The Association between Sleep Duration and Non-Alcoholic Fatty Liver Disease among Japanese Men and Women

Non-alcoholic fatty liver disease and sleep disorders

Studies have shown that non-alcoholic fatty liver disease (NAFLD) may be associated with sleep disorders. In order to explore the explicit relationship between the two, we systematically reviewed the effects of sleep disorders, especially obstructive sleep apnea (OSA), on the incidence of NAFLD, and analyzed the possible mechanisms after adjusting for confounding factors. NAFLD is independently associated with sleep disorders. Different sleep disorders may be the cause of the onset and aggravation of NAFLD. An excessive or insufficient sleep duration, poor sleep quality, insomnia, sleep-wake disorders, and OSA may increase the incidence of NAFLD. Despite that some research suggests a unidirectional causal link between the two, specifically, the onset of NAFLD is identified as a result of changes in sleep characteristics, and the reverse relationship does not hold true. Nevertheless, there is still a lack of specific research elucidating the reasons behind the higher risk of developing sleep disorders in individuals with NAFLD. Further research is needed to establish a clear relationship between NAFLD and sleep disorders. This will lay the groundwork for earlier identification of potential patients, which is crucial for earlier monitoring, diagnosis, effective prevention, and treatment of NAFLD.

Sleep duration is associated with liver steatosis in children depending on body adiposity

Sleep is a factor associated with overweight/obesity risk, wherein interactions with fatty liver should be ascertained. The aim of this cross-sectional study was to analyze the possible relationships of sleep with liver health and whether this interplay is related to body adiposity distribution in children and adolescents. Anthropometric, clinical, and biochemical measurements were performed in children and adolescents (2-18 years old) with overweight/obesity (n = 854). Body fat distribution was clinically assessed, and several hepatic markers, including hepatic steatosis index, were calculated. Sleep time mediation (hours/day) in the relationship between the hepatic steatosis index and body fat distribution was investigated. Differences among diverse fatty liver disease scores were found between children with overweight or obesity (p < 0.05). Linear regression models showed associations between hepatic steatosis index and lifestyle markers (p < 0.001). Hepatic steatosis index was higher (about + 15%) in children with obesity compared to overweight (p < 0.001). Pear-shaped body fat distribution may seemingly play a more detrimental role on liver fat deposition. The association between sleep time and hepatic steatosis index was dependent on body mass index z-score. Post hoc analyses showed that 39% of the relationship of body fat distribution on hepatic steatosis index may be explained by sleep time.  Conclusion: An association of sleep time in the relationship between body fat distribution and hepatic steatosis index was observed in children and adolescents with overweight/obesity, which can be relevant in the prevention and treatment of excessive adiposity between 2 and 18 years old.

CLINICAL TRIAL

NCT04805762.    Import: As part of a healthy lifestyle, sleep duration might be a modifiable factor in the management of fatty liver disease in children.

WHAT IS KNOWN

• Sleep is an influential factor of overweight and obesity in children. • Excessive adiposity is associated with liver status in children and adolescents.

WHAT IS NEW

• Sleep time plays a role in the relationship between body fat distribution and liver disease. • Monitoring sleep pattern may be beneficial in the treatment of hepatic steatosis in children with excessive body weight.

Short sleep duration and the risk of nonalcoholic fatty liver disease/metabolic associated fatty liver disease: a systematic review and meta-analysis

PURPOSE

It is unclear whether or not nonalcoholic fatty liver disease (NAFLD)/metabolic dysfunction-associated fatty liver disease (MAFLD) is related to short sleep duration. A meta-analysis was conducted to determine if inadequate sleep time increased the risk of NAFLD/MAFLD.

METHODS

A comprehensive systematic literature review was conducted in the Embase, PubMed, and Cochrane Library databases from inception to August 1, 2022. Studies examining the correlation between inadequate sleep time and the risk of NAFLD/MAFLD were included. We pooled the odds ratios (ORs) and 95% confidence intervals (CIs) using a random-effects model.

RESULTS

This meta-analysis included fifteen studies involving a total of 261,554 participants. In the pooled analysis, short sleep duration was found to be strongly correlated with an increased risk of NAFLD/MAFLD (OR, 1.15; 95% CI, 1.04-1.28; P = 0.01), with a moderate degree of heterogeneity between studies (I2 = 71.92%, Q = 49.87, P < 0.01). The sensitivity analysis suggested that the primary outcome was robust, and there was no significant publication bias.

CONCLUSION

This meta-analysis indicates that inadequate sleep duration is strongly correlated with an elevated risk of NAFLD/MAFLD. The findings suggest that obtaining an adequate amount of sleep may be useful for preventing NAFLD/MAFLD, which is especially important given the low rate of response to pharmacotherapy.

Daytime napping, nighttime sleeping duration, and risk of hepatocellular carcinoma and liver disease-related mortality

Background & Aims

Sleep duration has been linked to metabolic dysfunction and chronic inflammation, which may contribute to the development of liver cancer and chronic liver disease (CLD). However, little is known about the relationship between sleep or napping duration and hepatocellular carcinoma (HCC) risk and CLD mortality.

Methods

We followed 295,837 individuals in the National Institutes of Health-American Association of Retired Persons (NIH-AARP) Diet and Health Study. We examined the associations of nighttime sleep duration and daytime napping duration with risk of HCC incidence and CLD mortality. Cox proportional hazards regression was used to calculate multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs).

Results

A total of 357 incident HCC cases and 578 CLD deaths were identified after a median follow-up time of 15.5 years. After adjusting for confounder factors, we found U-shaped associations of nighttime sleep duration with the incidence of HCC (HR<5 vs. 7-8 h = 2.00, 95% CI: 1.22-3.26 and HR≥9 vs. 7-8 h = 1.63, 95% CI: 1.04-2.65) and CLD mortality (HR<5 vs. 7-8 h = 1.78, 95% CI: 1.18-2.69 and HR≥9 vs. 7-8 h = 1.91, 95% CI: 1.35-2.70). Daytime napping was associated with higher risk of HCC (HR≥1 vs. non-nappers = 1.46, 95% CI: 1.04-2.06) and higher CLD mortality (HR≥1 h vs. non-nappers = 1.54, 95% CI: 1.18-2.01) compared with no napping.

Conclusions

We observed U-shaped associations for nighttime sleeping and risk of HCC and CLD mortality. Additionally, longer daytime napping duration was associated with higher risk of HCC and CLD death. Our study suggests that clinical follow up of individuals at risk for liver cancer or living with a liver disease should include information on nighttime and daytime sleep.

Impact and implications

Sleep or napping duration may play a role in the development of liver cancer and chronic liver disease, but little is known about the relationship between them. In addition, abnormal sleep patterns in patients with chronic liver disease may further promote the development of liver disease, creating a vicious cycle. Our study suggests that clinical follow up of individuals at risk for liver cancer or living with a liver disease should include information on nighttime and daytime sleep, as they can be potentially important factors in the development and progression of liver disease.

Causal relationship between nonalcoholic fatty liver disease and different sleep traits: a bidirectional Mendelian randomized study

Background and aims

Non-alcoholic fatty liver disease(NAFLD) is common worldwide and has previously been reported to be associated with sleep traits. However, it is not clear whether NAFLD changes sleep traits or whether the changes in sleep traits lead to the onset of NAFLD. The purpose of this study was to investigate the causal relationship between NAFLD and changes in sleep traits using Mendelian randomization.

Methods

We proposed a bidirectional Mendelian randomization (MR) analysis and performed validation analyses to dissect the association between NAFLD and sleep traits. Genetic instruments were used as proxies for NAFLD and sleep. Data of genome-wide association study(GWAS) were obtained from the center for neurogenomics and cognitive research database, Open GWAS database and GWAS catalog. Three MR methods were performed, including inverse variance weighted method(IVW), MR-Egger, weighted median.

Results

In total,7 traits associated with sleep and 4 traits associated with NAFLD are used in this study. A total of six results showed significant differences. Insomnia was associated with NAFLD (OR(95% CI)= 2.25(1.18,4.27), P = 0.01), Alanine transaminase levels (OR(95% CI)= 2.79(1.70, 4.56), P =4.71×10-5) and percent liver fat(OR(95% CI)= 1.31(1.03,1.69), P = 0.03). Snoring was associated with percent liver fat (1.15(1.05,1.26), P =2×10-3), alanine transaminase levels (OR(95% CI)= 1.27(1.08,1.50), P =0.04).And dozing was associated with percent liver fat(1.14(1.02,1.26), P =0.02).For the remaining 50 outcomes, no significant or definitive association was yielded in MR analysis.

Conclusion

Genetic evidence suggests putative causal relationships between NAFLD and a set of sleep traits, indicating that sleep traits deserves high priority in clinical practice. Not only the confirmed sleep apnea syndrome, but also the sleep duration and sleep state (such as insomnia) deserve clinical attention. Our study proves that the causal relationship between sleep characteristics and NAFLD is the cause of the change of sleep characteristics, while the onset of non-NAFLD is the cause of the change of sleep characteristics, and the causal relationship is one-way.

Obesity, Chronic Stress, and Stress Reduction

The obesity epidemic is caused by the misalignment between human biology and the modern food environment, which has led to unhealthy eating patterns and behaviors and an increase in metabolic diseases. This has been caused by the shift from a "leptogenic" to an "obesogenic" food environment, characterized by the availability of unhealthy food and the ability to eat at any time of day due to advances in technology. Binge Eating Disorder (BED) is the most commonly diagnosed eating disorder, characterized by recurrent episodes of binge eating and a sense of loss of control over eating, and is treated with cognitive-behavioral therapy-enhanced (CBT-E). Shift work, especially night shift work, can disrupt the body's natural circadian rhythms and increase the risk of obesity and other negative health consequences, such as cardiovascular disease and metabolic syndrome. One dietary approach to address circadian dysregulation is time-restricted eating (TRE), which involves restricting food intake to specific periods of the day to synchronize the body's internal clock with the external environment. TRE has been found to cause modest weight loss and improve metabolic outcomes such as insulin sensitivity and blood pressure, but the extent to which it is beneficial may depend on adherence and other factors such as caloric restriction.

Daytime napping and risk of liver cancer: A large population-based prospective cohort study

INTRODUCTION AND OBJECTIVES

Liver cancer is a major cause of morbidity and mortality in Japan and worldwide. Daytime napping is a common behavior, especially among older adults, that was related in previous research to unfavorable health conditions. Herein, we investigated the association between daytime napping and liver cancer risk.

MATERIALS AND METHODS

In this prospective cohort study, data from 51,185 participants aged 40-79 years and registered in the Japan Collaborative Cohort Study (JACC Study) were analyzed. Incident cases of liver cancer were diagnosed using cancer registries, hospital records, and death certificates. Daytime napping was assessed using the JACC baseline self-administered questionnaire. We used the Cox regression to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident liver cancer among participants in the age categories of the 40s, 50s, 60s, and 70s who reported daytime napping compared with their counterparts who did not.

RESULTS

Within 669,734 person-years of follow-up, 341 participants developed liver cancer. Daytime napping was associated with a higher risk of liver cancer among participants who were in their 60s and 70s of age after adjusting for sex: HRs (95% CIs) 1.88 (1.35-2.61) and 1.96 (1.18-3.26), lifestyle and medical history: 1.76 (1.27-2.47) and 1.82 (1.07-3.09), and history of liver diseases: 1.66 (1.18-2.34) and 1.72 (1.01-2.94), respectively. No associations were detected among participants from the 40s and 50s age groups.

CONCLUSIONS

Daytime napping was associated with a higher risk of liver cancer among older adults.

The role of the circadian clock in the development, progression, and treatment of non-alcoholic fatty liver disease

The circadian clock comprises a cellular endogenous timing system coordinating the alignment of physiological processes with geophysical time. Disruption of circadian rhythms has been associated with several metabolic diseases. In this review, we focus on liver as a major metabolic tissue and one of the most well-studied organs with regard to circadian regulation. We summarize current knowledge about the role of local and systemic clocks and rhythms in regulating biological functions of the liver. We discuss how the disruption of circadian rhythms influences the development of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). We also critically evaluate whether NAFLD/NASH may in turn result in chronodisruption. The last chapter focuses on potential roles of the clock system in prevention and treatment of NAFLD/NASH and the interaction of current NASH drug candidates with liver circadian rhythms and clocks. It becomes increasingly clear that paying attention to circadian timing may open new avenues for the optimization of NAFLD/NASH therapies and provide interesting targets for prevention and treatment of these increasingly prevalent disorders.

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.

Isotemporal substitution of different behaviour patterns with the presence of MAFLD in Chinese adults

BACKGROUND

Lack of physical activity and excessive sitting time contributed to ectopic fat accumulation, especially in the liver. Previous studies have illustrated the harm of sedentary behaviour and the benefits of physical activity on fatty liver disease. We aimed to explore the association between the behaviour patterns and the risk of metabolic dysfunction-associated fatty liver disease (MAFLD) using isotemporal substitution model to examine the effect of replacing one behaviour to another while keeping the total time and other behaviours fixed among Chinese middle-aged and elderly population.

METHODS

This study included 161 147 participants aged ≥40 years old from the nationwide, population-based cohort of the REACTION study. The International Physical Activity Questionnaire was used to measure self-reported time for sleeping, sitting, walking and moderate-to-vigorous physical activity (MVPA). MAFLD was defined by evidence of fatty liver index (FLI) ≥ 60 in addition to one of the following three patterns, namely overweight/obesity, presence of diabetes, or evidence of metabolic dysregulation. Isotemporal substitution models using logistic regression models to evaluate the association of replacement of different behaviour patterns with each other and the risk of MAFLD.

RESULTS

Substitution of 60 minutes per day of sleeping, walking or total MVPA for sitting was associated with a 2%-8% reduction of MAFLD risk in overall participants. In employed individuals, replacing sitting time with occupational MVPA or nonoccupational MVPA both could bring benefits to liver steatosis. Stratified analysis found that replacing 60 minutes of sitting time with an equivalent time of other behaviour pattern could reduce approximately 8% of the risk among MAFLD participants with metabolic abnormalities. Such a relationship might be explained by the important mediated role of metabolic elements, such as waist circumference, body mass index, triglycerides and homoeostasis model assessment of insulin resistance. Furthermore, replacing sitting with MVPA showed a stronger association among participants who got enough sleep (sleep duration ≥7 hours per day).

CONCLUSION

Replacing sitting with other behaviour patterns could reduce the prevalence of MAFLD, and such substitution effect was much remarkably in individuals with abnormal metabolic status. Observably, obese individuals were more likely to benefit from appropriate changes in behaviour patterns. Moreover, the analysis of sleep duration stratification appealed that the adequacy of individual sleep duration also had a significant impact on the substitution effect. It is worth noting that adjusting the time allocation of behaviour patterns might have a beneficial impact on liver-metabolic health, and these findings might help us better recognize the importance of reasonable arrangement of behaviour patterns according to the individual's situation.

2019 Global NAFLD Prevalence: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The increasing rates of obesity and type 2 diabetes mellitus may lead to increased prevalence of nonalcoholic fatty liver disease (NAFLD). We aimed to determine the current and recent trends on the global and regional prevalence of NAFLD.

METHODS

Systematic search from inception to March 26, 2020 was performed without language restrictions. Two authors independently performed screening and data extraction. We performed meta-regression to determine trends in NAFLD prevalence.

RESULTS

We identified 17,244 articles from literature search and included 245 eligible studies involving 5,399,254 individuals. The pooled global prevalence of NAFLD was 29.8% (95% confidence interval [CI], 28.6%-31.1%); of these, 82.5% of included articles used ultrasound to diagnose NAFLD, with prevalence of 30.6% (95% CI, 29.2%-32.0%). South America (3 studies, 5716 individuals) and North America (4 studies, 18,236 individuals) had the highest NAFLD prevalence at 35.7% (95% CI, 34.0%-37.5%) and 35.3% (95% CI, 25.4%-45.9%), respectively. From 1991 to 2019, trend analysis showed NAFLD increased from 21.9% to 37.3% (yearly increase of 0.7%, P < .0001), with South America showing the most rapid change of 2.7% per year, followed by Europe at 1.1%.

CONCLUSIONS

Despite regional variation, the global prevalence of NAFLD is increasing overall. Policy makers must work toward reversing the current trends by increasing awareness of NAFLD and promoting healthy lifestyle environments.

Role of Circadian Clock on the Pathogenesis and Lifestyle Management in Non-Alcoholic Fatty Liver Disease

Several features of the modern lifestyle, such as weekly schedules or irregular daily eating patterns, have become major drivers of global health problems, including non-alcoholic fatty liver disease (NAFLD). Sleep is an essential component of human well-being, and it has been observed that when circadian rhythms are disrupted, or when sleep quality decreases, an individual's overall health may worsen. In addition, the discrepancy between the circadian and social clock, due to weekly work/study schedules, is called social jetlag and has also been associated with adverse metabolic profiles. Current management of NAFLD is based on dietary intake and physical activity, with circadian preferences and other environmental factors also needing to be taken into account. In this regard, dietary approaches based on chrononutrition, such as intermittent fasting or time-restricted feeding, have proven to be useful in realigning lifestyle behaviors with circadian biological rhythms. However, more studies are needed to apply these dietary strategies in the treatment of these patients. In this review, we focus on the impact of circadian rhythms and the role of sleep patterns on the pathogenesis and development of NAFLD, as well as the consideration of chrononutrition for the precision nutrition management of patients with NAFLD.

A Meta-Analysis of Sleep Disorders and Nonalcoholic Fatty Liver Disease: Potential Causality and Symptom Management

Nonalcoholic fatty liver disease is a type of metabolic disease, and recent research indicates that it may be associated with sleep disorders. We conducted a meta-analysis of current studies to estimate the associations between nonalcoholic fatty liver disease and sleep situation, including sleep duration, daytime sleepiness, and sleep disorder. This study follows the checklist of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). Articles in the recent 10 years were searched from five databases. Eighteen articles, which met the eligibility criteria, were included in this meta-analysis. The results show that patients with nonalcoholic fatty liver disease have a shorter sleep duration and higher Epworth Sleepiness Scale score. Patients with short sleep duration (≤6 hours per night) or with obstructive sleep apnea have a higher risk of nonalcoholic fatty liver disease. In conclusion, there is a significant association between nonalcoholic fatty liver disease and sleep disorders in the included studies. In addition, patients with nonalcoholic fatty liver disease may have more severe daytime sleepiness and shorter sleep duration. More attention should be paid to the sleep situation of nonalcoholic fatty liver disease patients to potentially slow the disease progression.

The Clock-NAD+ -Sirtuin connection in nonalcoholic fatty liver disease

Nonalcoholic or metabolic associated fatty liver disease (NAFLD/MAFLD) is a hepatic reflection of metabolic derangements characterized by excess fat deposition in the hepatocytes. Identifying metabolic regulatory nodes in fatty liver pathology is essential for effective drug targeting. Fatty liver is often associated with circadian rhythm disturbances accompanied with alterations in physical and feeding activities. In this regard, both sirtuins and clock machinery genes have emerged as critical metabolic regulators in maintaining liver homeostasis. Knockouts of either sirtuins or clock genes result in obesity associated with the fatty liver phenotype. Sirtuins (SIRT1-SIRT7) are a highly conserved family of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, protecting cells from metabolic stress by deacetylating vital proteins associated with lipid metabolism. Circadian rhythm is orchestrated by oscillations in expression of master regulators (BMAL1 and CLOCK), which in turn regulate rhythmic expression of clock-controlled genes involved in lipid metabolism. The circadian metabolite, NAD+ , serves as a crucial link connecting clock genes to sirtuin activity. This is because, NAMPT which is a rate limiting enzyme in NAD+ biosynthesis is transcriptionally regulated by the clock genes and NAD+ in turn is a cofactor regulating the deacetylation activity of sirtuins. Intriguingly, on one hand the core circadian clock regulates the sirtuin activity and on the other hand the activated sirtuins regulate the acetylation status of clock proteins thereby affecting their transcriptional functions. Thus, the Clock-NAD+-Sirtuin connection represents a novel "feedback loop" circuit that regulates the metabolic machinery. The current review underpins the importance of NAD+ on the sirtuin and clock connection in preventing fatty liver disorder.

Circadian Regulation of Gene Expression and Metabolism in the Liver

Circadian rhythms are approximately 24-hour cycles of variation in physiological processes, gene expression, and behavior. They result from the interplay of internal biological clocks with daily environmental rhythms, including light/dark and feeding/fasting. Note that 24-hour rhythms of liver metabolic processes have been known for almost 100 years. Modern studies reveal that, like metabolism, hepatic gene expression is highly rhythmic. Genetic or environmental changes can disrupt the circadian rhythms of the liver, leading to metabolic disorders and hepatocellular carcinoma. In this review, we summarize the current understanding of mechanisms regulating rhythmic gene expression in the liver, highlighting the roles of transcription factors that comprise the core clock molecular as well as noncanonical regulators. We emphasize the plasticity of circadian rhythms in the liver as it responds to multiple inputs from the external and internal environments as well as the potential of circadian medicine to impact liver-related diseases.

Nutrition and physical activity: An Obesity Medicine Association (OMA) Clinical Practice Statement 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) on Nutrition and Physical Activity provides clinicians an overview of nutrition and physical activity principles applicable to the care of patients with increased body fat, especially those with adverse fat mass and adiposopathic metabolic consequences.

Methods

The scientific information and clinical guidance is based upon referenced evidence and derived from the clinical perspectives of the authors.

Results

This OMA CPS on Nutrition and Physical Activity provides basic clinical information regarding carbohydrates, proteins, fats (including trans fats, saturated fats, polyunsaturated fats, and monounsaturated fats), general principles of healthful nutrition, nutritional factors associated with improved health outcomes, and food labels. Included are the clinical implications of isocaloric substitution of refined carbohydrates with saturated fats and vice-versa, as well as definitions of low-calorie, very low-calorie, carbohydrate-restricted, and fat-restricted dietary intakes. Specific dietary plans discussed include carbohydrate-restricted diets, fat-restricted diets, very low-calorie diets, the Mediterranean diet, Therapeutic Lifestyle diet, Dietary Approaches to Stop Hypertension (DASH), ketogenic (modified Atkins) diet, Ornish diet, Paleo diet, vegetarian or vegan diet (whole food/plant-based), intermittent fasting/time restricted feeding, and commercial diet programs. This clinical practice statement also examines the health benefits of physical activity and provides practical pre-exercise medical evaluation guidance as well as suggestions regarding types and recommended amounts of dynamic (aerobic) training, resistance (anaerobic) training, leisure time physical activity, and non-exercise activity thermogenesis (NEAT). Additional guidance is provided regarding muscle physiology, exercise prescription, metabolic equivalent tasks (METS), and methods to track physical activity progress.

Conclusion

This Obesity Medicine Association Clinical Practice Statement on Nutrition and Physical Activity provides clinicians an overview of nutrition and physical activity. Implementation of appropriate nutrition and physical activity in patients with pre-obesity and/or obesity may improve the health of patients, especially those with adverse fat mass and adiposopathic metabolic consequences.

Rotating night shift work, sleep duration and elevated gamma-glutamyl transpeptidase among steelworkers: cross-sectional analyses from a Chinese occupational cohort

OBJECTIVES

This study aimed to evaluate the separate and combined effects of rotating night shift work and lifestyle factors with elevated gamma-glutamyl transpeptidase (GGT) among steelworkers.

DESIGN, SETTING AND PARTICIPANTS

This cross-sectional study used the baseline information from a Chinese occupational cohort. The in-service workers of the production department of Tangsteel Company who participated in the occupational health examination in Tangshan from February to June 2017 were selected as the research objects.

MAIN OUTCOME MEASURES

The separate and combined effects of rotating night shift work and lifestyle factors with elevated GGT among steelworkers.

RESULTS

The information of 7031 subjects from the production department of Tangsteel Company was analysed. Results showed that the current shift workers and the workers with the duration of night shifts>19 years, the cumulative number of night shifts>1774 nights, the average frequency of night shifts≤7 nights/month and the average frequency of night shifts>7 nights/month had elevated odds of elevated GGT, compared with those who never worked night shifts, and ORs, (95% CIs) were 1.39, (1.10 to 1.75), 1.46, (1.15 to 1.86), 1.46, (1.15 to 1.85), 1.34, (1.04 to 1.73) and 1.37, (1.09 to 1.74) after adjustment for potential confounders. The independent effect of shorter sleep duration (<7 hours/day) on elevated GGT was not statistically significant. Among workers who had shorter sleep duration, the association between rotating night shift work and elevated GGT was statistically significant, but no associations were found among workers with the sleep duration of ≥7 hours/day. In addition, other lifestyle factors affected the association between rotating night shift work and elevated GGT.

CONCLUSIONS

Rotating night shift work is associated with elevated GGT among steelworkers. In particular, the effect of rotating night shift work on elevated GGT was affected by sleep duration and other lifestyle factors.

Sleep and liver disease: a bidirectional relationship

Sleep is a complex, highly regulated process essential for human health and wellbeing. Increasingly, sleep-wake disturbance has been implicated in the pathogenesis of chronic liver disease, particularly the development and progression of non-alcoholic fatty liver disease and alcohol-related liver disease. Patients with cirrhosis also have a high burden of sleep abnormalities with substantial implications for their quality of life and physical health. This Review summarises the epidemiology and pathophysiology of sleep-wake disturbance in liver disease and discusses the multiple converging pathways leading to abnormal sleeping patterns in patients with cirrhosis. This includes contributions from altered melatonin metabolism, neuromuscular complications, and aberrant thermoregulation. In turn, a vicious cycle is established whereby disrupted sleep can further contribute to liver disease progression. We also begin to unravel the complex, interlinking relationship between sleep-wake disturbance and hepatic encephalopathy, discussing both overlapping and distinct mechanisms and clinical features. Finally, we summarise the current and future therapeutic approaches aiming to improve sleep quality in patients with cirrhosis.

Physical activity and liver health among urban and rural Chinese adults: results from two independent surveys

BACKGROUND

Increased physical activity has been associated with reduced risks of various physical and mental conditions. However, the association between physical activity and liver health in the Chinese general adult population is not clear. This study investigated whether physical activity, stratified by intensity (i.e. walking (light), moderate-to-vigorous), was associated with alanine aminotransferase (ALT) level in middle-aged and older Chinese adults.

METHODS

Two independent surveys of urban (n = 5,824, males 44%, mean (standard deviation) age 52 (10) years) and rural populations (n = 20,269, males 41%, mean (standard deviation) age 51 (10) years) were undertaken. Physical activity was measured using the International Physical Activity Questionnaire, and in metabolic equivalents of task (MET) × minutes. Elevated serum level of ALT, a clinical surrogate of abnormal liver function, was defined as >40 IU/L (males) and >30 IU/L (females). Multivariable regression models were used.

RESULTS

Amount of moderate-to-vigorous activity was inversely associated with serum level of ALT (β = -0.147 per 1k MET-minutes, p < 0.001), whereas walking was not associated. People who reached the lower limit of WHO recommendation (≥600 MET-minutes per week) had a reduced odds of ALT elevation, compared to those who did not (adjusted odds ratio: 0.85 95%CI (0.76, 0.95)).

CONCLUSIONS

Meeting the moderate-to-vigorous recommendations for physical activity in adults may be associated with decreased likelihood of abnormal liver function both in Chinese urban and rural populations. Promoting such activities could be a low-cost strategy in maintaining liver health as well as providing many other health-related benefits.

Effects of sleep quality on non-alcoholic fatty liver disease: a cross-sectional survey

BACKGROUND

The effects of sleep quality on the risk of developing non-alcoholic fatty liver disease (NAFLD) remain uncertain. The purpose of this study was to clarify the association between sleep quality and NAFLD.

METHODS

The data of 4828 participants who underwent health check-ups at four hospitals were analysed. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index (PSQI), which comprised seven elements scored from 0 to 3. The global PSQI score and the score for each element were compared between NAFLD and non-NAFLD groups separately by sex. Logistic regression analysis was performed to determine the association between NAFLD and each PSQI score.

RESULTS

In both men and women, the mean PSQI score for sleep medication use was significantly higher in non-NAFLD than in NAFLD. With regard to sleep medication use in men, the OR (95% CI) for NAFLD was lower with a score of 3 (OR 0.60, 95% CI 0.38-0.95) than with a score of 0 on multivariate logistic regression analysis adjusted for age, smoking habits and physical activity. The OR for NAFLD based on daytime dysfunction was also higher with a score of 3 than with a score of 0 in both men (OR 2.82, 95% CI 1.39-5.75) and women (OR 2.08, 95% CI 1.10-3.92). After adjustment for body mass index, the sleep latency scores in men and daytime dysfunction in women were associated with NAFLD.

CONCLUSION

Sleep quality was associated with NAFLD, and there were sex differences.

Sleep deprivation and its association with diseases- a review

Sleep deprivation, a consequence of multiple health problems or a cause of many major health risks, is a significant public health concern in this era. In the recent years, numerous reports have been added to the literature to provide explanation and to answer previously unanswered questions on this important topic but comprehensive updates and reviews in this aspect remain scarce. The present study identified 135 papers that investigated the association between sleep deprivation and health risks, including cardiovascular, respiratory, neurological, gastrointestinal, immunology, dermatology, endocrine, and reproductive health. In this review, we aimed to provide insight into the association between sleep deprivation and the development of diseases. We reviewed the latest updates available in the literature and particular attention was paid to reports that detailed all possible causal relationships involving both extrinsic and intrinsic factors that may be relevant to this topic. Various mechanisms by which sleep deprivation may affect health were presented and discussed, and this review hopes to serve as a platform for ideas generation for future research.

Circadian Rhythms in the Pathogenesis and Treatment of Fatty Liver Disease

Circadian clock proteins are endogenous timing mechanisms that control the transcription of hundreds of genes. Their integral role in coordinating metabolism has led to their scrutiny in a number of diseases, including nonalcoholic fatty liver disease (NAFLD). Discoordination between central and peripheral circadian rhythms is a core feature of nearly every genetic, dietary, or environmental model of metabolic syndrome and NAFLD. Restricting feeding to a defined daily interval (time-restricted feeding) can synchronize the central and peripheral circadian rhythms, which in turn can prevent or even treat the metabolic syndrome and hepatic steatosis. Importantly, a number of proteins currently under study as drug targets in NAFLD (sterol regulatory element-binding protein [SREBP], acetyl-CoA carboxylase [ACC], peroxisome proliferator-activator receptors [PPARs], and incretins) are modulated by circadian proteins. Thus, the clock can be used to maximize the benefits and minimize the adverse effects of pharmaceutical agents for NAFLD. The circadian clock itself has the potential for use as a target for the treatment of NAFLD.

Non-alcoholic fatty liver disease among patients with sleep disorders: a Nationwide study of Taiwan

Background

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases. Studies have shown that sleep apnea is associated with NAFLD. However, studies on the association between sleep disorders in general and NAFLD are limited. We conducted a nationwide population-based longitudinal study to evaluate this potential association.

Methods

We identified patients diagnosed with sleep disorders in the years 2000 through 2005 in Taiwan using the National Health Insurance Research Database and selected an equal number of patients without sleep disorders from the same database as the comparison cohort. The patients were followed from the index date to the diagnosis of NAFLD or the end of 2013. We used Cox proportional hazards models to estimate the risk of NAFLD associated with sleep disorders.

Results

A total of 33,045 patients with sleep disorders were identified. The incidence of NAFLD was 14.0 per 10,000 person-year in patients with sleep disorders and 6.2 per 10,000 person-year in the comparison cohort. The adjusted hazard ratio (AHR) of NAFLD associated with sleep disorders was 1.78 (95% confidence interval [95%CI]: 1.46–2.16), and other independent risk factors included male sex (AHR = 1.31, 95%CI: 1.12–1.54), age 40–59 years (AHR = 1.49, 95%CI: 1.21–1.82), and dyslipidemia (AHR = 2.51, 95%CI: 2.08–3.04). In the subgroup analyses, both patients with (AHR = 2.24, 95%CI: 1.05–4.77) and without (AHR = 1.77, 95%CI: 1.46–2.15) sleep apnea had an increased risk of NAFLD.

Conclusions

Sleep disorders are associated with NAFLD, even in patients without sleep apnea. Further studies are warranted to explore the mechanisms of the association.

The Lifestyle Characteristics in Non-Alcoholic Fatty Liver Disease in the PERSIAN Guilan Cohort Study

BACKGROUND:

Non-Alcoholic Fatty Liver Disease (NAFLD) is the most common cause of chronic liver disease worldwide. Since the effect and safety of pharmacotherapy for NAFLD are unknown, the proper management of lifestyle is crucial.

AIM:

The present study was conducted to determine the status of food, Physical Activity (PA), and sleep in patients with and without NAFLD.

METHODS:

In this analytical- cross-sectional study, 630 clients with 36-60 years old who referred to the PERSIAN Guilan cohort study were included through simple non-random sampling. The developed questionnaire and lifestyle characteristics, including the status of nutrition, physical activity, and sleep, were completed for all samples. BMI was also calculated by determining weight and height, and fatty liver was confirmed based on abdominal ultrasound.

RESULTS:

The prevalence of NAFLD in this study was by 43.7% (275 / 630). Smoking, alcohol consumption, BMI, and weight loss over the past six months, regular exercise and exercise intensity, sedentary living, speed of eating, consuming fatty food, red meat, sweets beverages, and use of saturated fatty acid (SFA), and consuming fruits and vegetables were associated with presence of NAFLD (all p < 0.05). However, no significant relationship was observed between the parameters of sleep duration, the interval between dinner and night sleep, consuming breakfast and snack during the day and NAFLD (All p > 0.05).

CONCLUSION:

The onset and progression of NAFLD are associated with lifestyle. Therefore, dietary therapy solutions, physical activity, and sleep and rest situations should be paid attention for people with or at risk of NAFLD.

Autoimmune hepatitis, fatty liver, and Fukushima

The use of direct antiviral agents (DAAs) for hepatitis C virus has led to a paradigm shift from viral hepatitis to non-viral disease. Autoimmune hepatitis (AIH) remains to be an issue in liver disease after the DAAs era. Moreover, fatty liver had been increasing in incidence and has attracted attention because of its risk for hepatocellular carcinoma. In 2011, the Great East Japan Earthquake, with the associated tsunami and accident at Fukushima Daiichi Nuclear Power Plant, has changed the lifestyle of residents in Fukushima prefecture. In this manuscript, we outlined the recent topics about AIH, fatty liver, and Fukushima.

Circadian rhythms: a possible new player in non-alcoholic fatty liver disease pathophysiology

Over the last decades, a better knowledge of the molecular machinery supervising the regulation of circadian clocks has been achieved, and numerous findings have helped in unravelling the outstanding significance of the molecular clock for the proper regulation of our physiologic and metabolic homeostasis. Non-alcoholic fatty liver disease (NAFLD) is currently considered as one of the emerging liver pathologies in the Western countries due to the modification of eating habits and lifestyle. Although NAFLD is considered a pretty benign condition, it can progress towards non-alcoholic steatohepatitis (NASH) and eventually hepatocellular carcinoma (HCC). The pathogenic mechanisms involved in NAFLD development are complex, since this disease is a multifactorial condition. Major metabolic deregulations along with a genetic background are believed to take part in this process. In this light, the aim of this review is to give a comprehensive description of how our circadian machinery is regulated and to describe to what extent our internal clock is involved in the regulation of hormonal and metabolic homeostasis, and by extension in the development and progression of NAFLD/NASH and eventually in the onset of HCC.

The impact of the sleep duration on NAFLD score in Korean middle-aged adults: a community-based cohort study

BACKGROUND

Accumulated evidences indicates that sleep duration and sleep quality may potentially trigger the development of non-alcoholic fatty liver disease (NAFLD), but no studies have explored this causality. In this study, we aimed to investigate the effect of sleep duration on the incidence of NAFLD in Korean middle-aged adults.

METHODS

All participants were selected from the cohort of the Korean Genome and Epidemiology Study (KoGES) for a 10-year period. NAFLD was defined by Fatty Liver Index (FLI), NAFLD liver fat score (NLFS), Hepatic Steatosis Index (HSI) and Lipid Accumulation Product (LAP). Multiple logistic regression analysis was used to assess the relationship between sleep duration and NAFLD defined by NAFLD scores. ANCOVA and Spline curve was also used to verify the differences in means of NAFLD scores according to the four sleep duration groups.

RESULTS

In comparison with those of individuals in the reference group, the OR (95% CI) for NAFLD was 2.230 (1.304-3.813) for group of people who slept more than 8 h, 1.869 (1.298-2.691) for 7-8 h after adjusting for several confounding factors. The odds ratio for the incidence of NAFLD was 1.462 (1.029-2.077) for the group of people who sleep more than 8 h, 1.271 (1.001-1.615) for 7-8 h after adjusting for age, sex, BMI, SBP, DBP, TG, HDL, FDG, smoking, physical activity, daytime napping and night-time shifting (p < 0.01).

CONCLUSION

These findings indicate a relationship between long sleep duration and the elevation of NAFLD scores and support the causality of sleep duration and incidence of NAFLD in Korean middle-aged adults.

Association between Sleep Disturbances and Liver Status in Obese Subjects with Nonalcoholic Fatty Liver Disease: A Comparison with Healthy Controls

The relevance of sleep patterns in the onset or evolution of nonalcoholic fatty liver disease (NAFLD) is still poorly understood. Our aim was to investigate the association between sleep characteristics and hepatic status indicators in obese people with NAFLD compared to normal weight non-NAFLD controls. Ninety-four overweight or obese patients with NAFLD and 40 non-NAFLD normal weight controls assessed by abdominal ultrasonography were enrolled. Hepatic status evaluation considered liver stiffness determined by Acoustic Radiation Force Impulse elastography (ARFI) and transaminases. Additionally, anthropometric measurements, clinical characteristics, and biochemical profiles were determined. Sleep features were evaluated using the Pittsburgh Sleep Quality Index (PSQI). Hepatic status parameters, anthropometric measurements, and clinical and biochemical markers differed significantly in NAFLD subjects compared to controls, as well as sleep efficiency, sleep disturbance score, and sleep quality score. In the NAFLD group, a higher prevalence of short sleep duration (p = 0.005) and poor sleep quality (p = 0.041) were found. Multivariate-adjusted odds ratio (95% confidence interval) for NAFLD considering sleep disturbance was 1.59 (1.11–2.28). Regression models that included either sleep disturbance or sleep quality predicted up to 20.3% and 20.4% of the variability of liver stiffness, respectively, and after adjusting for potential confounders. Current findings suggest that sleep disruption may be contributing to the pathogenesis of NAFLD as well as the alteration of the liver may be affecting sleep patterns. Consequently, sleep characteristics may be added to the list of modifiable behaviors to consider in health promotion strategies and in the prevention and management of NAFLD.

The Relationship Between Sleep Duration, Falls, and Muscle Mass: A Cohort Study in an Elderly Chinese Population

Epidemiological studies report that more than half of the people over the age of 65 years suffer from variable sleep problems. In this study, we conducted a cohort study to investigate the relationship between sleep duration, muscle mass, and function within a community-dwelling, elderly Chinese population. Our study population consisted of residents living in the township central hospital of suburban Tianjin, China. We measured muscle strength and walking speed. We divided sleep duration into the following four groups: <7 hours, 7-8 hours, >8-9 hours, and >9 hours. A total of 902 participants completed the 3-year follow-up. We observed a U-shaped relationship between sleep duration and fall risk. Compared with the 7-8-hour group, fall risk within the <7-hour group was 3.67 (2.59, 5.42) times higher and fall risk within the >9-hour group was 2.35 (1.29, 3.52) times higher. After adjustment, muscle mass declined by -6.82% (-11.27%, -3.83%) in the <7-hour group. In summary, we observed a U-shaped relationship between sleep duration and falls. Short sleep duration has a negative relationship with muscle mass decline in a community-dwelling, elderly Chinese population.

The changing epidemiology of liver diseases in the Asia-Pacific region

This Review presents current epidemiological trends of the most common liver diseases in Asia-Pacific countries. Hepatitis B virus (HBV) remains the primary cause of cirrhosis; despite declining prevalence in most Asian nations, this virus still poses a severe threat in some territories and regions. Mortality resulting from HBV infection is declining as a result of preventive measures and antiviral treatments. The epidemiological transition of hepatitis C virus (HCV) infection has varied in the region in the past few decades, but the medical burden of infection and the prevalence of its related cancers are increasing. The lack of licensed HCV vaccines highlights the need for novel treatment strategies. The prevalence of nonalcoholic fatty liver disease (NAFLD) has risen in the past decade, mostly owing to increasingly urbanized lifestyles and dietary changes. Alternative herbal medicine and dietary supplements are major causes of drug-induced liver injury (DILI) in some countries. Complications arising from these chronic liver diseases, including cirrhosis and liver cancer, are therefore emerging threats in the Asia-Pacific region. Key strategies to control these liver diseases include monitoring of at-risk populations, implementation of national guidelines and increasing public and physician awareness, in concert with improving access to health care.

Role of the Circadian Clock in the Metabolic Syndrome and Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in industrialized nations and is strongly associated with the metabolic syndrome. The prevalence of NAFLD continues to rise along with the epidemic of the metabolic syndrome. Metabolic homeostasis is linked to the circadian clock (rhythm), with multiple signaling pathways in organs regulated by circadian clock genes, and recent studies of circadian clock gene functions suggest that disruption of the circadian rhythm is associated with significant morbidity and mortality, including the metabolic syndrome. In the industrialized world, various human behaviors and activities such as work and eating patterns, jet lag, and sleep deprivation interfere with the circadian rhythm, leading to perturbations in metabolism and development of the metabolic syndrome. In this review, we discuss how disruption of the circadian rhythm is associated with various metabolic conditions that comprise the metabolic syndrome and NAFLD.

The association of sleep duration and sleep quality with non-alcoholic fatty liver disease in a Taiwanese population

OBJECTIVE

The association of sleep duration/quality with nonalcoholic fatty liver disease (NAFLD) is inconclusive. Several important covariates were not adjusted concomitantly in some studies, and the severity of NAFLD was not considered. Furthermore, the gender impact of sleep duration or sleep quality on NAFLD remains unclear. We thus aimed to examine the association of sleep duration and quality with NAFLD by gender in a Taiwanese population.

METHODS

A total of 6663 subjects aged 18 years or more were enrolled. The severity of NAFLD was divided into mild, moderate, and severe degrees based on ultrasound findings. The sleep duration was classified into three groups: short (<6h), normal (6-8h), and long (>8h). Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality, and poor sleep quality was defined as a global PSQI score greater than 5.

RESULTS

After adjustment for potential confounders, multinomial logistic regression showed that poor sleep quality was negatively associated with both mild and moderate-to-severe NAFLD in males, but sleep duration was not independently related to NAFLD. In females, sleep condition was not related to NAFLD.

CONCLUSIONS

Poor sleep quality but not sleep duration was associated with a lower risk of not only moderate to severe but also mild NAFLD in males. In females, the association of sleep quality and duration with the risk of NAFLD was insignificant.

Correlation between ultrasound-diagnosed non-alcoholic fatty liver and periodontal condition in a cross-sectional study in Japan

This cross-sectional study investigated the relationship between periodontal condition and ultrasound-diagnosed non-alcoholic fatty liver disease (NAFLD) in a Japanese oral health check population. A total of 1226 consecutive participant were enrolled in the study. Abdominal ultrasonography was applied to diagnose NAFLD. Of the study participants, 339 (27.7%) had ultrasonography-diagnosed NAFLD. The participants with NAFLD had a significantly higher prevalence of probing pocket depth (PPD) ≥ 4 mm (86.7%) than those without NAFLD (72.9%) (p < 0.05). After adjusting for gender, age, Brinkman index, regular exercise habits, body mass index, number of teeth present, presence of periodontitis, blood pressure, and serum parameters, there was a statistically significant difference in the adjusted odds ratios of having PPD ≥ 4 mm for NAFLD (Odds ratio = 1.881, 95% confidence interval 1.184–2.987, p < 0.01). Having PPD ≥ 4 mm may be a risk factor for ultrasound-diagnosed NAFLD in this cross-sectional study of a Japanese oral health check population.

Neighborhood social capital and sleep duration: a population based cross-sectional study in a rural Japanese town

Background

Studies on social capital and health outcomes have become common, but the relationship between neighborhood social capital and sleep duration by gender is still unclear. We examined the relationship between neighborhood social capital and sleep duration by gender in adults living in a rural community in Japan.

Method

We conducted a cross-sectional survey of 12,321 residents aged ≥20 years in a town in Mie Prefecture in January–March 2013. Self-completed questionnaires were collected from the residents (n = 7782; valid participation rate, 63.2%). We used five items to assess the neighborhood social capital (Cronbach’s α = 0.86). We summed up the scores of each item, and then divided the participants into four groups by quartile of total scores of neighborhood social capital (lowest, low, high, and highest). Sleep duration of < 7 h/day was defined as insufficient sleep duration according to previous studies. To adjust for potential confounders, we performed a multiple log-binominal regression analysis and estimated the prevalence ratios (PRs) and 95% confidence intervals (CIs) for insufficient sleep.

Results

Overall 42% of the men and 45% of the women had insufficient sleep. In the men, the lowest group of neighborhood social capital presented a 22% higher prevalence of insufficient sleep (PR 1.22; 95% CIs 1.08–1.38) compared to the highest group of neighborhood social capital. Similarly the low group of neighborhood social capital and the high group of neighborhood social capital had 20 and 19% higher prevalence of insufficient sleep (PR 1.20; 95% CIs 1.06–1.36; PR 1.19; 95% CIs 1.06–1.34, respectively) compared to the highest group of neighborhood social capital. For women there was no significant association between neighborhood social capital and insufficient sleep after controlling for all potential confounders.

Conclusion

Having lower neighborhood social capital was associated with insufficient sleep among Japanese adults, particularly in the men. This suggests that the context of neighborhood social capital by gender should be considered to promote healthier behaviors with regard to getting enough sleep.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5204-4) contains supplementary material, which is available to authorized users.

Sleep Duration and Risk of Liver Cancer in Postmenopausal Women: The Women's Health Initiative Study

BACKGROUND

Sleep duration has been associated with nonalcoholic fatty liver disease, but its association with liver cancer remains unknown.

MATERIAL AND METHODS

In the prospective Women's Health Initiative Study, 139,368 postmenopausal women reported sleep habits at baseline (1993-1998). We ascertained 175 incident liver cancer cases during an average 13.8 years of follow-up through August 2014. We used multivariable Cox proportional hazard regression models to estimate a hazard ratio (HR) and its 95% confidence interval (95% CI) for risk of liver cancer in association with nocturnal sleep duration.

RESULTS

Compared to women reporting 6-8 hours of sleep, the HR for liver cancer was 1.94 (95% CI 1.07-3.53) for women reporting ≥9 hours of sleep. Among the obese women, the HR associated with ≥9 hours of sleep was 3.18 (95% CI 1.84-8.60). The HR was 0.93 (95% CI 0.34-2.53) among nonobese women (p value for interaction = 0.18). Short sleep duration (≤5 hours) was not associated with liver cancer risk.

CONCLUSION

Long sleep duration was associated with a moderate increase in liver cancer risk in obese postmenopausal women in the United States. Larger study is needed to confirm our observation on effect modification by adiposity status.

Reduced brain activity in female patients with non-alcoholic fatty liver disease as measured by near-infrared spectroscopy

Patients with non-alcoholic fatty liver disease (NAFLD) have impaired health-related quality of life including physical and mental state. Near-infrared spectroscopy (NIRS) is a useful tool for evaluation of brain activity and depressive state. This study aimed to determine the brain activity of female NAFLD patients using NIRS. Cerebral oxygenated hemoglobin (oxy-Hb) concentration during a verbal fluency task (VFT) was measured using NIRS in 24 female NAFLD patients and 15 female healthy controls. The Center for Epidemiologic Studies Depression Scale (CES-D) questionnaire was administered to both groups before NIRS. There was no significant difference in CES-D score between groups. However, the oxy-Hb concentration and number of words during the VFT were less in NAFLD compared to healthy controls. The mean value of oxy-Hb concentration during 0–60 s VFT in the frontal lobe was also smaller in NAFLD patients compared to healthy controls (0.082 ± 0.126 vs. 0.183 ± 0.145, P < 0.001). Cerebral oxygen concentration is poorly reactive in response to VFT in female NAFLD patients. This may indicate an association between decreased brain activity and NAFLD regardless of depression.

The association between sleep duration and physical performance in Chinese community-dwelling elderly

Background

Physical performance is an important healthy factor in elder people. Good living habits, which include sleep, can maintain physical strength and physical performance. The aim of the present study was to conduct a cross-sectional study to determine the association between total sleep duration and physical performance.

Methods

Our study population comprised residents of the township central hospital in the suburban of Tianjin, China. We measured muscle strength, walk speed and balance function by grip, 4-m walk test and timed up and go test (TUGT). We divided sleep duration into four groups <7h, 7-8h, >8-9h, >9h.

Results

A total 898 participants had completed data (392 men and 506 women, mean age 67.71 years). In man, adjusted sleep duration was associated with lower grip in > 9 h group, the mean value (95% CI) was 0.429 (0.409, 0.448), and longer TUGT time was also associated with long sleep duration, 10.46s (9.97 s, 10.95 s). In women, adjusted slower 4-m walk speed present an inverse U-shaped relation with sleep duration, by 0.93 m/s (0.86 m/s, 0.98 m/s), 0.97 m/s (0.96 m/s, 1.00 m/s), 0.97 m/s (0.95 m/s, 0.99 m/s) and 0.92 m/s (0.89 m/s, 0.96 m/s); longer TUGT time were associated with long sleep duration (> 9 h), by 11.23 s (10.70 s, 11.77 s).

Conclusion

In Chinese community-dwelling elderly, lower muscle strength and lower balance function were associated with long sleep duration in men. Slower walk speed and lower balance function were associated with long sleep duration in women.

Shiftwork Is Not Associated with Increased Risk of NAFLD: Findings from the National Health and Nutrition Examination Survey

AIMS

There is increased focus on the metabolic impact of shiftwork, especially given the significant number of employees who work nighttime or rotating shifts. Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. We conducted a cross-sectional study to examine the association between shiftwork and the risk of NAFLD.

METHODS

We used aggregated data from the 2005-2006, 2007-2008, and 2009-2010 cycles of the National Health and Nutrition Examination Survey (NHANES). We defined NAFLD by elevated serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels (males: AST > 40 or ALT > 37; females: AST > 31 or ALT > 31) in the absence of excessive alcohol use and viral hepatitis. We defined shiftworkers as participants who self-reported currently working regular night shifts or rotating shifts. We calculated adjusted odds ratios (OR) and 95% confidence intervals (CI) using multivariable logistic regression.

RESULTS

Overall, 8159 participants aged 20-79 years reported working at a job or business using the NHANES Occupation Questionnaire and were included in the analysis. Of these, 11.1% were classified as shiftworkers. Compared to non-shiftworkers, shiftworkers were younger, were less likely to be non-Hispanic White, and have health insurance or health care. The overall prevalence of NAFLD was 15.7%. NAFLD occurred more frequently in shiftworkers (17.0%) than non-shiftworkers (15.5%). However, in the overall multivariable analysis, shiftwork was not associated with the risk of NAFLD (OR 1.11, 95% CI 0.87-1.43).

CONCLUSIONS

The findings from this NHANES-based cross-sectional study do not support an association between shiftwork and increased risk of NAFLD.

Effect of evacuation on liver function after the Fukushima Daiichi Nuclear Power Plant accident: The Fukushima Health Management Survey

Background

The Great East Japan Earthquake and subsequent Fukushima Daiichi Nuclear Power Plant accident caused residents to switch from their normal lives to lives focused on evacuation. We evaluated liver function before and after this disaster to elucidate the effects of evacuation on liver function.

Methods

This study was a longitudinal survey of 26,006 Japanese men and women living near the Fukushima Daiichi Nuclear Power Plant. This study was undertaken using data from annual health checkups conducted for persons aged 40–90 years between 2008 and 2010. Follow-up examinations were conducted from June 2011 to the end of March 2013, with a mean follow up of 1.6 years. Changes in liver function before and after the disaster were compared among evacuees and non-evacuees. We also assessed groups according to alcohol drinking status.

Results

The prevalence of liver dysfunction significantly increased in all participants from 16.4% before to 19.2% after the disaster. The incidence of liver dysfunction was significantly higher in evacuees than in non-evacuees. Multivariate logistic regression analysis showed that evacuation was significantly associated with liver dysfunction among residents.

Conclusions

This is the first study to show that evacuation due to the Fukushima Daiichi nuclear power plant disaster was associated with an increase in liver dysfunction.

•

Prevalence of liver dysfunction increased after the Great East Japan Earthquake.

•

The change in prevalence of liver dysfunction was greatest in evacuees.

•

Evacuation is one risk factor associated with liver dysfunction.

Neglected features of lifestyle: Their relevance in non-alcoholic fatty liver disease

AIM

To investigated in non-alcoholic-fatty-liver-disease (NAFLD), with ultrasound (US)-detected fatty liver, and in a group of non-alcoholic and otherwise healthy subjects, relationship of neglected features of lifestyle with NAFLD and obesity.

METHODS

Five hundred and thirty-two NAFLD and 667 non-NAFLD healthy subjects, age 21-60 years were studied. Severity of liver steatosis was assessed by US bright liver score. The adherence to mediterranean diet score (AMDS) was assessed on the basis of a 1-wk recall computerized questionnaire which included a detailed physical activity reports (Baecke questionnaire). The western dietary profile score, as a simplified paradigm of unhealthy diet, a questionnaire quantifying sun exposure score and a sleep habits questionnaires provided a further comprehensive lifestyle assessment.

RESULTS

Body mass index (BMI), insulin resistance (HOMA), and triglycerides, poorer adherence to a mediterranean diet profile, sedentary habits, minor sun exposure and use of “western diet” foods are greater in NAFLD. Multiple linear regression analysis, weighted by years of age, displays BMI, HOMA and AMDS as the most powerful independent predictors of fatty liver severity; however, also the physical activity score, the western diet habit and the sun exposure score are acting inside the model with significant independent effects.

CONCLUSION

Articulated clinical intervention, according to our results, are justified in NAFLD and can be pursued addressing by focused intervention nutritional profile, physical exercise mainly in open-air subsets for enhancing sun exposure and healthier sleep duration and rhythm.

Associations Between Lifestyle Characteristics and the Presence of Nonalcoholic Fatty Liver Disease: A Case-Control Study

BACKGROUND

Dietary and physical activity (PA) habits have been suggested as important factors for nonalcoholic fatty liver disease (NAFLD). Published data are mainly focused on the effect of either diet or exercise, whereas data on other aspects like sleep remain sparse. The aim of this study was to explore potential associations between dietary intake, PA, and sleeping habits, and the presence of NAFLD.

METHODS

One hundred patients with ultrasound-proven NAFLD and 55 healthy controls matched for age, sex, and body mass index were included. Dietary habits were assessed through a semiquantitative validated food frequency questionnaire. PA level was assessed with a validated questionnaire. Total night sleep hours and duration of midday rest were also recorded. Optimal sleep duration was defined as sleep hours ≥7 and ≤9 hr/day.

RESULTS

Patients compared to controls consumed less vegetables and nuts, more sweets, drank less coffee and alcohol (all P < 0.05), and exhibited a lower level of PA (P = 0.006). PA level [odds ratio (OR) per 100 metabolic equivalent of task-min/day = 0.74, 95% confidence interval (CI) 0.61-0.89, P = 0.002] was associated with lower probability of having NAFLD, whereas sweets consumption (OR = 2.13, 95% CI 1.22-3.71, P = 0.008) was associated with increased probability, after adjusting for several confounders, including body weight status. Optimal sleep duration was marginally and inversely associated with NAFLD presence (OR = 0.38, 95% CI 0.14-1.01, P = 0.05).

CONCLUSION

Higher PA level and optimal sleep duration are associated with lower likelihood, whereas sweets consumption is associated with higher likelihood of having NAFLD. These associations are independent of body weight status and energy intake.

A "healthy diet-optimal sleep" lifestyle pattern is inversely associated with liver stiffness and insulin resistance in patients with nonalcoholic fatty liver disease

Several lifestyle habits have been described as risk factors for nonalcoholic fatty liver disease (NAFLD). Given that both healthy and unhealthy habits tend to cluster, the aim of this study was to identify lifestyle patterns and explore their potential associations with clinical characteristics of individuals with NAFLD. One hundred and thirty-six consecutive patients with ultrasound-proven NAFLD were included. Diet and physical activity level were assessed through appropriate questionnaires. Habitual night sleep hours and duration of midday naps were recorded. Optimal sleep duration was defined as sleep hours ≥ 7 and ≤ 9 h/day. Lifestyle patterns were identified using principal component analysis. Eight components were derived explaining 67% of total variation of lifestyle characteristics. Lifestyle pattern 3, namely high consumption of low-fat dairy products, vegetables, fish, and optimal sleep duration was negatively associated with insulin resistance (β = -1.66, P = 0.008) and liver stiffness (β = -1.62, P = 0.05) after controlling for age, sex, body mass index, energy intake, smoking habits, adiponectin, and tumor necrosis factor-α. Lifestyle pattern 1, namely high consumption of full-fat dairy products, refined cereals, potatoes, red meat, and high television viewing time was positively associated with insulin resistance (β = 1.66, P = 0.005), although this association was weakened after adjusting for adiponectin and tumor necrosis factor-α. A "healthy diet-optimal sleep" lifestyle pattern was beneficially associated with insulin resistance and liver stiffness in NAFLD patients independent of body weight status and energy intake.

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

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease worldwide. Several studies have suggested that short sleep duration could be a risk factor for NAFLD. However, results of those reports are inconsistent. This meta-analysis was conducted with an attempt to summarize all available data.

METHODS

A comprehensive literature review was performed using MEDLINE and EMBASE database. Studies that reported relative risks, odd ratios or hazard ratios comparing the risk of NAFLD among participants who had short sleep duration versus those with longer sleep duration were included. Pooled risk ratios and 95% confidence interval were calculated using a random-effect, generic inverse variance method.

RESULTS

Six studies met the eligibility criteria and were included in the meta-analysis. The risk of NAFLD in participants who had short sleep duration was significantly higher than participants with longer sleep duration with pooled risk ratios of 1.19 (95% confidence interval, 1.04-1.36, I2  = 0%).

CONCLUSIONS

Our study demonstrated a small but significantly increased risk of NAFLD among participants who had short sleep duration.

Nighttime sleep duration and risk of nonalcoholic fatty liver disease: the Dongfeng-Tongji prospective study

BACKGROUND

To examine the association between self-reported nighttime sleep duration and nonalcoholic fatty liver disease (NAFLD) risk by comparing the incidence rates of NAFLD among healthy subjects with different sleep duration during the 5 years follow-up.

METHODS

8965 eligible NAFLD-free subjects with a mean age of 61.6 years (males, 43.4%) from Dongfeng-Tongji cohort study at baseline were enrolled in the study. Logistic regression analysis was used to estimate the association between sleep duration and incident NAFLD with potential confounders adjusted. Sleep duration was categorized into five groups: <6 h, 6-7 h, 7-8 h, 8-9 h, ≥9 h.

RESULT

During the 5-years of follow-up, a total of 2,197 participants were newly diagnosed as NAFLD. Compared with those reported 7-8 h per day of nighttime sleep, the multivariable-adjusted odds ratio (95% confidence intervals) were 1.21 (1.07-1.38) for those who sleep 8-9 h/day, and 1.31 (1.13-1.52) for those who sleep over 9 h/day. However, no significant association was found with short nightly sleep duration (<7 h/day).

CONCLUSION

Long nighttime sleep duration was associated with a modestly increased risk of NAFLD in a middle-aged and elderly Chinese population. Key messages Long nighttime sleep duration was associated with a modestly increased risk of NAFLD in a middle-aged and elderly Chinese population. The effect of long nighttime sleep on the risk of incident NAFLD was attenuated greatly by body mass index (BMI) in men.

Sleep Duration and the Risk of Fatty Liver Disease: A Systematic Review and Meta-analysis

Recent studies have reported inconsistent results on the association between sleep duration and the risk of fatty liver disease (FLD). Thus, we quantitatively evaluated this association by performing a systematic review and meta-analysis, based on a comprehensive electronic search in databases of PubMed, Web of Science, EMBASE, ClinicalTrials.gov, Wanfangdata and Chinese National Knowledge Infrastructure (CNKI) (updated to April 2016). Multivariate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) were extracted and pooled by using a random-effects model. Eight eligible studies involving 97,371 participants were included. We found that neither short nor long sleep duration was significantly related with FLD risk. For short sleep duration, the pooled OR was 1.17 (95% CI = 0.98–1.38), and for long sleep duration, the pooled OR was 1.01 (95% CI = 0.72–1.41). Subgroup analyses by sex, outcome, and exposure reference also did not identify any effect of sleep duration on FLD onset. In summary, our findings suggested that short or long sleep duration was not significantly associated with FLD risk. Further cohort studies with refined designs are still warranted to validate our results.