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

Lifestyle intervention for metabolic dysfunction-associated fatty liver disease: a 24-h integrated behavior perspective

INTRODUCTION

The prevalence, health and socioeconomic burden of metabolic dysfunction-associated fatty liver disease (MAFLD) is growing, increasing the need for novel evidence-based lifestyle approaches. Lifestyle is the cornerstone for MAFLD management and co-existing cardiometabolic dysfunction. The aim of this review was to evaluate the evidence for lifestyle management of MAFLD, with a specific lens on 24-hour integrated behaviour and provide practical recommendations for implementation of the evidence.

RESULTS

Weight loss ≥ 7-10% is central to lifestyle management; however, liver and cardiometabolic benefits are attainable with improved diet quality and exercise even without weight loss. Lifestyle intervention for MAFLD should consider an integrated '24-h' approach that is cognisant of diet, physical activity/exercise, sedentary behavior, smoking, alcohol intake and sleep. Dietary management emphasises energy deficit and improved diet quality, especially the Mediterranean diet, although sociocultural adaptations to meet preferences should be considered. Increasing physical activity and reducing sedentary behavior can prevent MAFLD, with strongest evidence in MAFLD supporting regular structured moderate-vigorous aerobic exercise for 150-240 min/week. Resistance training in addition to aerobic exercise should be considered and prioritised for those who are losing body mass via diet and/or pharmacological approaches and those with sarcopenia, to minimise bone and lean mass loss. Limited evidence suggests that sleep is important for MAFLD prevention. Emerging novel approaches to diet and exercise may address some of the key barriers to behaviour change (e.g. lack of time, access to resources and social support).

FUTURE DIRECTIONS

Large-scale multidisciplinary trials in people with MAFLD with long-term follow-up, that can be scaled up into mainstream healthcare, are required. Future management guidelines should consider the heterogeneity of MAFLD and specialised models of care that coordinate the health workforce to manage the increased and growing MAFLD population.

Association of sleep patterns and disorders with metabolic dysfunction-associated steatotic liver disease and liver fibrosis in contemporary American adults

INTRODUCTION AND OBJECTIVES

The impact of sleep on metabolic dysfunction-associated steatotic liver disease (MASLD) in American adults remains unclear. This study aimed to address the relationship of sleep patterns and disorders with MASLD and liver fibrosis comprehensively.

MATERIALS AND METHODS

This cross-sectional study included adult participants from the National Health and Nutrition Examination Survey 2017-2020. Multivariate adjusted regression analysis were used to examine the association of sleep with MASLD and liver fibrosis. We further addressed these associations using restricted cubic splines, mediation analysis, stratified analysis and multiple sensitivity analysis.

RESULTS

We enrolled 5368 participants. Certain sleep disorders, sleep duration, high sleep debt and specific sleep-wake time were associated with MASLD. Late workday sleep was a shared risk factor for MASLD and liver fibrosis. Short sleep on workdays and free days favored MASLD, whereas average weekly long sleep protected against MASLD. Workday, free day and average weekly optimal sleep duration was 7.5 h, 8 h and 7.78 h, respectively. Mediation analysis suggested that fasting glucose and high-density lipoprotein cholesterol indirectly mediated the relationship between sleep duration and MASLD, whereas stratified analysis showed that sex influenced the relationship, and that the correlation was only observed in women and specific age groups.

CONCLUSIONS

Sleep duration independently affected MASLD but only in women and specific age groups. Moreover, late sleep on workdays was a shared risk factor for MASLD and liver fibrosis. These results suggest targeting sleep behaviors for MASLD prevention and developing age- and sex-specific strategies.

Shift work and non-alcoholic fatty liver disease in young, healthy workers

Non-alcoholic fatty liver disease (NAFLD) is a relatively common disease, and preventing its occurrence is important for both individual health and reducing social costs. Shift work is reported to have several negative effects on health. An association has been observed between NAFLD and both sleep time and quality; however, this association remains unclear in night shift workers. We aimed to evaluate the relationship between shift work and the incidence of NAFLD. Overall, 45,149 Korean workers without NAFLD were included at baseline. NAFLD was defined as the presence of a fatty liver observed on ultrasonography without excessive alcohol use. incidence rate ratios for incident NAFLD were estimated using negative binomial regression according to age groups (20s, 30s, 40s, and 50s). In the 20s age group, shift work showed a significant incidence rate ratio (IRR) for NAFLD in all models. After adjusting for all variables, the IRR (95% confidence interval) was 1.24 (1.08-1.43) in the 20s age group. In their 20s, a significant association between shift work and incident NAFLD was consistently observed among women and workers with poor sleep quality. In this large-scale cohort study, shift work was significantly associated with the development of NAFLD among young workers in their 20s.

Sleep duration in midlife and old age and risk of mortality over a 48-year follow-up: The Helsinki businessmen study (HBS) cohort

OBJECTIVES

Both short and long sleep duration have been associated with increased mortality, but there are few truly long-term studies.

STUDY DESIGN

This is a cohort study of 2504 men born between 1919 and 1934. In 1974-1975 (mean age 48), participants underwent baseline clinical examinations and sleep duration assessments. A follow-up examination took place 35 years later, in 2010 (mean age 82).

MAIN OUTCOME MEASURE

All-cause mortality data from baseline and from old age were collected through to December 31, 2022.

RESULTS

At baseline, short sleep duration (≤6 h per night), normal sleep duration (>6 and ≤ 8 h), and long sleep duration (>8 h) was reported by 266, 2019 and 219 men, respectively. Men with short sleep duration had higher levels of smoking, alcohol consumption, body mass index, and poorer self-rated health than those with normal sleep duration. During the 48-year follow-up, 2287 men died. The unadjusted hazard ratio for mortality was 1.20 (95 % confidence interval [CI] 1.05-1.37) for short compared with normal sleep duration, but this association vanished after adjustments (1.01, 95 % CI 0.87-1.17). In old age, the corresponding hazard ratios were 1.41 (1.16-1.72) and 1.19 (0.94-1.51) for short sleep duration and 1.33 (1.09-1.63) and 1.31 (1.02-1.67) for long sleep duration.

CONCLUSIONS

In a comprehensive lifespan follow-up, the modestly increased mortality among men with short sleep duration in midlife was attributed to unhealthy lifestyle factors. In old age both long and short sleep duration seemed to be associated with modestly increased mortality.

CLINICALTRIALS

gov identifier for the HBS: NCT02526082.

Interaction between dietary flavonoid intake and trouble sleeping on non-alcoholic fatty liver disease risk: a cross-sectional study

OBJECTIVE

The possible interaction of dietary flavonoid intake and sleep on non-alcoholic fatty liver disease (NAFLD) has not been well studied. This study investigated the interaction between dietary flavonoid intake and trouble sleeping on the risk of NAFLD.

METHODS

Three discrete National Health and Nutrition Examination Survey data cycles from 2007 to 2010 and 2017 to 2018 were used. NAFLD was diagnosed by a US Fatty Liver Index ≥30. A sleep questionnaire diagnosed trouble sleeping. Univariate and multivariate logistic regression, restricted cubic spline (RCS) and subgroup analyses were used to evaluate the association between dietary flavonoids, trouble sleeping and NAFLD. We employed the relative excess risk due to interaction, attributable proportion of interaction and synergy index to evaluate additive interactions.

RESULTS

Ultimately, 5056 participants were enrolled, and higher anthocyanidins and flavanones intake was negatively correlated with NAFLD. Conversely, trouble sleeping was positively associated with NAFLD. These correlations remained stable after adjusting for confounders, and there was a sex difference in this relationship. In the RCS model, anthocyanins were negatively non-linearly related to NAFLD, while flavanones showed a negative linear relationship. Moreover, there was a synergistic interplay between low dietary anthocyanin intake and trouble sleeping on the risk of NAFLD. A similar relationship existed for flavanone intake.

CONCLUSION

Anthocyanin and flavanone intake were negatively associated, whereas trouble sleeping was positively associated with NAFLD risk. There was a synergistic effect of low anthocyanin intake and trouble sleeping. The same relationship existed for low flavanone intake.

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.

Evaluation of weekend catch-up sleep and weekday sleep duration in relation to metabolic syndrome in Korean adults

PURPOSE

This study aimed to evaluate whether or not the relationship between weekday sleep duration and prevalence of metabolic syndrome (MetS) differs according to weekend catch-up sleep (CUS) in Korean adults.

METHODS

Data from the Korea National Health and Nutrition Examination Survey 2016-2020, including that regarding weekday sleep duration, weekend CUS, MetS components, and confounding factors such as sociodemographic factors, health behaviors, and illness-related factors, were evaluated in Korean adults aged 19 to 80 years. Complex-sample logistic regression was applied after adjusting for confounding factors.

RESULTS

Among 24,313 adults, the prevalence of MetS was lowest in individuals with 6-7 h of sleep on weekdays and CUS ≥ 2 h (17.7%, reference group). The interaction between weekday sleep duration and weekend CUS for MetS was significant. Compared to the reference group, the prevalence of MetS was higher in those who slept < 7 h and had a maximum CUS of 1 h (aORs, 1.42-1.66), and in those who slept ≥ 9 h and had a maximum CUS of 2 h (aORs, 1.28-1.82). In subjects with no CUS or CUS ≥ 2 h, the prevalence of MetS was greater even in those with adequate weekday sleep duration (7- 9 h) than in the reference group (aORs, 1.37 and 1.64, respectively).

CONCLUSION

Weekend CUS may help individuals with short weekday sleep duration reduce their odds of developing MetS, but it may worsen the condition in individuals with a long weekday sleep length.

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.

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.

Association between organophosphorus insecticides exposure and the prevalence of sleep problems in the US adults: An analysis based on the NHANES 2007-2018

OBJECTIVE

The aim of this study was to evaluate the association between organophosphorus pesticides (OPPs) exposure and sleep problems.

METHODS

In this study, data from 6295 participants aged 18 years or older were collected from the National Health and Nutrition Examination Survey (NHANES). The dialkyl phosphate compounds (DAPs) metabolites, OPPs exposure biomarker, were examined using solid phase extraction-high coupled with isotope dilution-ultrahigh performance liquid chromatography-tandem mass spectrometry. Data on short sleep duration (SSD), self-reported trouble sleeping and self-reported sleep disorder were collected from the database. Weighted generalized logistic model, weighted quantile sum (WQS) model, and quantile-based g calculation (QGC) methods were used for analyzing the collected data.

RESULTS

The prevalence of SSD, self-reported trouble sleeping and self-reported sleep disorder in this study were 28.91 % (1814/6274), 25.31 % (1593/6294), and 9.05 % (289/3195), respectively. After confounding factors adjustments, the prevalence of SDD in participants with high log-transformed DETP, DMTP, DEDTP, and DMDTP were 1.19 times (OR: 1.11-1.28, P < 0.001), 1.09 times (OR: 1.03-1.15, P = 0.003), 1.26 times (OR: 1.17-1.37, P < 0.0001), and 1.10 times (OR: 1.04-1.17, P = 0.003) than in participants with low showed, respectively. A non-linear relationship was noted between SSD with the urinary concentration of DEP (P for nonlinearity < 0.001), DMP (P for nonlinearity < 0.001), DMTP (P for nonlinearity = 0.006), and DMDTP (P for nonlinearity = 0.001). The WQS results showed that the prevalence of SDD was 1.28 times (95 % CI: 1.17-1.40, P < 0.001) higher in participants with high co-exposure to OPPs than in those with low co-exposure, with DEDTP having the enormous weights (0.50). The QGC results also revealed a significant positive association between the co-exposure of DAPs and SSD (OR: 1.08, 95 % CI:1.02-1.16, P = 0.01) with DETP having the most positive weight (0.44). As for the association between DAPs with self-report sleep disorder, only DEP was detected that it was positively associated with self-reported sleep disorder with all confounding factors adjusted (OR: 1.17; 95 % CI: 1.07-1.29, P = 0.001). However, all DAPs have not detected a significant association with the prevalence of self-reported trouble sleeping. Besides, there was no significant association between co-exposure to OPPs with self-reported trouble sleeping and self-reported sleep disorder.

CONCLUSION

The results of this study indicated that high levels of single or mixture urinary DAP, indicating for OPPs exposure, were associated with an increased prevalence of SSD in general adults, which has significant implications for preventing OPPs pollution and protecting sleep health.

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.

The association between sleep duration, quality, and nonalcoholic fatty liver disease: A cross-sectional study

Sleep can affect nonalcoholic fatty liver disease (NAFLD). We investigated the association between sleep duration, sleep quality, and NAFLD. From January to December 2018, 1,073 patients (age: 37.94 ± 10.88, Body Mass Index (BMI): 22.85 ± 3.27) were enrolled. Pittsburgh Sleep Quality Index Questionnaire and Munich Chronotype Questionnaire were used to assess sleep duration, quality, and habits. Ultrasonography was used to diagnose NAFLD. Multivariate logistic regression models were used to calculate the odds ratio (OR) and 95% confidence interval (CI) of the risk of NAFLD by different types of sleep duration and sleep quality. No significant differences in sleep time, sleep quality, and sleep habits between the NAFLD and the non-NAFLD groups were observed (P > 0.05). There was no correlation between sleep duration and NAFLD in the whole cohort. After adjusting for age, exercise, fasting plasma glucose, and BMI, the group with long sleep duration showed a decreased risk of NAFLD in men (OR = 0.01, 95% CI: 0.001-0.27, P = 0.032). However, in all four adjusted models, no correlation between sleep duration, quality, and NAFLD was found in women. In conclusion, sleep duration was significantly and negatively associated with NAFLD in men but not women. Prospective studies are required to confirm this association.

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.

Higher Adherence to Healthy Lifestyle Score Is Associated with Lower Odds of Non-Alcoholic Fatty Liver Disease

Growing evidence supports that individual lifestyle factors contribute to the development of non-alcoholic fatty liver disease (NAFLD) without considering the coexistence and synergistic effect of lifestyle factors. Our aim is to derive a healthy lifestyle score (HLS) and estimate its association with NAFLD. In this nationwide cross-sectional study, we derived a five-item HLS including dietary pattern, body mass index, physical activity, cigarette smoking, and sleep duration. NAFLD and clinically significant fibrosis (CSF) were assessed based on vibration-controlled transient elastography (VCTE). Liver function parameters were also tested. Multivariable logistic and linear regressions were applied to investigate the association between HLS and liver diseases. Of the 3893 participants with VCTE examination, approximately 14.1% of participants possessed zero or one healthy lifestyle, 62.5% possessed two or three healthy lifestyles, and 23.4% possessed four or five healthy lifestyles. Compared with participants with a low HLS (0−1 score), the adjusted odds ratios and 95% confidence intervals for those with a high HLS (4−5 score) were 0.25 (0.19~0.33, Ptrend < 0.001) for NAFLD and 0.30 (0.18~0.50, Ptrend < 0.001) for CSF. HLS was positively associated with albumin, total protein, and total bilirubin (all Ptrend ≤ 0.001), and was inversely associated with globulin, alanine aminotransferase, and gamma-glutamyl transaminase (all Ptrend ≤ 0.003). Higher adherence to HLS is associated with lower odds of NAFLD and CSF and may improve liver function. Strategies for the promotion of a healthy lifestyle should be considered as part of NAFLD prevention.

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.

Lifestyle as well as metabolic syndrome and non-alcoholic fatty liver disease: an umbrella review of evidence from observational studies and randomized controlled trials

BACKGROUND & AIMS

Recent epidemiological studies have indicated that NAFLD is pathologically associated with a sedentary lifestyle, unhealthy dietary habits and metabolic syndrome. An umbrella review of meta-analyses was performed to summarize the quality of evidence regarding the epidemiologic associations between lifestyle, metabolic syndrome, and non-alcoholic fatty liver disease (NAFLD) in regards to risk and treatment.

METHODS

We searched PubMed, Web of Science and Embase Database from inception until June 1, 2021. Meta-analyses of observational studies and randomized controlled trials (RCTs) examining the associations of lifestyle as well as metabolic syndrome with NAFLD risk or treatment were screened. We assessed meta-analyses of observational studies based on random-effect summary effect sizes and their P values, 95% prediction intervals, heterogeneity, and small-study effects. For meta-analyses of RCTs, outcomes with a random-effect P < 0.005 and a high-GRADE assessment were classified as strong evidence.

RESULTS

A total of 37 publications were included in this review: twenty-two publications reporting 41 meta-analyses of observational studies (37 unique outcomes) and 15 publications reporting 81 meta-analyses of RCTs (63 unique outcomes) met the inclusion criteria. Methodological quality was high for 97% of the included meta-analyses. Quality of evidence was rated high only for the association of sugar-sweetened soda consumption with increased NAFLD risk in meta-analyses of observational studies. Only 3 therapeutic interventions (green tea improving ALT, TG, TC and LDL, omega-3 PUFAs improving HOMR-IR and plasma glucose, and exercise improving RT and ALT) from meta -analyses of RCTs with suggestive (change to high/low/etc) levels of evidence were identified.

CONCLUSION

Despite many meta-analyses exploring the associations of lifestyle as well as metabolic syndrome with the risk or treatment of NAFLD, robust clinical RCTs are needed to further investigate the associations between lifestyle modifications and incidence of NAFLD or therapeutic effects on disease progression.

Decrease in Sleep Duration and Poor Sleep Quality over Time Is Associated with an Increased Risk of Incident Non-Alcoholic Fatty Liver Disease

The impact of changes in sleep duration and sleep quality over time on the risk of non-alcoholic fatty liver disease (NAFLD) is not known. We investigated whether changes in sleep duration and in sleep quality between baseline and follow-up are associated with the risk of developing incident NAFLD. The cohort study included 86,530 Korean adults without NAFLD and with a low fibrosis score at baseline. The median follow-up was 3.6 years. Sleep duration and quality were assessed using the Pittsburgh Sleep Quality Index. Hepatic steatosis (HS) and liver fibrosis were assessed using ultrasonography and the fibrosis-4 index (FIB-4). Cox proportional hazard models were used to determine hazard ratios (HRs) and 95% confidence intervals (Cis). A total of 12,127 subjects with incident HS and 559 with incident HS plus intermediate/high FIB-4 was identified. Comparing the decrease in sleep duration of >1 h, with stable sleep duration, the multivariate-adjusted HR (95% CIs) for incident HS was 1.24 (1.15–1.35). The corresponding HRs for incident HS plus intermediate/high FIB-4 was 1.58 (1.10–2.29). Comparing persistently poor sleep quality with persistently good sleep quality, the multivariate-adjusted HR for incident HS was 1.13 (95% CI, 1.05–1.20). A decrease in sleep duration or poor sleep quality over time was associated with an increased risk of incident NAFLD, underscoring an important potential role for good sleep in preventing NAFLD risk.

Sleep Duration, Sleep Quality, and the Development of Nonalcoholic Fatty Liver Disease: A Cohort Study

INTRODUCTION

The longitudinal relationship between sleep duration, sleep quality, and the risk of nonalcoholic fatty liver disease (NAFLD) is unknown. We aimed to examine the association between sleep duration, sleep quality, and NAFLD development.

METHODS

Using the Pittsburgh Sleep Quality Index, sleep duration and quality were evaluated for 143,306 NAFLD-free Korean adults with a mean age of 36.6 years, who were followed for an average of 4.0 years. Hepatic steatosis (HS) was assessed using ultrasonography and liver fibrosis by the fibrosis-4 index (FIB-4) or the NAFLD fibrosis score. Flexible parametric proportional hazard models were used to determine the hazard ratios (HRs) and 95% confidence intervals.

RESULTS

There were 27,817 subjects with incident HS, of whom 1,471 had incident HS plus intermediate/high FIB-4. Multivariable-adjusted HRs (95% confidence intervals) for incident HS comparing sleep durations of ≤5, 6, 8, and ≥ 9 hours with 7 hours were 1.19 (1.14-1.23), 1.07 (1.04-1.10), 0.98 (0.94-1.02), and 0.95 (0.87-1.03), respectively. The corresponding HRs for incident HS plus intermediate/high FIB-4 were 1.30 (1.11-1.54), 1.14 (1.01-1.29), 1.11 (0.93-1.33), and 1.08 (0.71-1.63). The association between sleep duration and HS plus intermediate/high FIB-4 was inverse in individuals with good sleep quality but tended to be U-shaped in those with poor sleep quality. The results were similar if FIB-4 was replaced by the NAFLD fibrosis score.

DISCUSSION

In young adults, short sleep duration was independently associated with an increased risk of incident NAFLD with or without intermediate/high fibrosis score, suggesting a role for inadequate sleep quantity in NAFLD risk and severity.

Synergistic Interaction of Dietary Pattern and Concordance Lifestyle with Abnormal Liver Function among Young Adults in Taiwan: A Population-Based Longitudinal Study

While diet and lifestyle are independently implicated in the etiology of liver disease, the interaction of diet and lifestyle may be more helpful for determining the risk of liver abnormality. Thus, our study aimed to evaluate the interaction between the dietary pattern associated with liver biomarkers and lifestyle factors among Taiwanese adults with abnormal liver enzymes. A liver-associated dietary pattern, generated using reduced rank regression, was characterized by high intake of soy sauce or other dips, sugar sweetened beverages, and preserved and processed foods, but low intake of seafood, fruits, eggs, and dark-colored vegetables. In the fully adjusted model, liver-associated dietary patterns or unhealthy concordance lifestyle factors were associated with an increased risk of having liver function abnormality (OR = 1.08, 95% CI: 1.04, 1.12 and OR = 1.42, 95% CI: 1.31, 1.53, respectively). Moreover, the interaction between liver-associated dietary pattern and unhealthy concordance lifestyle factors showed more significant correlation, with an elevated risk of abnormal liver function (OR = 2.14, 95% CI: 2.02, 2.26). Therefore, our study suggests that participants who have a strong liver-associated dietary pattern along with unhealthy concordance lifestyles are likely to have increased odds of abnormal liver function.

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.

Sleep duration and health outcomes: an umbrella review

PURPOSE

To collect existing evidence on the relationship between sleep duration and health outcomes.

METHODS

A thorough search was conducted in PubMed, Web of Science, Embase, and the Cochrane Database of Systematic Reviews from inception to January, 2021. Meta-analyses of observational and interventional studies were eligible if they examined the associations between sleep duration and human health.

RESULTS

In total, this umbrella review identified 69 meta-analyses with 11 outcomes for cancers and 30 outcomes for non-cancer conditions. Inappropriate sleep durations may significantly elevate the risk for cardiovascular disease (CVD), cognitive decline, coronary heart disease (CHD), depression, falls, frailty, lung cancer, metabolic syndrome (MS), and stroke. Dose-response analysis revealed that a 1-h reduction per 24 hours is associated with an increased risk by 3-11% of all-cause mortality, CHD, osteoporosis, stroke, and T2DM among short sleepers. Conversely, a 1-h increment in long sleepers is associated with a 7-17% higher risk of stroke mortality, CHD, stroke, and T2DM in adults.

CONCLUSION

Inappropriate sleep duration is a risk factor for developing non-cancer conditions. Decreasing and increasing sleep hours towards extreme sleep durations are associated with poor health outcomes.

Circadian Misalignment Rather Than Sleep Duration is Associated with MAFLD: A Population-Based Propensity Score-Matched Study

BACKGROUND AND AIMS

Circadian misalignment (CM) leads to metabolic disorder. Metabolic (dysfunction) associated fatty liver disease (MAFLD) is a novel definition for fatty liver disease that requires the presence of metabolic dysfunction. As the association between CM and MAFLD remains unclear, this study is designed to explore whether there is an association between CM and MAFLD.

METHODS

NHANES 2017-2018 database was used in this study. Liver steatosis and fibrosis were diagnosed by Fibroscan®. CM was defined by the presence of mistimed sleep, late sleep or irregular chronotype. Propensity score matching (PSM) was used to match subjects for their age and gender.

RESULTS

A total of 4552 participants were included in the study, with 2089 (45.89%) identified as MAFLD and 894 (19.64%) as CM. Participants with CM were significantly younger than those without (46.06 ± 18.06 vs 50.93 ± 17.78, p<0.001). PSM for age and gender resulted in 894 participants with CM and 892 with non-CM. CM group had higher body mass index, liver enzymes, glucose and lipid levels. The prevalence of MAFLD was higher in the CM group than the non-CM group (45.41% vs 28.48%, p<0.001). The presence of CM increased the risk of MAFLD by more than twofold. Short sleep duration (<6 hours) was not independently associated with MAFLD or fibrosis if additionally adjusting for CM.

CONCLUSION

CM is independently associated with MAFLD, while short sleep duration (<6 hours) is not an independent risk factor for MAFLD or liver fibrosis after adjusting for CM.

Cross-sectional association between long working hours and liver function: the Kangbuk Samsung Health Study

OBJECTIVES

Although the effects of long working hours on liver function remain unclear, in South Korea, there is a social perception that long working hours are associated with poor liver function. Thus, long working hours have recently become a major issue. This study aimed to determine the association between long working hours and liver function, as indicated by the alanine transaminase (ALT) levels.

DESIGN

Cross-sectional study.

SETTING

Large university hospitals in Seoul and Suwon, South Korea.

PARTICIPANTS

Workers in formal employment who underwent a comprehensive health examination at the Kangbuk Samsung Hospital Total Healthcare Centre clinics in Seoul and Suwon, South Korea, between January 2011 and December 2018. Of the 386 488 participants, 212 421 met the inclusion criteria and were included in the analysis.

PRIMARY OUTCOME MEASURE

ALT elevation.

RESULTS

The participants were predominantly well-educated (86.1%), male (69.3%) and in their 30s (49.6%). In total, 13.4% of the participants presented ALT elevation (>40 IU/L). There was no significant association between working hours and ALT elevation in the general population and in the hepatitis B surface antigen (HBsAg)-negative group. Conversely, in the HBsAg-positive group, working >60 hours per week compared with 35-40 hours per week was significantly associated with ALT elevation. The association was more pronounced in those with ALT levels >80 IU/L (OR 1.94, 95% CI 1.24 to 3.01) than in those with ALT levels >40 IU/L (OR: 1.45, 95% CI 1.20 to 1.75). The p values for trend were <0.05.

CONCLUSIONS

Long working hours were associated with ALT elevation only in hepatitis B virus carriers and not in the general population. Provided that there is adherence to the legal working hours, there is no need to further restrict working hours for liver health, irrespective of HBsAg status.

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 between cardiac conduction defect and nonalcoholic fatty liver disease: a systematic review and meta-analysis

Background

Cardiovascular disease is a common comorbidity of patients with nonalcoholic fatty liver disease (NAFLD), particularly coronary artery disease and congestive heart failure. However, the relation between NAFLD and cardiac conduction defects has not been well studied. This systematic review and meta-analysis was conducted to identify all available studies on this association and summarize their results.

Methods

A comprehensive literature review was conducted using MEDLINE and EMBASE databases through June 2020 to identify studies that compared the risk of a cardiac conduction defect among patients with NAFLD versus those without. Effect estimates from each study were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird.

Results

Three cross-sectional studies with 3651 participants fulfilled the eligibility criteria and were included in this meta-analysis. The risk of a cardiac conduction defect was significantly higher among patients with NAFLD than in those without NAFLD, with a pooled odds ratio of 5.17 (95% confidence interval 1.34-20.01; I² 96%).

Conclusion

A significantly greater risk of cardiac conduction defects among patients with NAFLD was observed in this meta-analysis. How this risk should be managed in clinical practice requires further investigation.

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.

Effects of Dietary and Lifestyle Interventions on Liver, Clinical and Metabolic Parameters in Children and Adolescents with Non-Alcoholic Fatty Liver Disease: A Systematic Review

Non-alcoholic fatty liver disease (NAFLD) affects 5.5–10.3% of children worldwide, while in obese individuals, it increases to almost 34%. Pediatric NAFLD is consistently associated with metabolic syndrome and insulin resistance. As no pharmacological agents exist for the treatment of NAFLD, lifestyle modifications remain the only therapy. However, as not all overweight/obese children have NAFLD, high-quality data, focused exclusively on NAFLD population are needed. Therefore, the present systematic review assessed the efficacy of lifestyle (diet or exercise) based on randomized controlled clinical trials (RCTs) on liver, anthropometric, glucose, and lipid parameters in children, with imaging or biopsy-proven NAFLD. In general, the results were inconclusive and therefore no specific recommendations could be drawn. In most studies, differences were derived from within group comparisons, which are known to be highly misleading. However, both low-carbohydrate and low-fat diets could benefit liver outcomes, as long as weight loss is achieved, but not necessary glucose and lipid parameters. No RCTs were found on exercise alone, as compared to no intervention on pediatric NAFLD. Concerning diet plus exercise interventions, all studies led to improvements in liver outcomes accompanied with weight loss. Resolution of NAFLD was found in considerably high percentages, while improvements were also seen in glucose but were modest in lipid parameters.

Association of Serum Fibroblast Growth Factor 23 Levels with the Presence and Severity of Hepatic Steatosis Is Independent of Sleep Duration in Patients with Diabetes

PURPOSE

Fibroblast growth factor (FGF) 23 is currently recognized to be involved in the occurrence and development of metabolic diseases. The present study aimed to investigate the association between serum FGF23 levels and hepatic steatosis, as well as the influence of sleep duration.

PATIENTS AND METHODS

The present study population was selected from patients with diagnosed diabetes hospitalized during February 2018 to April 2019. Serum FGF23 levels were assessed by two-side sandwich enzyme-linked immunosorbent assay. The presence and severity of hepatic steatosis were determined by controlled attenuation parameter (CAP). Hepatic steatosis was determined as CAP≥302 dB/m.

RESULTS

Serum FGF23 levels were significantly higher in individuals with hepatic steatosis than in those without hepatic steatosis (P=0.004). The present study population was divided into Q1-Q4 according to serum FGF23 quartiles. The risks of hepatic steatosis were increased more than 3 folds in Q2-Q4 (all P<0.01) compared to Q1. CAP showed an uptrend from Q1 to Q4 (P=0.005), even after adjustment for gender and age (P=0.001). Multivariate variance analyses showed significant differences in CAP among Q1-Q4 (P=0.008) and between individuals with short and long sleep duration (P=0.023), which were independent of each other. Serum FGF23 levels were positively associated with CAP independent of gender, age, total metabolic traits, and sleep duration (P=0.042).

CONCLUSION

Serum FGF23 levels were independently and positively associated with the severity of hepatic steatosis. The associations of serum FGF23 levels and sleep duration with hepatic steatosis were independent of each other.

Lifestyle and Food Habits Impact on Chronic Diseases: Roles of PPARs

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that exert important functions in mediating the pleiotropic effects of diverse exogenous factors such as physical exercise and food components. Particularly, PPARs act as transcription factors that control the expression of genes implicated in lipid and glucose metabolism, and cellular proliferation and differentiation. In this review, we aim to summarize the recent advancements reported on the effects of lifestyle and food habits on PPAR transcriptional activity in chronic disease.

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.

Lean non-alcoholic fatty liver disease patients had comparable total caloric, carbohydrate, protein, fat, iron, sleep duration and overtime work as obese non-alcoholic fatty liver disease patients

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial disease that involves a complex interaction between genetics, diet, and lifestyle. Although closely related with obese subjects, it is also common in lean humans. This study aimed to characterize the diet and lifestyle of lean and obese NAFLD patients in China.

METHODS

To characterize the diet and lifestyle of lean and obese NAFLD patients, we conducted a matched case-control study that included 351 Chinese adults. General characteristics, dietary intake, and lifestyle were gathered by using a valid and reliable dietary questionnaire. We compared the dietary intake and lifestyle between lean and obese NAFLD patients.

RESULTS

All NAFLD patients had more total caloric, calorigenic nutrients (carbohydrate, fat, and protein), grain, potato, fruit, and iron with higher levels of waist circumference and overtime work but shorter sleep duration than their corresponding controls. Particularly, lean NAFLD patients consumed comparable total caloric, calorigenic nutrients, iron, sleep duration, and overtime work as obese NAFLD patients, though they consumed lower levels of grain, potato, and fruit (lean NAFLD patients vs. obese NAFLD patients: mean ± SD, g/day grain: 291.8 ± 83.8, 365.2 ± 89.0; potato: 63.5 ± 33.1, 80.4 ± 37.6; fruit: 324.3 ± 148.4, 414.0 ± 220.4; P < 0.0001).

CONCLUSION

Non-alcoholic fatty liver disease patients had higher total caloric, calorigenic nutrients, grain, potato, fruit, iron, and overtime work but shorter sleep duration. Lean NAFLD patients had comparable total caloric, calorigenic nutrients, iron, sleep duration, and overtime work as obese NAFLD patients. These features could be used to the nutritional education and therapeutic guidance for lean NAFLD patients in the future.

Nonalcoholic fatty liver disease and albuminuria: a systematic review and meta-analysis

BACKGROUND/OBJECTIVES

The relationship between nonalcoholic fatty liver disease (NAFLD) and albuminuria has been shown in many epidemiologic studies, although the results were inconsistent. This meta-analysis was conducted to summarize all available data and to estimate the risk of albuminuria among patients with NAFLD.

METHODS

Comprehensive literature review was conducted utilizing Medline and Embase database through January 2018 to identify studies that compared the risk of albuminuria among patients with NAFLD versus those without NAFLD. Effect estimates from each study were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Nineteen studies (17 cross-sectional studies and two cohort studies) with 24 804 participants fulfilled the eligibility criteria and were included in this meta-analysis. The risk of albuminuria among patients with NAFLD was significantly higher than those without NAFLD with the pooled odds ratio (OR) of 1.67 [95% confidence interval (CI): 1.32-2.11]. Subgroup analysis demonstrated the significantly increased risk of albuminuria among patients with NAFLD without diabetes with pooled OR of 2.25 (95% CI: 1.65-3.06). However, we found no significant association between albuminuria and NAFLD among diabetic patients [pooled OR 1.28 (95% CI: 0.94-1.75)].

CONCLUSION

A significantly increased risk of albuminuria among patients with NAFLD was observed in this meta-analysis. Physicians should pay more attention to the early detection and subsequent treatment of individuals with microalbuminuria especially in patients with NAFLD.

Helicobacter pylori and Risk of Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis

BACKGROUND/OBJECTIVES

Helicobacter pylori (H. pylori) is the most common chronic bacterial infection. Patients with H. pylori infection may be at an increased risk of nonalcoholic fatty liver disease (NAFLD) because of chronic inflammation and insulin resistance. Several epidemiologic studies attempting to determine this risk have yielded inconsistent results. This meta-analysis was conducted with the aims to summarize all available evidence and estimate the risk of NAFLD in patients with H. pylori infection.

METHODS

A literature search was performed using MEDLINE and EMBASE database from inception to June 2016. Studies that reported relative risks, odd ratios, or hazard ratios comparing the risk of NAFLD among patients with H. pylori infection versus without H. pylori infection were included. Pooled odds ratios and 95% confidence intervals were calculated using a random-effect, generic inverse variance method.

RESULTS

Six studies met our eligibility criteria and were included in this analysis. We found a statistically significant increased risk of NAFLD among patients with H. pylori infection with the pooled odds ratios of 1.21 (95% confidence interval, 1.07-1.37). The statistical heterogeneity was low with an I of 49%.

CONCLUSIONS

A significantly increased risk of NAFLD among patients with H. pylori infection was demonstrated in this meta-analysis. Further studies are required to clarify how this risk should be addressed in clinical practice.

Sarcopenia and risk of nonalcoholic fatty liver disease: A meta-analysis

Background/Aim

The association between sarcopenia and nonalcoholic fatty liver disease (NAFLD) has been suggested by recent epidemiological studies, although the results have been inconsistent. This meta-analysis was conducted to summarize all available data and estimate the risk of NAFLD among patients with sarcopenia.

Materials and Methods

A comprehensive literature review was conducted using MEDLINE and EMBASE databases through November 2016 to identify all studies that compared the risk of NAFLD among patients with sarcopenia versus those without sarcopenia. Effect estimates from each study were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird.

Results

Five cross-sectional studies with 27,804 participants met the eligibility criteria and were included in the meta-analysis. The risk of NAFLD in patients with sarcopenia was significantly higher than those without sarcopenia with the pooled odds ratio of 1.54 (95% confidence interval, 1.05-2.26). The statistical heterogeneity was high with an I2of 83%.

Conclusions

A significantly increased risk of NAFLD among patients with sarcopenia was observed in this study.

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.

Association between gastroesophageal reflux disease and nonalcoholic fatty liver disease: A meta-analysis

BACKGROUND/AIM

The relationship between gastroesophageal reflux disease (GERD) and nonalcoholic fatty liver disease (NAFLD) has been demonstrated in recent epidemiologic studies although the results were inconsistent. This meta-analysis was conducted to summarize all available data and to estimate the risk of NAFLD among patients with GERD.

MATERIALS AND METHODS

Comprehensive literature review was conducted using MEDLINE and EMBASE database from inception through November 2016, to identify studies that compared the risk of NAFLD among patients with GERD versus those without GERD. Effect estimates from each study were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Eight studies (four cross-sectional studies and four case-control studies) with 31,322 participants met the eligibility criteria and were included in the meta-analysis. The risk of NAFLD among patients with GERD was significantly higher than those without GERD with the pooled odds ratio of 2.07 (95% confidence interval, 1.54-2.79). The statistical heterogeneity was high with an I2 of 87%.

CONCLUSIONS

A significantly increased risk of NAFLD among patients with GERD was observed in this meta-analysis.

An Overview of Dietary Interventions and Strategies to Optimize the Management of Non-Alcoholic Fatty Liver Disease

Aim: To investigate the efficacy of lifestyle adjustment strategies as a preventive measure and/or treatment of obesity-related non-alcoholic fatty liver disease in adults. Method: A systematic review of literature through 1 July 2017 on the PubMed Database was performed. A comprehensive search was conducted using key terms, such as non-alcoholic fatty liver disease (NAFLD), combined with lifestyle intervention, diet, and exercise. All of the articles and studies obtained from the search were reviewed. Redundant literature was excluded. Results: Several types of dietary compositions and exercise techniques were identified. Most studies concluded and recommended reduction in the intake of saturated and trans fatty acids, carbohydrates, and animal-based protein, and increased intake of polyunsaturated fatty acids (PUFAs), monounsaturated fatty acids (MUFAs), plant-based proteins, antioxidants, and other nutrients was recommended. The Mediterranean and Paleo diet both seem to be promising schemes for NAFLD patients to follow. Exercise was also encouraged, but the type of exercise did not affect its efficacy as a NAFLD treatment when the duration is consistent. Conclusions: Although these different dietary strategies and exercise regimens can be adopted to treat NAFLD, current literature on the topic is limited in scope. Further research should be conducted to truly elucidate which lifestyle adjustments individually, and in combination, may facilitate patients with obesity-related NAFLD.

Increased arterial stiffness in nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Arterial function is a marker of early atherosclerotic changes and cardiovascular disease. Several studies have suggested the possible association between nonalcoholic fatty liver disease (NAFLD) and increased arterial stiffness. Thus, we conducted a systematic review and meta-analysis to better characterize this association.

PATIENTS AND METHODS

A comprehensive search of the databases of the MEDLINE and EMBASE was carried out from inception through September 2016. All observational studies that compared arterial stiffness between NAFLD patients and healthy controls were included. Arterial stiffness was measured by pulse wave velocity (PWV) and augmentation index. We calculated pooled mean difference (MD) with 95% confidence intervals (CIs) using the random-effects model.

RESULTS

Data were extracted from 12 studies involving 9351 NAFLD patients and 17 684 controls. NAFLD is significantly associated with increased arterial stiffness as determined by carotid-femoral PWV (MD=0.75 m/s, 95% CI: 0.43-1.07, I=88%), brachial-ankle PWV (MD=0.82 m/s, 95% CI: 0.57-1.07, I=92%), and augmentation index (pooled MD=2.54%, 95% CI: 0.07-5.01, I=73%) compared with healthy controls.

CONCLUSION

In conclusion, our study demonstrated a higher degree of arterial stiffness in NAFLD patients compared with controls. However, this association might be related to the higher prevalence of cardiometabolic risk factors in NAFLD patients. Further studies are needed to determine an independent association between NAFLD and arterial stiffness adjusting to cardiometabolic risks.

Hyperuricaemia and risk of nonalcoholic fatty liver disease: A meta-analysis

BACKGROUND

The association between hyperuricaemia and nonalcoholic fatty liver disease (NAFLD), one of the leading causes of cirrhosis worldwide, has been demonstrated in recent epidemiological studies. This meta-analysis was conducted to summarize all available data and to estimate the risk of NAFLD among subjects with hyperuricaemia.

METHODS

Comprehensive literature review was conducted using MEDLINE and EMBASE database through August 2016 to identify studies that compared the risk of NAFLD among subjects with hyperuricaemia vs those with normal uric acid level. Effect estimates from individual study were extracted and combined together using random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Twenty-five studies met the eligibility criteria and were included in the meta-analysis. The risk of NAFLD in subjects with hyperuricaemia was significantly higher than subjects with normal uric acid level with the pooled odds ratio (OR) of 1.97 (95% confidence interval (CI), 1.69-2.29). The heterogeneity between studies of the overall analysis was high with an I² of 87%. Subgroup analysis based on 11 studies that provided data on males subgroup and nine studies that provided data on females subgroup showed that the risk was significantly increased for both sexes with pooled OR of 1.64 (95% CI, 1.40-1.93) among males and pooled OR of 2.21 (95% CI, 1.85-2.64) among females.

CONCLUSIONS

A significantly increased risk of NAFLD among patients with hyperuricaemia was demonstrated in this meta-analysis. Further studies are required to establish the role of uric acid in the pathogenesis of NAFLD.