Association between non-alcoholic fatty liver disease and obstructive sleep apnea

Interplay between gut microbiota and exosome dynamics in sleep apnea

Sleep-disordered breathing (SDB) is characterized by recurrent reductions or interruptions in airflow during sleep, termed hypopneas and apneas, respectively. SDB impairs sleep quality and is linked to substantive health issues including cardiovascular and metabolic disorders, as well as cognitive decline. Recent evidence suggests a link between gut microbiota (GM) composition and sleep apnea. Indeed, GM, a community of microorganisms residing in the gut, has emerged as a potential player in various diseases, and several studies have identified associations between sleep apnea and GM diversity along with shifts in bacterial populations. Additionally, the concept of "leaky gut," a compromised intestinal barrier with potentially increased inflammation, has emerged as another key player in the potential bidirectional relationship between GM and sleep apnea. One of the potential effectors could be extracellular vesicles (EVs) underlying gut-brain communication pathways that are relevant to sleep regulation and function. Thus, therapeutic implications afforded by targeting the GM or exosomes for sleep apnea management have surfaced as promising areas of research. This review explores current understanding of the relationship between GM, exosomes and sleep apnea, highlighting key research dynamics and potential mechanisms. A comprehensive review of the literature was conducted, focusing on studies investigating GM composition, intestinal barrier function and gut-brain communication in relation to sleep apnea.

Elastography as a non-invasive method of screening non-alcoholic fatty liver disease in the adult phenotype of paediatric obstructive sleep apnoea

PURPOSE

The high prevalence of non-alcoholic fatty liver disease (NAFLD) in obese children with obstructive sleep apnoea (OSA) calls for early non-invasive screening. The aim of this study was to use ultrasonographic liver echogenicity and elasticity to evaluate the early stages of liver injury in obese children with OSA.

METHODS

Fifty-five obese children with OSA aged 12 to 15 years were included. The control group (n = 56) consisted of healthy, non-obese children. All children underwent ultrasound examination to assess liver echogenicity using the hepatorenal index (HRI) and real-time elastography to determine the liver fibrosis index (LFI). Polysomnographic parameters, sonographic values, and clinical-biochemical assessment were statistically analysed according to OSA and its severity. Subgroup 1 was obese children with OSA and AHI < 5 and subgroup 2 was obese children with OSA and AHI ≥ 5.

RESULTS

Higher average values of HRI and LFI were recorded in the group of obese paediatric patients with OSA (mean age ± SD, 14.1 ± 2.2 year; 53% male; BMI z-score, 2.6 ± 0.35) compared to the control group (1.37 ± 0.19 vs. 1.12 ± 0.07, p < 0.001 and 1.82 ± 0.31 vs. 1.02 ± 0.27, p < 0.001). A significantly higher LFI was recorded in subgroup 2 compared to subgroup 1 (2.0 ± 0.3 vs. 1.6 ± 0.2, p < 0.001) while laboratory parameters and HRI (1.4 ± 0.2 vs. 1.4 ± 0.2, p = 0.630) did not change significantly. A strong positive correlation was found between the severity of OSA and the LFI (r = 0.454; p < 0.01).

CONCLUSIONS

These findings suggest that ultrasound elastography is a useful non-invasive screening test for OSA-related steatohepatitis in obese adolescents, but other clinical studies are needed to confirm this result.

Obstructive sleep apnea and 19 gastrointestinal diseases: a Mendelian randomization study

Background

Alterations gastrointestinal diseases (GDs) were reported in individuals with obstructive sleep apnea (OSA), however, the genetic background between OSA and GDs is still unclear.

Methods

This investigation employed Mendelian randomization (MR) analyses to evaluate the causal effect between OSA and 19 types of GDs (gastroesophageal reflux disease (GERD), ulcerative colitis, celiac disease, Crohn's disease, chronic gastritis, irritable bowel syndrome, primary biliary cholangitis, diverticular disease, gastroduodenal ulcer, acute pancreatitis, non-alcoholic fatty liver disease, primary sclerosing cholangitis, cirrhosis, calculus of bile duct, calculus of gallbladder, pancreatic cancer, gastric cancer, colorectal cancer, and esophageal cancer). The inverse-variance weighted (IVW) method was used to evaluate the main effects model of causality.

Results

This MR study suggests that OSA may play a causal role inflammation-related GDs (GERD, PIVW=5.94×10-9; gastroduodenal ulcer, PIVW=1×10-4; chronic gastritis, PIVW=0.0214; ulcerative colitis, PIVW=0.0296), and gallstones (calculi of the gallbladder, PIVW=0.0429; calculi of the bile duct, PIVW=0.0068). After accounting for obesity, type 2 diabetes, smoking, and alcohol consumption, the multivariate MR (MVMR) analysis identified that OSA is an independent risk factor for GERD, gastroduodenal ulcer, and calculus of the bile duct. The reverse MVMR analysis showed a causal effect of GERD on OSA. Besides, we did not find that the predisposition to OSA was associated with 4 cancers.

Conclusion

This MR analysis provides compelling evidence of an independent causal relationship between genetically predicted OSA and an elevated risk of inflammation-related GDs. Besides, no causal association was observed between OSA and cancers. Further studies should be carried out to verify our findings.

An international multidisciplinary consensus on pediatric metabolic dysfunction-associated fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent in children and adolescents, particularly those with obesity. NAFLD is considered a hepatic manifestation of the metabolic syndrome due to its close associations with abdominal obesity, insulin resistance, and atherogenic dyslipidemia. Experts have proposed an alternative terminology, metabolic dysfunction-associated fatty liver disease (MAFLD), to better reflect its pathophysiology. This study aimed to develop consensus statements and recommendations for pediatric MAFLD through collaboration among international experts.

METHODS

A group of 65 experts from 35 countries and six continents, including pediatricians, hepatologists, and endocrinologists, participated in a consensus development process. The process encompassed various aspects of pediatric MAFLD, including epidemiology, mechanisms, screening, and management.

FINDINGS

In round 1, we received 65 surveys from 35 countries and analyzed these results, which informed us that 73.3% of respondents agreed with 20 draft statements while 23.8% agreed somewhat. The mean percentage of agreement or somewhat agreement increased to 80.85% and 15.75%, respectively, in round 2. The final statements covered a wide range of topics related to epidemiology, pathophysiology, and strategies for screening and managing pediatric MAFLD.

CONCLUSIONS

The consensus statements and recommendations developed by an international expert panel serve to optimize clinical outcomes and improve the quality of life for children and adolescents with MAFLD. These findings emphasize the need for standardized approaches in diagnosing and treating pediatric MAFLD.

FUNDING

This work was funded by the National Natural Science Foundation of China (82070588, 82370577), the National Key R&D Program of China (2023YFA1800801), National High Level Hospital Clinical Research Funding (2022-PUMCH-C-014), the Wuxi Taihu Talent Plan (DJTD202106), and the Medical Key Discipline Program of Wuxi Health Commission (ZDXK2021007).

Hypoxia-Induced Insulin Resistance Mediates the Elevated Cardiovascular Risk in Patients with Obstructive Sleep Apnea: A Comprehensive Review

Patients with obstructive sleep apnea (OSA) experience insulin resistance and its clinical consequences, including hypertriglyceridemia, reduced high density lipoprotein-associated cholesterol (HDL-c), visceral adiposity, hepatic steatosis, increased epicardial fat thickness, essential hypertension, glucose intolerance, increased risk for type 2 diabetes, chronic kidney disease, subclinical vascular damage, and increased risk for cardiovascular events. Obesity is a major contributor to OSA. The prevalence of OSA is almost universal among patients with severe obesity undergoing bariatric surgery. However, insulin resistance and its clinical complications occur in OSA patients irrespective of general obesity (body mass index). In OSA patients, apnea episodes during sleep induce oxyhemoglobin desaturation and tissue hypoxia. Insulin resistance is an adaptive response to tissue hypoxia and develops in conditions with limited tissue oxygen supply, including healthy subjects exposed to hypobaric hypoxia (high altitude) and OSA patients. Indicators of oxyhemoglobin desaturation have been robustly and independently linked to insulin resistance and its clinical manifestations in patients with OSA. Insulin resistance mediates the elevated rate of type 2 diabetes, chronic kidney disease, and cardiovascular disease unexplained with traditional cardiovascular risk factors present in OSA patients. Pathophysiological processes underlying hypoxia-induced insulin resistance involve hypoxia inducible factor-1 upregulation and peroxisome proliferator-activated receptor-gamma (PPAR- γ ) downregulation. In human adipose tissue, PPAR- γ activity promotes glucose transport into adipocytes, lipid droplet biogenesis, and whole-body insulin sensitivity. Silencing of PPAR- γ in the adipose tissue reduces glucose uptake and fat accumulation into adipocytes and promotes insulin resistance. In conclusion, tissue hypoxia drives insulin resistance and its clinical consequences in patients with OSA, regardless of body mass index.

An autopsy case of an adult woman with Rapid-Onset Obesity with Hypoventilation, Hypothalamic, Autonomic Dysregulation, and Neuroendocrine Tumors (ROHHAD(NET)) syndrome developing nonalcoholic steatohepatitis and hepatocellular carcinoma: A case report

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is an important etiology of hepatocellular carcinoma (HCC), and there is no established therapy for this syndrome. Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, autonomic dysregulation, and neural crest tumor (ROHHAD(NET)) is an extremely rare syndrome considered to be life-threatening, with death occurring around 10 years of age. We present the oldest known autopsy case of this syndrome that developed HCC. This case provided important information on not only improving the course of this syndrome, but also understanding the natural history and therapeutic modalities of NASH and HCC.

METHODS

The patient was diagnosed with ROHHAD(NET) syndrome in childhood, and liver cirrhosis due to NASH was diagnosed at age 17. HCC was detected at age 20, and embolization and irradiation were performed. At age 21, she died from accidental acute pancreatitis and subsequent liver failure and pulmonary hemorrhage.

RESULTS

Rapid onset of obesity, hypoventilation, and hypothalamic disturbance appeared in childhood and was diagnosed as this syndrome. At age 17, liver cirrhosis due to NASH was diagnosed by liver biopsy, and at age 20, HCC was diagnosed by imaging. Transarterial chemoembolization and irradiation were performed, and the HCC was well controlled for a year.

CONCLUSION

At age 21, she died from accidental acute pancreatitis, subsequent liver failure and pulmonary hemorrhage. Autopsy revealed that the HCC was mostly necrotized. This case was valuable not only for other ROHHAD(NET) syndrome cases, but also in improving our understanding of the natural history of NASH and HCC.

Exosomes regulate SIRT3-related autophagy by delivering miR-421 to regulate macrophage polarization and participate in OSA-related NAFLD

PURPOSE

To analyze the role of and mechanism underlying obstructive sleep apnea (OSA)-derived exosomes in inducing non-alcoholic fatty liver (NAFLD).

METHODS

The role of OSA-derived exosomes was analyzed in inducing hepatocyte fat accumulation in mice models both in vivo and in vitro.

RESULTS

OSA-derived exosomes caused fat accumulation and macrophage activation in the liver tissue. These exosomes promoted fat accumulation; steatosis was more noticeable in the presence of macrophages. Macrophages could internalize OSA-derived exosomes, which promoted macrophage polarization to the M1 type. Moreover, it inhibited sirtuin-3 (SIRT3)/AMP-activated protein kinase (AMPK) and autophagy and promoted the activation of nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasomes. The use of 3-methyladenine (3-MA) to inhibit autophagy blocked NLRP3 inflammasome activation and inhibited the M1 polarization of macrophages. miR-421 targeting inhibited SIRT3 protein expression in the macrophages. miR-421 was significantly increased in OSA-derived exosomes. Additionally, miR-421 levels were increased in OSA + NAFLD mice- and patient-derived exosomes. In the liver tissues of OSA and OSA + NAFLD mice, miR-421 displayed similar co-localization with the macrophages. Intermittent hypoxia-induced hepatocytes deliver miR-421 to the macrophages via exosomes to inhibit SIRT3, thereby participating in macrophage M1 polarization. After OSA and NAFLD modeling in miR-421-/- mice, liver steatosis and M1 polarization were significantly reduced. Additionally, in the case of miR-421 knockout, the inhibitory effects of OSA-derived exosomes on SIRT3 and autophagy were significantly alleviated. Furthermore, their effects on liver steatosis and macrophage M1 polarization were significantly reduced.

CONCLUSIONS

OSA promotes the delivery of miR-421 from the hepatocytes to macrophages. Additionally, it promotes M1 polarization by regulating the SIRT3/AMPK-autophagy pathway, thereby causing NAFLD.

Mothers' Awareness of Obesity and Its Complications Among Children in the Western Region of Saudi Arabia: A Cross-Sectional Study

BACKGROUND

Awareness about obesity, its complications, and an age-appropriate, healthy, active lifestyle are essential to maintaining a healthy life. This study aimed to determine the level of awareness Saudi Arabian caregivers have regarding obesity and regular physical activity.

MATERIALS AND METHODS

In this cross-sectional study, a survey was conducted among parents in Saudi Arabia using a structured questionnaire. A convenience and snowball sampling method was employed to recruit participants from various regions of Saudi Arabia. The questionnaire assessed parents' knowledge about obesity, its complications, and healthy, active lifestyle practices. Data were analyzed using descriptive statistics, and associations between variables were examined using chi-squared tests.

RESULTS

In this study, responses from 256 moms in various Saudi Arabian locations were included in the analysis. Merely 35.5% of the participants demonstrated good knowledge about obesity and its complications. Regarding the promotion of a healthy, active lifestyle, only 11.3% of the participants were aware that kids should eat five types of vegetables and fruits daily, whereas 85% were aware that kids should have <2 hours a day of screen time, and 75.4% were aware that kids should be engaged in physical activity for at least one hour daily.

CONCLUSION

This study highlights a concerning gap in knowledge among caregivers in Saudi Arabia concerning obesity and its consequences, with merely 35.5% of participants demonstrating a good understanding of obesity and its complications. Alarmingly, only a fraction (11.3%) showed awareness of the importance of promoting a healthy, active lifestyle. These findings underscore the urgent need for enhanced awareness initiatives focused on obesity and its prevention to ensure optimal child health development, avert health issues, and strengthen positive dynamics between parents and children.

Linear Relationship between Hepatic Steatosis Index and Major Adverse Cardiovascular Events in Hypertensive Patients with Obstructive Sleep Apnea: A Real-World Cohort Study from China

Background

Hypertensive patients with obstructive sleep apnea (OSA) are at a high risk of cardiovascular disease (CVD), but assessments of CVD risk in this population are frequently constrained by the presence of comorbid medical conditions. The noninvasive and convenient hepatic steatosis index (HSI) can not only predict the degree of fatty liver degeneration but also correlates well with the severity of numerous diseases. However, the relationship between the HSI and CVD in hypertensive patients with OSA remains unclear.

Methods

This retrospective cohort study included patients aged ≥ 18 years with hypertension and a primary diagnosis of OSA and grouped them according to their baseline HSI. The primary outcome was new or recurrent major adverse cardiovascular and cerebrovascular events (MACCE), while the secondary outcomes were cardiac and cerebrovascular events. The relationship between the baseline HSI and the risk of endpoint events was evaluated using Kaplan-Meier curves, risk-factor graphs, and Cox regression models, while generalized additive models were used to identify linear relationships. The C-statistic, integrated discrimination improvement (IDI), and net reclassification index (NRI) were used to evaluate the predictive value of HSI increments for endpoint events.

Results

A total of 2467 participants were included in the analysis and separated into four groups (Q1-Q4) based on their HSI quartiles. Kaplan-Meier survival curves indicated that patients in the Q4 group had the lowest survival time. The Q4 group also showed a significantly higher risk of MACCE (HR [hazard ratio], 2.95; 95% CI [confidence interva]: 1.99-4.39; p < 0.001), cardiac events (HR, 2.80; 95% CI: 1.68-4.66; p < 0.001), and cerebrovascular events (HR, 3.21; 95% CI: 1.71-6.03; p < 0.001). The dose-response curve revealed a linear association between the HSI and the occurrence of endpoint events. For every unit increase in the HSI, the risks of MACCE, cardiac events, and cerebrovascular events increased by 43%, 38%, and 51%, respectively. The C-statistic, IDI, and NRI all indicated that the model including the HSI showed better discriminatory and classification efficacy for endpoint events in comparison with the conventional model (p < 0.05).

Conclusions

The HSI showed a linear relationship with the risk of MACCE in hypertensive OSA patients.

Pathobiology of Metabolic-Associated Fatty Liver Disease

Metabolic-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease, is highly associated with the metabolic syndrome. Given its high heterogeneity in patients along with unpredictable clinical outcomes, MAFLD is difficult to diagnose and manage. MAFLD is associated with obesity, diabetes, metabolic derangements, lipid disorders, cardiovascular disorders, sleep apnea, sarcopenia, gut dysbiosis, and sex hormone-related disorders. Identification of risk factors is imperative in understanding disease heterogeneity and clinical presentation to reliably diagnose and manage patients. The complexity of MAFLD pathobiology is discussed in this review in relation to its association with common metabolic and nonmetabolic disorders.

The effect of obstructive sleep apnea on fatty liver disease may be obscured by alcohol consumption: An ordinal logistic regression analysis

BACKGROUND

Obstructive sleep apnea (OSA) is closely associated with non-alcoholic fatty liver disease (NAFLD). The current definition of NAFLD cannot exclude the involvement of alcohol consumption in the development of fatty liver disease (FLD), but alcohol can aggravate OSA and participate in steatosis. There is limited evidence on the relationship between OSA and alcohol and its effect on FLD severity.

OBJECTIVE

To determine the effect of OSA on FLD severity based on ordinal responses, and its relationship with alcohol consumption, in order to develop strategies for the prevention and treatment of FLD.

METHODS

Patients with chief complaints of "snoring" who underwent polysomnography and abdominal ultrasound between January 2015 and October 2022 were selected. A total of 325 cases were divided into three groups according to abdominal ultrasound results: no FLD (n = 66), mild FLD (n = 116), and moderately severe FLD (n = 143) group. Patients were also categorized into alcoholic and nonalcoholic groups. Univariate analysis was used to examine the correlation between OSA and FLD severity. Multivariate ordinal logistic regression analysis was further used to identify the determinants of FLD severity and differences between the alcoholic and nonalcoholic groups.

RESULTS

A higher proportion of moderately severe FLD was observed in the group with an apnea/hypopnea index (AHI) > 30 compared to the AHI<15 group in all participants and in the nonalcoholic population (all p < 0.05). There was no significant difference among these groups in the alcoholic population. Ordinal logistic regression analysis found that in all participants, age [OR = 0.966(0.947-0.986)], BMI [OR = 1.293 (1.205-1.394)], diabetes mellitus [OR = 1.932(1.132-3.343)], hyperlipidemia [OR = 2.432(1.355-4.464)], severe OSA [OR = 2.36(1.315-4.259)] (all p < 0.05) were the independent risk factors for more severe FLD. However, different risk factors applied according to alcohol consumption. In addition to age and BMI, the independent risk factors for the alcoholic group also included diabetes mellitus [OR = 3.323(1.494-7.834)] while in the non-alcoholic group risk factors included hyperlipidemia [OR = 4.094(1.639-11.137)], and severe OSA[OR = 2.956(1.334-6.664)] (all p < 0.05).

CONCLUSION

Severe OSA is an independent determinant for developing more severe NAFLD in nonalcoholic population, and alcohol consumption may obscure the effect of OSA on the progression of FLD.

Risk factors of nonalcoholic fatty liver disease in healthy women

We investigated the risk factors of nonalcoholic fatty liver disease (NAFLD) in healthy women. This is a cross-sectional study. Healthy women who underwent physical examination were enrolled. Their basic information and medical history [including age, height, weight, body mass index (BMI)], abdominal ultrasound results, and, serological indexes [including white blood cells, platelet count, fasting blood glucose, triglyceride (TG), total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDLC), uric acid (UA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and glutamyl transpeptidase] were collected. Univariate and multivariate regression analysis was carried out to screen the risk factors of NAFLD. ALT/AST ratio, and BMI were significantly independent risk factors for the occurrence and severity of NAFLD. In addition, TG/HDLC ratio, and UA level also had significant independent correlation with NAFLD. ALT/AST ratio, BMI, TG/HDLC ratio, and UA are independent risk factors for the occurrence and severity of NAFLD. It is suggested that obesity, hyperlipidemia, hyperuricemia and high transaminase value are closely related to NAFLD. People with such conditions should pay more attention to early screening of NAFLD to avoid disease aggravation and the occurrence and development of other complications. In clinical practice, ALT/AST, BMI, TG/HDLC, and UA level should be closely monitored, so as to facilitate the follow-up management of the disease.

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

INTRODUCTION AND OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Insulin Resistance, but Not Obstructive Sleep Apnea Is Associated with Hepatic Steatosis in Chinese Patients with Severe Obesity

INTRODUCTION

Severe obesity is often present with non-alcoholic fatty liver disease (NAFLD) and obstructive sleep apnea (OSA). Emerging researches suggest OSA plays an important role in NAFLD development and progression while the relationship between OSA and NAFLD is still conflicting. The interaction of OSA and NAFLD should be further evaluated as obesity surges. The purpose of this study was to assess the prevalence of OSA and NAFLD in patients with obesity undergoing bariatric surgery and evaluate the association between OSA and severity of NAFLD.

METHODS

141 patients with severe obesity undergoing preoperative polysomnography and intraoperative liver biopsy during bariatric surgery were investigated. Clinical, anthropometric variables, liver enzymes, fasting blood glucose, fasting serum insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) were measured. The severity of NAFLD was assessed by degree of steatosis, ballooning, intralobular inflammation, and NAFLD activity score. The diagnosis and severity assessment of OSA was based on an apnea/hypopnea index (AHI).

RESULTS

OSA was diagnosed in 127 (90.07%), NAFLD in 124 (87.94%), and non-alcoholic steatohepatitis in 72 (51.06%) patients. There was a statistical difference in BMI, waist circumstance, neck circumstance, high-density lipoprotein cholesterol, fasting insulin, and HOMA-IR among the three groups divided by the severity of AHI. In addition, the distribution of hepatic steatosis grades among the three groups was statistically different (p = 0.025). AHI was significantly associated with HOMA-IR and hepatic steatosis when assessing the association between OSA parameters and liver histology in NAFLD (p < 0.05). Patients with steatosis of grades 1-3 had significantly elevated aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase, triglycerides, fasting insulin, fasting glucose, HOMA-IR, and AHI compared with the patients with steatosis of grade 0. In a multivariable logistic analysis, the positive association between AHI and hepatic steatosis attenuated after adjusting for HOMA-IR.

CONCLUSION

Prevalence of OSA and NAFLD was high in patients with obesity eligible for bariatric procedures. HOMA-IR, but not AHI, was an independent risk factor for hepatic steatosis in this population.

Risk factors in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease, with a global prevalence estimated at approximately 25%. NAFLD is also the leading cause of liver cirrhosis, hepatocellular carcinoma, and death. Additionally, the risk of cardiovascular disease increases with greater NAFLD severity. The liver- and cardiovascular disease-related mortality incident rate ratios among the NAFLD population were 0.77 and 4.79 per 1,000 person-years, respectively. We intend to discuss the risk factors associated with NAFLD in terms of development and progression. Obesity or higher body mass index is closely associated with NAFLD in a dose-dependent manner, but growing evidence suggests that central obesity plays a more important role in the development of NAFLD. Saturated fat and fructose have been reported to be closely related to NAFLD. Fructose intake promotes lipogenesis and impairs mitochondria fat oxidation. The presence of type 2 diabetes is the most powerful predictive risk factor for hepatic fibrosis in patients with NAFLD. Single nucleotide polymorphism is not only associated with the prevalence of NAFLD but also associated with increased liver disease mortality. Obstructive sleep apnea, intestinal dysbiosis, and sarcopenia are associated with the development of NAFLD.

The role of platelet-related parameters for the prediction of NAFLD in OSAHS patients

PURPOSE

As the detection of non-alcoholic fatty liver disease (NAFLD) is imperative for the prevention of its complications, we aimed to explore the predictive value of platelet to lymphocyte count ratio (PLR) and white blood cell count to mean platelet volume ratio (WBC/MPV) in relation to the occurrence of NAFLD among patients with obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHODS

This was a cross-sectional study consisting of 351 patients with OSAHS (279 with and 72 without NAFLD). The logistic regression analysis was performed to estimate associations between PLR, WBC/MPV, and NAFLD. Finally, the receiver operating characteristic curve (ROC curve) was used to analyze the efficacy of PLR and WBC/MPV in NAFLD prediction.

RESULTS

Compared to the OSAHS-only group, there was a rising trend in AHI and TS90% in the OSAHS + NAFLD group. And the logistic regression analysis identified average oxygen saturation (MaSO₂), WBC/MPV and PLR as predicted factors (odds ratio [OR] = 1.134, P = 0.031; OR = 7.559, P = 0.018, OR = 0.980, P < 0.001, respectively) for NAFLD in OSAHS patients. Moreover, compared with WBC/MPV, PLR, FLI, and APRI, a combination of WBC/MPV and PLR presented the largest AUC for the detection of NAFLD in BMI < 28 kg/m² (0.753, 95% CI 0.684-0.822), and in age ≥ 60 years subgroup (0.786, 95% CI 0.692-0.880) in ROC analysis. Meanwhile, a combination of WBC/MPV and PLR presented the second largest AUC for the detection of NAFLD in all subjects (0.743, 95% CI 0.708-0.831), as well as in the age < 60 years subgroup (0.729, 95% CI 0.652-0.806), only ranked after FLI, suggesting the combination of WBC/MPV and PLR has a good predictive value for NAFLD in OSAHS patients.

CONCLUSION

We confirmed that the levels of WBC/MPV, PLR, and MaSO₂ were closely related to the occurrence of NAFLD among OSAHS patients. Furthermore, our results highlighted the clinical combination of WBC/MPV and PLR levels could act as a simple and effective biomarker for screening NAFLD in patients with OSAHS.

Management of non-alcoholic fatty liver disease patients with sleep apnea syndrome

Nonalcoholic fatty liver disease (NAFLD) is strongly associated with sleep apnea syndrome (SAS). Many NAFLD patients have SAS, and obstructive sleep apnea hypopnea syndrome is also considered to be an independent risk factor for NAFLD, as it contributes to the progression of NAFLD via oxidative stress, lipid peroxidation, inflammation, and insulin resistance. This review aims to provide some recommendations for the management of NAFLD patients with SAS, including diet, exercise, weight loss, and continuous positive airway pressure. This review also highlights the importance of effective strategies in NAFLD prevention and treatment.

Liver Fibrosis Marker and Postoperative Mortality in Patients Without Overt Liver Disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) can progress to advanced fibrosis, which, in the nonsurgical population, is associated with poor hepatic and extrahepatic outcomes. Despite its high prevalence, NAFLD and related liver fibrosis may be overlooked during the preoperative evaluation, and the role of liver fibrosis as an independent risk factor for surgical-related mortality has yet to be tested. The aim of this study was to assess whether fibrosis-4 (FIB-4), which consists of age, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and platelets, a validated marker of liver fibrosis, is associated with postoperative mortality in the general surgical population.

METHODS

A historical cohort of patients undergoing general anesthesia at an academic medical center between 2014 and 2018 was analyzed. Exclusion criteria included known liver disease, acute liver disease or hepatic failure, and alcohol use disorder. FIB-4 score was categorized into 3 validated predefined categories: FIB-4 ≤1.3, ruling out advanced fibrosis; >1.3 and <2.67, inconclusive; and ≥2.67, suggesting advanced fibrosis. The primary analytic method was propensity score matching (FIB-4 was dichotomized to indicate advanced fibrosis), and a secondary analysis included a multivariable logistic regression.

RESULTS

Of 19,861 included subjects, 1995 (10%) had advanced fibrosis per FIB-4 criteria. Mortality occurred intraoperatively in 15 patients (0.1%), during hospitalization in 272 patients (1.4%), and within 30 days of surgery in 417 patients (2.1%). FIB-4 ≥2.67 was associated with increased intraoperative mortality (odds ratio [OR], 3.63; 95% confidence interval [CI], 1.25-10.58), mortality during hospitalization (OR, 3.14; 95% CI, 2.37-4.16), and within 30 days from surgery (OR, 2.46; 95% CI, 1.95-3.10), after adjusting for other risk factors. FIB-4 was related to increased mortality in a dose-dependent manner for the 3 FIB-4 categories ≤1.3 (reference), >1.3 and <2.67, and ≥2.67, respectively; during hospitalization (OR, 1.89; 95% CI, 1.34-2.65 and OR, 4.70; 95% CI, 3.27-6.76) and within 30 days from surgery (OR, 1.77; 95% CI, 1.36-2.31 and OR, 3.55; 95% CI, 2.65-4.77). In a 1:1 propensity-matched sample (N = 1994 per group), the differences in mortality remained. Comparing the FIB-4 ≥2.67 versus the FIB-4 <2.67 groups, respectively, mortality during hospitalization was 5.1% vs 2.2% (OR, 2.70; 95% CI, 1.81-4.02), and 30-day mortality was 6.6% vs 3.4% (OR, 2.26; 95% CI, 1.62-3.14).

CONCLUSIONS

A simple liver fibrosis marker is strongly associated with perioperative mortality in a population without apparent liver disease, and may aid in future surgical risk stratification and preoperative optimization.

The impact of non-alcoholic fatty liver disease on sleep apnea in healthy adults: A nationwide study of Korea

Background & aims

Nonalcoholic fatty liver disease (NAFLD) is one of the most common health problems worldwide. Sleep apnea (SA) causes cardiovascular and metabolic problems, as well as a significant socioeconomic burden. Although several studies have found that SA causes NAFLD, there is no evidence that NAFLD causes SA. The goal of this study was to look at the relationship between NAFLD and SA in realworld data.

Methods

We evaluated 334,334 healthy individuals without comorbidities who underwent National Health checkups in the Republic of Korea from 2009 to 2014. NAFLD was defined by a surrogate marker, the fatty liver index (FLI). The association between FLI and SA was analyzed using multivariate Cox proportional hazards regression models.

Results

During a median followup of 5.3 years, 1,351 patients (0.4%) were newly diagnosed with SA. Subjects were categorized into quartile groups according to FLI (range: Q1, 0–4.9; Q2, 5.0–12.5; Q3, 12.6–31.0; Q4, >31.0). Subjects with higher FLIs had a significantly higher cumulative incidence of SA than those with lower FLIs (Q1, 119 [0.1%]; Q2, 210 [0.3%]; Q3, 339 [0.4%]; Q4, 683 [0.8%]; P < 0.001). Adjusted hazard ratios (HRs) revealed that a higher FLI was independently associated with an increased risk of SA (HR between Q4 and Q1, 4.03; 95% confidence interval, 3.22–5.05; P < 0.001). This association remained statistically significant after further adjustment for Body mass index (BMI) (HR between Q4 and Q1, 2.19; 95% confidence interval, 1.69–2.83; P < 0.001). FLI was significantly associated with an increased risk of new-onset SA regardless of baseline characteristics.

Conclusion

This study demonstrated that NAFLD, assessed by FLI, was independently associated with increased risk for SA in the healthy Korean population.

Metabolic Syndrome but Not Fatty Liver-Associated Genetic Variants Correlates with Glomerular Renal Function Decline in Patients with Non-Alcoholic Fatty Liver Disease

The association between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) has been extensively demonstrated. Recent studies have focused attention on the role of patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 polymorphism in the association between NAFLD and CKD in non-metabolic adults and children, but the genetic impact on NAFLD-CKD association is still a matter of debate. The aim of the study was to investigate the impact of PNPLA3, transmembrane 6 superfamily member 2 (TM6SF2), membrane-bound O-acyltransferase domain containing 7 (MBOAT7) and glucokinase regulatory protein (GCKR) gene variants rather than metabolic syndrome features on renal function in a large population of NAFLD patients. The present study is a post hoc analysis of the Plinio Study (ClinicalTrials.gov: NCT04036357). PNPLA3, TM6SF2, MBOAT7 and GCKR genes were analyzed by using real-time PCR with TaqMan probes. Glomerular filtration rate (GFR) was estimated with CKD-EPI. We analyzed 538 NAFLD; 47.2% had GFR < 90 mL/min/1.73 m2 while 5.9% had GFR < 60 mL/min/1.73 m2. The distribution of genotypes was superimposable according to GFR cut-offs. Results from the multivariable regression model did not show any correlation between genotypes and renal function. Conversely, metabolic syndrome was highly associated with GFR < 90 mL/min/1.73 m2 (odds ratio (OR): 1.58 [1.10−2.28]) and arterial hypertension with GFR < 60 mL/min/1.73 m2 (OR: 1.50 [1.05−2.14]). In conclusion, the association between NAFLD and CKD might be related to the shared metabolic risk factors rather than the genetic NAFLD background.

You Cannot Hit Snooze on OSA: Sequelae of Pediatric Obstructive Sleep Apnea

Pediatric obstructive sleep apnea (OSA) has been shown to not only affect the quality of sleep, but also overall health in general. Untreated or inadequately treated OSA can lead to long-term sequelae involving cardiovascular, endothelial, metabolic, endocrine, neurocognitive, and psychological consequences. The physiological effects of pediatric OSA eventually become pathological. As the complex effects of pediatric OSA are discovered, they must be identified early so that healthcare providers can be better equipped to treat and even prevent them. Ultimately, adequate management of OSA improves overall quality of life.

Hypercoagulability in Patients with Non-Alcoholic Fatty Liver Disease (NAFLD): Causes and Consequences

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and it is anticipated that it could become even more prevalent in parallel with an increase in the incidence of metabolic diseases closely related to NAFLD, such as obesity, type II diabetes, dyslipidemia, and arterial hypertension. In addition to liver impairment, NAFLD is associated with cardiovascular diseases. Fibrosis, atherosclerosis, and venous thrombosis are basically the pathogenic mechanisms behind these clinical manifestations, and all are plausibly associated with hypercoagulability that may, in turn, develop because of an imbalance of pro- vs. anticoagulants and the presence of such procoagulant molecular species as microvesicles, neutrophil extracellular traps (NETs), and inflammation. The assessment of hypercoagulability by means of thrombin generation is a global procedure that mimics the coagulation process occurring in vivo much better than any other coagulation test, and is considered to be the best candidate laboratory tool for assessing, with a single procedure, the balance of coagulation in NAFLD. In addition to defining the state of hypercoagulability, the assessment of thrombin generation could also be used to investigate, in clinical trials, the best approach (therapeutic and/or lifestyle changes) for minimizing hypercoagulability and, hence, the risk of cardiovascular diseases, progression to atherosclerosis, and liver fibrosis in patients with NAFLD.

Changing Effects of Minimally Invasive Surgical Intervention on ALT, AST, and UA in Patients with Obstructive Sleep Apnea-Hypopnea Syndrome

BACKGROUND

This study aims at exploring the effect of obstructive sleep apnea-hypopnea syndrome (OSAHS) on the liver and kidney function indexes of patients and analyze the changes in these indexes after minimally invasive surgery.

METHOD

Patients with OSAHS (n = 51) who were diagnosed via polysomnography (PSG) and received minimally invasive surgery in the sleep disorders diagnosis and treatment center of the West China Fourth Hospital of Sichuan University from January 2017 to January 2019 were selected as test subjects and placed in the OSAHS group. At the same time, 79 healthy people with no snoring or breathing difficulties were selected from the medical examination center of the hospital as the control group (tested as normal by PSG). These two groups were used to compare the differences in the related indexes of serum liver and kidney function and evaluate the changes in sleep monitoring and related liver and kidney function indexes in patients with OSAHS after minimally invasive surgery.

RESULTS

The alanine aminotransferase (ALT), aspartate aminotransferase (AST), and uric acid (UA) levels were higher in the OSAHS group (48.98 ± 36.34, 28.88 ± 14.80, and 422.30 ± 98.65, respectively) than in the control group (21.91 ± 11.61, 22.18 ± 6.19, and 330.49 ± 64.45 and t = 6.514, 3.549, and 6.373, respectively; p < 0.05). Of the patients with OSAHS, 17 were followed up for one year. After minimally invasive surgery, ALT decreased from 44.29 ± 20.61 to 26.47 ± 9.91 (t = 4.395), AST decreased from 27.71 ± 8.32 to 21.82 ± 4.81 (t = 3.673), and UA decreased from 397.35 ± 92.14 umol/L to 362.94 ± 106.76 umol/L (t = 2.580), and these differences were statistically significant (p < 0.05).The changes in ALT (r = -0.635) and AST (r = -0.504) were related to the difference in the lowest blood oxygen saturation (p < 0.05), and the change in UA was related to the difference in the apnea-hypopnea index (r = -0.532, p < 0.05).

CONCLUSION

There are some abnormalities in liver- and kidney-function-related indexes in patients with OSAHS, and minimally invasive surgery can help to improve liver and kidney function in these patients.

Assessment of Sleep among Patients with Chronic Liver Disease: Association with Quality of Life

The present study aims to assess the sleep characteristics and health-related quality of life (HRQOL) among patients with chronic liver diseases (CLDs), as well as the relationship between them. We conducted a prospective cross-sectional study, over a period of eight months, on patients with CLDs. Sleep was assessed by subjective tools (self-reported validated questionnaires), semi-objective methods (actigraphy), and HRQOL by using the 36-Item Short Form Survey (SF-36) and Chronic Liver Disease Questionnaire (CLDQ). The results indicated that 48.21% of patients with CLDs had a mean Pittsburgh Sleep Quality Index (PSQI) score higher than five, suggestive of poor sleep; 39.29% of patients had a mean Epworth Sleepiness Scale (ESS) score ≥11, indicative of daytime sleepiness. Actigraphy monitoring showed that patients with cirrhosis had significantly more delayed bedtime hours and get-up hours, more awakenings, and more reduced sleep efficacy when compared to pre-cirrhotics. The CLDQ and SF-36 questionnaire scores were significantly lower in cirrhotics compared to pre-cirrhotics within each domain. Moreover, we identified significant correlations between the variables from each questionnaire, referring to HRQOL and sleep parameters. In conclusion, sleep disturbances are commonly encountered among patients with CLDs and are associated with impaired HRQOL. This is the first study in Romania that assesses sleep by actigraphy in a cohort of patients with different stages of CLD.

Characteristics of Patients with Obstructive Sleep Apnea at High Risk for Cardiovascular Disease

Background and Objectives: To evaluate the influence of obstructive sleep apnea (OSA)-related symptoms on prevalent cardiovascular disease (CVD) in a large clinical population of patients. Materials and Methods: A total of 2127 patients (mean age 55 years, 24% women) underwent diagnostic polysomnography and were evaluated using the Epworth sleepiness scale (ESS), the Athens Insomnia Scale (AIS), and the Beck Depression Inventory (BDI). We investigated the predictive value of OSA-associated symptoms for prevalent cardiovascular disease, after adjustment for relevant confounding factors including age, obesity, and co-morbidities. Results: Patients with OSA and CVD were older and had a higher Body Mass Index (BMI); the percentage of obese patients was also higher (83% vs. 70%, p < 0001). They also had greater neck, waist, and hip circumferences and a higher waist-to-hip ratio. Excessive daytime sleepiness (ESS ≥ 10) [odds ratio (95% CI) 1.112 (0.708–1.748), p = 0.64], insomnia symptoms (AIS ≥ 6) [odds ratio (95% CI) 0.748 (0.473–1.184), p = 0.21], frequent awakenings [odds ratio (95% CI) 1.599 (1.019–2.508), p = 0.06], and nocturia [odds ratio (95% CI) 1.359 (0.919–2.009), p = 0.124] were not associated with CVD after adjustment for the previous confounders. On the other hand, depressive symptoms (BDI ≥ 10) independently predicted prevalent CVD [odds ratio (95% CI) 1.476 (1.154–1.887), p = 0.002]. Further analysis in subgroups stratified by age, BMI, and gender demonstrated that depressive symptoms predicted prevalent CVD but only in the subgroup of younger (age group < 60 years), obese (BMI group ≥ 30), and male (OR = 1.959, 95% CI = 1.209–3.175, p = 0.006) OSA patients. Conclusions: OSA patients with CVD were more likely to complain of less typical OSA symptoms and depressive symptoms compared to patients without CVD in this large clinical patient cohort, supportingthecomplexity and heterogeneityof OSA.

Intermittent hypoxia aggravates non-alcoholic fatty liver disease via RIPK3-dependent necroptosis-modulated Nrf2/NFκB signaling pathway

AIMS

Hepatocyte necroptosis is a critical event in the progression of non-alcoholic fatty liver disease (NAFLD). Obstructive sleep apnea hypopnea syndrome (OSAHS) and chronic intermittent hypoxia (CIH) may be linked with the pathogenesis and the severity of NAFLD. However, the potential role of necroptosis in OSAHS-associated NAFLD has not been evaluated. The present study investigated whether IH could affect NAFLD progression through promoting receptor-interacting protein kinase-3 (RIPK3)-dependent necroptosis, oxidative stress, and inflammatory response, and further elucidated the underlying molecular mechanisms.

MAIN METHODS

LO2 cells were treated with palmitic acid (PA) and subjected to IH, and necroptosis, oxidative stress, and inflammation were assessed. The high-fat choline-deficient (HFCD)-fed mouse model was also used to assess the effects of CIH in experimental NAFLD in vivo.

KEY FINDINGS

In this study, we found that RIPK3-mediated necroptosis was activated both in the PA plus IH-treated LO2 cells and liver of HFCD/CIH mice, and which could trigger oxidative stress and inflammatory response by decreasing Nrf2 and increasing p-P65. RIPK3 downregulation significantly reduced hepatocyte necroptosis, and ameliorated oxidative stress and inflammation through modulating Nrf2/NFκB pathway in vitro and vivo. Similarly, pretreatment with TBHQ, an activator of Nrf2, effectively blocked the generation of oxidative productions and inflammatory cytokines. In addition, RIPK3 inhibitor GSK-872 or TBHQ administration obviously alleviated hepatic injury, including histology, transaminase activities, and triglyceride contents in vivo.

SIGNIFICANCE

IH aggravates NAFLD via RIPK3-dependent necroptosis-modulated Nrf2/NFκB signaling pathway, and which should be considered as a potential therapeutic strategy for the treatment of NAFLD with OSASH.

Association of Obstructive Sleep Apnea with Nocturnal Hypoxemia in Metabolic-Associated Fatty Liver Disease Patients: A Cross-sectional Analysis of Record-based Data

Rationale:

Obstructive sleep apnea (OSA) is often seen among obese individuals and the obesity has a linear association with MAFLD. The contribution of chronic intermittent nocturnal hypoxia of OSA and association of MAFLD with OSA is an unmet need. The present study aimed to determine the etiology, impact and association of OSA severity and nocturnal hypoxemia among patients ofChronic liver disease (CLD).

Methods:

In this study, analysis of the medical records and clinical details of the patients of CLD who had undergone polysomnography were analyzed after appropriate inclusion in study as per inclusion and exclusion criteria. After assessing the eligibility criteria, a total of 78 patients were included in the final analysis. Nocturnal hypoxemia was gauged from the baseline oxygen saturation record of study. Presence and severity of OSA were graded as per American Academy of Sleep Medicine (AASM) criteria. The primary objective of the study was to determine the association between OSA severity and nocturnal hypoxemia to the presence of Non-alcoholic Fatty Liver Disease (NAFLD). Secondary objectives were to assess the association of OSA severity and extent of nocturnal hypoxemia to the BMI and to determine the proportions of NAFLD subjects with OSA.

Results:

A total of 78 patients were screened, of which only 11 (14.1%) were female. Out of these, 56 (71.8%) were classified to MAFLD group while 22 (28.2%) were to the non-MAFLD group. The patients in MAFLD group with mean age of 56.02 years were older as compared to non-MAFLD with mean age of 51.05 years but that was not statistically different. Patients were categorized into MAFLD (n = 56) and non-MAFLD, representing other etiologies of CLD (n = 22; ethanol, chronic Hepatitis B virus (HBV), chronic Hepatitis C virus (HCV), cryptogenic, Non-cirrhosis portal fibrosis (NCPF), Primary sclerosing cholangitis (PSC), Autoimmune hepatitis (AIH), sarcoidosis, Wilson's disease). The mean BMI was significantly higher in MAFLD in comparison to non-MAFLD (34.51 ± 8.79 vs. 25.47 ± 5.75; P = 0.000) and also the median AHI of MAFLD group was significantly higher than the non-MAFLD 4.95 {(1.85, 25.47) vs. 0.85 (0.30, 2.72) (P value < 0.000)} [Table 1]. Among the desaturation indices, the number of desaturations >3% {median of 122.50 (75.00, 241.25) vs. 63.00 (13.75, 158.00), P value 0.009} and average desaturation {mean of (5.04 ± 2.16) vs. (3.78 ± 1.226)%, P value 0.002} were significantly higher in MAFLD versus non-MAFLD group [Table 2]. The AHI and all desaturation parameters, although not statistically significant, were worst in Child B [Table 3].

Conclusion:

MAFLD patients have higher prevalence and greater severity of OSA and worse nocturnal desaturation parameters as compared to non-MAFLD patients. OSA is independent of obesity among patients of CLD, but prevalent among NAFLD group. Further prospective studies are needed among MAFLD and OSA patients to elucidate the mechanism linking pathophysiology of OSA-MAFLD and guide therapy.

Nonalcoholic Fatty Liver Disease and the Kidney: A Review

Nonalcoholic fatty liver disease (NAFLD) is associated with several extrahepatic manifestations such as cardiovascular disease and sleep apnea. Furthermore, NAFLD is reported to be associated with an increased risk of incident chronic kidney disease (CKD). Inflammation and oxidative stress are suggested to be the key factors involved in the inflammatory mechanisms and pathways linking NAFLD to CKD and are responsible for both the pathogenesis and the progression of CKD in NAFLD patients. This review aims to provide a more comprehensive overview of the association between CKD and NAFLD, also considering the effect of increasing severity of NAFLD. A PubMed search was conducted using the terms "non-alcoholic fatty liver disease AND kidney". In total, 537 articles were retrieved in the last five years and 12 articles were included in the qualitative analysis. Our results showed that CKD developed more frequently in NAFLD patients compared to those without NAFLD. This association persisted after adjustment for traditional risk factors and according to the severity of NAFLD. Therefore, patients with NAFLD should be considered at high risk of CKD. Intensive multidisciplinary surveillance over time is needed, where hepatologists and nephrologists must act together for better and earlier treatment of NAFLD patients.

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.

Dietary Interventions in Patients With Non-alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Background: With no approved pharmacotherapy to date, the present therapeutic cornerstone for non-alcoholic fatty liver diseases (NAFLD) is a lifestyle intervention. Guidelines endorse weight loss through dietary modifications, physical exercise, or both. However, no consensus exists on the optimal dietary treatment. Objectives: The aim of our systematic review and meta-analysis was to summarize and assess the evidence for applied types of dietary interventions on the liver and metabolic outcomes in patients with NAFLD, aside from any effects of exercise intervention. Methods: This systematic review was conducted according to the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) statement guidelines. The search was conducted in PubMed, Scopus, and Cochrane databases in February 2020. Included were only dietary interventions without exercise. This study was registered at PROSPERO: CRD42020203573. Results: Eight randomized controlled trials, seven with endpoint reduction of hepatic steatosis, one with an assessment of endpoint fibrosis, were included in this systematic review, five of which were included in the meta-analysis. Mediterranean dietary interventions without energy restriction (n = 3) showed significant reduction of intrahepatic lipid content (IHL) (SDM: -0.57, 95% CI: -1.04, -0.10), but there was no significant change in alanine transaminase (ALT) (SDM: 0.59, 95% CI: -0.5, -1.68). Hypocaloric dietary interventions with foods high in unsaturated fatty acids (n = 2) led to a significant decrease in ALT (SDM: -1.09, 95% CI: -1.49, -0.69) and aspartate aminotransferase (AST) (SDM: -0.75, 95% CI: -1.27, 0.23); yet effects on steatosis could not be aggregated due to different assessment techniques. Mediterranean diet did not lead to significant changes in concentrations of gamma-glutamyl transpeptidase (γGT), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), fasting glucose or insulin, or homeostatic assessment for insulin resistance. Conclusions: In patients with NAFLD, Mediterranean and hypocaloric dietary interventions favoring unsaturated fatty acids result in improvements in IHL and transaminases. Since many dietary intervention studies are combined with exercise interventions and there is a paucity of ample-sized studies examining dietary interventions on the more advanced and clinically relevant stages of NAFLD, that is active and fibrotic NASH, with multiparametric imaging and liver histology as outcome measures, the optimal dietary invention in NAFLD remains to be defined.

Evaluation and management of extrahepatic manifestations of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a multisystemic disease and a rapidly growing cause of chronic liver disease in children and adults worldwide. Diagnosis and management of extrahepatic manifestations of NAFLD, including cardiovascular disease (CVD), type 2 diabetes mellitus, metabolic syndrome, chronic kidney disease, obstructive sleep apnea, polycystic ovarian syndrome, hypothyroidism, psoriasis, and extrahepatic malignancy are crucial for the treatment of patients with NAFLD. The leading cause of death in NAFLD is primarily from CVD, followed by liver-related mortality, extrahepatic cancer, liver cancer, and diabetes-related mortality. Therefore, clinicians need to identify high-risk patients earlier in the disease course and be aware of the extrahepatic manifestations of NAFLD to improve liver disease outcomes. In this review, we focus on the monitoring and management of the extrahepatic manifestations of NAFLD.

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.

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.