Short sleep duration and longer daytime napping are associated with non-alcoholic fatty liver disease in Chinese adults

Excessive Daytime Napping Increases the Risk of Non-Alcoholic Fatty Liver Disease: A Meta-Analysis and a Mendelian Randomization Study

Background

Prior research based on observations has furnished evidence that supports a connection between daytime napping and the prevalence of non-alcoholic fatty liver disease (NAFLD). Nevertheless, the question of whether this correlation is indicative of a causal link has not been definitively answered.

Methods

We used meta-analysis and Mendelian randomization (MR) to synthesize genetic and observational data. A two-sample MR analysis was conducted, leveraging 105 single-nucleotide polymorphisms (SNPs) known to be associated with daytime napping patterns. Additionally, summary-level data pertaining to NAFLD outcomes were acquired from the comprehensive UK Biobank study. Network meta-analyses were employed to investigate the relationship between excessive daytime napping and NAFLD, while subgroup was also performed.

Results

Significant associations were observed between daytime napping and NAFLD. The systematic review/meta-analysis uncovered a heightened risk of NAFLD development among individuals who engaged in daytime naps exceeding 30 minutes, when compared to those who did not nap(odds ratio [OR] = 1.32, 95% confidence interval [CI]: 1.05 to 1.66). Furthermore, MR analysis indicated that a genetic propensity towards longer daytime napping was significantly linked to an increased likelihood of NAFLD (OR = 2.26, 95% CI: 1.38 to 3.73).

Conclusion

Daytime napping has been found to be causally related to a higher risk of NAFLD. Furthermore, across all participants, napping for an average duration over 30 minutes was linked to an elevated likelihood of NAFLD.

Joint association of sleep quality and physical activity with metabolic dysfunction-associated fatty liver disease: a population-based cross-sectional study in Western China

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a growing threat leading to substantial disease burden globally. Poor sleep and physical inactivity are common in modern societies and independently associated with MAFLD, however, their joint effects on MAFLD remains unclear.

METHODS

This population-based cross-sectional study was conducted in Xinjiang Uygur Autonomous Region, China, between July 2019 and September 2021. Self-reported sleep behaviors and physical activity (PA) were assessed using validated questionnaires. The primary outcome was radiological diagnosis of MAFLD.

RESULTS

Of the 10 089 participants aged 47.0 (9.1) years (51.6% men), 3854 (38.2%) individuals had MAFLD. Poor sleep quality and physical inactivity were independently and jointly associated with an increased prevalence of MAFLD, independent of traditional risk factors (P < 0.05). Compared to subjects with guideline-recommended moderate-to-vigorous PA (MVPA) and good sleep quality, individuals with no recommended MVPA and poor sleep had the highest possibility of MAFLD (odds ratio = 2.36, 95% confidence interval: 1.81 - 3.08). Enhancing sleep quality substantially attenuated MAFLD prevalence regardless of the volume of PA, whereas, engaging in PA well above current guidelines did not adequately counteract the adverse impacts of poor sleep on MAFLD.

CONCLUSIONS

Public health awareness and strategies concurrently targeting both sleep quality and PA should be encouraged to curb the climbing prevalence of MAFLD.

Adherence to a healthy lifestyle including sleep and sedentary behaviors and risk of metabolic dysfunction-associated steatotic liver disease in Chinese adults

OBJECTIVE

Various lifestyle factors including smoking, alcohol, physical activity, sedentary behavior, diet quality, sleep behavior, and overweight have been related to metabolic dysfunction-associated steatotic liver disease (MASLD); however, their joint impact on risk of MASLD is not well known. We prospectively investigated the association between a combination of lifestyle factors and risk of MASLD.

METHODS

This prospective cohort study included 13,303 participants (mean age: 39.1 ± 11.3 years, female: 60.1%) in China. A novel healthy lifestyle score was created combining seven healthy factors: not smoking, no alcohol intake, regular physical activity, short sedentary time, healthy diet, healthy sleep, and healthy weight. Incident MASLD cases were ascertained annually by liver ultrasound and cardiometabolic risk factors. Multivariable Cox proportional hazards regression models were used to estimate the association of healthy lifestyle score with risk of MASLD.

RESULTS

Within 48,036 person-years of follow-up, 2823 participants developed MASLD. After adjusting for age, sex, education, occupation, household income, personal and family history of disease, and total energy intake, compared with participants with 0-2 healthy lifestyle factors, the multivariable hazard ratios (95% confidence interval) of MASLD were 0.81 (0.73, 0.89), 0.67 (0.61, 0.75), and 0.55 (0.49, 0.62) for healthy lifestyle score of 3, 4, and 5-7, respectively (P for trend <0.0001). Such associations were consistent across subgroup and sensitivity analyses.

CONCLUSION

Our results indicate that a higher healthy lifestyle score is associated with a lower risk of MASLD.

Age-specific difference in the temporal relationships between updated cardiovascular health construct and arterial stiffness in middle-aged and older adults

Previous studies have found that the association between modifiable risk factors and arterial stiffness varied with age. We aimed to explore the age-specific difference in the relationship between new cardiovascular health (CVH) score and arterial stiffness and further detected the age-specific temporal relationships in a prospective cohort study. During a median 4.3 years follow-up, 3757 participants were recruited in this study. A modified AHA "Life's Essential 8" construct (mLE8 with lacking information on diet habits) was used to evaluate CVH. Branchial-ankle pulse wave velocity (baPWV) was measured to assess arterial stiffness. Data were analyzed with logistic regression models, restricted cubic splines (RCS), and cross-lagged path analysis (age < 60 vs. age ≥ 60). In age-stratified analysis, moderate (OR = 2.21, 95% CI 1.11-4.43) and low (OR = 3.37, 95% CI 1.63-7.00) CVH were related with a higher incidence of elevated baPWV compared to high CVH in middle-aged adults, while this association was not detected in older adults. RCS curve showed a steeper linear association between CVH score and elevated baPWV in middle-aged adults than older individuals. In the cross-lagged path analysis, the decline in CVH score preceded the increment in arterial stiffness in middle-aged adults, but they appeared to alter simultaneously in older adults. Our study detected an age-specific difference in the relationship between mLE8 CVH score and elevated baPWV and showed that low CVH preceded alterations of baPWV in middle-aged adults, suggesting the importance of improvement in CVH during the early stage of the lifespan.

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.

Association between updated cardiovascular health construct and risks of non-alcoholic fatty liver disease

BACKGROUND AND AIMS

The American Heart Association (AHA) updated the construct and algorithm of cardiovascular health (CVH) recently. We aimed to explore the relationship between the new CVH score and the development of non-alcoholic fatty liver disease (NAFLD).

METHODS AND RESULTS

3266 adults free of NAFLD identified via ultrasound were recruited in this prospective study. A modified AHA "Life's Essential 8" (mLE8, i.e., physical activity, nicotine exposure, sleep health, body mass index, blood lipids, blood glucose, and blood pressure) were collected to evaluate the CVH score. Then participants were categorized into low, moderate, and high CVH subgroups based on overall mLE8 CVH score. According to modified Life's Simple 7 (mLS7) CVH construct, participants were also subdivided into poor, intermediate, and ideal CVH subgroups. During a median 4.3 years follow-up, 623 incident cases of NAFLD were recorded. Compared to those with high CVH, participants with low CVH (adjusted OR = 2.56, 95% CI 1.55-4.24) and moderate CVH (adjusted OR = 1.83, 95% CI 1.17-2.85) had a significantly increased risk of incident NAFLD. Participants with poor CVH (mLS7) but without low CVH (mLE8) did not show a significant elevated risk of incident NAFLD (P = 0.1053). A significant trend was found between increased changes in mLE8 score and a lower risk of NAFLD occurrence.

CONCLUSION

Our findings suggested high mLE8 CVH score was associated with a lower risk of NAFLD incidence. The new CVH construct showed a more reasonable classification of CVH status and was more robust in association with NAFLD risks compared with the original one.

Appropriate sleep duration modifying the association of insulin resistance and hepatic steatosis is varied in different status of metabolic disturbances among adults from the United States, NHANES 2017-March 2020

Steatosis is the hepatic manifestation of metabolic syndrome (MetS) and its developing is closely associated with insulin resistance. Shortened sleep has adverse effects on hepatic steatosis and the underlying mechanism remains unknown. We conceived to evaluate whether sleep duration was a lifestyle factor modifying the association between insulin resistance and hepatic steatosis and whether it was varied in different status of metabolic disturbances. We performed a cross-sectional analysis on 2264 adults of United States representing a population of 138,319,512 with MetS or pre-MetS from National Health and Nutrition Examination Survey (NHANES) 2017-March 2020. Participants underwent hepatic transient elastography and laboratory tests. The sleep duration was obtained from interviews. Results showed that insulin resistance was significantly associated with hepatic steatosis among participants with metabolic disturbances (OR = 1.85, 95% CI: 1.30-2.65). Significant moderation of sleep duration on the association between insulin resistance and hepatic steatosis was observed when sleep duration was dichotomized by 6.5- (P = 0.042) or 9.5-hour (P = 0.031). The risk of hepatic steatosis associated with insulin resistance was increased when sleep duration was ≤ 6.5 h and > 9.5 h. Furthermore, the moderation effect of 6.5-hour sleeping was only significant among participants with pre-MetS while that of 9.5-hour sleeping was only significant among participants with MetS. In conclusion, insufficient or excessive sleep increased the risk of hepatic steatosis associated with insulin resistance. Appropriate sleep duration was advocated and varied in different status of metabolic disturbances. Ensuring adequate sleep should be highlighted before MetS occurs and excessive sleep should be prevented for participants with MetS.

The impact of obstructive sleep apnea on nonalcoholic fatty liver disease

Obstructive sleep apnea (OSA) is characterized by episodic sleep state-dependent collapse of the upper airway, with consequent hypoxia, hypercapnia, and arousal from sleep. OSA contributes to multisystem damage; in severe cases, sudden cardiac death might occur. In addition to causing respiratory, cardiovascular and endocrine metabolic diseases, OSA is also closely associated with nonalcoholic fatty liver disease (NAFLD). As the prevalence of OSA and NAFLD increases rapidly, they significantly exert adverse effects on the health of human beings. The authors retrieved relevant documents on OSA and NAFLD from PubMed and Medline. This narrative review elaborates on the current knowledge of OSA and NAFLD, demonstrates the impact of OSA on NAFLD, and clarifies the underlying mechanisms of OSA in the progression of NAFLD. Although there is a lack of sufficient high-quality clinical studies to prove the causal or concomitant relationship between OSA and NAFLD, existing evidence has confirmed the effect of OSA on NAFLD. Elucidating the underlying mechanisms through which OSA impacts NAFLD would hold considerable importance in terms of both prevention and the identification of potential therapeutic targets for NAFLD.

Sleep Deprivation and Its Consequences

OBJECTIVE

This article reviews the clinical, cognitive, behavioral, and physiologic consequences of sleep deprivation in relation to general neurology practice.

LATEST DEVELOPMENTS

Despite being one of the most common sleep problems in modern society, the role of sleep deprivation is underrecognized and underestimated in clinical medicine and general neurology practice. The recognition, diagnosis, and management of sleep deprivation in neurologic practice have only recently received close attention. The consequences of sleep deprivation involve all aspects of general neurology practice, including individuals with neurologic disease, neurologists, communities, and health care systems. The identification and timely management of sleep deprivation symptoms may help to improve symptoms of underlying primary neurologic disorders.

ESSENTIAL POINTS

This article emphasizes complexities related to the identification and evaluation of sleep deprivation in general neurology practice and describes the consequences of sleep deprivation. By recognizing sleep deprivation in patients with neurologic conditions, the neurologist can provide comprehensive care and contribute to improved clinical and neurologic outcomes.

The relationship between daytime napping and obesity: a systematic review and meta-analysis

Daytime napping, a habit widely adopted globally, has an unclear association with obesity. In this study, we executed a meta-analysis to explore the relationship between daytime napping and obesity. We conducted a comprehensive search of the PubMed, Embase, Cochrane Library, Scopus, PsycINFO, and Web of Science databases for pertinent articles published up to April 2023. Random-effects models were utilized to calculate odds ratios (ORs) with 95% confidence intervals (CIs), and we assessed the heterogeneity of the included studies using the I² statistic. To explore potential sources of heterogeneity, subgroup analyses were performed. The methodological quality of the studies was evaluated using the Newcastle-Ottawa Scale (NOS), and funnel plots were employed to detect any publication bias. Sensitivity analyses were conducted by sequentially omitting each study. We conducted a meta-analysis of twelve studies that included one each from the UK and Spain, five from the USA, and five from China, totalling 170,134 participants, to probe the association between napping and obesity. The pooled analysis suggested a higher risk of obesity in individuals who nap (OR: 1.22 [1.10-1.35], p < 0.001, I² = 87%) compared to non-nappers. The meta-analysis results revealed variations in the summary ORs for studies conducted in China, Spain, the USA, and the UK. The ORs for China, Spain, the USA, and the UK were 1.05 (95% CI 0.90-1.23), 9.36 (95% CI 4.74-18.45), 1.27 (95% CI 1.10-1.47), and 1.39 (95% CI 1.32-1.47), respectively. A subgroup analysis based on age within the American population disclosed that napping in both adults and children heightened obesity incidence. A subgroup analysis based on nap duration found a significant rise in obesity occurrence when nap duration exceeded one hour, but no clear relationship emerged when nap duration was less than 1 h. In a subgroup analysis based on the definition of obesity, napping did not demonstrate a significant relationship with obesity when diagnostic criteria set obesity at a BMI of 25 or above. However, when the criteria were set at a BMI of 28 or 30 or more, napping significantly increased obesity risk. Our meta-analysis indicates a positive association between daytime napping and the risk of obesity. However, given the limited number of included studies, potential confounding factors might not have been fully addressed. Future well-designed prospective studies are required to further investigate this relationship. Large-scale studies are necessary to confirm our findings and elucidate the underlying mechanisms that drive these associations and causation.

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.

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.

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.

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.

Association between nocturnal sleep duration and the risk of hyperuricemia among Chinese government employees: A cross-sectional study

Objectives

Evidence has shown that nocturnal sleep duration is associated with the risk of hyperuricemia, yet the findings are inconsistent. Thus, we aimed at exploring the association between nocturnal sleep duration and the risk of hyperuricemia in Chinese government employees.

Methods

A total of 10,321 government employees aged 20-60 years were collected from the Cohort Study on Chronic Diseases among Government Employees in Hunan Province, China. Sleep duration was self-reported. And serum uric acid levels >420 μmol/L in men and >360 μmol/L in women were considered hyperuricemia. The association between nocturnal sleep duration and hyperuricemia risk was examined utilizing multivariate logistic regression models. To further examine the connection between nocturnal sleep duration and serum uric acid levels, multiple linear regression analyses were utilized.

Results

The prevalence of hyperuricemia was 17.2%. The results of logistic regression demonstrated that, in contrast to participants whose sleep duration was 7-8 h, those who slept for <7 h had an elevated risk of hyperuricemia (OR = 1.343, 95%CI: 1.126, 1.601). Further stratified analysis revealed that this association was still observed in those without obesity (OR = 1.365; 95%CI: 1.127, 1.655), hypertension (OR = 1.290, 95%CI: 1.054, 1.578), or diabetes mellitus (OR = 1.361, 95%CI: 1.136, 1.631). Multiple linear regression showed that shorter sleep duration (< 7 h) was positively correlated with serum uric acid levels. In comparison to individuals who slept for 7-8 h, those with sleep duration of fewer than 7 h had serum uric acid levels that were 7.231 μmol/L (95% CI: 2.875, 11.588) higher.

Conclusion

Short nocturnal sleep duration (< 7 h) was associated with a higher risk of hyperuricemia, especially in participants without obesity, hypertension, or diabetes mellitus. Besides, short nocturnal sleep duration was related to greater uric acid levels.

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.

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.

Investigating the Association Between Seven Sleep Traits and Nonalcoholic Fatty Liver Disease: Observational and Mendelian Randomization Study

Background and Aim: Aberrant sleep parameters are associated with the risk of nonalcoholic fatty liver disease (NAFLD). However, existing information is inconsistent among studies and involves reverse causation. Therefore, we aimed to investigate the observational associations and causations between sleep traits and NAFLD. Methods: We performed multivariable regression to assess observational associations of seven sleep traits (sleep duration, easiness of getting up in the morning, chronotype, nap during day, snoring, insomnia, and narcolepsy), and NAFLD in the UK Biobank (1,029 NAFLD). The Cox proportional hazards model was applied to derive hazard ratios and 95% confidence intervals (CIs). Furthermore, a bidirectional two-sample Mendelian randomization (MR) approach was used to explore the causal relationships between sleep traits and NAFLD. Results: In the multivariable regression model adjusted for potential confounders, getting up in the morning not at all easy (HR, 1.51; 95% CI, 1.27-1.78) and usually insomnia (HR, 1.46; 95% CI, 1.21-1.75) were associated with the risk of NAFLD. Furthermore, the easiness of getting up in the morning and insomnia showed a dose-response association with NAFLD (P_trend <0.05). MR analysis found consistent causal effects of NAFLD on easiness of getting up in the morning (OR, 0.995; 95% CI, 0.990-0.999; p = 0.033) and insomnia (OR, 1.006; 95% CI, 1.001-1.011; p = 0.024). These results were robust to weak instrument bias, pleiotropy, and heterogeneity. Conclusions: Findings showed consistent evidence of observational analyses and MR analyses that trouble getting up in the morning and insomnia were associated with an increased risk of NAFLD. Bidirectional MR demonstrated causal effects of NAFLD on sleep traits.

Sleep disruption in nonalcoholic fatty liver disease: What is the role of lifestyle and diet?

BACKGROUND

Patients with nonalcoholic fatty liver disease (NAFLD) have sleep disruption. The aim of this study is to understand how underlying factors such as diet, degree of liver disease and morningness-eveningness tendencies contribute to this sleep disruption.

METHODS

Patients with NAFLD were recruited from liver clinics at a University and Veterans Affairs practice. Patients with decompensated cirrhosis were excluded. Patients completed self-reported surveys to evaluate sleep disturbance using the Epworth Sleepiness Scale (ESS) and chronotype (circadian preference) using the morningness-eveningness questionnaire (MEQ). Information on occupation, physical activity and dietary intake were collected at clinic intake. Dietary intake was evaluated via food-frequency questionnaire and analyzed as individual categories or grouped on the basis of dietary composition.

RESULTS

A 54 patients completed the survey; 37% were female. Median ESS was 8 ± 4.2 and 37% of NAFLD patients were found to have sleep disturbance as defined by ESS >10. Sleep disturbance was common in NAFLD regardless of the liver disease stage. Dietary factors, including higher added sugar (P = 0.01), candy intake (P = 0.01), elevated Ferritin level (P = 0.04) and elevated platelet count (P = 0.05), were significantly associated with sleep disturbance. Chronotype, time to sleep, and duration of sleep were not associated with sleep disruption.

CONCLUSIONS

Sleep disruption is present in NAFLD regardless of underlying cirrhosis. Interventions aimed at improving dietary and lifestyle practices such as reduced sugar intake may help mitigate the risk for sleep disruption in NAFLD. Further longitudinal studies are needed to further delineate these links.

Daytime napping is associated with retinal microcirculation: a large population-based study in China

STUDY OBJECTIVES

To investigate the association between daytime napping and retinal microcirculation.

METHODS

This is a cross-sectional study from a prospective population-based cohort. 2,662 participants were recruited after quota sampling. Information on napping was collected through face-to-face interviews. Retinal vascular calibers (RVCs), including central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), and arterio-to-venous ratio (AVR), were obtained from fundus photography. Multivariate regression and restricted cubic spline curve were performed to determine the association between RVCs and daytime napping duration.

RESULTS

56.4% participants reported daytime napping regularly. Compared to no nap, daytime nap was related to higher CRAE, with nap duration of 0.5-1 h showing the most significant association. 0.5-1 h daytime nappers displayed an average of 4.18 µm (95% confidence interval [CI] 2.45-5.91, p < 0.001) wider CRAE than non-nappers after adjustment. No significant association was found between CRVE and daytime napping. Moreover, individuals with 0.5-1 h daytime napping had a lower risk for AVR reduction (odds ratio [OR] 0.70, 95% confidence interval [CI] 0.56-0.86, p = 0.001) than non-nappers. Similar association persisted in non-hypertensive population. Restricted cubic spline indicated a J-shaped relationship between AVR reduction and nap duration.

CONCLUSION

Retinal microcirculation was positively associated with self-reported 0.5-1 h daytime napping. Better indicators of retinal microcirculation were probably related to nap duration in a J-shaped manner. Also, the possibly beneficial role of 0.5-1 h daytime napping on retinal microcirculation might be independent of clinically diagnosed vascular diseases.

Circadian Clock-Controlled Checkpoints in the Pathogenesis of Complex Disease

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

Cerebrovascular alterations in NAFLD: Is it increasing our risk of Alzheimer's disease?

Non-alcoholic fatty liver disease (NAFLD) is a multisystem disease, which has been classified as an emerging epidemic not only confined to liver-related morbidity and mortality. It is also becoming apparent that NAFLD is associated with moderate cerebral dysfunction and cognitive decline. A possible link between NAFLD and Alzheimer's disease (AD) has only recently been proposed due to the multiple shared genes and pathological mechanisms contributing to the development of these conditions. Although AD is a progressive neurodegenerative disease, the exact pathophysiological mechanism remains ambiguous and similarly to NAFLD, currently available pharmacological therapies have mostly failed in clinical trials. In addition to the usual suspects (inflammation, oxidative stress, blood-brain barrier alterations and ageing) that could contribute to the NAFLD-induced development and progression of AD, changes in the vasculature, cerebral perfusion and waste clearance could be the missing link between these two diseases. Here, we review the most recent literature linking NAFLD and AD, focusing on cerebrovascular alterations and the brain's clearance system as risk factors involved in the development and progression of AD, with the aim of promoting further research using neuroimaging techniques and new mechanism-based therapeutic interventions.

Sleep duration and anthropometric indices in an Iranian population: the Fasa PERSIAN cohort study

Recent decades have seen a dramatic rise in the prevalence of obesity. While genetic factors can influence obesity, environmental factors and lifestyle may play important roles as well. Sleep can be regarded as one of these factors. This study aimed to examine sleep duration, as a potential risk factor for obesity in an Iranian population. In this cross-sectional study, the Fasa PERSIAN cohort study data was used and 10,136 subjects aged 35-70 were entered. Anthropometrics indices have been measured and the total body fat percentage (BFP) was obtained by Bio-Impedance Analysis. Also, physical activity and dietary intake have been recorded. Sleep duration was obtained and individuals categorized into two groups of "< 8" and "≥ 8" h of sleep. The mean age and sleep duration of the participants were 48.63 ± 9.57 years and 6.92 ± 1.62 h in the total population, respectively. All of the anthropometric indices were significantly higher in the "< 8 h of sleep" group than in the "≥ 8 h of sleep" group. Regarding BFP and fat mass index (FMI) the same results was seen (p-value < 0.05). Body mass index (BMI), Waist and hip circumferences (WC, HC), and waist-to-height ratio (WHtR) were in a significant negative association with night time sleep (p-value < 0.001), while these associations with daytime napping were positive (p-value < 0.001). After multi-variable adjusting, BMI, WC, HC, WHtR, and wrist circumference showed significant negative associations with 24-h sleep duration (p-value < 0.05). This study established the association between nocturnal, daytime napping, 24-h sleep duration and obesity parameters. Daytime napping was positively associated with obesity parameters and short 24-h sleep duration was associated with higher risk of overweight/obesity. These results indicate that insufficient sleep can be a screening indicator for an unhealthy lifestyle and poor health outcomes.

Association of night-time sleep and day napping with the prevalence of MOSH in young obese men

BACKGROUND

Obesity in men is also shown to be associated with reduced reproductive potential, and this particular subtype was described as male obesity-associated secondary hypogonadism (MOSH). Recent studies showing the influence of sleep disorders on testosterone levels suggested a potential role of sleep disorders in determining the development of MOSH.

OBJECTIVES

To assess the association between night-time sleep duration and day napping and the prevalence of MOSH.

MATERIALS AND METHODS

In this cross-sectional study, 226 obese male participants aged 18-30 years were enrolled. Daytime napping and night-time sleep duration data were collected using a standardized self-reported Chinese-language questionnaire. MOSH was defined as obese men (BMI ≥ 30 kg/m² ) with hypogonadal symptoms and decreased total testosterone level and/or free testosterone level, excluding other causes of hypogonadism.

RESULTS

The overall prevalence of MOSH was 48.2% in this study. An inverse association was observed between night sleep duration and the risk of prevalent MOSH. Men who reported fewer than 6 h of night-time sleep had reduced total testosterone and free testosterone levels and an increased risk of MOSH. Further regression analysis revealed that after adjustment for potential confounders, the odds ratio of MOSH for the short night-time sleep group (<6 h vs. 6-8 h) was 6.17 (p = 0.040). No significant association was observed between day napping status and prevalence of MOSH.

DISCUSSION AND CONCLUSION

Short night sleep duration was associated with an increased risk of MOSH in the young obese Chinese population. Chronic sleep curtailment has a negative effect on obese men's health in terms of hypogonadism.

Relationship between coffee consumption, sleep duration and smoking status with elastographic parameters of liver steatosis and fibrosis; controlled attenuation parameter and liver stiffness measurements

AIM

our aim was to explore the association between life habits and the controlled attenuation parameter (CAP) and liver stiffness measurements (LSM) as the surrogate markers of liver steatosis and fibrosis in a large cohort of non-alcoholic fatty liver disease (NAFLD) patients.

METHODS

In this prospective, cross-sectional study we had analysed 1998 patients with diagnosed NAFLD. Sleeping duration was categorised in three groups: short (S) (<6 hours), moderate (M) (6-8 hours) and long (L) (>8 hours) sleep duration. Coffee drinking was categorized into no (0), moderate (1-2) and frequent (≥3) consumption (in cups/day). Smoking was categorised as yes versus no.

RESULTS

Frequent coffee consumers had the lowest prevalence of obesity, hypertension, dyslipidaemia and diabetes. Furthermore, coffee non-consumers had highest values of hepatic enzymes, CAP and LSM. Moderate sleep duration was associated with lower values of CAP and LSM. Coffee consumption was associated with lower CAP in all the multivariate models (CAP unadjusted and model 1, 2 and 3), with largest effect in most frequent coffee consumers (≥3, model 3). Also, most frequent coffee consumers were associated with lower LSM in unadjusted model, model 1 and 2, while this was not the case for model 3 and those who consumed 1-2 cups of coffee per day. Reduced sleeping was confirmed as risk factor for elevated CAP in most of the models (unadjusted and model 1 and 2). Also, negative association of LSM was also confirmed in unadjusted model and model 2. Patients which slept 6-8 hours per day were mostly associated with lower CAP and LSM. Smoking status was not associated with CAP or LSM values.

CONCLUSION

Coffee consumption has beneficial effect on CAP and LSM and this effect is dose dependent since and independent of a variety of relevant confounders. We have shown that moderate sleep duration has also beneficial effect on CAP and LSM.

Sleep disorder in patients with chronic liver disease: a narrative review

Sleep disturbance is a common feature of chronic liver disease (CLD) with impact on health-related quality of life; 60-80% of patients with CLD report subjective poor sleep; frequent presentations of sleep disturbance include insomnia, reduced sleep efficiency, increased sleep latency, reduced time in rapid eye movement (REM) sleep, restless leg syndrome and excessive daytime sleepiness (EDS). Key contributors to sleep disturbance include hepatic encephalopathy (HE) and circadian rhythm imbalance due to altered melatonin metabolism. Specific conditions causing CLD, such as non-alcoholic fatty liver disease (NAFLD), chronic viral hepatitis and primary biliary cholangitis (PBC) result in different types of sleep disturbance, and the treatment of these conditions can often also lead to sleep disturbance. There are currently limited management options for sleep disturbance in CLD. Obstructive sleep apnoea (OSA) is a common condition that causes chronic intermittent hypoxia due to airway collapse during sleep. This chronic intermittent hypoxia appears to contribute to the development of NAFLD. The presence of reactive oxygen species and the overexpression of hypoxia inducible factor 1-alpha secondary to hypoxia may be responsible for the second 'hit' of the 'two-hit' hypothesis of NAFLD. Treatment of the intermittent hypoxia with continuous positive airway pressure therapy has limited efficacy against liver dysfunction. There remain many outstanding areas of investigation in the management of sleep disturbance in CLD, and of liver dysfunction in OSA.

A double-edged sword: the association of daytime napping duration and metabolism related diseases in a Chinese population

BACKGROUND

Some studies have suggested that daytime napping may increase the risk of type 2 diabetes. However, limited data have revealed the association between nap duration and other metabolic diseases. Data from the baseline survey of Lanxi Cohort Study, a population-based study of natural residents in Zhejiang Province, China, were used to investigate the relationship between nap duration and metabolic abnormalities.

METHODS

A total of 3236 participants underwent a physical examination, laboratory tests, and face to face interview. They were categorized into four groups according to nap duration. Logistic regression models were used to examine the odds ratios (ORs) of napping duration with four metabolism-related diseases. Stratified analysis was further used to explore the interaction effects of gender and age on results.

RESULTS

Compared to the no daytime napping group, people who napped during the daytime for more than 1 h were independently associated with a greater prevalence of diabetes (OR 1.56). Those who napped during the daytime within a half hour showed a lower prevalence of fatty liver, dyslipidemia, and central obesity. To be more specific, those who habitually napped during the daytime for more than 1 h exhibited an increasing prevalence of diabetes among female older than 50 years old. Those who habitually napped during the daytime within a half hour exhibited a decreasing prevalence of fatty liver and dyslipidemia among male <50 years old, and that of central obesity among female <50 years old.

CONCLUSIONS

Short daytime napping duration is associate with reduced rate of metabolism-related diseases and may protects people from negative health conditions, whereas long daytime napping duration is associate with higher prevalence of diabetes, which then can be harmful for health.

Insufficient nocturnal sleep was associated with a higher risk of fibrosis in patients with diabetes with metabolic associated fatty liver disease

BACKGROUND

Metabolic associated fatty liver disease (MAFLD) refers to metabolic dysfunction associated with fatty liver disease, and liver fibrosis stage is closely connected with liver-related and all-cause mortality. This study aimed to explore the association of sleep duration with liver fibrosis in the diabetic subgroup of the MAFLD population.

METHODS

This retrospective study analyzed 342 patients with MAFLD. Anthropometric measurements, clinical and biochemical markers, and lifestyle parameters were collected. Fibrosis was defined as fibrosis-4 ⩾1.3. Propensity score matching (PSM) was performed to match cases. Student's t-test and chi-square tests were applied for group comparisons, and binary regression models were used to explore the independent risk factors of liver fibrosis.

RESULTS

Among the 342 subjects, 87 (25.4%) were diagnosed with fibrosis and 255 (74.6%) without. Baseline characteristic comparisons showed differences in age and diabetes duration between the two groups, and adjustment was made by PSM. Ultimately, the fibrosis group and nonfibrosis group each had 87 patients. The fibrosis group had shorter duration of nocturnal sleep (6.77 ± 1.59 h) than the nonfibrosis group (7.77 ± 1.92 h, p < 0.001). More patients in the fibrosis group stayed up late at night (32.2% versus 14.9%, p < 0.01). Visceral adipose tissue (VAT) areas were larger in the fibrosis group than in the nonfibrosis group (p < 0.001). Glycemic profile, lipid profile, gamma-glutamyl transferase level, and serum uric acid level were not significantly different between the two groups. In the multivariate regression analysis, nocturnal sleep and VAT areas were independently associated with liver fibrosis, with odds ratios of 0.694 [95% confidence interval (CI) 0.551-0.875, p < 0.01] for nocturnal sleep and 1.031 (95% CI 1.014-1.048, p < 0.001) for VAT areas.

CONCLUSION

Insufficient nocturnal sleep was independently related to a higher risk of fibrosis. Sleep modification might be beneficial in promoting the health of patients with MAFLD.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

High-Coverage Targeted Lipidomics Reveals Novel Serum Lipid Predictors and Lipid Pathway Dysregulation Antecedent to Type 2 Diabetes Onset in Normoglycemic Chinese Adults

OBJECTIVE

Comprehensive assessment of serum lipidomic aberrations before type 2 diabetes mellitus (T2DM) onset has remained lacking in Han Chinese. We evaluated changes in lipid coregulation antecedent to T2DM and identified novel lipid predictors for T2DM in individuals with normal glucose regulation (NGR).

RESEARCH DESIGN AND METHODS

In the discovery study, we tested 667 baseline serum lipids in subjects with incident diabetes and propensity score-matched control subjects (n = 200) from a prospective cohort comprising 3,821 Chinese adults with NGR. In the validation study, we tested 250 lipids in subjects with incident diabetes and matched control subjects (n = 724) from a pooled validation cohort of 14,651 individuals with NGR covering five geographical regions across China. Differential correlation network analyses revealed perturbed lipid coregulation antecedent to diabetes. The predictive value of a serum lipid panel independent of serum triglycerides and 2-h postload glucose was also evaluated.

RESULTS

At the level of false-discovery rate <0.05, 38 lipids, including triacylglycerols (TAGs), lyso-phosphatidylinositols, phosphatidylcholines, polyunsaturated fatty acid (PUFA)-plasmalogen phosphatidylethanolamines (PUFA-PEps), and cholesteryl esters, were significantly associated with T2DM risk in the discovery and validation cohorts. A preliminary study found most of the lipid predictors were also significantly associated with the risk of prediabetes. Differential correlation network analysis revealed that perturbations in intraclass (i.e., non-PUFA-TAG and PUFA-TAGs) and interclass (i.e., TAGs and PUFA-PEps) lipid coregulation preexisted before diabetes onset. Our lipid panel further improved prediction of incident diabetes over conventional clinical indices.

CONCLUSIONS

These findings revealed novel changes in lipid coregulation existing before diabetes onset and expanded the current panel of serum lipid predictors for T2DM in normoglycemic Chinese individuals.

Independent Association of Physical Activity with Nonalcoholic Fatty Liver Disease and Alanine Aminotransferase Levels

The aim of the current study was to examine the independent association of physical activity with nonalcoholic fatty liver disease (NAFLD) and aminotransferases while adjusting for obesity and diet. Cross-sectional data from 32,391 participants aged ≥20 years in the Korea National Health and Nutrition Examination Surveys (KNHANES) was analyzed by logistic regression models and general linear models. Physical activity was assessed from the questionnaire by health-enhancing physical activity (HEPA). The physical activity was negatively associated with NAFLD and lean NAFLD after adjustment for multiple factors with an odds ratio of 0.7 (95% CI, 0.6–0.8) and 0.5 (95% CI, 0.4–0.7) comparing the most active (HEPA active) and the least active (inactive) participants. Among the participants with NAFLD, physical activity also showed an independent negative association with alanine aminotransferase (ALT) levels but not with aspartate aminotransferase levels. These independent associations were not observed when comparing the minimally active and inactive participants except for the risk of lean NAFLD. Physical activity is independently associated with the degree of hepatocellular injury in patients with NAFLD as well as the risk of NAFLD and lean NAFLD in the general population. Sufficiently active physical activity greater than a minimally active level may be needed to lower the risk of NAFLD and ALT levels.

Interaction Between AGTR1 and PPARγ Gene Polymorphisms on the Risk of Nonalcoholic Fatty Liver Disease

AIMS

Nonalcoholic fatty liver disease (NAFLD) is an important public health issue worldwide. Several recent studies have reported that peroxisome proliferator-activated receptor-γ (PPARγ) and angiotensin II type 1 receptor (AGTR1) variants are associated with NAFLD occurrence, but the results have been inconsistent. The aim of this study was to analyze the interactions between PPARγ and AGTR1 polymorphisms and their associations with NAFLD in Chinese adults.

METHODS

Seven single nucleotide polymorphisms (SNPs) of the PPARγ gene and 5 SNPs of the AGTR1 gene were selected and genotyped in 1591 unrelated Chinese adults. The SNPAssoc package of R was used to examine the relationships between the selected SNPs and NAFLD.

RESULTS

After adjusting the covariance, the results from the overdominant model showed that participants carrying the T/C genotype of rs2638360 in AGTR1 have a decreased risk of NAFLD compared with those with T/T-C/C genotypes (odds ratio: 0.70, 95% confidence interval: 0.49-1.00). However, our results showed that none of the selected PPARγ variants were significantly associated with the risk of NAFLD after applying a false discovery rate correction. Among the 12 selected SNPs from PPARγ and AGTR1, model-based multifactor dimensionality reduction (MB-MDR) analyses for gene-gene interactions revealed that all the models were significantly associated with the increased risk of NAFLD (p < 0.05) except the 2-, 10-, 11-, and 12-locus models. Further, among the 10 SNPs negatively associated with NAFLD, the four-locus model (rs13431696 and rs3856806 in PPARγ, and rs5182, rs1492100 in ATGR1) and the five-locus model (rs9817428, rs1175543, rs13433696, and rs2920502 in PPARγ, and rs1492100 in ATGR1) were closely related with NAFLD susceptibility (p = 0.019 and p = 0.048, respectively).

CONCLUSION

Our present study suggests that interactions among multiple AGTR1 and PPARγ polymorphisms are associated with the risk of NAFLD in the Chinese population.

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.

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 Sleep and Body Weight: A Panel Data Model Based on a Retrospective Longitudinal Cohort of Chinese Infants

The focus of this article is on sleep duration and sleep problems in infants and their association with body weight. A retrospective birth cohort of 519 infants was enrolled in a community-based study conducted in Changsha, China. Infant weight and other health-related information were collected during regular standard checkups at the Community Health Service Centers when infants were 1, 3, 6, 8, and 12 months old. The sleep duration and sleep problems of infants were assessed by maternal self-reports. Panel data model was used to evaluate the association of sleep duration and sleep problems with infant body weight. Significant relevance between self-reported sleep duration and weight of infants has been reported in the literature tested by the fixed effects model (p < 0.01). However, this study indicated that sleep problems of infants had no effect on their weight (p = 0.151), after adjusting feeding patterns and socioeconomic factors of their families. This paper argues that, as a potentially modifiable risk factor, infant sleep duration deserves more attention from their parents and families in order to prevent and control overweight or obesity in infants as well as reducing the incidence of obesity in adults.