.45 [95% CI, 0.37-0.54]). In mediation analyses, the racial disparity in total ICH score was attenuated by neighborhood physical environment (5.14%), neighborhood safety (6.27%), neighborhood social cohesion (1.41%), and discrimination (11.01%). In stratified analyses, the factors that most attenuated the racial disparity in total ICH scores were neighborhood safety among men (12.32%) and discrimination among women (14.37%). Perceived stress did not attenuate the racial disparity in total ICH scores.

Conclusions and Relevance

In this cross-sectional study of Black and White US adults aged 45 years and older, neighborhood-level factors, including safety and physical and social environments, and individual-level factors, including discrimination, attenuated racial disparities in cardiovascular health. Interventional approaches to improve ICH that separately target neighborhood context and discrimination by gender and race are warranted.

The mediating effect of fatigue in impaired quality of life in systemic lupus erythematosus: mediation analysis of the French EQUAL cohort

OBJECTIVES

Mediation analyses were conducted to measure the extent to which musculoskeletal (MSK) flares and depression affected physical health through excessive fatigue.

METHODS

Mediation analyses were performed in a large multicentre cohort of SLE patients. Domains of the LupusQoL and SLEQOL questionnaires were selected as outcomes, MSK flares according to the SELENA-SLEDAI flare index (SFI-R) score and depression defined by Center for Epidemiologic Studies-Depression scale (CES-D) scale as exposures and different fatigue domains from MFI-20 and LupusQoL questionnaires as mediators. For each model, total, direct, indirect effects and proportion of effect mediated by fatigue (i.e. proportion of change in health-related quality of life) were determined.

RESULTS

Of the 336 patients, 94 (28%) had MSK flares at inclusion and 99 (29.5%) were considered with depression. The proportion of the total effect of MSK flares on physical health impairment explained by fatigue ranged from 59.6% to 78% using the LupusQOL 'Physical health' domain and from 51.1% to 73.7% using the SLEQOL 'Physical functioning' domain, depending on the fatigue domain selected. The proportion of the total effect of depression on physical health impairment explained by fatigue ranged from 68.8% to 87.6% using the LupusQOL 'Physical health' domain and from 79.3% to 103.2% using the SLEQOL 'Physical functioning' domain, depending on the fatigue domain selected.

CONCLUSIONS

The effect of MSK flares and depression on physical health impairment is largely mediated by fatigue. Thus, the patient's perception of disease activity as measured by physical health is largely influenced by fatigue. In addition, fatigue has a significant negative impact on quality of lifeof SLE patients with depression.

TRIAL REGISTRATION

ClinicalTrials.gov, http://clinicaltrials.gov, NCT01904812.

Does Growth Velocity Affect Associations between Birth Weight and Neurodevelopment for Infants Born Very Preterm?

OBJECTIVE

To determine how neonatal growth velocity affects the association between birth weight and neurodevelopmental outcomes in infants born preterm.

STUDY DESIGN

This study is a secondary analysis of the Maternal Omega-3 Supplementation to Reduce Bronchopulmonary Dysplasia in Very Preterm Infants (MOBYDIck) randomized multicenter trial conducted in breastfed infants born at <29 weeks of gestation, whose mothers were supplemented with docosahexaenoic acid or placebo during the neonatal period. Neurodevelopmental outcomes were assessed at 18-22 months of corrected age using the Bayley-III cognitive and language composite scores. The role of neonatal growth velocity was assessed with causal mediation and linear regression models. Subgroup analyses were stratified by birth weight z-score categories (<25th, ≥25th-≤75th, and >75th percentiles).

RESULTS

Neurodevelopmental outcomes were available for 379 children (mean gestational age, 26.7 ± 1.5 weeks). Growth velocity partially mediated the relationships between birth weight and cognitive (β = -1.1; 95% CI, -2.2 to -0.02; P = .05) and language scores (β = -2.1; 95% CI, -3.3 to -0.8; P = .002). An increase by 1 g/kg/day in growth velocity was associated with an increase by 1.1 point in the cognitive score (95% CI, -0.03 to 2.1; P = .06) and 1.9 point in the language score (95% CI, 0.7 to 3.1; P = .001), after adjustment for birth weight z-score. For children with birth weight <25th percentile, a 1 g/kg/day increase in growth velocity was associated with an increase by 3.3 points in the cognitive score (95% CI, 0.5 to 6.0; P = .02) and 4.1 points in the language score (95% CI, 1.3 to 7.0; P = .004).

CONCLUSIONS

Postnatal growth velocity mediated the relationship between birth weight and neurodevelopmental performance, with larger effects for children with lower birth weight.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02371460.

Do markers of adiposity and glycaemia mediate the association between low carbohydrate diet and cardiovascular risk factors: findings from the UK National Diet and Nutrition Survey (NDNS) 2008-2016

Objectives

To examine the associations between low carbohydrate diet (LCD) and conventional cardiovascular risk factors and investigate whether these associations are mediated by body mass index (BMI), waist circumference (WC) and haemoglobin A1c (HbA1c) applying causal mediation analyses.

Methods

We included 3640 adults aged 45-80 years from the UK National Diet and Nutrition Survey programme (2008-2016) with data on dietary intake, anthropometric and biochemical parameters. Four hypothetical interventions were examined: (1) LCD, (2) Low carbohydrate (LC) and high fibre diet (LCHF), (3) LC and high saturated fat diet (LCHS) and (4) LC and high unsaturated fat diet (LCHU). BMI and WC were used as markers of obesity. Biochemical markers included HbA1c, total cholesterol, high-density lipoprotein and low-density lipoprotein (LDL) cholesterol, triglycerides, systolic and diastolic blood pressure and C reactive protein (CRP). BMI, WC and HbA1c were used as a mediator of the effects. The analysis was adjusted for sociodemographic characteristic, smoking, estimated total energy intake, alcohol consumption and antihypertensive medication. To identify a potential causal effect of LCD on cardiovascular disease (CVD) risk, we estimated the average treatment effect, and corresponding p values and CI for the total, indirect and direct effect of the treatment on the outcome.

Results

BMI, WC and HbA1c fully mediated the association between LCD and triglycerides and fully mediated the effects of LCHF on LDL, although BMI and WC were not sufficient to fully mediate the effects of LCHF on triglycerides and CRP. BMI alone fully mediated the effects of LCHS on HbA1c, triglycerides, LDL and CRP. None of these mediators explained the effect of LCHU on CVD risk markers.

Conclusion

The causal hypotheses tested in this study demonstrate that individuals on LCD with high fibre intakes improved their CVD markers as expected, but those on LCD who increase fat intake had no effects on CVD markers mediated by obesity and diabetes.

Combination of HBA1, TTR, and SERPINF2 in plasma defines phenotype correlated with severe burn outcome

Recent advancements in proteomics allow for the concurrent identification and quantification of multiple proteins. This study aimed to identify proteins associated with severe burn pathology and establish a clinically useful molecular pathology classification. In a retrospective observational study, blood samples were collected from severe burn patients. Proteins were measured using mass spectrometry, and prognosis-related proteins were extracted by comparing survivors and non-survivors. Enrichment and ROC analyses evaluated the extracted proteins, followed by latent class analysis. Measurements were performed on 83 burn patients. In the non-survivor group, ten proteins significantly changing on the day of injury were associated with metabolic processes and toxin responses. ROC analysis identified HBA1, TTR, and SERPINF2 with AUCs > 0.8 as predictors of 28-day mortality. Latent class analysis classified three molecular pathotypes, and plasma mass spectrometry revealed ten proteins associated with severe burn prognosis. Molecular pathotypes based on HBA1, TTR, and SERPINF2 significantly correlated with outcomes.

Age-related and amyloid-beta-independent tau deposition and its downstream effects

Amyloid-β (Aβ) is hypothesized to facilitate the spread of tau pathology beyond the medial temporal lobe. However, there is evidence that, independently of Aβ, age-related tau pathology might be present outside of the medial temporal lobe. We therefore aimed to study age-related Aβ-independent tau deposition outside the medial temporal lobe in two large cohorts and to investigate potential downstream effects of this on cognition and structural measures. We included 545 cognitively unimpaired adults (40-92 years) from the BioFINDER-2 study (in vivo) and 639 (64-108 years) from the Rush Alzheimer's Disease Center cohorts (ex vivo). 18F-RO948- and 18F-flutemetamol-PET standardized uptake value ratios were calculated for regional tau and global/regional Aβ in vivo. Immunohistochemistry was used to estimate Aβ load and tangle density ex vivo. In vivo medial temporal lobe volumes (subiculum, cornu ammonis 1) and cortical thickness (entorhinal cortex, Brodmann area 35) were obtained using Automated Segmentation for Hippocampal Subfields packages. Thickness of early and late neocortical Alzheimer's disease regions was determined using FreeSurfer. Global cognition and episodic memory were estimated to quantify cognitive functioning. In vivo age-related tau deposition was observed in the medial temporal lobe and in frontal and parietal cortical regions, which was statistically significant when adjusting for Aβ. This was also observed in individuals with low Aβ load. Tau deposition was negatively associated with cortical volumes and thickness in temporal and parietal regions independently of Aβ. The associations between age and cortical volume or thickness were partially mediated via tau in regions with early Alzheimer's disease pathology, i.e. early tau and/or Aβ pathology (subiculum/Brodmann area 35/precuneus/posterior cingulate). Finally, the associations between age and cognition were partially mediated via tau in Brodmann area 35, even when including Aβ-PET as covariate. Results were validated in the ex vivo cohort showing age-related and Aβ-independent increases in tau aggregates in and outside the medial temporal lobe. Ex vivo age-cognition associations were mediated by medial and inferior temporal tau tangle density, while correcting for Aβ density. Taken together, our study provides support for primary age-related tauopathy even outside the medial temporal lobe in vivo and ex vivo, with downstream effects on structure and cognition. These results have implications for our understanding of the spreading of tau outside the medial temporal lobe, also in the context of Alzheimer's disease. Moreover, this study suggests the potential utility of tau-targeting treatments in primary age-related tauopathy, likely already in preclinical stages in individuals with low Aβ pathology.

The association between lead exposure and crime: A systematic review

Prior research has demonstrated an association between lead exposure and criminal behavior at the population-level, however studies exploring the effect of lead exposure on criminal behavior at the individual-level have not been reviewed systematically. The intent of this study is to complete a systematic review of all studies assessing individual-level exposures to lead and the outcomes of crime and antisocial behavior traits. We included peer reviewed studies that were published prior to August 2022 and were classified as cohort, cross-sectional, or case-control. Studies measuring the outcomes of crime, delinquency, violence, or aggression were included. The following databases were searched using a standardized search strategy: ProQuest Environmental Science Database, PubMed, ToxNet and the Public Affairs Information Service (PAIS). Seventeen manuscripts met our inclusion criteria. Blood lead was measured in 12 studies, bone lead in 3 studies, and dentine lead levels in 2 studies. This systematic review identified a wide range of diverse outcomes between exposure to lead at multiple windows of development and later delinquent, criminal and antisocial behavior. A review of all potential confounding variables included within each study was made, with inclusion of relevant confounders into the risk of bias tool. There is limited data at the individual level on the effects of prenatal, childhood, and adolescent lead exposure and later criminal behavior and more evidence is necessary to evaluate the magnitude of the associations seen in this review. Our review, in conjunction with the available biological evidence, suggests that an excess risk for criminal behavior in adulthood exists when an individual is exposed to lead in utero or in the early years of childhood. The authors report no conflict of interest and no funding source. Clinical trial registration: PROSPERO ID: CRD42021268379.

Intersectional inequities in the birthweight gap between twin and singleton births: A random effects MAIHDA analysis of 2012-2018 New York City birth data

Birthweight is a widely-used biomarker of infant health, with inequities patterned intersectionally by maternal age, race/ethnicity, nativity/immigration status, and socioeconomic status in the United States. However, studies of birthweight inequities almost exclusively focus on singleton births, neglecting high-risk twin births. We address this gap using a large sample (N = 753,180) of birth records, obtained from the 2012-2018 New York City (NYC) Department of Health and Mental Hygiene, Bureau of Vital Statistics, representing 99% of all births registered in NYC, and a novel random coefficients intersectional MAIHDA (Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy) model. Our results show evidence of intersectional inequities in birthweight outcomes for both twin and singleton births by maternal age, race/ethnicity, education, and nativity status. Twins have considerably lower predicted birthweights than singletons overall (-930 g on average), and this is especially true for babies born to mothers who are younger (11-19 years), older (40+), racial/ethnic minoritized, foreign-born, and have lower education. However, the magnitude of this birthweight 'gap' between twins and singletons varies considerably across social identity strata, ranging between 830.8 g (observed among 40+ year old Black foreign-born mothers with high school degrees) and 1013.7 g (observed among 30-39 year old Hispanic/Latina foreign-born mothers with less than high school degrees). This study underscored the needs of a high-risk population and the need for aggressive social policies to address health inequities and dismantle intersectional systems of marginalization, oppression, and socioeconomic inequality. In addition to our substantive contributions, we add to the growing methods literature on intersectional quantitative analysis by demonstrating how to apply intersectional MAIHDA with random coefficients and random slopes. We conclude with a discussion of the significant potential for this methodological extension in future research on inequities.

The direct and mediating effects of cognitive impairment on the occurrence of falls: a cohort study based on community-dwelling old adults

Background

Cognitive impairment has been reported to be associated with falls in older adults. However, the complex relationship among falls, cognitive impairment and its associated factors, which could be targeted with specific interventions, remains to be elucidated. This study aimed to examine the direct effects of cognitive impairment on falls, to identify the factors associated with cognitive impairment and to explore the mediation role of cognitive impairment in the association of fall with cognition related factors.

Methods

This 1-year follow-up cohort study enrolled old adults aged 60  years or over. Information about demographic and anthropometric characteristics, fall outcomes, function and nutritional status were collected through face-to-face interview. Cognitive function was evaluated by the Montreal Cognitive Assessment (MoCA). Multivariable regression analyses were used to test the association between cognitive impairment and falls and to identify the factors related to cognitive impairment. Additionally, we conduct causal mediation analyses to estimate the mediation effects of cognitive impairment in the pathways of fall occurrence.

Results

Of the 569 participants included in this study, 366 (64.32%) had cognitive impairment, 96 (16.87%) had fall history in the past 1  year, 81 (14.24%) experienced fall and 47 (8.26%) received treatment because of falling during the 1-year follow-up. The association between cognitive impairment and 1-year fall risk was confirmed after adjusting for multiple covariates [odds ratio (OR):2.03, 95% confidence interval (CI): 1.13-3.80]. IADL disability, depression and low grip strength were associated with a higher prevalence of cognitive impairment. While overweight, higher education and higher income level were found to be related to a lower risk of cognitive impairment. Among these associated factors, cognitive impairment mediated the positive association of falling with IADL ability and depression, and a negative relationship with education and income level.

Conclusion

Our study not only confirmed the direct influence of cognitive impairment on fall risk in older adults, but also suggested a mediating role that cognitive impairment played in the pathways of fall occurrence. Our finding could help develop more specific interventions for fall prevention.

"Residential greenness, gestational diabetes mellitus (GDM) and microbiome diversity during pregnancy"

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with reduced gut microbiota richness that was also reported to differ significantly between those living in rural compared to urban environments. Therefore, our aim was to examine the associations between greenness and maternal blood glucose levels and GDM, with microbiome diversity as a possible mediator in these associations.

METHODS

Pregnant women were recruited between January 2016 and October 2017. Residential greenness was evaluated as mean Normalized Difference Vegetation Index (NDVI) within 100, 300 and 500 m buffers surrounding each maternal residential address. Maternal glucose levels were measured at 24-28 weeks of gestation and GDM was diagnosed. We estimated the associations between greenness and glucose levels and GDM using generalized linear models, adjusting for socioeconomic status and season at last menstrual period. Using causal mediation analysis, the mediation effects of four different indices of microbiome alpha diversity in first trimester stool and saliva samples were assessed.

RESULTS

Of 269 pregnant women, 27 participants (10.04%) were diagnosed with GDM. Although not statistically significant, adjusted exposure to medium tertile levels of mean NDVI at 300 m buffer had lower odds of GDM (OR = 0.45, 95% CI: 0.16, 1.26, p = 0.13) and decreased change in mean glucose levels (β = -6.28, 95% CI: 14.91, 2.24, p = 0.15) compared to the lowest tertile levels of mean NDVI. Mixed results were observed at 100 and 500 m buffers, and when comparing highest tertile levels to lowest. No mediation effect of first trimester microbiome on the association between residential greenness and GDM was observed, and a small, possibly incidental, mediation effect on glucose levels was observed.

CONCLUSION

Our study suggests possible associations between residential greenness and glucose intolerance and risk of GDM, though without sufficient evidence. Microbiome in the first trimester, while involved in GDM etiology, is not a mediator in these associations. Future studies in larger populations should further examine these associations.

Acceptability and perception of COVID-19 vaccines among foreign medical students in China: A cross-sectional study

Background

Acceptability and perception of the COVID-19 vaccine among different social groups have been the subject of several studies. However, little is known about foreign medical students in Chinese universities.

Aim

This study, therefore, fills the literature gap using a focus group technique to assess the acceptance and perception of the COVID-19 vaccine among foreign medical students in China.

Methods

The study adopted an online cross-sectional survey method following the Chinese universities' lockdowns to collect the data between March and April 2022. A data collection questionnaire was developed, and then the link was shared with the respondents through key informants in different universities in China to obtain the data. The data collection process only included foreign medical students who were in China from May 2021 to April 2022. The authors received a total of 403 responses from the respondents. During data processing, we excluded 17 respondents since they were not in China while administering the questionnaire to enhance the data validity. The authors then coded the remaining 386 respondents for the estimation process. We finally applied the multilinear logistics regression technique to model the COVID-19 vaccine acceptance with the response or influencing factors, including the mediating factors among the foreign medical students in China.

Results

The data statistics show that 4.9% of the respondents were younger than 20 years, 91.5% were 20–40 years old, and 3.6% were older than 40 years; 36.3% of respondents were female subjects and 63.7% were male subjects. The results also show that the respondents are from six continents, including the African continent, 72.4%, Asia 17.4%, 3.1% from Europe, 2.8% from North America, 1.6% from Australia, and 2.3% from South America. The mediation analysis for the gender variable (β = 0.235, p = 0.002) suggests that gender is a significant channel in COVID-19 vaccine acceptance and perception among foreign medical students in China. Also, the main analysis shows that opinion on the safety of the vaccine (β = 0.081, p = 0.043), doses of the vaccine to receive (β = 0.175, p = 0.001), vaccine safety with some side effects (β = 0.15, p = 0.000), and the possibility of acquiring COVID-19 after vaccination (β = 0.062, p = 0.040) are all positive factors influencing vaccine acceptability and perception. Also, the home continent (β = −0.062, p = 0.071) is a negative factor influencing COVID-19 vaccine acceptance and perception. Furthermore, the finding shows that fear perceptions has affected 200 (51.81%) respondents. The medical students feared that the vaccines might result in future implications such as infertility, impotence, and systemic health conditions such as cardiovascular, respiratory, or deep vein thrombosis. In addition, 186 (48.19%) students feared that the vaccines were intended to shorten life expectancy.

Conclusion

COVID-19 vaccination acceptability and perception among medical students in China is high, most predominantly due to their knowledge of medicine composition formulation. Despite widespread acceptance by the general public and private stakeholders, we concluded that vaccination resistance remains a significant factor among medical students and trainees. The study further adds that in considering the COVID-19 vaccine, the factor of the home continent plays a significant role in vaccine hesitancy among foreign medical students. Also, knowledge, information, and education are important pillars confronting new medicine administered among medical trainees. Finally, there is a low rate of COVID-19 vaccine hesitancy among foreign medical students in China. The study, therefore, recommends targeted policy strategies, including sensitization, detailed public information, and education, especially for medical colleges and institutions on the COVID-19 vaccination, to achieve 100%. Furthermore, the study recommends that future researchers explore other factors influencing accurate information and education for successful COVID-19 vaccination implementation.

Protocol for analysis of liquid chromatography-mass spectrometry metabolomics data using R to understand how metabolites affect disease

Liquid-chromatography-mass-spectrometry-based metabolomics is widely used in prospective case-control studies for disease prediction. Given the large amount of clinical and metabolomics data involved, data integration and analyses are crucial to provide an accurate understanding of the disease. We provide a comprehensive analysis approach to explore associations among clinical risk factors, metabolites, and disease. We describe steps for performing Spearman correlation, conditional logistic regression, casual mediation, and variance partitioning to investigate the potential effects of metabolites on disease. For complete details on the use and execution of this protocol, please refer to Wang et al. (2022).1.

Effect of Carnitine Supplementation in Pediatric Patients with Left Ventricular Dysfunction

Carnitine is an essential amino acid involved in transporting fatty acids across the mitochondrial membrane. Fatty acids are a primary source of energy for the myocardium. Studies in adults demonstrated decreased carnitine levels in the ischemic myocardium, but subsequent exogenous carnitine supplementation showed improvement of myocardial metabolism and left ventricular function. However, only limited data regarding carnitine are available in pediatrics. A single-center retrospective, paired data study was conducted. Patients < 18 years, left ventricular ejection fraction (LVEF) < 55% by echocardiography, and had received at least 7 days of oral or intravenous carnitine supplementation between January 2018 and March 2021 are included in the study. Several endpoints and covariates were collected for each patient: before, one week after, one month after, and 6 months after carnitine supplementation. Univariate analysis consisted of an analysis of variance (ANOVA), followed by an analysis of covariance (ANCOVA) to model LVEF while adjusting for other variables. 44 patients included in the final analyses. LVEF significantly improved from 50.5 to 56.6% (p < 0.01). When LVEF was adjusted for other interventions (mechanical ventilation, afterload reduction, diuretic therapy, spironolactone), the estimated means demonstrated a significant increase from 45.7 to 58.0% (p < 0.01). Free carnitine level increased significantly (p = 0.03), and N-terminal-pro-brain natriuretic peptide (p = 0.03), creatinine (p < 0.01), and lactate (p < 0.01) all significantly decreased over the study period. Carnitine supplementation in pediatric patients with left ventricular systolic dysfunction may be associated with an increase in LVEF and improvement in laboratory markers of myocardial stress and cardiac output.

Do family characteristics contribute to a socioeconomic gradient in overweight in early childhood? - Single mediation analyses of data on preschool children of Germany

Children's overweight is strongly associated with family socioeconomic position (SEP) and family characteristics (FC). There is limited research on the extent to which FC account for a socioeconomic gradient in childhood overweight. This study examined whether FC explain SEP differences in the prevalence of overweight. The study used baseline data of preschool-aged children from the German 'PReschool INtervention Study'. The sample (n = 872, 48% girls) was recruited at kindergartens in Baden-Württemberg, Germany. Data included children's measured weight status and parents' reports on socioeconomic indicators (e.g., school education, vocational education, income) and FC. Variables represent main determinants of overweight (nutrition: sweets consumption in front of TV, soft drink consumption, regular breakfast, child sets table; physical activity: outdoor sports; parental role model). In single mediation analyses indirect effects of SEP on overweight were analysed (OR[95%CI]). Preschool girls and boys with low parental education had higher odds for overweight than children with high parental education. Among boys, low levels of parental education contributed to the odds of overweight via indirect effects by both factors 'sweets consumption in front of TV' (OR = 1.31[1.05-1.59]) and 'no sports' (OR = 1.14[1.01-1.38]). Among girls, FC measured did not explain SEP differences in overweight. Family nutrition and parental/family physical activity contribute to inequalities in overweight among preschool boys, but not girls. Research is needed to identify FC that explain inequalities in overweight for both.

Socio-economic, governance and health indicators shaping antimicrobial resistance: an ecological analysis of 30 european countries

BACKGROUND

Previous evidence shows that antibiotic use and antimicrobial resistance (AMR) spread are not always perfectly correlated within and between countries. We conducted an ecological analysis to evaluate how demographic, economic, governance, health, and freedom characteristics of 30 European countries contribute to antibiotic consumption and AMR.

METHODS

Using three sources of data (World Bank DataBank, ECDC atlas, and the ESAC-Net database), we created a dataset of: 22 indicators of demographics, health, economic, governance, and freedom; AMR proportions for 25 combinations of pathogens and antibiotics; consumption of antibiotics in the community. We also computed five indexes of demographic, health, economic, governance, and freedom, and an aggregate AMR measure. Relationships between indexes, antibiotic consumption, and AMR proportions were explored using bivariate, multivariable, multivariate, and mediation analyses.

RESULTS

Multivariate analysis identified three clusters of countries that mainly differed for demographic, health, governance, and freedom indexes. AMR proportion was lower in countries with better indexes (p < 0.001), but not necessarily with lower antibiotic consumption. In multivariable models including all five indexes, an increase in the governance index resulted in significant decreases of overall antibiotic consumption (p < 0.001) and AMR proportion (p = 0.006). Mediation analysis showed that the governance index had an indirect effect on AMR via reducing antibiotic consumption, which accounted only for 31.5% of the total effect.

CONCLUSIONS

These findings could be - at least partially - explained by the contagion theory, for which other factors contribute to high levels of AMR in countries with poor governance. As a result of this evidence, reducing antibiotic use alone is unlikely to solve the AMR problem, and more interventions are needed to increase governance efficiency at global level.

Aspirin Use and Risk of Alzheimer's Disease: A 2-Sample Mendelian Randomization Study

BACKGROUND

Observational studies have shown inconsistent findings of the relationships between aspirin use and the risk of Alzheimer's disease (AD).

OBJECTIVE

Since residual confounding and reverse causality were challenging issues inherent in observational studies, we conducted a 2-sample Mendelian randomization analysis (MR) to investigate whether aspirin use was causally associated with the risk of AD.

METHODS

We conducted 2-sample MR analyses utilizing summary genetic association statistics to estimate the potential causal relationship between aspirin use and AD. Single-nucleotide variants associated with aspirin use in a genome-wide association study (GWAS) of UK Biobank were considered as genetic proxies for aspirin use. The GWAS summary-level data of AD were derived from a meta-analysis of GWAS data from the International Genomics of Alzheimer's Project (IGAP) stage I.

RESULTS

Univariable MR analysis based on these two large GWAS data sources showed that genetically proxied aspirin use was associated with a decreased risk of AD (Odds Ratio (OR): 0.87; 95%CI: 0.77-0.99). In multivariate MR analyses, the causal estimates remained significant after adjusting for chronic pain, inflammation, heart failure (OR = 0.88, 95%CI = 0.78-0.98), or stroke (OR = 0.87, 95%CI = 0.77-0.99), but was attenuated when adjusting for coronary heart disease, blood pressure, and blood lipids.

CONCLUSION

Findings from this MR analysis suggest a genetic protective effect of aspirin use on AD, possibly influenced by coronary heart disease, blood pressure, and lipid levels.

Instrumental variable-based high-dimensional mediation analysis with unmeasured confounders for survival data in the observational epigenetic study

Background: High dimensional mediation analysis is frequently conducted to explore the role of epigenetic modifiers between exposure and health outcome. However, the issue of high dimensional mediation analysis with unmeasured confounders for survival analysis in observational study has not been well solved. Methods: In this study, we proposed an instrumental variable based approach for high dimensional mediation analysis with unmeasured confounders in survival analysis for epigenetic study. We used the Sobel's test, the Joint test, and the Bootstrap method to test the mediation effect. A comprehensive simulation study was conducted to decide the best test strategy. An empirical study based on DNA methylation data of lung cancer patients was conducted to illustrate the performance of the proposed method. Results: Simulation study suggested that the proposed method performed well in the identifying mediating factors. The estimation of the mediation effect by the proposed approach is also reliable with less bias compared with the classical approach. In the empirical study, we identified two DNA methylation signatures including cg21926276 and cg26387355 with a mediation effect of 0.226 (95%CI: 0.108-0.344) and 0.158 (95%CI: 0.065-0.251) between smoking and lung cancer using the proposed approach. Conclusion: The proposed method obtained good performance in simulation and empirical studies, it could be an effective statistical tool for high dimensional mediation analysis.