Association between bedtime and the prevalence of newly diagnosed non-alcoholic fatty liver disease in adults

Sleep Duration, Midpoint, Variability, Irregularity and Metabolic Dysfunction-Associated Steatotic Liver Disease

OBJECTIVES

The relationship between actigraphy-derived sleep parameters, day-to-day deviations in sleep parameters, and metabolic dysfunction-associated steatotic liver disease (MASLD), a new definition of nonalcoholic fatty liver disease (NAFLD), remains unclear. We aimed to explore the associations of sleep duration, midpoint, variability and irregularity with MASLD risk.

METHODS

We used data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Sleep duration and midpoint were estimated from 4 to 7 days of 24-hour actigraphy measurements. Sleep duration and midpoint standard deviation were used as indicators of sleep variability and irregularity, respectively. MASLD was diagnosed according to the multi-society Delphi consensus. Hepatic steatosis was defined as fatty liver index ≥ 60. Multivariable weighted logistic regression models were used to explore correlations and perform subgroup analyses.

RESULTS

A total of 5,316 participants were included, of whom 2,339 had MASLD. After adjusting for socio-demographic characteristics, lifestyle factors, and depression, compared to sleep variability < 60 minutes, the odds ratio (OR) [95% confidence interval (CI)] was 1.13 (0.96-1.34) for 60-90 minutes, and 1.17 (1.00-1.38) for > 90 minutes (P for trend = .034). After further adjustment for other sleep variables, short sleep duration (<7 hours) was associated with a 24% higher risk of MASLD (OR: 1.24, 95% CI: 1.01-1.53); compared to sleep irregularity < 38 minutes, OR (95% CI) was 1.27 (1.02-1.59) for 38-61 minutes and 1.43 (1.24-1.65) for > 61 minutes (P for trend = .003).

CONCLUSION

In addition to sleep duration, sleep irregularity may need to be considered in the prevention of MASLD.

Association of occupational noise exposure and shift work with non-alcoholic fatty liver disease: a cross-sectional study of male workers in the Chinese automobile manufacturing industry

OBJECTIVE

This study aimed to determine the relationship between occupational noise, shift work and non-alcoholic fatty liver disease (NAFLD) in male workers in the automobile manufacturing industry.

DESIGN

Cross-sectional study.

SETTING

This study was carried out at the Guangzhou Twelfth People's Hospital using data from April to September 2022.

PARTICIPANTS

A total of 4672 eligible participants were included in the study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Diagnosis of NAFLD was made using ultrasound. Noise was detected according to the Measurement of Physical Factors in the Workplace-Part 8: Noise. Environmental noise intensity was assessed using an EDGE personal noise dosimeter manufactured by CASELLA (UK). The working status of workers was investigated by questionnaire.

RESULTS

The OR of NAFLD was 1.39 (1.03, 1.88) in the cumulative noise exposure (CNE)≥95 group compared with CNE<85 group. Improved risk of NAFLD in workers with shift work compared with those without shift work (OR=1.35, 95% CI: 1.09, 1.68). As stratified analyses showed, the ORs of NAFLD prevalence related to occupational noise and shift work exposure appear to be increased in young workers. When both shift work and noise exposure work are present simultaneously, the synergy index between them was 0.47 (95% CI: 0.25, 0.89). Combined effects analysis revealed that the OR of NAFLD was 2.02 (95% CI: 1.34, 2.99) in CNE≥95 and cumulative length of night shifts work>2920 hours.

CONCLUSION

Occupational noise exposure may be an independent risk factor for NAFLD. It may synergistically affect disease when combined with night shift work, particularly among younger workers. These findings underscore the importance for companies to prioritise the management and training of younger workers, along with targeted occupational health education initiatives, as crucial measures for reducing the incidence of NAFLD.

Association between cardiovascular health and markers of liver function: a cross-sectional study from NHANES 2005-2018

Background

Cardiovascular health (CVH) has been associated with various systemic diseases. However, the relationship between CVH, as measured by Life's Essential 8 (LE8), and liver function markers in the general population remains poorly understood.

Methods

This study analyzed data from 21,156 participants (aged ≥ 20) from the NHANES 2005-2018 to investigate the associations between CVH and liver function markers [alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), albumin and AST/ALT ratio]. Linear regression models were used, along with a restricted cubic spline (RCS) to assess dose-response. Weighted quantile sum (WQS) regression and quantile g-computation (QGC) analyses were employed to evaluate the association between CVH and liver function markers.

Results

Linear regression analysis showed that each 1-point increase in CVH score was significantly associated with decreased levels of liver enzymes [ALT: -0.200 U/L (95% CI: -0.223, -0.176), AST: -0.043 U/L (-0.062, -0.024), GGT: -0.453 U/L (-0.509, -0.397), ALP: -0.310 U/L (-0.340, -0.281)] and increased levels of albumin [0.040 g/dL (0.036, 0.045)] and AST/ALT ratio [0.0056 (0.0051, 0.0061)]. Notably, CVH score demonstrated non-linear dose-response relationships with ALT, ALP, and AST/ALT ratio. Age significantly modified these associations, while nicotine exposure, BMI, and blood lipids were identified as primary contributors through WQS and QGC analyses. E-value analysis suggested robustness to unmeasured confounding.

Conclusion

This study demonstrates robust associations between CVH and liver function markers in United States adults, with nicotine exposure, BMI, and blood lipids identified as significant contributors. These findings suggest that maintaining optimal cardiovascular health may have beneficial effects on liver function, highlighting potential targets for integrated prevention strategies.

Association between sleep duration and risk of nonalcoholic fatty liver disease: A systematic review and meta-analysis

Introduction

Considering that both long and short sleep duration may have an association with nonalcoholic fatty liver disease (NAFLD), in this meta-analysis, we analyzed the dose-response association between sleep duration and NAFLD along with meta-analyses of the differences in mean sleep duration between NAFLD patients and healthy controls, and linear meta-analysis of the association between sleep duration and NAFLD.

Methods

PubMed (665 articles), Scopus (442 articles), and Web of Sciences (200 articles) were searched from inception until November 2023. Observational studies were included if they assess the association between sleep duration and NAFLD or compare the mean sleep duration between patients with NAFLD and healthy population. All studies done in humans without restriction on sex, age, and language were included. The methological quality of studies was assessed by Joanna Briggs Institute (JBI) tools. The meta-analysis was conducted using STATA.

Results

Thirty-one studies that included 836,117 participants were included in this systematic review. The results indicated no significant differences between NAFLD patients and healthy controls regarding mean sleep duration [Mean difference: -7.08, 95 % CI: -20.10, 5.94]. The subgroup meta-analysis did not show any significant differences between groups. The long versus short sleep duration meta-analysis showed a significant association between sleep duration and NAFLD (OR: 0.8 [95 % CI, 0.74-0.91]). The results of the dose-response meta-analysis do not suggest a linear or nonlinear relationship between sleep duration and NAFLD (p-value = 0.9).

Conclusion

The highest category of sleep duration was associated with a lower risk of NAFLD. However, no dose-response association was observed.

Circadian Deregulation: Back Facing the Sun Toward Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) Development

Earth's rotation around its axis has pressured its inhabitants to adapt to 24 h cycles of day and night. Humans adapted their own circadian rhythms to the Earth's rhythms with a light-aligned awake-sleep cycle. As a consequence, metabolism undergoes drastic changes throughout the circadian cycle and needs plasticity to cope with opposing conditions in the day (when there is an increase in energy demands and food availability), and during the night (when prolonged fasting couples with cyclic changes in the energy demands across the sleep stages). In the last century, human behavior changed dramatically with a disregard for the natural circadian cycles. This misalignment in sleep and eating schedules strongly modulates the metabolism and energy homeostasis, favoring the development of obesity, metabolic syndrome, and metabolic dysfunction-associated steatotic liver disease (MASLD). This review summarizes the effects of circadian disruption, with a particular focus on the feeding and sleep cycles in the development of MASLD and hepatocellular carcinoma.

Association between sleep and gallstone disease in United States adults: A cross-sectional study

BACKGROUND

Both gallstone disease and sleep disorders are important public health problems. Few studies to date have investigated the associations between sleep and gallstone disease in humans. This study aimed to assess whether sleep factors (sleep time, sleep amounts, trouble sleeping) were associated with gallstone disease in the United States adults.

METHODS

This was a population-based cross-sectional study of US adults, which included data of participants aged over 20 years from the National Health and Nutrition Examination Survey (NHANES) gathered between 2017 and March 2020. The assessment of gallstone disease and sleep factors was based on self-reported data. We used sample-weighted logistic regression and restricted cubic spline models to explore the associations between sleep factors and gallstone disease. Subgroup analyses were conducted to assess the interaction between trouble sleeping and interacting factors.

RESULTS

The prevalence of gallstone disease was 11% among the 9,210 adult participants. Going to bed late on weekdays (OR, 1.41; 95% CI, 1.15 to 1.74) and weekends (OR, 1.43; 95% CI, 1.14 to 1.78), and short sleep duration on weekdays (OR, 1.29; 95% CI, 1.00 to 1.68) were factors associated with increased risk of gallstone disease, and we detected dose-response associations with the restricted cubic spline model (RCS) models, after adjusting for confounders. Presenting trouble sleeping was associated with increased risk of gallstone disease (OR, 1.52; 95% CI, 1.03 to 2.23) and the association was influenced by the presence of thyroid disease (P for interaction = 0.037).

CONCLUSIONS

Our study results indicate that going to bed late, short sleep duration, and trouble sleeping were associated with increased risk of gallstone disease in a nationally representative sample of adults in the US.

Day napping and metabolic-associated fatty liver disease: A systematic review and meta-analysis of observational studies

BACKGROUND

Napping inevitably affects human health, and the association between napping and metabolism-related diseases is being more seriously considered. However, the conclusions of studies on the relationship between napping and fatty liver disease (NAFLD)/metabolic-associated fatty liver disease (MAFLD) remain controversial.

METHODS

We performed a systematical search to identify eligible studies up to July 31, 2024. The fixed effects model was used to calculate the pooled odds ratio (OR). Subgroup were performed. Sensitivity analyses and meta-regression analysis were carried to explore the heterogeneity. Publication bias was assessed by funnel plot and Egger's test.

RESULTS

48,248 participants from 13 studies were included in this meta-analysis. The pooled analysis found napping to have an association between the incidence of NAFLD/MAFLD (OR, 1.13; 95% confidence interval (CI), 1.08-1.19; P < .001). The robustness of this study was confirmed using a sensitivity analysis. No apparent heterogeneity or publication bias was observed. Further meta-analysis revealed that short nap duration did not greatly affect the incidence of the disease (OR, 1.01; 95% CI, 0.91-1.12; P = .80). However, long nap duration was significantly linked to high risk of the disease (OR, 1.21; 95% CI, 1.02-1.44; P = .03).

CONCLUSION

Patients with NAFLD/MAFLD may had higher prevalence of napping habit. Future research is warranted to conduct a dose-response analysis, measure the effects of confounding factors, and explore the causal relationships between NAFLD/MAFLD. The research protocol was registered and approved in PROSPERO (registration no: CRD42023439507).

Night shift-induced circadian disruption: links to initiation of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis and risk of hepatic cancer

The circadian system plays a crucial role in regulating metabolic homeostasis at both systemic and tissue levels by synchronizing the central and peripheral clocks with exogenous time cues, known as zeitgebers (such as the light/dark cycle). Our body's behavioral rhythms, including sleep-wake cycles and feeding-fasting patterns, align with these extrinsic time cues. The body cannot effectively rest and repair itself when circadian rhythms are frequently disrupted. In many shift workers, the internal rhythms fail to fully synchronize with the end and start times of their shifts. Additionally, exposure to artificial light at night (LAN), irregular eating patterns, and sleep deprivation contribute to circadian disruption and misalignment. Shift work and jet lag disrupt the normal circadian rhythm of liver activity, resulting in a condition known as "circadian disruption". This disturbance adversely affects the metabolism and homeostasis of the liver, contributing to excessive fat accumulation and abnormal liver function. Additionally, extended working hours, such as prolonged night shifts, may worsen the progression of non-alcoholic fatty liver disease (NAFLD) toward non-alcoholic steatohepatitis (NASH) and increase disease severity. Studies have demonstrated a positive correlation between night shift work (NSW) and elevated liver enzymes, indicative of hepatic metabolic dysfunction, potentially increasing the risk of hepatocellular carcinoma (HCC) related to NAFLD. This review consolidates research findings on circadian disruption caused by NSW, late chronotype, jet lag, and social jet lag, drawing insights from studies involving both humans and animal models that investigate the effects of these factors on circadian rhythms in liver metabolism.

Sleep timing and the prevalence of hypertension in middle-aged and older populations: the sleep heart health study

OBJECTIVES

Sleep characteristics such as duration, continuity, and irregularity are associated with the risk of hypertension. This study aimed to investigate the association between sleep timing (including bedtime, wake-up time, and sleep midpoint) and the prevalence of hypertension.

METHODS

Participants were selected from the Sleep Heart Health Study (n = 5504). Bedtime and wake-up times were assessed using sleep habit questionnaires. The sleep midpoint was calculated as the halfway point between the bedtime and wake-up time. Restricted cubic splines and logistic regression analyses were performed to explore the association between sleep timing and hypertension.

RESULTS

A significant nonlinear association was observed between bedtime (Poverall<0.001; Pnonlinear<0.001), wake-up time (Poverall=0.024; Pnonlinear=0.076), sleep midpoint (Poverall=0.002; Pnonlinear=0.005), and the prevalence of hypertension after adjusting for potential confounders. Multivariable logistic regression showed that both late (> 12:00AM and 23:01PM to 12:00AM) and early (≤ 22:00PM) bedtimes were associated with an increased risk of hypertension compared to bedtimes between 22:01PM and 23:00PM. In addition, individuals with late (> 7:00AM) and early (≤ 5:00AM) wake-up times had a higher prevalence of hypertension than those with wake-up times ranging between 5:01AM and 6:00AM. Delaying the sleep midpoint (> 3:00AM) was also associated with an increased risk of hypertension. Furthermore, no significant interaction effect was found in the subgroup analyses stratified by age, sex, or apnea-hypopnea index.

CONCLUSIONS

Our findings identified a nonlinear association between sleep timing and hypertension. Individuals with both early and late sleep timing had a high prevalence of hypertension.

Sleep disturbances in chronic liver disease

Sleep disturbances are common in chronic liver disease and significantly impact patient outcomes and quality of life. The severity and nature of sleep disturbances vary by liver disease etiology and severity. While there is ongoing research into the association between liver disease and sleep-wake dysfunction, the underlying pathophysiology varies and, in many cases, is poorly understood. Liver disease is associated with alterations in thermoregulation, inflammation, and physical activity, and is associated with disease-specific complications, such as HE, that may directly affect sleep. In this article, we review the relevant pathophysiologic processes, disease-specific sleep-wake disturbances, and clinical management of CLD-associated sleep-wake disturbances.

Sleep patterns, genetic predisposition, and risk of chronic liver disease: A prospective study of 408,560 UK Biobank participants

BACKGROUND

Little is known about the role that combined sleep behaviors play in the association with chronic liver disease (CLD) risk.

METHODS

We included 408,560 participants initially free of CLD from the UK Biobank. A healthy sleep pattern was defined by early chronotype, sleep duration of 7-8 h/day, no insomnia, no snoring, and no excessive daytime sleepiness. Cox regression models were used to examine the association of healthy sleep pattern with incident CLD and their interaction with PNPLA3 genetic risk.

RESULTS

During a median 12.5 years of follow-up, we documented 10,915 incident all-cause CLD cases, including 388 viral hepatitis, 4782 non-alcoholic fatty liver disease (NAFLD), 1356 cirrhosis, 973 alcoholic liver disease, and 725 liver cancer cases. Compared to participants with a healthy sleep score of 0-1, the hazard ratio (HR) (95 % confidence interval [CI]) for those with a sleep score of 5 was 0.54 (0.49, 0.60) for CLD, 0.52 (0.30, 0.90) for viral hepatitis, 0.47 (0.41, 0.55) for NAFLD, 0.57 (0.43, 0.75) for cirrhosis, 0.32 (0.23, 0.44) for alcoholic liver disease, and 0.53 (0.37, 0.77) for liver cancer. Healthy sleep pattern and PNPLA3 genetic risk exerted significant additive effects on CLD risk (relative excess risk due to the interaction: 0.05; attributable proportion due to the interaction: 13 %).

LIMITATIONS

Measurement error was unavoidable for self-reported data on sleep behaviors.

CONCLUSIONS

Our analyses provide evidence that healthy sleep pattern was inversely associated with the development of CLD, and participants with higher genetic risk were more likely to develop CLD when exposed to the unhealthy sleep pattern.

The relationship between infertility and sleep quality in women: Systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis study aimed to examine the relationship between infertility and sleep quality in women.

METHODS

The literature search was conducted between October and November 2022 with full-text studies from PubMed (MEDLINE), Cochrane, Google Scholar, and Scientific Information Database (SID). The study is based on the recommendations of the Cochrane guidelines. The data were analyzed using the Review Manager computer software (Version 5.3).

RESULTS

A systematic literature review was conducted, with 11 studies included. The meta-analysis revealed a significant difference between infertility and sleep quality in women, that the sleep quality of infertile patients decreased (SMD: -0.75 95% CI: -0.84 to -0.66, Z = 16.46, P < .00001), and that there was a significant difference between infertility and depression (SMD: -0.18 95% CI: -0.27 to -0.09, Z = 4.00, P < .0001).

CONCLUSION

The results of this study indicate that sleep quality is low in infertile women. PROSPERO ID: (CRD42023404389).

Association of sleep timing with all-cause and cardiovascular mortality: the Sleep Heart Health Study and the Osteoporotic Fractures in Men Study

STUDY OBJECTIVES

Previous studies have highlighted the importance of sleep patterns for human health. This study aimed to investigate the association of sleep timing with all-cause and cardiovascular disease mortality.

METHODS

Participants were screened from two cohort studies: the Sleep Heart Health Study (SHHS; n = 4,824) and the Osteoporotic Fractures in Men Study (n = 2,658). Sleep timing, including bedtime and wake-up time, was obtained from sleep habit questionnaires at baseline. The sleep midpoint was defined as the halfway point between the bedtime and wake-up time. Restricted cubic splines and Cox proportional hazards regression analyses were used to examine the association between sleep timing and mortality.

RESULTS

We observed a U-shaped association between bedtime and all-cause mortality in both the SHHS and Osteoporotic Fractures in Men Study groups. Specifically, bedtime at 11:00 pm and waking up at 7:00 am was the nadir for all-cause and cardiovascular disease mortality risks. Individuals with late bedtime (> 12:00 am) had an increased risk of all-cause mortality in SHHS (hazard ratio 1.53, 95% confidence interval 1.28-1.84) and Osteoporotic Fractures in Men Study (hazard ratio 1.27, 95% confidence interval 1.01-1.58). In the SHHS, late wake-up time (> 8:00 am) was associated with increased all-cause mortality (hazard ratio 1.39, 95% confidence interval 1.13-1.72). No significant association was found between wake-up time and cardiovascular disease mortality. Delaying sleep midpoint (> 4:00 am) was also significantly associated with all-cause mortality in the SHHS and Osteoporotic Fractures in Men Study.

CONCLUSIONS

Sleep timing is associated with all-cause and cardiovascular disease mortality. Our findings highlight the importance of appropriate sleep timing in reducing mortality risk.

CITATION

Ma M, Fan Y, Peng Y, et al. Association of sleep timing with all-cause and cardiovascular mortality: the Sleep Heart Health Study and the Osteoporotic Fractures in Men Study. J Clin Sleep Med. 2024;20(4):545-553.

Development of a prediction model for predicting the prevalence of nonalcoholic fatty liver disease in Chinese nurses: the first-year follow data of a web-based ambispective cohort study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is gradually becoming a huge threat to public health. With complex working characteristics, female nurses had been found with high risk of NAFLD. To develop and validate a prediction model to predict the prevalence of NAFLD based on demographic characteristics, work situation, daily lifestyle and laboratory tests in female nurses.

METHODS

This study was a part of the Chinese Nurse Cohort Study (The National Nurse Health Study, NNHS), and data were extracted from the first-year follow data collected from 1st June to 1st September 2021 by questionnaires and physical examination records in a comprehensive tertiary hospital. The questionnaires included demographic characteristics, work situation and daily lifestyle. Logistic regression and a nomogram were used to develop and validate the prediction model.

RESULTS

A total of 824 female nurses were included in this study. Living situation, smoking history, monthly night shift, daily sleep time, ALT/AST, FBG, TG, HDL-C, UA, BMI, TBil and Ca were independent risk factors for NAFLD occurance. A prediction model for predicting the prevalence of NAFLD among female nurses was developed and verified in this study.

CONCLUSION

Living situation, smoking history, monthly night shift, daily sleep time, ALT/AST, FBG, TG, UA, BMI and Ca were independent predictors, while HDL-C and Tbil were independent protective indicators of NAFLD occurance. The prediction model and nomogram could be applied to predict the prevalence of NAFLD among female nurses, which could be used in health improvement.

TRIAL REGISTRATION

This study was a part of the Chinese Nurse Cohort Study (The National Nurse Health Study, NNHS), which was a ambispective cohort study contained past data and registered at Clinicaltrials.gov ( https://clinicaltrials.gov/ct2/show/NCT04572347 ) and the China Cohort Consortium ( http://chinacohort.bjmu.edu.cn/project/102/ ).

Association between chronotype and metabolic-associated fatty liver disease in employed adults: A longitudinal study in Southwestern China

The circadian system is an essential physiological regulator of mammals, and sleep chronotype may be associated with the risk of metabolic disorders. However, evidence regarding the role of sleep chronotype in the development of metabolic-associated fatty liver disease (MAFLD) is scarce, particularly in employed adults. We conducted a longitudinal study of 1,309 employed adults in Southwestern China with a five-year follow-up from 2017 to 2021. MAFLD was assessed by the presence of hepatic steatosis using abdominal ultrasonography, overweight/obese status, diabetes mellitus, metabolic dysregulation, or elevation of high-sensitivity C-reactive protein. Chronotype was assessed by the Morning and Evening Questionnaire-5 (MEQ-5). The logistic random effects model was applied to analyze the 5-year panel data to estimate the association between chronotype and MAFLD, and the potential effect modification of demographics on such association. The MAFLD prevalence of participants was 38.6% at baseline and showed an increasing trend during follow-up (p for trends < 0.05). Compared with morning chronotype, evening chronotype was positively associated with MAFLD (OR = 2.19, 95%CI: [1.09, 4.40]) after controlled for covariates. Age, sex, ethnicity, and educational level did not modify the association between chronotype and MAFLD. These findings suggest that improving circadian rhythms could reduce the risk of MAFLD and chronic disease burden among employed adults.

Association of Bedtime with Early-Onset Diabetes and Islet Beta Cell Function in Patients with Newly Diagnosed Type 2 Diabetes Mellitus

Objective

To investigate the association of bedtime with the risk of early-onset diabetes mellitus (DM) and islet beta cell function.

Methods

138 participants with treat-naïve DM were included in this study. All participants underwent a 75g oral glucose tolerance test. Sleep habit was obtained through a standardized questionnaire. Bedtime was categorized as < 22:00, 22:00-24:00, and ≥ 24:00 in this study. Multivariate logistic regression and multiple linear regression were used to estimate the association between bedtime and risk of early-onset DM and islet beta cell function, respectively.

Results

Patients with early-onset DM had a later bedtime than those with late-onset DM. Individuals with bedtime ≥ 24:00 had a higher prevalence of early-onset DM than those with bedtime at 22:00-24:00 and < 22:00 (51.2% vs 29.3% vs 14.3%, respectively, p = 0.028). The multivariate logistic regression showed that per hour later in bedtime was associated with a 52% increased risk of early-onset DM (p = 0.023). Patients with bedtime after 24:00 had a 146% increased risk of early-onset DM compared to those went to bed between 22:00 to 24:00 (OR = 2.46, 95% CI 1.05 to 5.77, p = 0.039). The multiple linear regression showed that bedtime was independently negatively correlated with late-phase insulin secretion (assessed by disposition index, DI120).

Conclusion

Later bedtime was associated with worse late-phase insulin secretion and may be a risk factor for early-onset DM. Proper bedtime to lower risk of early-onset DM deserves further investigation.

Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.

Sleep characteristics of middle-aged adults with non-alcoholic fatty liver disease: findings from the Shahrekord PERSIAN cohort study

BACKGROUND

Several studies have reported short sleep duration in people with non-alcoholic fatty liver disease (NAFLD) but other sleep characteristics have been less studied. We aimed to assess the cross-sectional association of NAFLD with sleep duration and quality in an Iranian population sample.

METHODS

We used data from 9,151 participants in the Shahrekord Prospective Epidemiological Research Studies in Iran (PERSIAN) Cohort Study, including 1,320 that were diagnosed with NAFLD. Log-binomial regression models sequentially adjusted for sociodemographic, lifestyle, clinical and biological variables were used to estimate relative risks (RR) and 95% confidence intervals (95% CI) for the association between NAFLD and sleep characteristics.

RESULTS

Participants with NAFLD had shorter sleep duration, later wake-up time and bedtime, worse sleep efficiency, and more frequent daytime napping and use of sleeping pills, in age- and sex-adjusted models. After controlling for sociodemographic, lifestyle, clinical, and biological variables the associations remained strong for sleep efficiency (per 10%, RR = 0.92, 95%CI: 0.88-0.96) and use of sleeping pills (RR = 1.48, 95%CI: 1.17-1.88). The association between NAFLD and sleep efficiency was stronger in participants aged > 60 years (RR = 0.81, 0.70-0.93) and 40-60 years (RR = 0.87, 0.82-0.94), compared with those aged < 40 years (P-heterogeneity < 0.001). More frequent daytime napping in participants with NAFLD, compared with non-NAFLD, was observed in males but not females (P-heterogeneity = 0.007), and in those with body mass index (BMI) < 30 but not in obese participants (P-heterogeneity < 0.001).

CONCLUSIONS

Diagnosis of NAFLD is associated with several poor sleep characteristics in middle-aged Iranians. Although longitudinal studies would help to clarify the direction of causality, our study shows that poor sleep is an important aspect of NAFLD.

Shift work and nonalcoholic fatty liver disease incidence among Chinese rail workers: a 4-year longitudinal cohort study

PURPOSE

Occupational harmful factors, such as shift work, are attracting increasing attention as a potential cause of nonalcoholic fatty liver disease (NAFLD). In this study, we aimed to identify the association between shift work and NAFLD incidence in Chinese rail population.

METHODS

A cohort study was conducted among 14,112 rail workers for 4-year follow-up. Shift work frequency and other potential variables were recorded by questionnaires, including demographic, lifestyle, and occupation information. Besides, body mass index, blood pressure, fasting blood glucose, total cholesterol, triglyceride, alanine aminotransferase, and aspartate aminotransferase were measured by anthropometric measurement and blood test. Diagnosis of new NAFLD case was based on abdominal ultrasonography. Cox proportional hazards regression model was used to determine whether shift work has effect on occurrence of NAFLD.

RESULTS

The incidence of NAFLD was 30.43% in total subjects. After adjustment for possible confounders, the RRs of NAFLD were 1.069 (95% CI 0.998-1.146) and 1.179 (95% CI 1.059-1.312) in occasionally shift work group and frequently shift work group respectively, compared to the seldom shift work group. In stratified analyses, the RRs of NAFLD incidence linked to shift work exposure seems increase among female and elder. The results of three sensitivity analyses were similar with main analysis.

CONCLUSIONS

This research provided further evidence of positive harmful effect of shift work on NAFLD incidence in Chinese rail workers, particularly in frequently shift work population. The risk estimate of shift work on NAFLD was higher in female and elder.

The association between bedtime at night and hypertension in adults

OBJECTIVE

This research was conducted to explore the association between bedtime at night and the prevalence of hypertension in adults.

METHODS

We conducted a cross-sectional study of 14,536 participants with data from the NHANES database. Bedtime was determined from the question in the sleep questionnaire: 'What time do you usually fall asleep on weekdays or workdays?.' Hypertension was defined as systolic blood pressure (SBP) ≥ 140 mmHg, or diastolic blood pressure (DBP) ≥ 90 mmHg, or having been told by a doctor to have high blood pressure, or taking antihypertensive medication. We conducted a weighted multiple logistic regression analysis to explore the relationship between bedtime at night and the prevalence of hypertension in adults.

RESULTS

The association between bedtime and hypertension showed a significantly U-shaped relationship. People who went to bed at 23:00 had the lowest risk of developing hypertension (OR, 0.68 [95%CI, 0.58, 0.81]). This U-shaped association still existed in different genders. In males (n = 7159), the adjusted OR was still lowest at 23:00. However, the adjusted OR was lowest at 0:00 in females(n = 7377). The interaction effect between bedtime and gender was significant (P = 0.0187).

CONCLUSION

With the delay in bedtime, the association between bedtime and hypertension showed a significantly U-shaped relationship. Falling asleep at 23:00 has the lowest risk of developing hypertension.

Sleep Factors in Relation to Metabolic Dysfunction-Associated Fatty Liver Disease in Middle-Aged and Elderly Chinese

CONTEXT

Accumulating evidence implies that sleep disturbance is involved in metabolic disorders.

OBJECTIVE

We comprehensively evaluated the association between various dimensions of sleep behaviors and the risk for metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

In this cross-sectional study of 5011 participants with self-reported sleep behaviors and radiologically diagnosed MAFLD, a comprehensive healthy sleep score was generated to evaluate the associations between sleep behaviors and MAFLD risk using multivariate logistic regression adjusting for demographics, lifestyles, medication, and metabolic comorbidities. Furthermore, mediation analysis was utilized to assess the extent to which obesity explains the effect of sleep quality on MAFLD risk.

RESULTS

Late bedtime, snoring, and daytime napping for over 30 minutes significantly associated with an increased risk of MAFLD, with odds ratios (OR) of 1.37 (95% CI 1.10, 1.70), 1.59 (95% CI 1.33, 1.91), and 1.17 (95% CI 1.02, 1.35), respectively, after full adjustments including obesity. Participants with disturbance in nighttime sleep and prolonged daytime napping showed the highest risk for MAFLD (OR 2.38, 95% CI 1.73, 3.27). Each additional increase of healthy sleep score was associated with a 16% reduction in MAFLD risk. Further stratified analysis revealed that people with a sedentary lifestyle and central obesity experienced more prominent adverse effects from poor sleep quality than others. Moreover, obesity accounted for only 20.77% of the total effect of sleep quality on MAFLD risk.

CONCLUSIONS

Sleep behaviors, both cumulatively and individually, are associated with MAFLD risk. Public health awareness and strategies should be encouraged to curb MAFLD.

Sleep Behavior and Self-Reported Infertility: A Cross-Sectional Analysis Among U.S. Women

OBJECTIVE

To investigate the associations between sleep behaviors and female infertility.

METHODS

We conducted a cross-sectional study composed of 2175 U.S. women 18-44 years of age from the National Health and Nutrition Examination Survey (NHANES) (2015-2018). Bedtime/waketime and sleep duration were extracted from the sleep disorder questionnaire. Self-reported infertility was defined as a binary variable based on the participants' response to the question, "Have you ever attempted to become pregnant over a period of at least a year without becoming pregnant?". Multivariate logistic regression analyses were done to explore the relationship between sleep behaviors and female infertility.

RESULTS

Bedtime (OR=1.24; 95% CI, 1.10-1.40, P = 0.001) and waketime (OR=1.14; 95% CI, 1.01-1.28, P = 0.037) were associated with infertility. Waketime of 08:00 was the inflection point, above which the probability of infertility increased rapidly (OR=1.41; 95% CI, 1.11-1.79, P = 0.004). Sleep-wake behavior was significantly associated with infertility (OR=1.34; 95% CI, 1.16-1.53, P < 0.001) and participants with early-bed/early-rise behavior had the lowest risk.

CONCLUSIONS

Among U.S. women 18-44 years of age, bedtime and waketime were significantly linearly and non-linearly correlated with infertility, respectively. Early-bed/early-rise behavior was associated with the lowest infertility rate. Further study is needed because the timing of sleep behaviors are modifiable factors and could be a novel strategy to cope with infertility.

Sleeping Late Increases the Risk of Myocardial Infarction in the Middle-Aged and Older Populations

Objective: Sleep has a significant influence on the incidence of myocardial infarction (MI). The purpose of this study was to investigate the association between sleep timing including bedtime, wake-up time and sleep midpoint, and the incidence of MI.

Methods: A total of 4,576 patients (2,065 men, 2,511 women; age 63.4 ± 11.0 years) were selected from the Sleep Heart Health Study. Sleep timings on weekdays and weekends were recorded or calculated based on the sleep habits questionnaire completed by the participants at baseline. Bedtime was divided into 10:00 PM and before, 10:01 PM−11:00 PM, 11:01 PM−12:00 AM, and later than 12:00 AM. Cox proportional hazards regression analysis was used to examine the relationship between sleep timings and MI.

Results: Participants with a weekday bedtime later than 12:00 AM, between 11:01 PM−12:00 AM, and 10:00 PM or before had a higher incidence of MI than those with a bedtime between 10:01 PM and 11:00 PM (9.2% vs. 7.0% vs. 6.9% vs. 5.1%, respectively; P = 0.008). Multivariable Cox regression analysis showed that sleeping on weekdays later than 12:00 AM was associated with an increased risk of incident MI after adjusting for potential covariates (hazard ratio, 1.628; 95% confidence interval, 1.092–2.427; P = 0.017). However, there was no significant association between late bedtime on weekends and MI. In addition, no significant association of late wake-up time and delayed sleep midpoint on both weekdays and weekends with the incidence of MI was observed.

Conclusion: Sleeping late on weekday (>12:00 AM) independently increased the risk of MI. This finding emphasizes the importance of a proper bedtime for the maintenance of the health of the cardiovascular system.

Advances in Unhealthy Nutrition and Circadian Dysregulation in Pathophysiology of NAFLD

Unhealthy diets and lifestyle result in various metabolic conditions including metabolic syndrome and non-alcoholic fatty liver disease (NAFLD). Much evidence indicates that disruption of circadian rhythms contributes to the development and progression of excessive hepatic fat deposition and inflammation, as well as liver fibrosis, a key characteristic of non-steatohepatitis (NASH) or the advanced form of NAFLD. In this review, we emphasize the importance of nutrition as a critical factor in the regulation of circadian clock in the liver. We also focus on the roles of the rhythms of nutrient intake and the composition of diets in the regulation of circadian clocks in the context of controlling hepatic glucose and fat metabolism. We then summarize the effects of unhealthy nutrition and circadian dysregulation on the development of hepatic steatosis and inflammation. A better understanding of how the interplay among nutrition, circadian rhythms, and dysregulated metabolism result in hepatic steatosis and inflammation can help develop improved preventive and/or therapeutic strategies for managing NAFLD.

Associations of Nutritional, Lifestyle, and Metabolic Factors With Non-alcoholic Fatty Liver Disease: An Umbrella Review With More Than 380,000 Participants

Background & Aims: Nonalcoholic fatty liver disease (NAFLD) is the most common liver injury. We performed this umbrella review of meta-analyses to summarize the evidence on the associations of nutritional, lifestyle, and metabolic factors with NAFLD.

Methods: We searched the PubMed, Embase, and Web of Science databases from inception until July 2, 2020, to identify meta-analyses of observational studies which explored the associations of nutritional, lifestyle, and metabolic factors with NAFLD. Evidence levels were assessed using summary effect sizes, 95% prediction intervals, between-study heterogeneity, evidence of small-study effects, and evidence of excess significance bias for each meta-analysis. (No. of PROSPERO, CRD42020200124).

Results: Twenty two risk or protective factors from 10 published meta-analyses were included and studied. Three risk factors (sugar-sweetened beverage consumption, serum fetuin-A, and waist circumference) with highly suggestive levels of evidence and three risk factors (soft drink consumption, former smoking, and body mass index) with suggestive levels of evidence were identified. Only two protective factors (physical activity and serum vitamin D level [among adults in Western countries]) with suggestive levels of evidence were identified. Furthermore, other six risk factors and two protective factors with weak levels of evidence were identified.

Conclusions: We found varying levels of evidence of associations of nutritional, lifestyle, and metabolic factors and NAFLD. The results suggest that nutritional and lifestyle management should be considered as a major primary preventive strategy for NAFLD. Moreover, considering the low quality of included meta-analyses and limited area of research topics, future high-quality original studies and meta-analyses should be performed to study these associations.

Circadian Clock-Controlled Checkpoints in the Pathogenesis of Complex Disease

The circadian clock coordinates physiology, metabolism, and behavior with the 24-h cycles of environmental light. Fundamental mechanisms of how the circadian clock regulates organ physiology and metabolism have been elucidated at a rapid speed in the past two decades. Here we review circadian networks in more than six organ systems associated with complex disease, which cluster around metabolic disorders, and seek to propose critical regulatory molecules controlled by the circadian clock (named clock-controlled checkpoints) in the pathogenesis of complex disease. These include clock-controlled checkpoints such as circadian nuclear receptors in liver and muscle tissues, chemokines and adhesion molecules in the vasculature. Although the progress is encouraging, many gaps in the mechanisms remain unaddressed. Future studies should focus on devising time-dependent strategies for drug delivery and engagement in well-characterized organs such as the liver, and elucidating fundamental circadian biology in so far less characterized organ systems, including the heart, blood, peripheral neurons, and reproductive systems.

Long working hours are associated with a higher risk of non-alcoholic fatty liver disease: A large population-based Korean cohort study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), a common chronic liver disease, may progress to fibrosis, cirrhosis, hepatocellular carcinoma, and liver failure. But only a few cross-sectional studies have reported an association of NAFLD with working hours. This cohort study further examined the association between working hours and the development of NAFLD.

METHODS

We included 79,048 Korean adults without NAFLD at baseline who underwent a comprehensive health examination and categorized weekly working hours into 35-40, 41-52, 53-60, and >60 hours. NAFLD was defined as the presence of fatty liver, in the absence of excessive alcohol use, as observed by ultrasound.

RESULTS

During a median follow-up of 6.6 years, 15,095 participants developed new-onset NAFLD (incidence rate, 5.55 per 100 person-years). After adjustment for confounders, the hazard ratios (95% confidence interval) for the development of NAFLD in 41-52, 53-60, and >60 working hours compared with that in 35-40 working hours were 1.07 (1.02-1.13), 1.06 (1.00-1.13), and 1.13 (1.05-1.23), respectively. Furthermore, the association remained significant after confounders were treated as time-varying covariates.

CONCLUSION

In this large-scale cohort, long working hours, especially >60 working hours a week, were independently associated with incident NAFLD. Our findings indicate that long working hours are a risk factor for NAFLD.

Grip strength and depressive symptoms in a large-scale adult population: The TCLSIH cohort study

BACKGROUND

Previous studies suggest that muscle-derived cytokines (myokines) are linked with brain function. Although muscle strength measured by handgrip strength is a prognostic indicator of functional decline, epidemiological studies directly examining the association between grip strength and mental health remain scarce. The aim of this study is to clarify the association between grip strength and depressive symptoms in the general adult population.

METHODS

This is a cross-sectional study of 24,109 Chinese adults (41. 5  ± 11.9 years; 46.0% females). Grip strength was measured by dynamometer and the greatest force was normalized to body weight (NGS, kg/kg). Depressive symptoms were assessed using the Self-Rating Depression Scale (SDS). Models of logistic regression were conducted to assess the association between NGS and depressive symptoms, with adjustment for established confounding factors.

RESULTS

Of the 24,109 participants, the prevalence of depressive symptoms (SDS ≥45) was 16.8% (males 15.7%, females 18.0%). After adjusting for multiple confounding factors, the odds ratios and 95% confidence interval for depressive symptoms in the quartiles of NGS were 1.00, 0.96 (0.84-1.10), 0.91 (0.79-1.05), and 0.91 (0.78-1.07) (P = 0.03) in males; 1.00, 0.92 (0.80-1.06), 0.90 (0.77-1.04), and 0.80 (0.69-0.94) (P = 0.0002) in females, respectively.

LIMITATIONS

This cross-sectional study cannot determine causality.

CONCLUSIONS

Grip strength was inversely associated with depressive symptoms, with stronger association observed among females than males.  Further prospective studies or randomized trials are required to clarify these findings.

Later bedtime is associated with angina pectoris in middle-aged and older adults: results from the Sleep Heart Health Study

OBJECTIVES

Sleep timing is related to several risk factors for angina pectoris (AP), such as obesity and diabetes. This study was designed to evaluate the relationship between sleep timing and AP, specifically whether later bedtime was associated with AP in middle-aged and older adults.

METHODS

This community-based study was based on the Sleep Heart Health Study cohort and included 4710 participants (45.9% men, aged 63.3 ± 11.0 years). Lifestyle and epidemiological information were obtained from baseline records. Self-reported sleep measures provided information on bedtime and wake-up time of weekdays and weekends. Individuals were divided into three categories according to bedtime (≤22:00, 22:01-23:00, and >23:00). Odds ratios (OR) and 95% confidence intervals (CIs) of AP for bedtimes were estimated with multivariate logistic regression analysis.

RESULTS

The prevalence of AP was 44.2% and the distribution of weekday bedtimes ≤22:00, 22:01-23:00_, and >23:00 were 36.6%, 47.5% and 46.0%, respectively. After adjusting for potential confounders, weekday bedtimes >23:00 (OR 1.34; 95% CI 1.13-1.60; P = 0.001) and 22:01-23:00 (OR 1.54; 95% CI 1.29-1.82; P < 0.001) were significantly associated with an increased risk of AP compared with the reference group (≤22:00). In addition, weekend bedtimes >23:00 (OR 1.44; 95% CI 1.20-1.73; P < 0.001) and 22:01-23:00 (OR 1.70; 95% CI 1.40-2.05; P < 0.001) increased the risk of AP.

CONCLUSIONS

Later bedtimes on both weekdays and weekends were significantly associated with an increased prevalence of AP. Early bedtimes may help people decrease the risk of AP.

Nonalcoholic fatty liver disease in lean subjects: Prognosis, outcomes and management

Nonalcoholic fatty liver disease (NAFLD) accounts for most cases of chronic liver disease worldwide, with an estimated global prevalence of approximately 25% and ranges from simple steatosis to nonalcoholic steatohepatitis and cirrhosis. NAFLD is strongly connected to metabolic syndrome, and for many years, fatty liver was considered to be an exclusive feature of obese patients. However, recent studies have highlighted the presence of NAFLD in non-obese subjects, with or without increased visceral fat or even in lean subjects without increased waist circumference. "Lean NAFLD" is a relatively new concept and there is significant scientific interest in understanding the differences in pathophysiology, prognosis and management compared with NAFLD in overweight/obese patients. In the present editorial, we discuss the clinical and metabolic profiles and outcomes of lean NAFLD compared with both obese NAFLD and lean healthy individuals from Asian and Western countries. Moreover, we shed light to the challenging topic of management of NAFLD in lean subjects since there are no specific guidelines for this population. Finally, we discuss open questions and issues to be addressed in the future in order to categorize NAFLD patients into lean and non-lean cohorts.

Association of bedtime with the risk of non-alcoholic fatty liver disease among middle-aged and elderly Chinese adults with pre-diabetes and diabetes

BACKGROUND

Emerging evidence indicated that sleep characteristics may play important roles in the development of metabolic disorders. However, little is known as to the association between bedtime and the risk of non-alcoholic fatty liver disease (NAFLD) in individuals with pre-diabetes and diabetes.

METHODS

In a prospective cohort of 10 375 adults aged ≥40 years, 1960 of 3484 eligible pre-diabetic and diabetic individuals were identified for the current study. NAFLD was diagnosed using liver ultrasonography at baseline and at follow-up. Information on bedtime was obtained at baseline using a standard questionnaire.

RESULTS

We documented 433 incident cases of NAFLD among this study population. In multivariable-adjusted logistic regression model, later bedtime was associated with increased risk of NAFLD (29% increased risk per hour of later bedtime). Compared to individuals with bedtime ≤20:00, the odds ratios (95% confidence intervals) of NAFLD for bedtime of 20:00-22:00 and ≥22:00 were 1.56 (1.04-2.34) and 2.05 (1.31-3.20), respectively. In the subgroup analysis, significant associations were observed among those who were overweight or physically inactive, or those with metabolic syndrome or elevated 10-year risks for atherosclerotic cardiovascular disease. When estimating the joint effect of bedtime and other sleep characteristics, higher risk of incident NAFLD was observed in groups of late bed/early rise, late bed/napping (yes), late bed/bad sleeper, or late bed/shorter sleep durations.

CONCLUSIONS

Later bedtime was significantly associated with an increased risk of incident NAFLD in adults with pre-diabetes and diabetes, underscoring the importance of sleep behaviour management in the prevention of NAFLD.

Rotating night shift work and non-alcoholic fatty liver disease among steelworkers in China: a cross-sectional survey

OBJECTIVES

In a 24/7 society, the negative metabolic effects of rotating night shift work have been increasingly explored. This study aimed to examine the association between rotating night shift work and non-alcoholic fatty liver disease (NAFLD) in steelworkers.

METHODS

A total of 6881 subjects was included in this study. Different exposure metrics of night shift work including current shift status, duration of night shifts (years), cumulative number of night shifts (nights), cumulative length of night shifts (hours), average frequency of night shifts (nights/month) and average length of night shifts (hours/night) were used to examine the relationship between night shift work and NAFLD.

RESULTS

Current night shift workers had elevated odds of NAFLD (OR, 1.23, 95% CI 1.02 to 1.48) compared with those who never worked night shifts after adjustment for potential confounders. Duration of night shifts, cumulative number of night shifts and cumulative length of night shifts were positively associated with NAFLD. Both the average frequency of night shifts (>7 nights/month vs ≤7 nights/month: OR, 1.24, 95% CI 1.06 to 1.45) and average length of night shifts (>8 hours/night vs ≤8 hours/night: OR, 1.27, 95% CI 1.08 to 1.51) were independently associated with overall NAFLD after mutually adjusting for the duration of night shifts and other potential confounders among night shift workers. No significant association was found in female workers between different exposure metrics of night shift work and NAFLD.

CONCLUSIONS

Rotating night shift work is associated with elevated odds of NAFLD in male steelworkers.

Non-Alcoholic Fatty Liver Disease in Non-Obese Individuals: Prevalence, Pathogenesis and Treatment

Non-alcoholic fatty liver disease (NAFLD) parallels comorbidities such as metabolic syndrome, dyslipidaemia or diabetes. Although NAFLD is very prevalent in overweight-obese individuals (i.e. body mass index ≥25 kg/m2), recent studies point to the presence of NAFLD in non-obese individuals, for both the Asian (<25 kg/m2) and Caucasian (<30 kg/m2) populations. This paper discusses the pathogenic pathways and current treatment options of NAFLD in non-obese populations. In this respect, non-obese subjects also need to undergo the medical screening for NAFLD. Across the scientific community, we aim to promote the advancement of knowledge in this emerging field.

Association between edible mushroom intake and the prevalence of newly diagnosed non-alcoholic fatty liver disease: results from the Tianjin Chronic Low-Grade Systemic Inflammation and Health Cohort Study in China

Animal studies have suggested that mushroom intake can alleviate non-alcoholic fatty liver disease (NAFLD) due to its anti-inflammatory and antioxidant properties. However, the association between mushroom intake and NAFLD is unknown in humans. We aimed to investigate the association of mushroom intake with NAFLD among Chinese adults. This is a cross-sectional study of 24 236 adults (mean (standard deviation) age: 40·7 (sd 11·9) years; 11 394 men (47·0 %)). Mushroom intake was assessed via a validated FFQ. Newly diagnosed NAFLD was identified based on the results of annual health examinations, including ultrasound findings and a self-reported history of the disease. Multiple logistic models were used to examine the association between mushroom intake and NAFLD. The prevalence of newly diagnosed NAFLD was 19·0 %. Compared with those consuming mushrooms less frequently (≤1 time/week), the fully adjusted OR of newly diagnosed NAFLD were 0·95 (95 % CI 0·86, 1·05) for those consuming 2-3 times/week and 0·76 (95 % CI 0·63, 0·92) for those consuming ≥4 times/week (Pfor trend = 0·01). The inverse association was consistent in subgroups defined by age, sex and BMI. In conclusion, higher mushroom intake was significantly associated with lower prevalence of NAFLD among Chinese adults. Future research is required to understand the causal association between mushroom intake and NAFLD.

Distinct associations of computer/mobile devices use and TV watching with depressive symptoms in adults: A large population study in China

BACKGROUND

Recent evidence shows that screen time may be an important risk factor for mental health. The aim of this study was to examine the association of computer/mobile devices (CMD) use and TV watching separately with depressive symptoms in a large representative sample of Chinese adults.

METHODS

A sample of 18,994 adults in Tianjin, China was studied in a cross-sectional analysis. Depressive symptoms were assessed using the Self-Rating Depression Scale (SDS). CMD use and TV watching time were self-reported and divided into five categories. The associations were estimated by odds ratios (ORs) using logistic regression models adjusted for multiple confounders.

RESULTS

The prevalence of elevated depressive symptoms was 16.3% (SDS ≥ 45). For CMD use, the ORs of the depressive symptoms decreased across time levels. Compared with the least use time (<1 hr/day), multivariable-adjusted ORs (95% confidence interval [CI]) of other time categories for elevated depressive symptoms were 0.78 (0.66, 0.91), 0.67 (0.57, 0.80), 0.65 (0.54, 0.77), and 0.77 (0.62, 0.96) respectively. For TV watching, the ORs of the depressive symptoms increased across time levels. Compared with the least watching time (<1 hr/day), multivariable-adjusted ORs (95% CI) for elevated depressive symptoms across the time categories were 1.00 (0.89, 1.12), 1.28 (1.11, 1.48), 1.26 (0.98, 1.60), and 1.95 (1.10, 3.35), respectively.

CONCLUSIONS

These findings suggested that different types of screen time may play different roles in the mental health of general adults. Further studies are needed to clarify the reasons for these distinct associations.

Association between nut consumption and non-alcoholic fatty liver disease in adults

BACKGROUND & AIMS

Increased nut consumption has been associated with reduced inflammation, insulin resistance, and oxidative stress. Although these factors are closely involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD), few studies have focused on the association between nut consumption and NAFLD in the general population. We aimed to investigate the association of nut consumption and NAFLD in an adult population.

METHODS

A total of 23 915 participants from Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) Cohort Study were included in this study. Information on dietary intake was collected using a validated food frequency questionnaire. Abdominal ultrasonography was done to diagnose NAFLD. Multivariable logistic regression was used to assess the association of nut consumption with NAFLD.

RESULTS

After adjusting for sociodemographic, medical, dietary, and lifestyle variables, the odds ratios (95% confidence interval) for NAFLD across categories of nut consumption were 1.00 (reference) for <1 time/week, 0.91 (0.82, 1.02) for 1 time/week, 0.88 (0.76, 1.02) for 2-3 times/week, and 0.80 (0.69, 0.92) for ≥4 times/week (P for trend < 0.01). These associations were attenuated but remained significant after further adjustment for blood lipids, glucose, and inflammation markers.

CONCLUSIONS

Higher nut consumption was significantly associated with lower prevalence of NAFLD. Further prospective studies and randomized trials are required to ascertain the causal association between nut consumption and NAFLD.

Relationship Between Grip Strength and Prediabetes in a Large-Scale Adult Population

INTRODUCTION

Prediabetes has been a growing health problem in China, and it is a high-risk state for developing diabetes and cardiovascular disease. In previous studies, low grip strength has been associated with diabetes. However, few population-based studies have examined the relationship between grip strength and prediabetes. Thus, the purpose of this study was to investigate whether grip strength is related to prediabetes in a large-scale adult population.

METHODS

A total of 27,295 participants aged 20 to 90 years were included from the 2013-2016 Tianjin Chronic Low-grade Systemic Inflammation and Health Cohort Study. Grip strength was assessed using an electronic hand-grip dynamometer and the greatest force was normalized to body weight. Prediabetes was diagnosed based on the American Diabetes Association criteria. Multiple logistic regression analysis was conducted in 2018 to assess the relationship of grip strength to the prevalence of prediabetes, while controlling for age, BMI, smoking, drinking, physical activities, dietary patterns, and other confounders.

RESULTS

Of the 27,295 participants, 28.5% (7,783) had prediabetes. After adjusting for potential confounders, a one unit increase in grip strength per body weight was associated with 52% lower odds of having prediabetes for men (OR=0.48, 95% CI=0.30, 0.74, p<0.01) and 62% lower odds of having prediabetes for women (OR=0.38, 95% CI=0.20, 0.70, p<0.01).

CONCLUSIONS

Increased grip strength is independently associated with lower prevalence of prediabetes in Chinese adults, suggesting that grip strength may be a useful marker for screening individuals at risk of prediabetes.

Vitamin D is related to handgrip strength in adult men aged 50 years and over: A population study from the TCLSIH cohort study

OBJECTIVE

Handgrip strength (HGS) begins an accelerating decline around 50 years. Many of the studies performed in old adults have demonstrated a significant relationship between vitamin D and HGS, but the studies performed in participants with a broad age range have yielded conflicting results. The purpose of the study was to investigate the relationship between vitamin D and HGS using age 50 as a specific cut-off.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

Totally 5102 participants (2911 males, 2191 females) from the TCLSIH Cohort.

MEASUREMENTS

Serum concentration of 25-hydroxyvitamin D (25(OH)D) was measured using an enzyme immunoassay. We divided participants into quartiles according to 25(OH)D, and the ranges for increasing quartiles were as follows: (males [≥50 years]: 10.94-31.85, 31.88-43.01, 43.20-56.06, 56.20-143.0; males [<50 years]: 11.11-34.68, 34.71-46.91, 46.96-59.45, 59.50-143.7; females [≥50 years]: 7.21-30.01, 30.02-40.18, 40.21-52.44, 52.49-275.4; females [<50 years]: 5.29-28.91, 28.92-40.19, 40.20-51.90, 51.91-140.2). HGS was measured with a hydraulic hand-held dynamometer. Analysis of covariance was employed to explore the relationship.

RESULTS

Among males aged above 50 years, the means (95% confidence interval) for HGS per body weight across the categories of serum 25(OH)D concentration were 0.523 (0.430-0.638), 0.545 (0.447-0.664), 0.543 (0.446-0.661), 0.546 (0.449-0.664) (P_trend  < 0.01) after adjustment for potential confounding factors. However, no relationships were observed between serum 25(OH)D concentration and HGS in males aged below 50 years and females in the whole age range.

CONCLUSIONS

Serum 25(OH)D concentration was significantly related to HGS in males aged above 50 years, independent of confounding factors. Future studies are needed to clarify the age and sex relationship between serum 25(OH)D concentration and HGS.