Role of physical activity in nonalcoholic fatty liver disease in terms of visceral obesity and insulin resistance

Nephrological, Pulmonary, and Dermatological Complications in the Context of MAFLD/NAFLD: A Narrative Review

Background: The most common cause of chronic liver disease is now known to be non-alcoholic fatty liver disease (NAFLD), recently redefined as metabolic-associated fatty liver disease (MAFLD). This review aims to synthesize current evidence on the pathophysiology and clinical implications of nephrological, pulmonary, and dermatological manifestations among NAFLD/MAFLD patients. In order to find safe and efficient treatments, NAFLD/MAFLD has emerged as a primary concern for hepatologists worldwide. Methods: We conducted a comprehensive review of the literature from major databases, focusing on studies that evaluated the extrahepatic manifestations of NAFLD/MAFLD. Emphasis was placed on identifying pathophysiological mechanisms and assessing their clinical impact on renal, pulmonary, and dermatological systems. Results: Recent developments in the management of chronic viral hepatitis have lowered the mortality rate associated with chronic liver disease. However, the prevalence of NAFLD/MAFLD continues to rise, making chronic liver disease a significant health concern for the future. An increasing percentage of patients on liver transplant waiting lists now have cirrhosis and hepatocellular carcinoma due to non-alcoholic liver disease. Furthermore, the incidence and prevalence of chronic kidney disease have surged, linking NAFLD/MAFLD to higher morbidity, mortality, and healthcare costs. Conclusions: NAFLD/MAFLD is underdiagnosed and underappreciated, yet its incidence is rapidly increasing, raising concerns about a potential global epidemic. Given its multisystemic impact-extending to renal, pulmonary, and dermatological complications-it is crucial to develop interdisciplinary strategies for early detection and effective management of the disease.

Role of MASLD in CVD: A review of emerging treatment options

Metabolic dysfunction-associated steatotic liver disease (MASLD), represents a growing health concern due to its strong association with metabolic syndrome, obesity, and type 2 diabetes mellitus (T2DM). This condition, characterized by excessive fat accumulation in the liver not attributed to alcohol consumption, has emerged as a leading cause of chronic liver disease globally. MASLD significantly elevates the risk of major adverse cardiovascular events (MACE) through mechanisms like increased oxidative stress, insulin resistance, and chronic inflammation, all of which contribute to the development of atherosclerosis and endothelial dysfunction. Effective management of MASLD is crucial not only for liver health but also for cardiovascular disease (CVD) prevention. Lifestyle modifications, particularly weight loss achieved through dietary changes and increased physical activity, are the cornerstone of MASLD treatment. Additionally, pharmacological interventions, especially antihyperglycemic agents, play a pivotal role in treating MASLD in patients with T2DM. Novel therapeutic agents targeting various pathways of metabolic and liver dysfunction are under investigation, offering hope for more effective management strategies. This review explores the interconnectedness of MASLD and CVD, highlighting current and emerging therapeutic approaches.

Impact of lifestyle interventions on pathogenesis of nonalcoholic fatty liver disease

This editorial builds on the article titled "Establishment and validation of an adherence prediction system for lifestyle interventions in non-alcoholic fatty liver disease" by Zeng et al. We carried out a critical examination of nonalcoholic fatty liver disease (NAFLD) pathogenesis and how lifestyle interventions could facilitate disease resolution, particularly highlighting that non-alcoholic steatohepatitis (NASH) is a severe form of NAFLD. Our discussion details that weight loss is a pivotal factor in disease outcomes: A 3%-5% reduction is enough for resolution in 50% of non-obese individuals, while a 7%-10% reduction achieves similar benefits in obese individuals, as demonstrated by magnetic resonance spectroscopy. Additionally, the editorial underscores that such lifestyle changes are instrumental not only in resolving NAFLD but also in reversing hepatic steatosis and inflammation. These insights, derived from the research, emphasize the critical role of personalized lifestyle modifications in halting the progression of NAFLD to NASH and even reversing fibrosis, thus offering a template for effective patient management.

Effect of functional resistance training on the structure and function of the heart and liver in patients with non-alcoholic fatty liver

The current study is of the quasi-experimental type, with a pre-and post-test design, and subjects were randomly assigned to one of two groups: control (n = 8) and experimental (test) (n = 8). Based on the patient's self-report and using daily diet control tables, the patient's diet planning percentage of energy supply was managed and controlled for 3 days. The protocol for functional resistance training for these circular exercises, including the squat, lunge, bear crawl, rock press, jumping jack, and back fly lunge, was performed three times per week without specialized apparatus. Ejection fraction (EF) and fractional shortening (FS) were measured before and after functional resistance training, using echocardiography. Liver Stiffness and steatosis were measured using FibroScan, and the liver function was determined using biochemical assays. The average age of patients in the control group and the test group were 46.02 ± 5.4 and 48.6 ± 2.51, respectively. Pre-test and post-test of the body mass index were 32.06 ± 5.06 and 30.02 ± 3.97, and for the body fat percentage were 33.65 ± 6.09 and 25.41 ± 4.99. In non-alcoholic fatty liver patients, due to functional resistance training, EF (p-value = 0.003) and FS (p-value = 0.03) significantly increased, and C-reactive protein (Hs-CRP) (p-value = 0.001), steatosis (p-value = 0.04), and stiffness (p-value = 0.01) decreased. According to the results and without considering clinical trials, functional resistance training affects the structure and function of the heart and Liver in NAFLD patients.

The Global Prevalence of Nonalcoholic Fatty Liver Disease and its Association With Cancers: Systematic Review and Meta-Analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the common causes of chronic liver disease globally. Obesity, metabolic diseases, and exposure to some environmental agents contribute to NAFLD. NAFLD is commonly considered a precursor for some types of cancers. Since the leading causes of death in people with NAFLD are cardiovascular disease and extrahepatic cancers, it is important to understand the mechanisms of the progression of NAFLD to control its progression and identify its association with extrahepatic cancers. Thus, this review aims to estimate the global prevalence of NAFLD in association with the risk of extrahepatic cancers.

OBJECTIVE

We aimed to determine the prevalence of various cancers in NAFLD patients and the association between NAFLD and cancer.

METHODS

We searched PubMed, ProQuest, Scopus, and Web of Science from database inception to March 2022 to identify eligible studies reporting the prevalence of NAFLD and the risk of incident cancers among adult individuals (aged ≥18 years). Data from selected studies were extracted, and meta-analysis was performed using random effects models to obtain the pooled prevalence with the 95% CI. The quality of the evidence was assessed with the Newcastle-Ottawa Scale.

RESULTS

We identified 11 studies that met our inclusion criteria, involving 222,523 adults and 3 types of cancer: hepatocellular carcinoma (HCC), breast cancer, and other types of extrahepatic cancer. The overall pooled prevalence of NAFLD and cancer was 26% (95% CI 16%-35%), while 25% of people had NAFLD and HCC (95% CI 7%-42%). NAFLD and breast cancer had the highest prevalence out of the 3 forms of cancer at 30% (95% CI 14%-45%), while the pooled prevalence for NAFLD and other cancers was 21% (95% CI 12%-31%).

CONCLUSIONS

The review suggests that people with NAFLD may be at an increased risk of cancer that might not affect not only the liver but also other organs, such as the breast and bile duct. The findings serve as important evidence for policymakers to evaluate and recommend measures to reduce the prevalence of NAFLD through lifestyle and environmental preventive approaches.

TRIAL REGISTRATION

PROSPERO CRD42022321946; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=321946.

Behavioural activity pattern, genetic factors, and the risk of nonalcoholic fatty liver disease: A prospective study in the UK Biobank

BACKGROUND & AIMS

Physical activity, sedentary behaviour, and genetic variants have been associated with the nonalcoholic fatty liver disease (NAFLD). However, whether and how the degree of healthy activity patterns may modify the impact of genetic susceptibility on NAFLD remains unknown.

METHODS

Behaviour activity factors were determined according to total physical activity (TPA) and sedentary time. The polygenic risk score (PRS) was calculated by variants in PNPLA3, TM6SF2, MBOAT7, and GCKR. Cox regression was used to analyse the associations of genetic and behaviour activity factors with incident NAFLD in the UK Biobank (N = 338 087).

RESULTS

During a median follow-up of 12.4 years, 3201 incident NAFLD cases were ascertained. Analyses of TPA and sedentary time simultaneously showed a dose-response association with the risk of NAFLD (ptrend  < .001). The association of behaviour activity patterns with NAFLD varied by genetic variants. Of the subjects with high genetic risk, we observed a null protective effect of moderate or high TPA on NAFLD risk, while sitting less than three hours a day significantly decreased the risk of NAFLD (p = 3.50 × 10-4 ). The high genetic risk of NAFLD can also be offset by the combination of moderate physical activity and shorter sedentary time. Moreover, the high genetic risk group has the greatest reduction of 10-year absolute risk (6.95 per 1000 person-years) if reaching both healthy activities.

CONCLUSIONS

Moderate-to-high physical activity and favourable sedentary behaviour may be lifestyle modifications in preventing NAFLD, which could offset the harmful effect of predisposing genetic factors.

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

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

Nutritional and Lifestyle Therapy for NAFLD in People with HIV

HIV infection and nonalcoholic fatty liver disease (NAFLD) are two major epidemics affecting millions of people worldwide. As people with HIV (PWH) age, there is an increased prevalence of metabolic comorbidities, along with unique HIV factors, such as HIV chronic inflammation and life-long exposure to antiretroviral therapy, which leads to a high prevalence of NAFLD. An unhealthy lifestyle, with a high dietary intake of refined carbohydrates, saturated fatty acids, fructose added beverages, and processed red meat, as well as physical inactivity, are known to trigger and promote the progression of NAFLD to nonalcoholic steatohepatitis, liver fibrosis, and hepatocellular carcinoma. Furthermore, with no currently approved pharmacotherapy and a lack of clinical trials that are inclusive of HIV, nutritional and lifestyle approaches still represent the most recommended treatments for PWH with NAFLD. While sharing common features with the general population, NAFLD in PWH displays its own peculiarities that may also reflect different impacts of nutrition and exercise on its onset and treatment. Therefore, in this narrative review, we aimed to explore the role of nutrients in the development of NAFLD in PWH. In addition, we discussed the nutritional and lifestyle approaches to managing NAFLD in the setting of HIV, with insights into the role of gut microbiota and lean NAFLD.

Associations of physical activity domains and muscle strength exercise with non-alcoholic fatty liver disease: a nation-wide cohort study

It is unclear if various types and domains of exercise have an identical effect on non-alcoholic fatty liver disease (NAFLD). Thus, this study aimed to investigate associations of different physical activity domains and muscle strength exercise with NAFLD using a nation-wide cohort database. Adults aged 20-79 years who participated in the Korean National Health and Nutrition Examination Survey between 2014 and 2018 were analyzed. Hepatic steatosis index was used to identify NAFLD. Physical activity was assessed with the Global Physical Activity Questionnaire. Of 21,015 participants, 4942 (23.5%) had NAFLD. Participants with ≥ 150 min/week of total physical activity had a lower risk of NAFLD than those with < 150 min/week (the fully adjusted OR: 0.86, 95% CI 0.78-0.95). When the individual domain of physical activity was assessed, ≥ 150 min/week of recreation activity was associated with a reduced risk of NAFLD (OR: 0.77, 95% CI 0.67-0.88), whereas ≥ 150 min/week of travel or work activity was not. The fully adjusted OR for NAFLD comparing participants with ≥ 2/week to those with < 2/week of muscle strength exercise was 0.83 (95% CI 0.73-0.94). Muscle strength exercise ≥ 2/week showed a lower risk of NAFLD for all levels of total and each specific domains of physical activity except for ≥ 150 min/week of work activity. An increased level of physical activity and muscle strength exercise was associated with a reduced risk of NAFLD, albeit the effect varied depending on domains of physical activity. Thus, physical activity should be differentiated by domains for the management of NAFLD. Muscle strength exercise could also be a good option for individuals who could not perform moderate-to-vigorous physical activity.

Types of Physical Activity in Nonalcoholic Fatty Liver Disease and All-Cause and Cardiovascular Mortality

The impact of different types of physical activity (PA) on mortality in the context of nonalcoholic fatty liver disease (NAFLD) is not clearly defined and was investigated. This prospective study was performed using the 2007-2014 US National Health and Nutrition Examination Survey with mortality follow-up through 2019. Over a median follow-up of 8.6 years, leisure-time and transportation-related PA that fulfilled the criteria outlined in the PA guidelines (≥150 min/week) in NAFLD were associated with a risk reduction in all-cause mortality (hazard ratio [HR]: 0.76, 95% confidence interval [CI]: 0.59-0.98 for leisure-time PA; HR: 0.62, 95% CI: 0.45-0.86 for transportation-related PA). Leisure-time and transportation-related PA in NAFLD were inversely associated with all-cause mortality in a dose-dependent manner (p for trends <0.01). Furthermore, the risk for cardiovascular mortality was lower in those meeting the PA guidelines for leisure-time PA (HR: 0.63, 95% CI: 0.44-0.91) and transportation-related PA (HR: 0.38, 95% CI: 0.23-0.65). Increasing sedentary behavior was linked to an increased risk of all-cause and cardiovascular mortality (p for trend <0.01). Meeting PA guidelines (≥150 min/week) for leisure-time and transportation-related PA has beneficial health effects on all-cause and cardiovascular mortality among individuals with NAFLD. Sedentary behavior in NAFLD showed harmful effects on all-cause and cardiovascular mortality.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

AGA Clinical Practice Update: Diagnosis and Management of Nonalcoholic Fatty Liver Disease in Lean Individuals: Expert Review

DESCRIPTION

Nonalcoholic fatty liver disease (NAFLD) is well recognized as a leading etiology for chronic liver disease, affecting >25% of the US and global populations. Up to 1 in 4 individuals with NAFLD have nonalcoholic steatohepatitis, which is associated with significant morbidity and mortality due to complications of liver cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Although NAFLD is observed predominantly in persons with obesity and/or type 2 diabetes mellitus, an estimated 7%-20% of individuals with NAFLD have lean body habitus. Limited guidance is available to clinicians on appropriate clinical evaluation in lean individuals with NAFLD, such as for inherited/genetic disorders, lipodystrophy, drug-induced NAFLD, and inflammatory disorders. Emerging data now provide more robust evidence to define the epidemiology, natural history, prognosis, and mortality of lean individuals with NAFLD. Multiple studies have found that NAFLD among lean individuals is associated with increased cardiovascular, liver, and all-cause mortality relative to those without NAFLD. This American Gastroenterological Association Clinical Practice Update provides Best Practice Advice to assist clinicians in evidence-based approaches to the diagnosis, staging, and management of NAFLD in lean individuals.

METHODS

This expert review was commissioned and approved by the American Gastroenterological Association (AGA) Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. Best Practice Advice Statements BEST PRACTICE ADVICE 1: Lean NAFLD should be diagnosed in individuals with NAFLD and body mass index <25 kg/m2 (non-Asian race) or body mass index <23 kg/m2 (Asian race). BEST PRACTICE ADVICE 2: Lean individuals with NAFLD should be evaluated routinely for comorbid conditions, such as type 2 diabetes mellitus, dyslipidemia, and hypertension. BEST PRACTICE ADVICE 3: Lean individuals with NAFLD should be risk stratified for hepatic fibrosis to identify those with advanced fibrosis or cirrhosis. BEST PRACTICE ADVICE 4: Lean individuals in the general population should not undergo routine screening for NAFLD; however, screening should be considered for individuals older than 40 years with type 2 diabetes mellitus. BEST PRACTICE ADVICE 5: NAFLD should be considered in lean individuals with metabolic diseases (such as type 2 diabetes mellitus, dyslipidemia, and hypertension), elevated liver biochemical tests, or incidentally noted hepatic steatosis. BEST PRACTICE ADVICE 6: Clinicians should query patients routinely regarding alcohol consumption patterns in all patients with lean NAFLD. BEST PRACTICE ADVICE 7: In patients with lean NAFLD, other causes of liver disease should be ruled out, including other causes of fatty liver, such as HIV, lipodystrophy, lysosomal acid lipase deficiency, familial hypobetalipoproteinemia, and medication-induced hepatic steatosis (methotrexate, amiodarone, tamoxifen, and steroids). BEST PRACTICE ADVICE 8: Current evidence is inadequate to support routine testing for genetic variants in patients with lean NAFLD. BEST PRACTICE ADVICE 9: Liver biopsy, as the reference standard, should be considered if there is uncertainty regarding contributing causes of liver injury and/or the stage of liver fibrosis. BEST PRACTICE ADVICE 10: Serum indices (NAFLD fibrosis score and Fibrosis-4 score) and imaging techniques (transient elastography and magnetic resonance elastography) may be used as alternatives to liver biopsy for fibrosis staging and patient follow-up. These tests can be performed at the time of diagnosis and repeated at intervals of 6 months to 2 years, depending on fibrosis stage and the patient's response to intervention. BEST PRACTICE ADVICE 11: If noninvasive tests (eg, Fibrosis-4 and NAFLD fibrosis score) are indeterminate, a second noninvasive test (eg, transient elastography or magnetic resonance elastography) should be performed to confirm the stage and prognosis of NAFLD. BEST PRACTICE ADVICE 12: In lean patients with NAFLD, lifestyle intervention, including exercise, diet modification, and avoidance of fructose- and sugar-sweetened drinks, to target a modest weight loss of 3%-5% is suggested. BEST PRACTICE ADVICE 13: Administration of vitamin E may be considered in lean persons with biopsy-confirmed nonalcoholic steatohepatitis, but without type 2 diabetes mellitus or cirrhosis. Oral pioglitazone 30 mg daily may be considered in lean persons with biopsy-confirmed nonalcoholic steatohepatitis without cirrhosis. BEST PRACTICE ADVICE 14: The therapeutic role of glucagon-like peptide-1 agonists and sodium-glucose cotransporter-2 inhibitors in the management of lean NAFLD is not fully defined and requires further investigation. BEST PRACTICE ADVICE 15: Hepatocellular carcinoma surveillance with abdominal ultrasound with or without serum α-fetoprotein twice per year is suggested in patients with lean NAFLD and clinical markers compatible with liver cirrhosis.

Physical Activity Is Associated With Nonalcoholic Fatty Liver Disease and Significant Fibrosis Measured by FibroScan

BACKGROUND AND AIMS

Studies evaluating the association of 2018 Physical Activity Guidelines for Americans (PA Guidelines) with nonalcoholic fatty liver disease (NAFLD) and significant fibrosis or cirrhosis are needed. We evaluated the association of meeting PA Guidelines with NAFLD and significant fibrosis or cirrhosis by transient elastography in the United States.

METHODS

A cross-sectional analysis was performed using the 2017-2018 U.S. National Health and Nutrition Examination Survey data. NAFLD and significant fibrosis or cirrhosis were defined by transient elastography in the absence of other causes of chronic liver disease. The detailed PA questionnaire assessed the leisure-time, occupation-related, and transportation-related PA. PA was categorized based on the PA Guidelines.

RESULTS

Of the 4304 subjects, leisure-time PA, which met the PA Guidelines (≥150 min/wk), was associated with 44% lower risk of NAFLD (odds ratio [OR]: 0.56; 95% confidence interval [CI]: 0.46-0.67). Subjects who reported 1-2 times (150-299 min/wk) or over 2 times (≥300 min/wk) the recommended amount of PA Guidelines had 40% (OR, 0.60; 95% CI, 0.41-0.90) and 49% (OR, 0.51; 95% CI, 0.40-0.65) lower odds of NAFLD, respectively. Over 8 hours of sitting time had a 44% higher risk of NAFLD (OR, 1.44; 95% CI, 1.01-2.05) when we considered leisure-time PA and sitting time simultaneously. Over 2 times (≥300 min/wk) the recommended amount of PA Guidelines for leisure-time PA had 59% (OR, 0.41; 95% CI, 0.22-0.74) lower risk for significant fibrosis and 63% (OR, 0.37; 95% CI, 0.21-0.64) lower odds of cirrhosis.

CONCLUSIONS

Meeting PA Guidelines for leisure-time PA has beneficial effects on NAFLD, and over 2 times the recommended amount of PA Guidelines had lower risk for significant fibrosis or cirrhosis.

Interaction between Lifestyle Changes and PNPLA3 Genotype in NAFLD Patients during the COVID-19 Lockdown

The coronavirus disease 2019 (COVID-19) lockdown dramatically changed people’s lifestyles. Diet, physical activity, and the PNPLA3 gene are known risk factors for non-alcoholic fatty liver disease (NAFLD). Aim: To evaluate changes in metabolic and hepatic disease in NAFLD patients after the COVID-19 lockdown. Three hundred and fifty seven NAFLD patients were enrolled, all previously instructed to follow a Mediterranean diet (MD). Anthropometric, metabolic, and laboratory data were collected before the COVID-19 lockdown in Italy and 6 months apart, along with ultrasound (US) steatosis grading and information about adherence to MD and physical activity (PA). In 188 patients, PNPLA3 genotyping was performed. After the lockdown, 48% of patients gained weight, while 16% had a worsened steatosis grade. Weight gain was associated with poor adherence to MD (p = 0.005), reduced PA (p = 0.03), and increased prevalence of PNPLA3 GG (p = 0.04). At multivariate analysis (corrected for age, sex, MD, PA, and PNPLA3 GG), only PNPLA3 remained independently associated with weight gain (p = 0.04), which was also associated with worsened glycemia (p = 0.002) and transaminases (p = 0.02). During lockdown, due to a dramatic change in lifestyles, half of our cohort of NAFLD patients gained weight, with a worsening of metabolic and hepatologic features. Interestingly, the PNPLA3 GG genotype nullified the effect of lifestyle and emerged as an independent risk factor for weight gain, opening new perspectives in NAFLD patient care.

Adherence to lifestyle modification in patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) makes a major impact on morbidity and mortality among the workingage population in developed countries. In the lack of effective pharmacological methods, the leading role in treatment of NAFLD belongs to lifestyle modification, consistent and gradual weight loss, and its maintenance. The qualitative and quantitative structure of the diet, intensity of physical activity, and most importantly, regularity and consistency of implementation of lifestyle modification activities are the key to successful management of patients with NAFLD.

To date, there are very few studies on adherence to lifestyle modification activities in this group of patients, which is mainly due to a deficiency of methodological tools. The questionnaire “QAA-25” recommended by the Russian Scientific Medical Society of Therapists for quantitative assessment of adherence to treatment allows to assess both adherence to therapy in general and adherence to its individual components (adherence to drug therapy, adherence to medical counseling, and adherence to lifestyle modification), which requires further study taking into account features of therapeutic strategies in treating NAFLD. 

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

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

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

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

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

Non-alcoholic fatty liver disease: A patient guideline

This patient guideline is intended for all patients at risk of or living with non-alcoholic fatty liver disease (NAFLD). NAFLD is the most frequent chronic liver disease worldwide and comes with a high disease burden. Yet, there is a lot of unawareness. Furthermore, many aspects of the disease are still to be unravelled, which has an important impact on the information that is given (or not) to patients. Its management requires a close interaction between patients and their many healthcare providers. It is important for patients to develop a full understanding of NAFLD in order to enable them to take an active role in their disease management. This guide summarises the current knowledge relevant to NAFLD and its management. It has been developed by patients, patient representatives, clinicians and scientists and is based on current scientific recommendations, intended to support patients in making informed decisions.

Non-Alcoholic Fatty Liver Disease in Lean and Non-Obese Individuals: Current and Future Challenges

Non-alcoholic fatty liver disease (NAFLD), which approximately affects a quarter of the world’s population, has become a major public health concern. Although usually associated with excess body weight, it may also affect normal-weight individuals, a condition termed as lean/non-obese NAFLD. The prevalence of lean/non-obese NAFLD is around 20% within the NAFLD population, and 5% within the general population. Recent data suggest that individuals with lean NAFLD, despite the absence of obesity, exhibit similar cardiovascular- and cancer-related mortality compared to obese NAFLD individuals and increased all-cause mortality risk. Lean and obese NAFLD individuals share several metabolic abnormalities, but present dissimilarities in genetic predisposition, body composition, gut microbiota, and susceptibility to environmental factors. Current treatment of lean NAFLD is aimed at improving overall fitness and decreasing visceral adiposity, with weight loss strategies being the cornerstone of treatment. Moreover, several drugs including PPAR agonists, SGLT2 inhibitors, or GLP-1 receptor agonists could also be useful in the management of lean NAFLD. Although there has been an increase in research regarding lean NAFLD, there are still more questions than answers. There are several potential drugs for NAFLD therapy, but clinical trials are needed to evaluate their efficacy in lean individuals.

Association of Physical Activity with the Risk of Hepatocellular Carcinoma in Patients with Chronic Hepatitis B

Simple Summary

Although viral replication in patients with a chronic hepatitis B (CHB) infection is effectively suppressed by potent antiviral therapy such as entecavir or tenofovir, the risk of hepatocellular carcinoma (HCC) development in CHB patients cannot be totally eliminated. Thus, control of modifiable risk factors for HCC development such as lifestyle modification is important to minimize the HCC risk. In this study, we analyzed a nationwide population-based cohort to evaluate whether there is a significant association between physical activity and development of HCC in CHB patients treated with entecavir or tenofovir. Results in this study suggest that physical activity was significantly associated with a lower risk of HCC development in CHB patients treated with potent antiviral therapy. Increasing physical activity can have beneficial outcomes on HCC development in CHB patients treated with entecavir or tenofovir.

Abstract

Background and Aims: In the general population, previous studies reported that physical activity was associated with risk of hepatocellular carcinoma (HCC) development. However, it is unclear whether physical activity is associated with risk of HCC development in patients with chronic hepatitis B (CHB). We aimed to elucidate the association between physical activity and risk of HCC development in CHB patients. Methods: This nationwide cohort study involved treatment-naive patients with CHB (n = 9727) who started treatment with entecavir or tenofovir and answered self-reported questionnaires between January 2012 and December 2017, using data from the Korean National Health Insurance Service database. The primary endpoint was development of HCC. Multivariable Cox regression and competing risk analyses were used. Results: During a median follow-up of 3.1 years, cumulative HCC incidence rates were 8.3%. There was an inverse association between physical activity and the risk of HCC (p < 0.001). Patients with 1000–1500 metabolic equivalent task (MET)-min/week, compared to those without physical activity, showed a significantly lower risk of HCC in both patients without cirrhosis (adjusted hazard ratio [aHR] 0.66, p = 0.02) and patients with cirrhosis (aHR 0.61, p = 0.02). In patients who were younger (<60), male, without diabetes, and with high BMI, amounts of physical activity of 1000–1500 MET-min/week showed an inverse association with the risk of HCC (aHR 0.65, 0.63, 0.65, and 0.64, respectively, all p < 0.05). Conclusion: Physical activity was significantly associated with a low risk of HCC in CHB patients treated with entecavir or tenofovir.

Physical Activity, Measured Objectively, Is Associated With Lower Mortality in Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

The association between physical activity (PA) and all-cause and cause-specific mortality from nonalcoholic fatty liver disease (NAFLD) requires investigation. We studied whether PA, measured by accelerometer, is associated with all-cause and cause-specific mortality among individuals with NAFLD.

METHODS

We performed a longitudinal analysis using the 2003 to 2006 US National Health and Nutrition Examination Survey data of adults (age, ≥20 y) and collecting mortality data through December 2015. NAFLD was defined based on the hepatic steatosis index or US fatty liver index scores, in the absence of other causes of chronic liver disease. PA was measured from participants who wore accelerometers 10 h/d for a minimum of 4 days over a 7-day period and were classified as total PA, moderate to vigorous PA (MVPA), and sedentary behavior.

RESULTS

Over an average follow-up period of 10.6 years, increasing the duration of total PA was associated with a reduced risk of death, from any cause, in an age- and sex-adjusted model (hazard ratio [HR], 0.52; 95% CI, 0.32-0.86 for highest quartile vs lowest quartile; P for trend = .001) and multivariable model (HR, 0.46; 95% CI, 0.28-0.75; P for trend < .001) among individuals with NAFLD. Increasing the duration of MVPA was associated with a lower risk of death from any cause in individuals with NAFLD. Furthermore, longer total PA was associated with a lower risk for cardiovascular disease-related death in individuals with NAFLD (HR, 0.28; 95% CI, 0.08-0.98 for highest quartile vs lowest quartile; P for trend = .007). We did not find this association for cancer-related mortality in individuals with NAFLD. Increasing the duration of sedentary behavior did not affect all-cause or cause-specific mortality in individuals with NAFLD.

CONCLUSIONS

Longer total PA and MVPA, measured by accelerometers over a 7-day period, are associated with lower all-cause and cardiovascular mortality in individuals with NAFLD.

Aerobic Exercise in the Management of Metabolic Dysfunction Associated Fatty Liver Disease

Sedentarism is the pandemic of modern times. It is associated with several medical conditions including obesity, type 2 diabetes mellitus, cardiovascular diseases and also liver disease, particularly metabolic dysfunction associated fatty liver disease (MAFLD). In an era when MAFLD is the most prevalent chronic liver disease worldwide, whilst no pharmacological therapy has been approved for it, exercise has proved to be effective in improving liver steatosis. Interestingly, exercise decreases liver fat even in the absence of weight loss. The challenge for the clinician is to motivate the obese patient with MAFLD, and associated co-morbidities, who has crystallized a sedentary behavior, at times when every need is at the distance of a click on the Internet, and the entire world can be visited behind a screen. In this review, the aggregate evidence on the mechanisms and effects of exercise in the management of MAFLD is summarized, with simple recommendations for everyday clinical practice.

Inadequate Physical Activity and Sedentary Behavior Are Independent Predictors of Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIMS

In general, physical activity (PA) and nonalcoholic fatty liver disease (NAFLD) have an inverse association. However, studies assessing the impact of the widely accepted Physical Activity Guidelines for Americans (PA Guidelines) on NAFLD are lacking.

APPROACH AND RESULTS

We performed a serial, cross-sectional analysis among adults by using the 2007-2016 US National Health and Nutrition Examination Survey. NAFLD and advanced fibrosis were defined by using various noninvasive panels. A PA questionnaire assessed the leisure-time PA, occupation-related PA, transportation-related PA, and total sitting time as sedentary behavior. PA was categorized according to the PA Guidelines. Of the 24,588 individuals (mean age, 47.4 years; 47.9% males), leisure-time PA (≥150 minutes per week) demonstrated 40% lower odds of NAFLD, whereas transportation-related PA was associated with a 33% risk reduction in NAFLD. Analysis of total PA and sitting times simultaneously showed a dose-response association between sitting time and NAFLD (P for trend < 0.001). Compliance with the PA Guidelines was lower in individuals with NAFLD versus those without NAFLD. The trends in compliance with the PA Guidelines for any type of PA remained stable in individuals with NAFLD except for a downtrend in transportation-related PA. In contrast, an improvement in compliance with the PA Guidelines for leisure time was noted in the cohort without NAFLD. Although PA demonstrated a 10% stronger association with risk reduction of NAFLD in women, women showed a lower tendency of meeting the PA Guidelines. Trends in total sitting time increased significantly regardless of NAFLD status.

CONCLUSIONS

Sedentary behavior emerged as an independent predictor of NAFLD. Overall compliance with the PA Guidelines was lower in the cohort with NAFLD, with sex- and ethnicity-based differences. Implementation of these observations in clinical practice may improve our understanding as well as clinical outcomes.

Negative Energy Balance Induced by Exercise or Diet: Effects on Visceral Adipose Tissue and Liver Fat

The indisputable association between visceral adipose tissue (VAT) and cardiometabolic risk makes it a primary target for lifestyle-based strategies designed to prevent or manage health risk. Substantive evidence also confirms that liver fat (LF) is positively associated with increased health risk and that reduction is associated with an improved metabolic profile. The independent associations between reductions in VAT, LF, and cardiometabolic risk is less clear. In this narrative review, we summarize the evidence indicating whether a negative energy balance induced by either an increase in energy expenditure (aerobic exercise) or a decrease in energy intake (hypocaloric diet) are effective strategies for reducing both VAT and LF. Consideration will be given to whether a dose-response relationship exists between the negative energy balance induced by exercise or diet and reduction in either VAT or LF. We conclude with recommendations that will help fill gaps in knowledge with respect to lifestyle-based strategies designed to reduce VAT and LF.

Extrahepatic Manifestations of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and encompasses a spectrum of pathology from simple steatosis to inflammation and significant fibrosis that leads to cirrhosis. NAFLD and its comorbid conditions extend well beyond the liver. It is a multisystemic clinical disease entity with extrahepatic manifestations such as cardiovascular disease, type 2 diabetes, chronic kidney disease, hypothyroidism, polycystic ovarian syndrome, and psoriasis. Indeed, the most common causes of mortality in subjects with NAFLD are cardiovascular disease, followed by malignancies and then liver-related complications as a distant third. This review focuses on several of the key extrahepatic manifestations of NAFLD and areas for future investigation. Clinicians should learn to screen and initiate treatment for these extrahepatic manifestations in a prompt and timely fashion before they progress to end-organ damage.

Influence of lifestyle factors and staple foods from the Mediterranean diet on non-alcoholic fatty liver disease among older individuals with metabolic syndrome features

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver morbidity. This condition often is accompanied by obesity, diabetes, and metabolic syndrome (MetS). The aim of this study was to evaluate the connection between lifestyle factors and NAFLD in individuals with MetS.

METHODS

A cross-sectional study with 328 participants (55-75 y of age) diagnosed with MetS participating in the PREDIMED-Plus trial was conducted. NAFLD status was evaluated using the non-invasive hepatic steatosis index (HSI). Sociodemographic, clinical, and dietary data were collected. Adherence to the Mediterranean diet (mainly assessed by the consumption of olive oil, nuts, legumes, whole grain foods, fish, vegetables, fruits, and red wine) and physical activity were assessed using validated questionnaires.

RESULTS

Linear regression analyses revealed that HSI values tended to be lower with increasing physical activity tertiles (T2, β = -1.47; 95% confidence interval [CI], -2.73 to -0.20; T3, β = -1.93; 95% CI, -3.22 to -0.65 versus T1, Ptrend = 0.001) and adherence to the Mediterranean diet was inversely associated with HSI values: (moderate adherence β = -0.70; 95% CI, -1.92 to 0.53; high adherence β = -1.57; 95% CI, -3.01 to -0.13 versus lower, Ptrend = 0.041). Higher tertiles of legume consumption were inversely associated with the highest tertile of HSI (T2, relative risk ratio [RRR], 0.45; 95% CI, 0.22-0.92; P = 0.028; T3, RRR, 0.48; 95% CI, 0.24-0.97; P = 0.041 versus T1).

CONCLUSION

Physical activity, adherence to the Mediterranean diet, and consumption of legumes were inversely associated with a non-invasive marker of NAFLD in individuals with MetS. This data can be useful in implementing precision strategies aimed at the prevention, monitoring, and management of NAFLD.

Treatment of non-alcoholic fatty liver disease - Current perspectives

Therapeutics aimed at treating non-alcoholic fatty liver disease (NAFLD) target the pathogenic process from deranged metabolism leading to steatosis to cell stress and death, leading to a cascade of inflammation and fibrosis, ultimately culminating into cirrhosis. The development of drugs for management of NAFLD has bloomed over the past decade, although at present there is no approved pharmacological agent for its management. Not all patients with the disease progress to cirrhosis and decompensation; hence, treatment specifically is provided for those with a high risk of progression such as those with biopsy-proven steatohepatitis or fibrosis. Along with disease-specific management, all patients must receive therapies directed at risk factors such as dyslipidemia, insulin resistance, type 2 diabetes mellitus and obesity. Comorbidities such as cardiovascular disease, sleep apnoea and chronic kidney disease need management. A current perspective on the therapeutic options is detailed in this review.

Physical exercise and liver "fitness": Role of mitochondrial function and epigenetics-related mechanisms in non-alcoholic fatty liver disease

BACKGROUND

Modern lifestyles, especially high-caloric intake and physical inactivity, contribute to the increased prevalence of non-alcoholic fatty liver disease (NAFLD), which becomes a significant health problem worldwide. Lifestyle changes, however, affect not only parental generation, but also their offspring, reinforcing the need for efficient preventive approaches to deal with this disease. This transgenerational influence of phenotypes dependent on parents (particularly maternal) behaviours may open additional research avenues. Despite persistent attempts to design an effective pharmacological therapy against NAFLD, physical activity, as a non-pharmacological approach, emerges as an exciting strategy.

SCOPE OF REVIEW

Here we briefly review the effect of physical exercise on liver mitochondria adaptations in NAFLD, highlighting the importance of mitochondrial metabolism and transgenerational and epigenetic mechanisms in liver diseases.

MAJOR CONCLUSIONS

A deeper look into cellular mechanisms sheds a light on possible effects of physical activity in the prevention and treatment of NAFLD through modulation of function and structure of particular organelles, namely mitochondria. Additionally, despite of increasing evidence regarding the contribution of epigenetic mechanisms in the pathogenesis of different diseases, the role of microRNAs, DNA methylation, and histone modification in NAFLD pathogenesis still needs to be elucidated.

Lifestyle modification in NAFLD/NASH: Facts and figures

The development of non-alcoholic fatty liver disease is closely linked to lifestyle factors, namely excessive caloric intake coupled with reduced physical activity and exercise. This review aims to examine the evidence behind lifestyle change as a tool to improve hepatic steatosis and liver histology in patients with non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. Furthermore, potential barriers to adopting lifestyle changes and strategies to overcome these barriers in the clinical setting are discussed.

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.

Partitioning of radiological, stress and biochemical changes in pre-diabetic women subjected to Diabetic Yoga Protocol

BACKGROUND

Yoga is an ancient system of wellness with Asana and Pranayama as its most popular and propagated modules for management of lifestyle disorders.

OBJECTIVES

The aim of the study was to characterise the liver abnormalities, biochemical changes, and stress levels after Yoga intervention in prediabetic females.

MATERIALS AND METHODS

37 females were randomly divided into Yoga practising and non-practising control groups. The Yoga practising group performed Diabetic Yoga Protocol (DYP) for 3 months. Parameters including size of liver, fatty infiltration, and grade of severity were measured using ultrasonography along with biochemical parameters and stress levels at baseline and after Yoga practice.

RESULTS

The glycosylated hemoglobin (HbA1c) and glucose levels were found significantly reduced in prediabetic (p = 0.015) women after practising DYP, although cholesterol levels increased in menopausal women. No escalation of fatty liver was noted among women practising DYP.

CONCLUSION

DYP reduced the HbA1c and stress levels and therefore, could be a cost-effective tool for preventing prediabetes to diabetes progression.

Dose-response association between physical activity and non-alcoholic fatty liver disease: a case-control study in a Chinese population

AIM

Physical activity plays an important role in the development of non-alcoholic fatty liver disease (NAFLD).However, the optimal intensity and dose of physical activity for the treatment of NAFLD have yet to be found. In the present study, we aimed to provide a dose-response association between physical activity and NAFLD in a Chinese population.

METHODS

We recruited 543 patients with NAFLD diagnosed by abdominal ultrasonography, and 543 age-matched and sex-matched controls. The amount of physical activity, sedentary time and energy intake was collected through a structured questionnaire. Logistic regression analyses were performed to investigate the association between physical activity and NAFLD.

RESULTS

After adjusting for hypertension, diabetes, body mass index, fasting blood glucose, energy intake and sedentary time, the total amount of physical activity was found to be inversely associated with NAFLD in a dose-dependent manner in men (>3180 metabolic equivalent of energy [MET]-min/week vs ≤1440 MET-min/week: OR 0.60, 95% CI 0.40 to 0.91, p for trend=0.01). In addition, both moderate-intensity and vigorous-intensity physical activity were effective in reducing the risk of NAFLD, independent of confounding variables in men (moderate-intensity physical activity: >684 MET-min/week vs none: OR 0.58, 95% CI 0.40 to 0.86, p for trend=0.01; vigorous-intensity physical activity: >960 MET-min/week vs none: OR 0.63, 95% CI 0.41 to 0.95, p for trend=0.02).

CONCLUSIONS

Physical activity was inversely associated with risk of NAFLD in a dose-dependent manner in men. Vigorous-intensity and moderate-intensity physical activity were both beneficial to NAFLD, independent of sedentary time and energy intake.

Association of non-alcoholic fatty liver disease with cardiovascular disease and subclinical atherosclerosis

Non-alcoholic fatty liver disease (NAFLD) refers to fatty infiltration of liver in the absence of significant alcohol intake, use of steatogenic medication, or hereditary disorders. It is a common cause of chronic liver disease with a worldwide estimated prevalence ranging from 6.3% to 33%. The NAFLD is considered a hepatic manifestation of the metabolic syndrome. Insulin resistance and increased oxidative stress are central to pathogenesis of NAFLD, and risk factors include metabolic syndrome, diabetes mellitus, obesity, lack of physical activity, smoking, and high fat diet. NAFLD is associated with higher mortality as compared to the general population with cardiovascular disease being the most common cause of death. The NAFLD is associated with a higher prevalence of subclinical atherosclerosis as evidenced by odds of higher coronary artery calcification, higher average and maximum carotid intima-media thickness. It is also associated with stiff arteries as evidenced by higher cardio-ankle vascular index and higher brachial-ankle pulse wave velocity. Increasing evidence has linked NAFLD with atherosclerotic cardiovascular diseases. The NAFLD is associated with a higher prevalence of coronary artery disease (CAD), more severe CAD, poor coronary collateral development, and higher incidence of coronary events. The NAFLD is also associated with ischemic stroke. Studies have shown that the association between NAFLD and atherosclerotic cardiovascular diseases is independent of shared risk factors.

Applicability of a Web-Based, Individualized Exercise Intervention in Patients With Liver Disease, Cystic Fibrosis, Esophageal Cancer, and Psychiatric Disorders: Process Evaluation of 4 Ongoing Clinical Trials

Background

In the primary and secondary prevention of civilization diseases, regular physical activity is recommended in international guidelines to improve disease-related symptoms, delay the progression of the disease, or to enhance postoperative outcomes. In the preoperative context, there has been a paradigm shift in favor of using preconditioning concepts before surgery. Web-based interventions seem an innovative and effective tool for delivering general information, individualized exercise recommendations, and peer support.

Objective

Our first objective was to assess feasibility of our Web-based interventional concept and analyze similarities and differences in a sustained exercise implementation in different diseases. The second objective was to investigate the overall participants’ satisfaction with our Web-based concept.

Methods

A total of 4 clinical trials are still being carried out, including patients with esophageal carcinoma scheduled for oncologic esophagectomy (internet-based perioperative exercise program, iPEP, study), nonalcoholic fatty liver disease (hepatic inflammation and physical performance in patients with nonalcoholic steatohepatitis, HELP, study), depression (exercise for depression, EXDEP, study), and cystic fibrosis (cystic fibrosis online mentoring for microbiome, exercise, and diet, COMMED, study). During the intervention period, the study population had access to the website with disease-specific content and a disease-specific discussion forum. All participants received weekly, individual tailored exercise recommendations from the sports therapist. The main outcome was the using behavior, which was obtained by investigating the log-in rate and duration.

Results

A total of 20 participants (5 from each trial) were analyzed. During the intervention period, a regular contact and a consequent implementation of exercise prescription were easily achieved in all substudies. Across the 4 substudies, there was a significant decrease in log-in rates (P<.001) and log-in durations (P<.001) over time. A detailed view of the different studies shows a significant decrease in log-in rates and log-in durations in the HELP study (P=.004; P=.002) and iPEP study (P=.02; P=.001), whereas the EXDEP study (P=.58; P=.38) and COMMED study (P=.87; P=.56) showed no significant change over the 8-week intervention period. There was no significant change in physical activity within all studies (P=.31). Only in the HELP study, the physical activity level increased steadily over the period analyzed (P=.045). Overall, 17 participants (85%, 17/20) felt secure and were not scared of injury, with no major differences in the subtrials.

Conclusions

The universal use of the Web-based intervention appears to be applicable across the heterogonous collectives of our study patients with regard to age and disease. Although the development of physical activity shows only moderate improvements, flexible communication and tailored support could be easily integrated into patients’ daily routine.

Trial Registration

iPEP study: ClinicalTrials.gov NCT02478996; https://clinicaltrials.gov/ct2/show/NCT02478996 (Archived by WebCite at http://www.webcitation.org/6zL1UmHaW); HELP study: ClinicalTrials.gov NCT02526732; http://www.webcitation.org/6zJjX7d6K (Archived by WebCite at http://www.webcitation.org/6Nch4ldcL); EXDEP study: ClinicalTrials.gov NCT02874833; https://clinicaltrials.gov/ct2/show/NCT02874833 (Archived by WebCite at http://www.webcitation.org/6zJjj7FuA)

Health and Prevention Enhancement (H-PEACE): a retrospective, population-based cohort study conducted at the Seoul National University Hospital Gangnam Center, Korea

PURPOSE

The Health and Prevention Enhancement (H-PEACE) study was designed to investigate the association of diagnostic imaging results, biomarkers and the predisease stage of non-communicable diseases (NCDs), such as malignancies and metabolic diseases, in an average-risk population in Korea.

PARTICIPANTS

This study enrolled a large-scale retrospective cohort at the Healthcare System Gangnam Center, Seoul National University Hospital, from October 2003 to December 2014.

FINDINGS TO DATE

The baseline and follow-up information collected in the predisease stage of NCDs allows for evaluation of an individual's potential NCD risk, which is necessary for establishing personalised prevention strategies. A total of 91 336 health examinees were included in the cohort, and we repeatedly measured and collected information for 50.9% (n=46 484) of the cohort members. All participants completed structured questionnaires (lifestyle, medical history, mini-dietary assessment index, sex-specific variables and psychiatric assessment), doctors' physical examinations, laboratory blood and urine tests and digital chest X-ray imaging. For participants with available data, we also obtained information on specific diagnostic variables using advanced diagnostic tests, including coronary CT for coronary calcium scores, colonoscopy and brain MRI. Furthermore, 17 455 of the participants who provided informed consent and donated blood samples were enrolled into the Gene-environmental interaction and phenotype study, a subcohort of the H-PEACE, from October 2013, and we analysed genome-wide single-nucleotide polymorphism array data for 6579 of these blood samples.

FUTURE PLANS

The data obtained from this cohort will be used to facilitate advanced and accurate diagnostic techniques related to NCDs while considering various phenotypes. Potential collaborators can access the dataset after receiving approval from our institutional review board. Applications can be submitted on the study homepage (http://en-healthcare.snuh.org/HPEACEstudy).

Effect of longitudinal changes of body fat on the incidence and regression of nonalcoholic fatty liver disease

AIMS

To investigate the longitudinal association between changes in body fat amount and the incidence and regression of nonalcoholic fatty liver disease (NAFLD).

METHODS

We performed a cohort study of 2017 subjects without liver disease or significant alcohol consumption from 2007 to 2008 and participated in a voluntary follow-up between 2011 and 2013. Of the 2017 subjects, we enrolled 956 (47.4%) subjects who had available abdominal fat data in both 2007-2008 and 2011-2013. NAFLD was diagnosed on the basis of ultrasonographic findings. Adipose tissue area was evaluated by computed tomography.

RESULTS

We observed 145 incident cases of NAFLD (22.6% of 642), and 79 subjects experienced a regression of NAFLD (25.2% of 314) during a median of 4.64 years. An increasing change in visceral adipose tissue (VAT) area was associated with a higher incidence of NAFLD (highest tertile vs. lowest tertile of VAT hazard ratio [HR] 2.45, 95% confidence interval [CI] 1.56-3.85, P for trend <0.001) in the multivariable analysis. An increasing change in VAT area was inversely associated with the regression of NAFLD (highest tertile vs. lowest tertile of VAT HR 0.40, 95% CI 0.20-0.80, P for trend = 0.008).

CONCLUSIONS

An increasing change in VAT area was longitudinally associated with a higher risk of incident NAFLD and inversely associated with the regression of NAFLD.

Physical activity levels and hepatic steatosis: A longitudinal follow-up study in adults

BACKGROUND AND AIM

This study aimed to evaluate the impact of physical activity (PA) on the course of hepatic steatosis (HS) in adults.

METHODS

Hepatic steatosis status (ultrasonography) and PA levels were evaluated in 5860 subjects at baseline and after approximately 2.5 years (range: 19-50 months). At follow up, possible exposures to different PA levels were those who remained inactive, became inactive, became active, and remained active. After follow up, subjects were then classified according to the four possible states (outcomes): "remained without HS," "developed HS" (subjects without HS at baseline), "remained with HS," or "reverted HS."

RESULTS

After multivariate adjustments, individuals without HS that became or remained physically active were less likely to develop HS compared with those who remained physically inactive (odds ratio = 0.75, P = 0.04 and 0.75, P = 0.03, respectively). Among those with HS at baseline, becoming and remaining physically active beneficially improved the HS status (odds ratio = 0.64, P = 0.01 and 0.66, P = 0.01, respectively). However, the significance was lost when adjusted for changes in body mass index.

CONCLUSION

Higher levels of PA were associated with prevention and treatment of HS, with evidence of effect mediation by changes in body mass index.

Non-alcoholic fatty liver disease and lifestyle modifications, focusing on physical activity

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and the prevalence of non-alcoholic steatohepatitis (NASH) with fibrosis is increasing as the population with NAFLD ages. To date, lifestyle modifications including weight loss, increased physical activity, and dietary changes remain the treatment of choice for NAFLD because there are no approved effective pharmacologic agents. Increased physical activity has therapeutic effects on NAFLD by reducing hepatic fat independent of weight reduction. Indeed, even minimal physical activity below the recommended threshold may have a beneficial impact on NAFLD. Aerobic activity and resistance training have similar effects on NAFLD. Universal recommendations for the optimal intensity and dose of physical activity have not been established. Therefore, physical activity should be tailored based on a patient's clinical characteristics, comorbidities, and fitness capacity. Physical activity also prevents the development of NAFLD and may represent a valuable strategy for reducing the public health burden. However, there are insufficient data supporting the effects of physical activity on the progression of non-alcoholic fatty liver to NASH with advanced fibrosis, and on extrahepatic disease-related morbidity and mortality. In this paper, we review the role of physical activity in the management of NAFLD.

Body Fat Distribution and the Risk of Incident Metabolic Syndrome: A Longitudinal Cohort Study

The effect of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) area on metabolic syndrome (MS) has been debated. We aimed to evaluate the effects of VAT and SAT on the incidence of MS and its components in a large and apparently healthy Asian population. We performed a longitudinal cohort study of 1,964 subjects who received health screenings over a 5-year follow-up period; 317 incidents of MS (16.1%) were observed during a median follow-up of 4.5 years. The VAT area was significantly associated with a higher incidence of MS; the adjusted HR for incident MS per 1 SD of VAT was 1.50 (95% CI 1.29-1.74), and the adjusted HR of the 5th VAT quintile compared with the 1st quintile was 3.73 (95% CI 2.22-6.28). However, the SAT area was not associated with incident MS. Although the VAT area was longitudinally associated with the incidence of each component of MS, the SAT area was inversely associated with the risk of high blood pressure, fasting blood sugar, and triglycerides, with marginal significance. In conclusion, the VAT area is longitudinally associated with an increased risk of incident MS, while SAT may have a protective effect against the incidence of individual MS components.

Association between physical activity and risk of nonalcoholic fatty liver disease: a meta-analysis

BACKGROUND

Increased physical activity (PA) is a key element in the management of patients with nonalcoholic fatty liver disease (NAFLD); however, its association with NAFLD risk has not been systematically assessed. This meta-analysis of observational studies was to quantify this association with dose-response analysis.

METHODS

Electronic databases were searched to January 2017 for studies of adults reporting the risk of NAFLD in relation to PA with cohort or case-control designs. Studies that reported sex-specific data were included as separate studies. The overall risk estimates were pooled using a random-effects model, and the dose-response analysis was conducted to shape the quantitative relationship.

RESULTS

A total of 6 cohort studies from 5 articles with 32,657 incident NAFLD cases from 142,781 participants, and 4 case-control studies from 3 articles with 382 NAFLD cases and 302 controls were included. Compared with the lowest PA level, the highest PA level was associated with a risk reduction of NAFLD in cohort [RR (risk ratio) 0.79, 95% CI (confidence interval) 0.71-0.89] and case-control studies [OR (odds ratio) 0.43, 95% CI 0.27-0.68]. For cohort studies, both highest and moderate PA levels were superior to the light one in lowering NAFLD risk (p_{for interaction} = 0.006 and 0.02, respectively), and there was a log-linear dose-response association (p_{for nonlinearity} = 0.10) between PA and NAFLD risk [RR 0.82 (95% CI 0.73-0.91) for every 500 metabolic equivalent (MET)-minutes/week increment in PA].

CONCLUSIONS

Increased PA may lead to a reduced risk of NAFLD in a dose-dependent manner, and the current guideline-recommended minimum PA level that approximates to 500 MET-minutes/week is able to moderately reduce the NAFLD risk.

The preventive effect of sustained physical activity on incident nonalcoholic fatty liver disease

BACKGROUND & AIMS

Physical activity (PA) is inversely associated with nonalcoholic fatty liver disease (NAFLD) prevalence. However, few studies evaluated the effect of PA on NAFLD incidence in regard to visceral adipose tissue (VAT) and insulin resistance (IR). We investigated whether PA at baseline and change in PA during follow-up have any effect on incident NAFLD.

METHODS

We enrolled subjects who underwent health screenings between 2007 and 2008 and participated in voluntary follow-up between 2011 and 2013 (median 4.42 years). Incident NAFLD was defined as NAFLD absence at baseline and presence at follow-up by ultrasonography. PA was measured using a detailed questionnaire-based metabolic equivalent at baseline and follow-up; the difference during follow-up was calculated.

RESULTS

Of the 1373 subjects enrolled, 288 (21.0%) developed NAFLD. Both total and leisure-time PA at baseline were inversely associated with incident NAFLD (P for trend=.005 and .003 respectively). Decreased PA at follow-up was associated with increased incident NAFLD risk after adjusting for age, gender, body mass index, smoking, hypertension, diabetes and diet [hazard ratio (HR) 1.45, 95% confidence interval (CI) 1.04-2.02, 4th (most decreased PA) vs 1st quartile (increased PA), P=.028]. This relationship was attenuated but remained statistically significant after adjustment for VAT(HR 1.48, 95% CI 1.06-2.06, 4th vs 1st quartile) and IR(HR 1.59, 95% CI 1.11-2.27, 4th vs 1st quartile).

CONCLUSIONS

This study shows an independent protective effect of PA at baseline on incident NAFLD after 4-year follow-up. Furthermore, sustained or increased PA had a preventive effect on incident NAFLD independent of VAT and IR.

Visceral obesity is associated with white matter hyperintensity and lacunar infarct

BACKGROUND

The presence of white matter hyperintensity (WMH) and lacunar infarct are recognized as risk factors of dementia, stroke and mortality. It is undetermined whether visceral adipose tissue (VAT) area is associated with an increased risk of cerebral small vessel disease. We explored whether VAT area was responsible for cerebral small vessel disease through the identification of WMH and lacunar infarct.

SUBJECTS

A total of 2046 subjects free of cerebrovascular disease who underwent brain magnetic resonance imaging and abdominal fat computed tomography during a general health check-up were enrolled.

RESULTS

The prevalence of cerebral WMH was 37.7%. Subjects with WMH had greater VAT area and higher BMI and waist circumference than those without WMH, although significant differences in subcutaneous adipose tissue (SAT) area were not shown. Subjects with lacunar infarct also had significantly greater VAT area and higher waist circumference and BMI than those without lacunar infarct. Multivariate analyses adjusted for age, sex, diabetes, hypertension, smoking and alcohol, showed VAT area was an independent risk factor of cerebral WMH (odds ratio (OR): 1.13, 95% confidence interval (CI): 1.02-1.24, P=0.016), whereas waist circumference and SAT area were not significantly associated with the risk of WMH. Likewise, VAT area was also independently associated with lacunar infarct (OR: 1.38, 95% CI: 1.06-1.81, P=0.018), whereas the other anthropometric measures were not related with lacunar infarct.

CONCLUSIONS

VAT has a significant association with cerebral small vessel disease, which was defined as WMH or lacunar infarct. Visceral obesity can be a potential therapeutic target for the prevention of cerebral small vessel disease.

Nonobese Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) refers to a group of conditions characterized by hepatic steatosis in the absence of significant alcohol consumption. NAFLD is seen commonly in patients with metabolic abnormalities associated with obesity, such as type II diabetes, dyslipidemia, and metabolic syndrome. Evidently, however, not all obese subjects develop NAFLD and, more importantly, NAFLD can be found in nonobese individuals. Although NAFLD occurring in nonobese subjects has been reported in children and adults of all ethnicities, it appears to be recognized more frequently in Asians, even when strict ethnicity-specific body mass index criteria are used to define obesity. Studies based on liver biopsies suggest that the prevalence of nonalcoholic steatohepatitis and fibrosis does not differ significantly between nonobese NAFLD and NAFLD in obese patients. Visceral obesity as opposed to general obesity, high fructose and cholesterol intake, and genetic risk factors (eg, palatin-like phospholipase domain-containing 3) may be associated with nonobese NAFLD. In general, nonalcoholic steatohepatitis is associated with increased mortality, primarily from cardiovascular causes, independent of other metabolic factors. Although data regarding the mortality impact of nonobese NAFLD are not as mature, it may be important to identify high-risk nonobese NAFLD patients and manage their metabolic profile. Currently, lifestyle modification to reduce visceral adiposity, including dietary changes and physical activity, remains the standard of care in patients with nonobese NAFLD.

Metabolic profiling of fatty liver in young and middle-aged adults: Cross-sectional and prospective analyses of the Young Finns Study

Nonalcoholic fatty liver is associated with obesity-related metabolic disturbances, but little is known about the metabolic perturbations preceding fatty liver disease. We performed comprehensive metabolic profiling to assess how circulating metabolites, such as lipoprotein lipids, fatty acids, amino acids, and glycolysis-related metabolites, reflect the presence of and future risk for fatty liver in young adults. Sixty-eight lipids and metabolites were quantified by nuclear magnetic resonance metabolomics in the population-based Young Finns Study from serum collected in 2001 (n = 1,575), 2007 (n = 1,509), and 2011 (n = 2,002). Fatty liver was diagnosed by ultrasound in 2011 when participants were aged 34-49 years (19% prevalence). Cross-sectional associations as well as 4-year and 10-year risks for fatty liver were assessed by logistic regression. Metabolites across multiple pathways were strongly associated with the presence of fatty liver (P < 0.0007 for 60 measures in age-adjusted and sex-adjusted cross-sectional analyses). The strongest direct associations were observed for extremely large very-low-density lipoprotein triglycerides (odds ratio [OR] = 4.86 per 1 standard deviation, 95% confidence interval 3.48-6.78), other very-low-density lipoprotein measures, and branched-chain amino acids (e.g., leucine OR = 2.94, 2.51-3.44). Strong inverse associations were observed for high-density lipoprotein measures, e.g., high-density lipoprotein size (OR = 0.36, 0.30-0.42) and several fatty acids including omega-6 (OR = 0.37, 0.32-0.42). The metabolic associations were attenuated but remained significant after adjusting for waist, physical activity, alcohol consumption, and smoking (P < 0.0007). Similar aberrations in the metabolic profile were observed already 10 years before fatty liver diagnosis.

CONCLUSION

Circulating lipids, fatty acids, and amino acids reflect fatty liver independently of routine metabolic risk factors; these metabolic aberrations appear to precede the development of fatty liver in young adults. (Hepatology 2017;65:491-500).

Body Fat Distribution and Risk of Incident and Regressed Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

Some studies have examined correlations between visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) with nonalcoholic fatty liver disease (NAFLD) or between VAT and NAFLD. We investigated the longitudinal association between body fat distribution (VAT vs SAT) and incidence and regression of NAFLD, adjusting for risk factors, in a large population-based cohort.

METHODS

We collected data from adults who underwent abdominal ultrasonography (to identify liver fat), abdominal fat computed tomography scan, and blood tests from March 2007 through December 2008. Each patient underwent an anthropometric assessment and completed a questionnaire about their medical history, physical activity, and diet. Our final analysis involved 2017 subjects from the initial cohort who participated in a voluntary follow-up health screen performed in 2011 and 2013. The median follow-up time was 4.43 years.

RESULTS

We found 288 incident cases of NAFLD; 159 patients had NAFLD regression during the follow-up period. An increasing area of VAT was associated with higher incidence of NAFLD in the multivariable analysis (highest quintile vs lowest quintile of VAT hazard ratio [HR], 2.23; 95% confidence interval [CI], 1.28-3.89; P for trend = .002; HR, 1.36 [per 1 standard deviation]; 95% CI, 1.16-1.59). An increased area of SAT was significantly associated with regression of NAFLD (highest quintile vs lowest quintile of SAT HR, 2.30; 95% CI, 1.28-4.12; P for trend = .002; HR, 1.36 [per 1 standard deviation]; 95% CI, 1.08-1.72).

CONCLUSIONS

In a large cohort study, larger areas of VAT were longitudinally associated with higher risk of incident NAFLD (during a period of approximately 4 years). In contrast, larger areas of SAT were longitudinally associated with regression of NAFLD. These data indicate that certain types of body fat are risk factors for NAFLD, whereas other types could reduce risk for NAFLD.

Relationship of sitting time and physical activity with non-alcoholic fatty liver disease

BACKGROUND & AIMS

The goal of this study was to examine the association of sitting time and physical activity level with non-alcoholic fatty liver disease (NAFLD) in Korean men and women and to explore whether any observed associations were mediated by adiposity.

METHODS

A cross-sectional study was performed on 139,056 Koreans, who underwent a health examination between March 2011 and December 2013. Physical activity level and sitting time were assessed using the validated Korean version of the international Physical Activity Questionnaire Short Form. The presence of fatty liver was determined using ultrasonographic findings. Poisson regression models with robust variance were used to evaluate the association of sitting time and physical activity level with NAFLD.

RESULTS

Of the 139,056 subjects, 39,257 had NAFLD. In a multivariable-adjusted model, both prolonged sitting time and decreased physical activity level were independently associated with increasing prevalence of NAFLD. The prevalence ratios (95% CIs) for NAFLD comparing 5-9 and ⩾10 h/day sitting time to <5h/day were 1.04 (1.02-1.07) and 1.09 (1.06-1.11), respectively (p for trend <0.001). These associations were still observed in subjects with BMI <23 kg/m(2). The prevalence ratios (95% CIs) for NAFLD comparing minimally active and health-enhancing physically active groups to the inactive group were 0.94 (0.92-0.95) and 0.80 (0.78-0.82), respectively (p for trend <0.001).

CONCLUSIONS

Prolonged sitting time and decreased physical activity level were positively associated with the prevalence of NAFLD in a large sample of middle-aged Koreans, supporting the importance of reducing time spent sitting in addition to promoting physical activity.

Visceral adipose tissue area as an independent risk factor for elevated liver enzyme in nonalcoholic fatty liver disease

Chronic elevations in alanine aminotransferase (ALT) levels are associated with body composition. The aim of this study was to evaluate the relationship between elevated liver enzyme levels and the visceral tissue area in subjects with and without nonalcoholic fatty liver disease (NAFLD).An observational cohort study was conducted with subjects undergoing general health examinations. To evaluate the visceral and subcutaneous abdominal adipose tissue area, a computed tomography scan was performed. NAFLD was diagnosed if a person demonstrated fatty liver on ultrasonography without a history of significant alcohol consumption or chronic liver disease. Abnormal liver enzyme levels were based on ALT elevations according to the updated Asian definition.Of the 5100 subjects, 3712 (72.8%) met the inclusion criteria, and NAFLD was found in 1185 subjects. Elevated ALT values were positively correlated with body mass index, waist circumference, and subcutaneous and visceral adipose tissue area. These relationships were attenuated, although they remained significant in a dose-dependent manner, after adjusting for multiple liver injury risk factors. In addition, when body mass index and subcutaneous and visceral tissue areas were finally considered in combination, only visceral adipose tissue remained independently associated with elevated ALT levels in the ultrasonographically diagnosed NAFLD group (P for trend <0.001 for men and women).Elevated ALT levels were independently and dose-dependently associated with visceral fat accumulation in the healthy general population, especially in ultrasonographically diagnosed NAFLD patients. These results reemphasize the importance of visceral fat in the pathogenesis of NAFLD.