Non-linear associations between metabolic syndrome and four typical heavy metals: Data from NHANES 2011-2018

Metabolomics analysis reveals the effects of high dietary copper on mitochondria-mediated autophagy and apoptosis in spleen of broiler chicken

Copper (Cu) is a necessary micro-element and plays important roles in many biochemical processes. However, excessive Cu intake can lead to multi-organ toxicity, especially in the spleen. To gain further insights into the specific mechanisms of splenic toxicity associated with Cu-induced metabolic disorders, 192 one-day-old chickens were selected and randomly divided into four groups for this study. The broilers were fed with diets containing Cu at final concentrations of 11, 110, 220 and 330 mg/kg for 49 days. The results showed that high dietary Cu caused nuclear shrinkage and mitochondrial vacuolization in the spleen and induced splenic injury through regulating the glutathione metabolism, pentose and gluconate interconversion, tryptophan metabolism and glycerophosphatidylcholine metabolism pathways. Moreover, excess Cu could disorder the mitochondrial dynamics via up-regulating the levels of Drp1, Parkin PINK1, and Dynein, and down-regulating the levels of Mfn1, Mfn2 and OPA1. Cu treatment increased the levels of LC3A, LC3B, mTOR, Beclin1, and ATG5 and decreased the p62 level to promote autophagy of splenocytes. Meanwhile, a high dose of Cu promoted splenocyte apoptosis by increasing the levels of p53, BAK-1, Bax, Cyt C and Caspase-3 and decreasing the level of Bcl-2. These results demonstrated that high dietary Cu could cause autophagy and apoptosis via inducing metabolic disturbances and disordering mitochondrial dynamics in the spleen of broiler chicken.

Osteoporosis risk and its association with all-cause and cause-specific mortality among the elderly: a 16-year nationwide cohort study

BACKGROUND

Aged osteoporosis poses a significant threat to the well-being and longevity of older individuals, yet evidence regarding the relationship between osteoporosis risk and mortality among the elderly population in Asia remains unknown.

AIMS

Our study aimed to investigate associations between osteoporosis risk and all-cause mortality, as well as cause-specific mortality, among the Chinese elderly population.

METHODS

Pooled data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) conducted between 2002 and 2018 were utilized to analyze the associations between osteoporosis risk and all-cause, heart disease, cardiovascular disease (CVD), respiratory disease, and cancer mortality. Cox proportional hazards models were employed for this analysis. Osteoporosis risk was assessed using the Osteoporosis Self-Assessment Tool for Asians (OSTA). Restricted cubic spline (RCS) functions were applied to explore the nonlinear relationship between OSTA and mortality. The robustness of the Cox models was evaluated through internal verification, subgroup analyses, and sensitivity analyses.

RESULTS

A total of 12,711 elderly individuals aged ≥ 65 years were included for analysis at baseline. During a 16-year follow-up, 7,963 individuals in the cohort were identified as deceased. Compared to those with low osteoporosis risk, elderly individuals with high osteoporosis risk demonstrated a significantly elevated risk of all-cause, heart disease, CVD, respiratory disease and cancer mortality. The relationship between OSTA level and all-cause and cause-specific mortality exhibited a significant L-shaped pattern.

CONCLUSIONS

The risk of osteoporosis is independently associated with the prediction of mortality. The OSTA may serve as a suitable predictor for mortality related to osteoporosis among the Asian population.

The correlation between serum alkaline phosphatase and grip strength in middle-aged and elderly people: NHANES 2011-2014

BACKGROUND

Serum alkaline phosphatase (ALP) plays a crucial role in bone and muscle health. Previous studies have demonstrated that serum alkaline phosphatase (ALP) is closely associated with muscle mass. Nevertheless, the association between serum alkaline phosphatase (ALP) and grip strength remains unclear. Therefore, the present study focused on exploring the association of serum ALP with grip strength in middle-aged and elderly people.

METHODS

We conducted a cross-sectional study using data from the National Health and Nutrition Examination Survey conducted from 2011 to 2014. A total of 3514 participants (1891 males and 1623 females) aged 40-80 years were included in this study. Serum ALP and pelvic grip strength were analyzed as independent and dependent variables, additional variables were the possible impact modifiers. weighted generalized linear models and stratified analysis by gender, age group, and race were applied to assess the relationship between serum ALP and grip strength. Smooth curve fitting and threshold effect analysis/saturation effect analysis were used to analyze the nonlinear relationship between the 2 variables.

RESULTS

In the gender-stratified subgroup analysis, we observed an inverse association between serum ALP and grip strength in both male and female. When stratified by age group, the association remained significant among participants 40-59 years of age, but not among those ≥ 60 years old. When stratified by race, the association remained significant among Non-Hispanic White and Non-Hispanic Black. It is noteworthy that serum ALP and grip strength showed a significant negative correlation among female aged 40-59 years, but not among female aged ≥ 60 years. Additionally, Smooth curve fitting showed that serum ALP had a nonlinear relationship with grip strength in male aged 40-59 years and male aged over 60 years, the inflection points are 54 IU and 97 IU respectively.

CONCLUSION

Our study revealed an inverse relationship between serum ALP and grip strength, this finding offers new insights and avenues for understanding how serum alkaline phosphatase affects skeletal muscle health.

Novel insights into carbohydrate-to-fiber ratio and constipation: NHANES findings suggest a turning point

BACKGROUND

Constipation, a widespread global issue, prompted an investigation into the intricate relationship between dietary factors and this condition. This study delves into the association between carbohydrate-to-fiber (CF) ratio and constipation, employing data from the National Health and Nutrition Examination Survey (NHANES) and a comprehensive meta-analysis.

METHODS

Utilizing NHANES data (2005-2010) from 7752 adults, constipation was defined based on stool type (Bristol Stool Form Scale types 1 or 2). The CF ratio was calculated, revealing an L-shaped, non-linear association with constipation. A meta-analysis of 16 studies (1626 participants) confirmed a positive effect of dietary fiber on constipation, emphasizing the robustness of the findings.

RESULTS

Among participants, constipation prevalence stood at 13.98%. The CF ratio exhibited a turning point at 26.92/day, with adjusted odds ratios for constipation indicating a decrease with higher CF ratios. Meta-analysis results supported these findings, demonstrating a significant positive effect of dietary fiber on constipation.

CONCLUSION

This study illuminates a nuanced relationship between CF ratio and constipation, suggesting a critical turning point at 26.92/day. These findings underscore the importance of dietary assessment, offering valuable insights for clinicians and individuals. Further prospective research is warranted to validate the CF ratio as a robust dietary assessment tool.

Association between blood manganese and cardiovascular diseases among U.S. adult population

Manganese (Mn) is a known toxicant and an essential trace element, and it plays an important role in various mechanisms in relation to cardiovascular health. However, epidemiological studies of the association between blood Mn and cardiovascular diseases (CVD) among U.S. adults are rare. A cross-sectional study of 12,061 participants aged ≥ 20 was conducted using data from the National Health and Nutrition Examination Survey 2011-2018. Logistic regression and restricted cubic spline were used to examine the relationship between blood Mn levels and total CVD risk and specific CVD subtypes. Bayesian kernel-machine regression (BKMR) and weighted quantile sum (WQS) analyses were performed to explore the joint effects of Mn with other metals on CVD. The results showed that individuals with the third quartile group of blood Mn levels had significantly lower risks of CVD, displaying a non-linear U-shaped dose-response relationship. A significant interaction of age on this association was observed. No significant associations were found between Mn levels and specific CVD subtypes. BKMR and WQS analyses showed a positive association between heavy metal mixtures and CVD risks, with no interaction between Mn and other metals. In conclusion, blood Mn levels were significantly associated with CVD risks with a U-shaped relationship in U.S. adults, with possible age-specific differences. Future larger prospective studies are warranted to validate these findings.

Vitamin E Intake Attenuated the Association Between Elevated Blood Heavy Metal (Pb, Cd, and Hg) Concentrations and Diabetes Risk in Adults Aged 18-65 Years: Findings from 2007-2018 NHANES

The association between heavy metal exposure and diabetes is controversial and vitamin E (VE) may reduce diabetes risk. We aimed to examine the associations between blood heavy metals (BHMs) and diabetes risk and VE's role in the relationship. From the 2007-2018 NHANES, 10,721 participants aged ≥ 18 were included for multiple statistical analyses, which revealed that BHMs and dietary VE intake were negatively associated with diabetes and fasting plasma glucose (FPG). The diabetes prevalence in each quartile (Q) of heavy metal exposure increased with age, but within age Q4, it generally decreased with exposure quartiles. Moreover, BHMs were positively associated with all-cause and diabetes-related mortalities with aging, which induced an age breakpoint of 65 years for age-stratified analyses on the associations between BHMs and diabetes risk. In those aged > 65, BHMs were negatively correlated with diabetes risk and its biomarkers; however, in adults aged 18-65, the correlation was positive. At higher VE intake levels, blood lead was associated with a lower diabetes risk and all three BHMs demonstrated lower FPG levels than those at lower VE intake levels. In conclusion, consuming sufficient VE and avoiding heavy metal exposure are highly recommended to reduce diabetes risk.

Volatile organic compounds (VOC) metabolites in urine are associated with increased systemic inflammation levels, and smokers are identified as a vulnerable population

BACKGROUND

Previous studies indicated that exposure to VOCs was linked to increased systemic inflammation levels. However, the dose-response relationships between urine VOCs metabolites and systemic inflammation have not been established, and the key metabolite of the toxic compounds has not been identified.

METHODS

We used data in 7007 US adults in the NHANES cycles (2011-2018) across 8 years. Urinary VOC metabolites were measured using ultra-performance liquid chromatography and electrospray tandem mass spectrometry (UPLC-ESI/MSMS). VOC metabolites were adjusted by urinary creatinine level before analysis. Systemic inflammation was assessed by systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI) indices. Generalized linear models, restricted cubic splines (RCS), and weighted quantile sum (WQS) regression were applied to evaluate the associations, exposure-response (E-R) curve and identify the key contributor compound, adjusting for gender, age, race, BMI, marital condition, education level, smoking level, alcohol consumption and physical activity. Smoking status was assessed as an effect modifier.

RESULTS

Significant and robust positive correlations were found between 8 VOC metabolites and both SII and SIRI. They were N-Acetyl-S-(2-carboxyethyl)-L-cysteine (CEMA), N-Acetyl-S-(2-cyanoethyl)-L-cysteine (CYMA), N-Acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), N-Acetyl-S-(3-hydroxypropyl)-L-cysteine (3HPMA), mandelic acid (MA), N-Acetyl-S-(4-hydroxy-2-butenyl)-L-cysteine (MHBMA3), phenylglyoxylic acid (PGA), and N-Acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine (HPMMA). The RCS curves showed J-shaped or exponential shaped E-R relationships for most VOC metabolites. WQS regression found that exposure to the mixture of VOC metabolites was related to increased systemic inflammation, and MA was the key VOC metabolite contributing most to systemic inflammation levels. Smokers exhibited higher levels of urinary VOCs and larger susceptibility to VOC-related increases in SII and SIRI compared to non-smokers.

CONCLUSION

This study demonstrated a strong link between urinary VOC metabolites and increased systemic inflammation, and smokers were more susceptible. Our findings highlighted the significance of reducing VOC exposure to mitigate the inflammation levels, particularly for smokers.

Associations of exposure to phthalate with serum uric acid and hyperuricemia risk, and the mediating role of systemic immune inflammation

BACKGROUND

Previous studies found that urinary phthalates (PAEs) metabolites may be associated with increased serum uric acid concentration and hyperuricemia risk. However, no population-based study has investigated the underlying biological mechanisms.

METHODS

This nationwide cross-sectional study analyzed the data from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Urinary PAEs metabolites were measured and 8 PAEs metabolites (MCPP, MECPP, MEHHP, MEOHP, MBzP, MiBP, MBP, and MEP) were incorporated into the analysis. Serum uric acid was determined and hyperuricemia cases were identified. Multi-variable generalized linear model, exposure-response (E-R) function and weighted quantile sum (WQS) regression were utilized to investigate the relationships of PAEs metabolites with serum uric acid concentration and hyperuricemia risk. Systemic immune inflammation (SII) was assessed using the SII index and its mediation effects were explored using causal mediation effect model.

RESULTS

Data from 10,633 US adults in the NHANES 2003-2018 was analyzed. Except for MEP, individual PAEs metabolite and total PAEs metabolites were associated with increased serum uric acid concentration and hyperuricemia risk. E-R function of PAEs metabolites with serum uric acid concentration and the risk of hyperuricemia showed significantly positive associations with most curves in a nearly linear relationship. WQS regression showed that the mixture of PAEs metabolites was related to elevated serum uric acid and hyperuricemia risk, and MBzP was identified as the most contributing PAEs metabolite. The causal mediation effect model found that SII significantly mediated the relationships of PAEs metabolites with serum uric acid and hyperuricemia risk.

CONCLUSION

Individual and mixture of urinary PAEs metabolites were associated with increased serum uric acid concentration and the risk of hyperuricemia. MBzP exhibited the highest contribution to the overall effects. SII alteration may be an important biological mechanism underlining the impact of PAEs metabolites on serum uric acid concentration and hyperuricemia risk.

Association Between Urinary Rare Earth Element Levels and Metabolic Syndrome: A Cross-sectional Study in the Minority Population of Guangxi in China

OBJECTIVE

This study aimed to investigate the association between rare earth elements (REEs) and metabolic syndrome (MetS).

METHODS

We used a cross-sectional design based on the baseline data of the Prospective Cohort Study of Chronic Diseases in Ethnic Minority Natural Population in Guangxi in China. Logistic regression and BKMR models were employed to evaluate the association between REEs and risk of MetS.

RESULTS

Although REEs were not significantly associated with MetS, certain elements such as La, Pr, and Nd were negatively associated with abdominal obesity, whereas Ce, Pr, Nd, and Dy were positively associated with hypertension. BKMR models suggested a U-shaped relationship between mixed REEs and MetS, with varying effects on abdominal obesity and high blood pressure.

CONCLUSIONS

This study suggests that exposure to REEs may be associated with a reduced risk of abdominal obesity and an increased risk of high blood pressure.

Association of plain water intake with risk of all-cause and cause-specific mortality in individuals with non-alcoholic fatty liver disease or metabolic dysfunction-associated steatotic liver disease

Non-alcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD)-related mortality have increased dramatically in past decades. Our study aims to investigate the association between plain water and this prevalent metabolic disease, as water plays a crucial role in regulating metabolic processes. A total of 3,543/3,428 individuals with NAFLD/MASLD were included in this study from National Health and Nutrition Examination Survey (NHANES). Daily plain water intake was recorded, and mortality status was tracked until December 31, 2019. Multivariate Cox regression models and restricted cubic spline (RCS) regression models were used to assess the association between plain water intake and long-term all-cause as well as cause-specific mortality among participants with NAFLD/MASLD. Furthermore, we investigated the relationship between substituting other beverages with plain water intake and the risk of mortality. The multivariate Cox regression analyses revealed a significant association between higher plain water intake and lower all-cause mortality, cerebrovascular diseases mortality, and cancer mortality in both NAFLD or MASLD patients. Dose-response analyses revealed a non-linear trend between plain water intake and mortality among NAFLD/MASLD patients. Additionally, replacing sugar or artificial beverages with plain water was linked to reduced all-cause mortality, cerebrovascular diseases mortality, and cancer mortality in patients with NAFLD/MASLD. Higher plain water intake is independently linked to lower risk of all-cause, cerebrovascular diseases mortality, and cancer mortality in NAFLD/MASLD patients. Increasing plain water intake may be an effective way for these patients to reduce their risk of mortality.

Association between dietary intake of carotenoids and metabolic dysfunction-associated fatty liver disease in US adults: National Health and Nutrition Examination Survey 2017-March 2020

OBJECTIVE

To assess the relationship between dietary intake of α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein+zeaxanthin (LZ) and occurrence of metabolic dysfunction-associated fatty liver disease (MAFLD).

DESIGN

Cross-sectional study design. The MAFLD diagnosis was based on hepatic steatosis and metabolic dysregulation. Carotenoid intake was adjusted for using an energy-adjusted model. Logistic regression and restricted cubic spline (RCS) analyses were used to assess the relationships, with sensitivity analysis to validate the findings. Weighted quantile sum regression (WQS) was used to explore the combined effect of these carotenoids on MAFLD. Subgroup analyses were conducted to identify population-specific associations.

SETTING

National Health and Nutrition Examination Survey (NHANES) 2017-March 2020.

PARTICIPANTS

This study included 5098 individuals aged 18 years and older.

RESULTS

After adjusting for potential confounders, a weak inverse association was observed between α-carotene and β-carotene intakes and MAFLD occurrence (all P value <0·05). The highest quartile of β-carotene intake showed a significantly lower occurrence of MAFLD compared with the lowest quartile (OR = 0·65; 95 % CI: 0·44, 0·97). RCS analysis showed that a significantly lower occurrence of MAFLD was associated with a higher intake of the four carotenoids, excluding lycopene. Furthermore, the WQS analysis revealed a negative relationship between combined carotenoid intake and MAFLD occurrence (OR = 0·95, 95 % CI: 0·90, 1·00, P = 0·037). Subgroup analyses showed dietary carotenoid intake was associated with reduced MAFLD occurrence in populations aged 50-69 years, females, physically active individuals and non-drinkers.

CONCLUSION

Higher dietary intake of carotenoids is associated with lower MAFLD occurrence. However, this relationship varies among individuals of different ages, sexes and lifestyles.

Contextualizing toxic elements in the diet: a case for integration of toxic element data into food databases

Food composition data plays a key role in the practice of nutrition. However, nutrition professionals may currently lack the resources they need to integrate information about toxic elements - such as arsenic, cadmium, and lead - in food into the advice they give consumers. Geographic, sociocultural, and individual factors may impact not only the toxic element content of food, but also how the balance between potentially toxic and health-promoting components of food must be weighed. Better integration and contextualization of toxic element data into key food databases could allow for more nuanced, comprehensive nutrition guidance.

Impact of treatment delays on future survival outcomes in non-surgical patients with esophageal cancer in Shandong Province, China

The treatment process of tumors in surgical patients is typically prompt and efficient, whereas non-surgical patients are more prone to treatment delay due to various factors. However, the relationship between treatment delay and survival outcomes in non-surgical Esophageal cancer (EC) patients has received limited study. This study aims to evaluate the impact of waiting time from diagnose to treatment on survival outcomes among non-surgical EC patients in Shandong Province, China. Over a 20-year follow-up period, a total of 12,911 patients diagnosed with EC and not receiving surgical intervention were identified from 2000 to 2020. The Kaplan-Meier methodology was employed to determine overall survival (OS) and cancer-specific survival (CSS). Univariate and multivariate Cox regression analyses were performed to evaluate the impact of treatment delays on future outcomes. The nonlinear association between waiting time and survival outcomes was investigated using restricted cubic spline (RCS) functions. The average delay in initiating EC treatment from the initial medical consultation for symptoms of EC was 1.18 months (95%CI=1.16-1.20). Patients with a long delay (≥3 months) in treatment demonstrated significantly lower rates of 1-, 3-, and 5-year OS and CSS compared to those with a brief delay in treatment initiation. A long delay in EC treatment independently associated with an increased risk of mortality from all causes and cancer. The association between waiting time and both all-cause and cause-specific mortality illustrated a pronounced J-shaped pattern. The prolong delay in treatment initiation significantly impacts the OS and CSS outcomes for non-surgical EC patients. Timely administration of treatment has the potential to enhance survival outcomes in patients with EC who are ineligible for surgery, including those in advanced stages without surgical options available.

Associations of exposure to bisphenol-A or parabens with markers of liver injury/function among US adults in NHANES 2011-2016

BACKGROUND

Bisphenol-A (BPA) and parabens are common endocrine-disrupting compounds (EDCs) that are used extensively in consumer products worldwide and are widely found in the environment.

OBJECTIVE

The purpose of this study was to comprehensively explore the correlations between urinary BPA/parabens levels and liver injury/function markers.

METHODS

In this cross-sectional study, we used National Health and Nutrition Examination Survey (NHANES) data from 2011 to 2016. The exposure variables were urinary BPA and four urinary parabens [methylparaben (MPB), ethylparaben (EPB), propylparaben (PPB), and butylparaben (BPB)], while the outcome variables were indicators of liver function/injury [alanine aminotransferase (ALT), aspartate aminotransferase (AST), AST/ ALT, albumin (ALB), total protein (TP), total bilirubin (TBIL), alkaline phosphatase (ALP), and the fibrosis-4 index (FIB-4)]. Multiple linear regression and weighted quantile sum (WQS) regression analyses were applied to explore the relationships between the individual/combined exposure variables and the liver injury/function indicators, respectively. Furthermore, stratified analysis was employed to detect the associations influenced by age and sex.

RESULTS

A total of 2,179 adults were eligible for the present analysis. Multivariate linear regression analysis revealed positive associations of EPB with AST, ALT, TP, and FIB-4 scores and negative associations of BPA with TP and ALB. The effects of urinary parabens on adverse outcomes in the liver (AST and ALT) were significant in the female and middle-aged subgroups. In addition, the WQS analysis revealed that the mixture of four compounds was negatively associated with ALB. BPA had the greatest effect on the serum ALB concentration (weight = 0.688).

IMPACT

Our present study provided novel evidence of significant associations between BPA or certain parabens and numerous markers of liver injury/function indicators. We found that higher urinary BPA concentrations were associated with worse liver function. Exposure to high EPB/PPB ratios was significantly associated with biomarkers of liver injury.

Associations of lifestyle characteristics with circulating immune markers in the general population based on NHANES 1999 to 2014

Lifestyles maybe associated with the immune and inflammatory state of human body. We aimed to comprehensively explore the relationship between lifestyles and circulating immune-inflammatory markers in the general population. Data from NHANES 1999-2014 was used. Lifestyle factors included leisure-time physical activity (LTPA), diet quality (Healthy Eating Index-2015, HEI-2015), alcohol consumption, cigarettes smoking, sleep hour and sedentary time. Immune makers included C-reactive protein (CRP), neutrophil-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), platelet-lymphocyte ratio (PLR) and monocyte-lymphocyte ratio (MLR). Generalized linear regression models were used to adjust confounders. Regressions of restricted cubic splines were utilized to evaluate the potentially non-linear relationships between exposures and outcomes. As results, HEI was negatively associated with CRP (P < 0.001), SII (P < 0.001), and NLR (P < 0.001). Cigarettes per day was positively associated with CRP (P < 0.001), SII (P < 0.001), and NLR (P = 0.008). Alcohol consumption was negatively associated with CRP (P < 0.001), but positively associated with PLR (P = 0.012) and MLR (P < 0.001). Physical activity was negatively associated with CRP (P < 0.001), SII (P = 0.005), and NLR (P = 0.002), but positively associated with PLR (P = 0.010). Participants with higher healthy lifestyle score had significantly lower CRP, SII and NLR (all P values < 0.05). Most of the sensitivity analyses found similar results. In conclusion, we found significant associations between lifestyles and immune markers in the general population, which may reflect a systemic inflammatory response to unhealthy lifestyles.

Impact of heavy metals exposure on herpes simplex virus type I infection: A population-based cross-sectional study

This study aims to investigate the significant relationship between serum heavy metals (lead [Pb], cadmium [Cd], mercury [Hg]) and the risk of herpes simplex virus type 1 (HSV-1) infection. Data were derived from the National Health and Nutrition Examination Survey (NHANES) conducted in the United States from 2007 to 2016. This nationally representative survey, conducted by the National Center for Health Statistics, assessed the health status of participants through interviews, physical examinations, and laboratory tests. After excluding participants lacking serum Pb, Cd, and Hg data, as well as those missing HSV-1 testing data and pregnant women, the analysis included 13 772 participants, among whom 3363 were adolescents. A survey-weighted multivariate logistic regression model was used to evaluate the association between heavy metal exposure and the risk of HSV-1 infection, and to explore the dose-response relationship between them. In adults and adolescents, serum concentrations of Pb and Cd were higher in those infected with HSV-1 than in those not infected. However, an increase in serum Hg concentration was observed only in infected adolescents. After adjusting for potential confounders, elevated serum Pb and Cd concentrations in adults were associated with an increased risk of HSV-1 infection. Higher serum Pb and Cd concentrations were associated with an increased risk of HSV-2 infection, irrespective of HSV-1 infection status. In adults, serum concentrations of Pb and Hg showed an approximately linear relationship with HSV-1 infection risk (p for nonlinearity > 0.05), whereas the dose-response relationship between serum Cd concentration and HSV-1 infection was nonlinear (p for nonlinearity = 0.004). In adolescents, serum concentrations of heavy metals (Pb, Cd, Hg) showed an approximately linear relationship with HSV-1 infection (p for nonlinearity > 0.05). Furthermore, the study examined the relationship between serum heavy metal levels and the risk of HSV-1 infection across different genders, races, income levels, weight statuses, and immune statuses. In conclusion, there is a significant association between serum heavy metal concentrations and HSV-1 infection, which warrants further investigation into the causal relationship between them.

A review of common statistical methods for dealing with multiple pollutant mixtures and multiple exposures

Traditional environmental epidemiology has consistently focused on studying the impact of single exposures on specific health outcomes, considering concurrent exposures as variables to be controlled. However, with the continuous changes in environment, humans are increasingly facing more complex exposures to multi-pollutant mixtures. In this context, accurately assessing the impact of multi-pollutant mixtures on health has become a central concern in current environmental research. Simultaneously, the continuous development and optimization of statistical methods offer robust support for handling large datasets, strengthening the capability to conduct in-depth research on the effects of multiple exposures on health. In order to examine complicated exposure mixtures, we introduce commonly used statistical methods and their developments, such as weighted quantile sum, bayesian kernel machine regression, toxic equivalency analysis, and others. Delineating their applications, advantages, weaknesses, and interpretability of results. It also provides guidance for researchers involved in studying multi-pollutant mixtures, aiding them in selecting appropriate statistical methods and utilizing R software for more accurate and comprehensive assessments of the impact of multi-pollutant mixtures on human health.

Urinary volatile organic compound metabolites and COPD among US adults: mixture, interaction and mediation analysis

BACKGROUND

Volatile organic compounds (VOCs) encompass hundreds of high production volume chemicals and have been reported to be associated with adverse respiratory outcomes such as chronic obstructive pulmonary disease (COPD). However, research on the combined toxic effects of exposure to various VOCs on COPD is lacking. We aimed to assess the effect of VOC metabolite mixture on COPD risk in a large population sample.

METHODS

We assessed the effect of VOC metabolite mixture on COPD risk in 5997 adults from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2020 (pre-pandemic) using multivariate logistic regression, Bayesian weighted quantile sum regression (BWQS), quantile-based g-Computation method (Qgcomp), and Bayesian kernel machine regression (BKMR). We explored whether these associations were mediated by white blood cell (WBC) count and total bilirubin.

RESULTS

In the logistic regression model, we observed a significantly increased risk of COPD associated with 9 VOC metabolites. Conversely, N-acetyl-S-(benzyl)-L-cysteine (BMA) and N-acetyl-S-(n-propyl)-L-cysteine (BPMA) showed insignificant negative correlations with COPD risk. The overall mixture exposure demonstrated a significant positive relationship with COPD in both the BWQS model (adjusted odds ratio (OR) = 1.30, 95% confidence interval (CI): 1.06, 1.58) and BKMR model, and with marginal significance in the Qgcomp model (adjusted OR = 1.22, 95% CI: 0.98, 1.52). All three models indicated a significant effect of the VOC metabolite mixture on COPD in non-current smokers. WBC count mediated 7.1% of the VOC mixture associated-COPD in non-current smokers.

CONCLUSIONS

Our findings provide novel evidence suggesting that VOCs may have adverse associations with COPD in the general population, with N, N- Dimethylformamide and 1,3-Butadiene contributing most. These findings underscore the significance of understanding the potential health risks associated with VOC mixture and emphasize the need for targeted interventions to mitigate the adverse effects on COPD risk.

Association of multiple serum minerals and vitamins with metabolic dysfunction-associated fatty liver disease in US adults: National Health and Nutrition Examination Survey 2017-2018

Background

Despite the rapid increase in the global prevalence of Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD), there are no approved therapeutic drugs for MAFLD yet. Nutrient supplementation might mitigate the risk of MAFLD. It is more typical for individuals to consume multiple nutrients simultaneously. However, the studies exploring the combined effects of multiple nutrients on MAFLD are limited. This study aimed to investigate the relationship between both individual nutrients and their combined influence on the risk of MAFLD.

Methods

Data were obtained from National Health and Nutrition Examination Survey (NHANES), and 18 types of nutrients were considered in this study. Logistic regression analysis was performed to evaluate the correlation between single nutrients and the risk of MAFLD. The Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis was performed to pinpoint the most relevant nutrient associated with the risk of MAFLD. Subsequently, both Weighted Quantile Sum (WQS) regression and Quantile g-computation (Qgcomp) were used to assess the combined effects of multiple nutrients on the risk of MAFLD.

Results

A total of 3,069 participants were included in this study. LASSO regression analysis showed that Se, α-tocopherol, and γ-tocopherol exhibited a positive association with the risk of MAFLD. In contrast, the serum levels of Co, P, α-cryptoxanthin, LZ, and trans-β-carotene were inversely associated with the prevalence of MAFLD. When Se and two types of vitamin E were excluded, the WQS index showed a significant inverse relationship between the remaining 15 nutrients and the risk of MAFLD; α-cryptoxanthin showed the most substantial contribution. Similarly, Qgcomp suggested that the combined effects of these 15 nutrients were associated with a lower risk of MAFLD, with α-cryptoxanthin possessing the most significant negative weights.

Conclusion

This study suggested that the complex nutrients with either a low proportion of Se, α-tocopherol, and γ-tocopherol or without them should be recommended for patients with MAFLD to reduce its risk.

Association of Serum Concentrations of Copper, Selenium, and Zinc with Grip Strength Based on NHANES 2013-2014

Increasing evidence has found metals to be strongly associated with muscle strength, but the correlations between serum copper (Cu), selenium (Se), and zinc (Zn) with grip strength in adult populations have not yet been established. We examined the linear and non-linear associations between these three metals and grip strength via multiple linear regression and restricted cubic spline (RCS) regression using data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014. A higher concentration of serum Cu was monotonically linked with lower grip strength [β = - 0.004 m2 (95% CI: - 0.005, - 0.002)], and serum Zn was positively associated with grip strength [β = 0.004 m2 (95% CI: 0.002, 0.006)]. We observed a positive association between serum Se and grip strength in the unadjusted model but not in covariate-adjusted models. Interestingly, the results of RCS regression showed that serum Cu had an L-shaped non-linear association with grip strength in all participants and subgroups. We further found a linear-increased trend between serum Zn and the grip strength in all participants. There were also non-linear associations that varied across different subgroups. Taken together, serum Cu and Zn were significantly associated with grip strength, while Se was not. This study offers new evidence to help formulate a reference concentration range for serum Cu and Zn.

Environmental exposure to lead and cadmium are associated with triglyceride glucose index

The triglyceride glucose (TyG) index was suggested as a novel reliable surrogate marker for insulin resistance and related cardiovascular-metabolic diseases. We aimed to evaluate the association between the TyG index and environmental exposure to lead (Pb), mercury (Hg), and cadmium (Cd). A total of 9645 adults who enrolled in the Korea National Health and Nutrition Examination Survey in 2005, 2008-2013, and 2016 were included. Fasting plasma glucose and triglyceride levels were used to calculate the TyG index. Multivariate logistic regression model was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). We noted an increasing trend in the TyG index with increment of blood Pb and Cd concentrations. Participants in the highest quartile of blood Pb and Cd concentrations had higher TyG index values than those in the lowest quartile, with ORs (95% CIs) of 1.32 (1.07-1.63) and 1.29 (1.04-1.59) for Pb and Cd, respectively. Strong associations between blood Pb and Cd concentrations and the TyG index were found in men. Blood Hg concentrations did not show a significant association with the TyG index. Our study suggests that public health strategies for cardiovascular-metabolic disorder prevention should be directed toward individuals exposed to priority heavy metals.

Association of insulin resistance indicators with hepatic steatosis and fibrosis in patients with metabolic syndrome

BACKGROUND

To investigate the association of four insulin resistance (IR) indicators with hepatic steatosis and fibrosis in patients with metabolic syndrome (MetS), as well as to compare the diagnostic value of these indicators in identifying hepatic steatosis and fibrosis in individuals with MetS.

METHODS

This cross-sectional study used the data from the National Health and Nutrition Examination Survey 2017-2018. IR indicators included homeostasis model assessment of IR (HOMA-IR), triglyceride/glucose (TyG) index, triglyceride glucose-waist-to-height ratio (TyG-WHtR), and metabolic score for IR (METS-IR). The main endpoints of this study were hepatic steatosis and hepatic fibrosis. Weighted univariate and multivariate logistic regression models were employed to evaluate the association between four IR indicators and both hepatic steatosis, hepatic fibrosis. The efficacy of various IR indicators in the detection of hepatic steatosis and hepatic fibrosis were assessed using receiver operating characteristics curve (ROC).

RESULTS

A total of 876 participants with MetS were enrolled. Among the participants, hepatic steatosis was observed in 587 MetS individuals, while hepatic fibrosis was identified in 151 MetS individuals. In multivariate logistic regression model, HOMA-IR, TyG, TyG-WHtR, and METS-IR were related to the increased odd of hepatic steatosis. Additionally, HOMA-IR, TyG-WHtR, and METS-IR were associated with increased odd of hepatic fibrosis. According to the ROC analysis, the area under the curve (AUC) of the TyG-WHtR (AUC = 0.705, 95%CI: 0.668-0.743) was higher than HOMA-IR (AUC = 0.693, 95%CI: 0.656-0.730), TyG (AUC = 0.627, 95%CI: 0.587-0.666), and METS-IR (AUC = 0.685, 95%CI: 0.648-0.722) for identifying hepatic steatosis of MetS patients. Likewise, TyG-WHtR was also higher than HOMA-IR, TyG, and METS-IR for identifying hepatic fibrosis of MetS patients.

CONCLUSION

HOMA-IR, TyG-WHtR, and METS-IR may be associated with the risk of hepatic steatosis and fibrosis among the U.S. adult population with MetS. In addition, TyG-WHtR may have a good predictive value for hepatic steatosis and hepatic fibrosis.

Associations of urinary caffeine and caffeine metabolites with metabolic syndrome in US adults

Aims

The relationship between caffeine and metabolic syndrome (MetS) has only been evaluated from the perspective of caffeine consumption. The association between urinary caffeine and MetS is still unclear. This study examined the associations between urinary caffeine and its metabolites and MetS and its components among adults.

Methods

Data from the United States (US) National Health and Nutrition Examination Survey (NHANES) 2011-2014 was analyzed. NHANES is a stratified, multi-stage survey of all non-institutionalized persons in the US. A total of 2,394 subjects aged ≥ 18 years without missing data were selected in this study. Urinary caffeine and caffeine metabolite levels were quantified using high-performance liquid chromatography-electrospray ionization-tandem quadrupole mass spectrometry (HPLC-ESI-MS/MS) with stable isotope-labeled internal standards. We performed principal components analysis (PCA) to investigate the underlying correlation structure of 15 features of urinary caffeine and its metabolites and then used these principal components (PCs) as independent variables to conduct logistic regression analysis with or without restricted cubic spline (RCS) terms to explore the associations between caffeine metabolites and MetS.

Results

Two main PCs that were derived from the PCA explained 90.67% of the total variance of caffeine and its metabolites. The first PC (PC1, strongly correlated with 1-MU, 1,3-DMU, 1,7-DMU, 1,3,7-TMU, 1-MX, 1,3-DMX, 1,7-DMX, 1,3,7-TMX, and AAMU) was positively correlated with risk of MetS (OR = 1.27, p < 0.001) and all its components (all ORs > 1, all p-values < 0.001) in the unadjusted models, while in the adjusted models, it was positively correlated with MetS (OR = 1.16, p = 0.042) and central obesity (OR = 1.22, p < 0.001). In the unadjusted model, there were significant associations between the second PC (PC2, correlated with 3-MU, 7-MU, 3,7-DMU, 3-MX, 7-MX, and 3,7-DMX) and MetS (OR = 1.11, P = 0.030) and central obesity (OR = 1.16, P < 0.001), while in the adjusted models (adjustment variables include gender, age, race/ethnicity, education level and income-poverty ratio, smoking status, drinking, and physical activity), PC2 was positively associated with MetS (OR = 1.15, p = 0.035) and central obesity (OR = 1.15, p = 0.005) and negatively associated with raised triglycerides (TG) (OR = 0.84, p = 0.008). Moreover, we observed U-shaped associations between PC1 and the risk of raised TG both in unadjusted (Pnon-linear = 0.017) and adjusted (Pnon-linear = 0.014) models.

Conclusion

Urinary caffeine metabolites were positively associated with the risk of MetS and its components through different linear or non-linear patterns.

Associations of mixed urinary metals exposure with metabolic syndrome in the US adult population

BACKGROUND

Metals are harmful to human health in many ways. However, the association between metals and metabolic syndrome (MetS) remains unclear. Aims of this study is to discuss the relationship between urinary metal and MetS.

METHODS

This study included 3419 adult participants from the National Health and Nutrition Examination Survey (NHANES) (2005-2018). Logistic regression analysis, Bayesian kernel machine regression (BKMR), weighted quantile sum (WQS), and restricted cubic spline (RCS) were used to explore the associations of nine urinary metal and MetS.

RESULTS

BKMR and WQS showed the effects of combined nine urinary metal were negatively correlated with MetS. Logistic regression analysis, WQS, and BKMR all suggested that cesium (Cs) and lead (Pb) were negatively correlated with MetS (all PFDCR <0.05). And RCS suggested log2-transformed Cs (χ2 = 20, P < 0.001) and log2-transformed Pb (χ2 = 19.9, P < 0.001) were negatively and linearly associated with MetS.

CONCLUSION

Existing evidence suggests that urine metal content is related to MetS. Cs and Pb are negatively related to MetS. It is still necessary to study and further discuss the causal relationship and mechanism.

The association of female reproductive factors with risk of metabolic syndrome in women from NHANES 1999-2018

BACKGROUND

Female reproductive factors such as age at first birth (AFB), age at last birth (ALB), number of pregnancies and live births play an essential role in women's health. However, few epidemiological studies have evaluated the association between female reproductive factors and metabolic syndrome (MetS). We therefore conducted a cross-sectional study to investigate the association between MetS risk and female reproductive factors.

METHODS

We investigated the relationship between AFB, ALB, number of pregnancies and live births and the incidence of MetS using publicly available data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018. Weighted multivariable logistic regression analysis, restricted cubic spline (RCS) model, and subgroup analysis were used to evaluate the association between AFB and ALB and the risk of MetS in women. In addition, the relationship between the number of pregnancies, live births and MetS risk was also explored.

RESULTS

A total of 15,404 women were included in the study, and 5,983 (38.8%) had MetS. RCS models showed an N-shaped relationship between AFB and MetS risk, whereas ALB, number of pregnancies, and live births were linearly associated with MetS. Weighted multivariable logistic regression analysis showed that the number of live births was associated with MetS risk, with ORs of 1.18 (95% CI: 1.04, 1.35) for women with ≥ 5 deliveries compared to women with ≤ 2 births.

CONCLUSIONS

AFB was associated with the risk of MetS in an N-shaped curve in women. In addition, women with high live births have a higher incidence of MetS.

Association between heavy metal exposures and the prevalence of pelvic inflammatory disease: a cross-sectional study from the National Health and Nutrition Examination Survey 2013-2018

Pelvic inflammatory disease (PID) is a common medical condition in women. However, the correlation between exposure to heavy metals, including cadmium (Cd), lead (Pb), manganese (Mn), mercury (Hg), and selenium (Se), and PID, is unclear. Using a large sample size from the National Health and Nutrition Examination Survey, these relationships were studied and verified. PID diagnosis was acquired through a self-reported questionnaire (2013-2018). Heavy metal exposure (Cd, Pb, Mn, Hg, and Se) was measured using mass spectrometry of blood samples. Covariate data were obtained through questionnaires and physical tests. Individuals with complete covariate data were included in the study. The relationship between heavy metal exposure (Cd, Pb, Mn, Hg, and Se) and PID was demonstrated using logistic regression analysis, weighted quantile sum (WQS) regression analysis, and restricted cubic splines (RCS). Overall, 2743 participants were included. Of these, 183 were diagnosed with PID. Through weighted univariate and multivariate regression analyses, the heavy metals of Cd and Pb were positively correlated with the prevalence of PID. However, no significant relationship was observed in the heavy metals of Mn, Hg, and Se. The joint effect of heavy metals further confirmed the important role of Cd and Pb in WQS analysis. After visualizing the RCS, significant curved and linear relationships were observed for Cd and Pb, respectively. Most subgroup analyses confirmed these results. In conclusion, exposure to Cd was nonlinearly correlated with the risk of PID, whereas exposure to Pb showed a linear relationship. Our findings increase the awareness of the environmental effects of exposure to heavy metals in PID. However, further studies are needed to elucidate the causality and underlying mechanisms between heavy metal exposure and the prevalence of PID.

Association between Heavy Metals, Metalloids and Metabolic Syndrome: New Insights and Approaches

Metabolic syndrome (MetS) is an important public health issue that affects millions of people around the world and is growing to pandemic-like proportions. This syndrome is defined by the World Health Organization (WHO) as a pathologic condition characterized by abdominal obesity, insulin resistance, hypertension, and hyperlipidemia. Moreover, the etiology of MetS is multifactorial, involving many environmental factors, including toxicant exposures. Several studies have associated MetS with heavy metals exposure, which is the focus of this review. Environmental and/or occupational exposure to heavy metals are a major risk, contributing to the development of chronic diseases. Of particular note, toxic metals such as mercury, lead, and cadmium may contribute to the development of MetS by altering oxidative stress, IL-6 signaling, apoptosis, altered lipoprotein metabolism, fluid shear stress and atherosclerosis, and other mechanisms. In this review, we discuss the known and potential roles of heavy metals in MetS etiology as well as potential targeted pathways that are associated with MetS. Furthermore, we describe how new approaches involving proteomic and transcriptome analysis, as well as bioinformatic tools, may help bring about an understanding of the involvement of heavy metals and metalloids in MetS.

The mediating role of telomere length in multi-pollutant exposure associated with metabolic syndrome in adults

Metabolic syndrome is a chronic and complex disease characterized by environmental and genetic factors. However, the underlying mechanisms remain unclear. This study assessed the relationship between exposure to a mixture of environmental chemicals and metabolic syndrome (MetS) and further examined whether telomere length (TL) moderated these relationships. A total of 1265 adults aged > 20 years participated in the study. Data on multiple pollutants (polycyclic aromatic hydrocarbons, phthalates, and metals), MetS, leukocyte telomere length (LTL), and confounders were provided in the 2001-2002 National Health and Nutrition Examination Survey. The correlations between multi-pollutant exposure, TL, and MetS in the males and females were separately assessed using principal component analysis (PCA), logistic and extended linear regression models, Bayesian kernel machine regression (BKMR), and mediation analysis. Four factors were generated in PCA that accounted for 76.2% and 77.5% of the total environmental pollutants in males and females, respectively. The highest quantiles of PC2 and PC4 were associated with the risk of TL shortening (P < 0.05). We observed that the relationship between PC2, PC4, and MetS risk was significant in the participants with median TL levels (P for trend = 0.04 for PC2, and P for trend = 0.01 for PC4). Furthermore, mediation analysis revealed that TL could explain 26.1% and 17.1% of the effects of PC2 and PC4 associated with MetS in males, respectively. The results of BKMR model revealed that these associations were mainly driven by 1-PYE (cPIP = 0.65) and Cd (cPIP = 0.29) in PC2. Meanwhile, TL could explain 17.7% of the mediation effects of PC2 associated with MetS in the females. However, the relationships between pollutants and MetS were sparse and inconsistent in the females. Our findings suggest that the effects of the risk of MetS associated with mixed exposure to multiple pollutants are mediated by TL, and this mediating effect in the males is more pronounced than that in the females.

Associations of perchlorate, nitrate, and thiocyanate with metabolic syndrome and its components among US adults: A cross-sectional study from NHANES

Perchlorate, nitrate and thiocyanate are common endocrine disruptors. Herein, this study was undertaken to evaluate the associations between perchlorate, nitrate, and thiocyanate exposures (alone or in combination) and risk of metabolic syndrome (MetS) among adults, which has not been explored so far. Analytical data were extracted from different datasets in the National Health and Nutrition Examination Survey (NHANES) database. Multivariate logistic regression models were constructed to investigate the associations between perchlorate, nitrate, and thiocyanate exposures, and the prevalence of MetS. Subsequently, odds ratios (OR) and their corresponding 95 % confidence intervals (CIs) were adopted to represent the magnitude of the effect size. We performed a series of subgroup analyses and sensitivity analyses as well. Moreover, three commonly used mixture modeling strategies [Weighted quantile sum (WQS) regression, quantile-based g-computation (Qgcomp), and Bayesian kernel machine regression (BKMR)] were utilized to evaluate the joint mixture effect on MetS. This study included 12,007 participants in the subsequent analyses. After adjustment for confounding factors, higher levels of perchlorate, and thiocyanate concentrations were significantly associated with the risk of MetS (OR = 1.15, 95%CI:1.00, 1.32; OR = 1.21, 95%CI:1.04, 1.41, respectively). Analyses of WQS and Qgcomp showed that a quartile increase in chemical mixture was correlated with the occurrence of MetS with ORs of 1.07 (95%CI: 0.99, 1.16) and 1.07 (95%CI: 1.00, 1.14), respectively. This positive association was mainly driven by perchlorate and thiocyanate. Analysis of BKMR revealed that perchlorate, nitrate, and thiocyanate mixture was positively associated with the risk of MetS while perchlorate, and thiocyanate were major predictors in the mixture. In summary, our study reveals positive relationships between perchlorate, thiocyanate and MetS. Co-exposure to perchlorate, nitrate and thiocyanate is positively associated with the risk of MetS, with perchlorate and thiocyanate contributing the most to the overall mixture effect.

Mediterranean diet lowers all-cause and cardiovascular mortality for patients with metabolic syndrome

A Mediterranean-style diet (MED) can promote people lengthen the span of life and avoid atherosclerotic cardiovascular disease (ASCVD) in primary prevention. Metabolic syndrome (MetS) can significantly reduce life expectancy and increase the risk of ASCVD. However, few studies have focused on the role of the Mediterranean diet in patients with MetS. Participants in the National Health and Nutrition Examination Survey (NHANES) with MetS (N = 8301) from 2007 to 2018 were examined. A 9-point evaluation scorewas used to measure the degree of adherence to the MED diet. In order to compare the various levels of adherence to the MED diet and the effects of the specific MED diet components on all-cause and cardiovascular mortality, Cox regression models were utilized. Among the 8301 participants with MetS, about 13.0% (1080 of 8301) died after a median follow-up of 6.3 years. In this study, participants with MetS with adherence to high-quality and moderate-quality Mediterranean diet were significantly associated with lower all-cause mortality as well as cardiovascular mortality during the follow-up period. Futhermore, in joint analysis of the Mediterranean diet and sedentary behavior or depression, we found that high-quality or moderate-quality Mediterranean diet could attenuate, even reverse the adverse effects of sedentary behavior and depression on all-cause and cardiovascular mortality in participants with MetS. Among the components of the MED diet, greater intakes of vegetables, legumes, nuts and high MUFA/SFA ratio were significantly associated with lower all-cause mortality and greater vegetables intake was significantly associated with lower cardiovascular mortality, while more red/processed meat intake was significantly associated with higher cardiovascular mortality in participants with MetS.

The combined effect of heavy metals and polycyclic aromatic hydrocarbons on arthritis, especially osteoarthritis, in the U.S. adult population

The evaluation of heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) impact on arthritis is usually limited to the analysis of the arthritis subtype (rheumatoid arthritis, RA), whereas studies on osteoarthritis (OA) are relatively sparse. Furthermore, the combined effect of HMs and PAHs co-exposure on arthritis also has rarely been analyzed. Herein, we aimed to comprehensively estimate the association between HMs and PAHs (three blood HMs and six urinary PAHs metabolites) co-exposure and arthritis. Using data from the National Health and Nutrition Examination Survey (NHANES), 2003-2016, we included 9735 adults, of whom 2464 had total arthritis, 1371 had OA, and 468 had RA. The logistic regression model was conducted to estimate the single effect of HMs and PAHs on arthritis. Moreover, weighted quantile sum (WQS) regression, quantile-based g computation (qgcomp), and Bayesian kernel machine regression (BKMR) were separately performed to assess the combined effect of HMs and PAHs co-exposure on arthritis. In the single-exposure analyses, cadmium (Cd) and lead (Pb) statistically grew the risk of total arthritis, OA, and RA. Among PAHs, 1-hydroxynaphthalene (1-NAP) and 3-hydroxyfluorene (3-FLU) showed a positive association with total arthritis, OA, and RA. Meanwhile, 2-NAP also was significantly associated with total arthritis. 2-NAP, 2-FLU, and 1-hydroxyphenanthrene (1-PHE) also were significantly associated with RA. Furthermore, the three complementary models consistently demonstrated that co-exposure to high levels of HMs and PAHs was positively associated with total arthritis, OA, and RA risk. The above associations were more obvious in young and medium-aged people. Interestingly, BKMR analyses indicated that 1-NAP might interact with Cd and 3-FLU in total arthritis, while Pb might interact with Cd in OA. Therefore, this study provided novel evidence that co-exposure to HMs and PAHs positively correlated with arthritis, especially OA, and these results were worthy of further prospective studies.

Exploring the relationship between blood toxic metal(oid)s and serum insulin levels through benchmark modelling of human data: Possible role of arsenic as a metabolic disruptor

The major goal of this study was to estimate the correlations and dose-response pattern between the measured blood toxic metals (cadmium (Cd), mercury (Hg), chromium (Cr), nickel (Ni))/metalloid (arsenic (As)) and serum insulin level by conducting Benchmark dose (BMD) analysis of human data. The study involved 435 non-occupationally exposed individuals (217 men and 218 women). The samples were collected at health care institutions in Belgrade, Serbia, from January 2019 to May 2021. Blood sample preparation was conducted by microwave digestion. Cd was measured by graphite furnace atomic absorption spectrophotometry (GF-AAS), while inductively coupled plasma-mass spectrometry (ICP-MS) was used to measure Hg, Ni, Cr and As. BMD analysis of insulin levels represented as quantal data was done using the PROAST software version 70.1 (model averaging methodology, BMD response: 10%). In the male population, there was no correlation between toxic metal/metalloid concentrations and insulin level. However, in the female population/whole population, a high positive correlation for As and Hg, and a strong negative correlation for Ni and measured serum insulin level was established. BMD modelling revealed quantitative associations between blood toxic metal/metalloid concentrations and serum insulin levels. All the estimated BMD intervals were wide except the one for As, reflecting a high degree of confidence in the estimations and possible role of As as a metabolic disruptor. These results indicate that, in the case of As blood concentrations, even values higher than BMD (BMDL): 3.27 (1.26) (male population), 2.79 (0.771) (female population), or 1.18 (2.96) μg/L (whole population) might contribute to a 10% higher risk of insulin level alterations, meaning 10% higher risk of blood insulin increasing from within reference range to above reference range. The obtained results contribute to the current body of knowledge on the use of BMD modelling for analysing human data.

Associations of serum perfluoroalkyl substances with concentrations of blood manganese and selenium

The aim of this study was to estimate the associations of blood manganese and selenium with serum concentrations of selected perfluoroalkyl substances (PFAS). The presence or absence of this association is important because PFAS have documented pro-oxidant properties, whereas manganese and selenium are critical to antioxidant responses. For this purpose, the data from NHANES for US adults aged ≥ 20 years (N = 3982), adolescents aged 12-19 years (N = 1524), and children aged 3-11 years (N = 639) were analyzed. Among adults, concentrations of blood manganese were found to be inversely associated with serum concentrations of perfluorooctanoic acid or PFOA (β =  - 0.04204, p < 0.01), perfluorononanoic acid or PFNA (β =  - 0.02700, p < 0.01), perfluorohexane sulfonate or PFHxS (β =  - 0.04306, p < 0.01), and perfluorooctane sulfonate or PFOS (β =  - 0.04494, p < 0.01). Blood concentrations of selenium were found to be positively associated with PFHxS only among adults (β = 0.000678, p = 0.047) and adolescents (β = 0.01377, p = 0.02). The Mn results but not the less consistent Se associations were robust to adjustments for serum albumin. Possible reasons for the inverse association of PFOA, PFHxS, PFNA, and PFOS with Mn among US adults are discussed. The finding raises concerns about manganese's diminished ability to mount antioxidant responses to PFAS exposure.

Combined exposure to multiple metals on cardiovascular disease in NHANES under five statistical models

BACKGROUND

It is well-documented that heavy metals are associated with cardiovascular disease (CVD). However, there is few studies exploring effect of metal mixture on CVD. Therefore, the primary objective of present study was to investigate the joint effect of heavy metals on CVD and to identify the most influential metals in the mixture.

METHODS

Original data for study subjects were obtained from the National Health and Nutrition Examination Survey. In this study, adults with complete data on 12 kinds of urinary metals (antimony, arsenic, barium, cadmium, cobalt, cesium, molybdenum, mercury, lead, thallium, tungsten, and uranium), cardiovascular disease, and core covariates were enrolled. We applied five different statistical strategies to examine the CVD risk with metal exposure, including multivariate logistic regression, adaptive elastic net combined with Environmental Risk Score, Quantile g-computation, Weighted Quantile Sum regression, and Bayesian kernel machine regression.

RESULTS

Higher levels of cadmium, tungsten, cobalt, and antimony were significantly associated with Increased risk of CVD when covariates were adjusted for multivariate logistic regression. The results from multi-pollutant strategies all indicated that metal mixture was positively associated with the risk of CVD. Based on the results of multiple statistical strategies, it was determined that cadmium, tungsten, cobalt, and antimony exhibited the strongest positive correlations, whereas barium, lead, molybdenum, and thallium were most associated with negative correlations.

CONCLUSION

Overall, our study demonstrates that exposure to heavy metal mixture is linked to a higher risk of CVD. Meanwhile, this association may be driven primarily by cadmium, tungsten, cobalt, and antimony. Further prospective studies are warranted to validate or refute our primary findings as well as to identify other important heavy metals linked with CVD.

Association between Blood Manganese Levels and Visceral Adipose Tissue in the United States: A Population-Based Study

Background: Manganese (Mn) is an essential trace element with a narrow toxic margin for human health. The association between Mn exposure and adverse visceral adipose tissue (VAT) accumulation is unclear. Objective: This study aimed to estimate the associations of blood Mn levels with VAT mass or visceral obesity in the general population in the United States. Method: This cross-sectional study included data of 7297 individuals released by National Health and Nutrition Examination Survey (NHANES). VAT was quantified with dual-energy X-ray absorptiometry, and blood Mn was measured using inductively coupled plasma mass spectrometry. The generalized linear model and generalized additive model (GAM) were applied to estimate the linear and non-linear associations between Mn levels and VAT mass, respectively. Logistic regression was used to estimate the associations between blood Mn levels and the risk of visceral obesity. Results: Fully adjusted generalized linear regression revealed that individuals in the higher quantile of Mn had increased VAT mass compared with those in the lower quantile (β per quantile change = 0.025; 95% CI of 0.017, 0.033; p < 0.001). Positive associations were also observed in males and females (males: β per quantile change = 0.012, 95% CI of 0.002, 0.022 (p = 0.020); female: β per quantile change = 0.036; 95% CI of 0.023, 0.048 (p < 0.001)). The GAM illustrated that the non-linear associations between blood Mn levels and VAT mass were in U-shape patterns (effective degree of freedom >1 in total participants, males, and females). A stratified analysis found significant interactions between Mn and the family income-to-poverty ratio (PIR) in males, with stronger associations in males with a PIR < 1.3 (β = 0.109; 95% CI of 0.048, 0.170). Additional analyses revealed that individuals in the highest quantile of Mn had a 39% higher risk of visceral obesity (OR = 1.39; 95% CI of 1.15−1.69; p < 0.001). Conclusions: Higher blood Mn levels were positively associated with increased VAT mass and visceral obesity risk. The adverse VAT phenotype associated with excessive blood Mn levels should be further investigated.

Lead exposure is non-linearly associated with subclinical myocardial injury in the general population without cardiovascular disease

Background and aims

Growing studies have focused on the effect of lead exposure on human circulatory system, while the relationship between lead exposure and subclinical myocardial injury (SC-MI) is still poorly known. Therefore, this study was to explore the effect of lead exposure on SC-MI.

Methods

The study included 6,272 individuals aged 40 and older without cardiovascular disease (CVD) from the third National Health and Nutrition Examination Survey. Blood lead was used as an alternative marker of lead exposure. Multivariable logistic regression models, restricted cubic spline and threshold effect analyses were performed to investigate the effect of blood lead on SC-MI.

Results

After adjusting for age, sex, race, diabetes, hypertension, systolic blood pressure, body mass index, waist-to-hip ratio, triglycerides, total cholesterol, creatinine, fasting plasma glucose and hemoglobin Alc, higher blood lead level was independently related to higher risk of SC-MI (OR 1.047, 95% CI [1.018, 1.077]; P = 0.003). Restricted cubic spline curve showed that there was a non-linear correlation between blood lead and SC-MI. Threshold effect analysis determined that the inflection point of blood lead was 3.8 ug/dl. When the blood lead level was higher than 3.8 ug/dl, there was an independent positive correlation between blood lead level and the risk of SC-MI (OR 1.031, 95% CI [1.009, 1.053]; P < 0.01). And similar associations were also observed among subgroups of male, ≤60 years, >60 years, never smoker, non-Hispanic White, non-Hispanic Black or without hypertension and diabetes.

Conclusions

Blood lead was non-linearly related to SC-MI in population free from CVD.

A Longitudinal Study of Exposure to Manganese and Incidence of Metabolic Syndrome

The association between manganese (Mn) and metabolic syndrome (MetS) is unclear, and no prior study has studied this association longitudinally. The aim of this study was to assess longitudinal associations of Mn exposure with MetS and metabolic outcomes. We used data from the San Luis Valley Diabetes Study (SLVDS), a prospective cohort from rural Colorado with data collected from 1984−1998 (n = 1478). Urinary Mn was measured at baseline (range = 0.20−42.5 µg/L). We assessed the shape of the cross-sectional association between Mn and MetS accounting for effect modification by other metals at baseline using Bayesian kernel machine regression. We assessed longitudinal associations between baseline quartiles of Mn and incident MetS using Fine and Gray competing risks regression models (competing risk = mortality) and between quartiles of Mn and metabolic outcomes using linear mixed effects models. We did not observe evidence that quartiles of Mn were associated with incident MetS (p-value for trend = 0.52). Quartiles of Mn were significantly associated with lower fasting glucose (p-value for trend < 0.01). Lead was found to be a possible effect modifier of the association between Mn and incident MetS. Mn was associated with lower fasting glucose in this rural population. Our results support a possible beneficial effect of Mn on diabetic markers.

Association between environmental lead/cadmium co-exposure in drinking water and soil and type 2 diabetes mellitus/obesity in Southern China

Lead (Pb) and cadmium (Cd) in environment can be directly absorbed by drinking water and soil. However, data on human Pb and Cd exposure by drinking water and soil and its long-term consequence for type 2 diabetes mellitus (T2DM) and obesity are lacking. Our study aims to explore the association of typical heavy metals co-exposure in drinking water and soil to the community residents with T2DM and obesity indices in two cities of southern China. A cross-sectional study enrolling total 1,274 participants was performed and the local water and soil samples were collected in two communities in southern China. The average daily dose (ADD) of heavy metals was calculated to assess the exposure. The obesity indices comprise body mass index (BMI), waist-to-hip ratio (WHR) and waist circumference (WC). Binary, multiple logistic and linear regressions were employed for assessing the associations of Pb and Cd exposure with T2DM and obesity. The results showed that there weren't any significant correlations between ADDs of Pb/Cd and T2DM in community residents (all Ps>0.05). Compared with those with 18.5 ≤ BMI <24, with 1 μg/kg bw/d ADD of Pb increase in exposure are associated with 49.2-56.1% lower likelihood of overweight. Besides, with ADDs of Pb exposure was increased by 1 μg/kg bw/d and WHR decreasing by 0.01-0.02, and WC decreasing by 2.22-4.67 cm. We speculate that Pb causes weight loss because it damages the absorption function of the gastrointestinal tract as an initial injury. 1μg/kg bw/d ADD of Cd increase is associated with 100.9% upper likelihood of low weight in Model 1. It suggests that Pb/Cd pollution in the local environment was serious and harmful to residents' health. Government should introduce relevant oversight and accountability systems to improve the prevention and management of lifestyle-related chronic diseases in the future.

Manganese Exposure and Metabolic Syndrome: A Systematic Review and Meta-Analysis

Manganese (Mn) is an essential element acting as a co-factor of superoxide dismutase, and it is potentially beneficial for cardiometabolic health by reducing oxidative stress. Although some studies have examined the relationship between Mn and metabolic syndrome (MetS), no systematic review and meta-analysis has been presented to summarize the evidence. Therefore, the present review examined the association between dietary and environmental Mn exposure, and MetS risk. A total of nine cross-sectional studies and three case-control studies were included, which assessed Mn from diet, serum, urine, and whole blood. The association of the highest Mn level from diet (three studies, odds ratio (OR): 0.83, 95% confidence interval (C.I.) = 0.57, 1.21), serum (two studies, OR: 0.87, 95% C.I. = 0.66, 1.14), urine (two studies, OR: 0.84, 95% C.I. = 0.59, 1.19), and whole blood (two studies, OR: 0.92, 95% C.I. = 0.53, 1.60) were insignificant, but some included studies have suggested a non-linear relationship of urinary and blood Mn with MetS, and higher dietary Mn may associate with a lower MetS risk in some of the included studies. While more evidence from prospective cohorts is needed, future studies should use novel statistical approaches to evaluate relative contribution of Mn on MetS risk along with other inter-related exposures.