Non-alcoholic fatty liver disease is associated with higher levels of objectively measured sedentary behaviour and lower levels of physical activity than matched healthy controls

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.

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

BACKGROUND:

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

AIM:

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

METHODS:

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

RESULTS:

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

CONCLUSION:

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

Improvement of non-invasive markers of NAFLD from an individualised, web-based exercise program

BACKGROUND

Lifestyle modifications remain the cornerstone of treatment in non-alcoholic fatty liver disease (NAFLD). However, they requently fail related to the inability of patients to implement lasting changes.

AIMS

To evaluate the effects of a short, web-based, individualised exercise program on non-invasive markers of hepatic steatosis, inflammation and fibrosis.

METHODS

Patients with histologically confirmed NAFLD underwent an 8-week, web-based, individualised exercise program that contained bidirectional feedback.

RESULTS

Forty-four patients entered the study and 41 completed the assigned training goal (93.2%). In the completer population, 8 weeks of individualised exercise increased the VO_2peak by 12.2% compared to baseline (P < .001). ALT and AST decreased by 14.3% (P = .002) and 18.2% (P < .001) and remained at this level until follow-up 12 weeks after the intervention. Markers of inflammation including hsCRP, ferritin, and M30 decreased. In parallel, gut microbiota exhibited increased metagenomic richness (P < .05) and at the taxonomic levels Bacteroidetes and Euryarchaeota increased whereas Actinobacteria phylum decreased. Surrogate scores of steatosis and fibrosis including the fatty liver index (FLI), FiB-4, APRI and transient elastography showed significant reductions. In parallel, a marker of procollagen-3 turnover (PRO-C3) decreased while C4M2, reflecting type IV collagen, degradation increased suggesting beneficial hepatic fibrosis remodelling from exercise. Also, an enhancement in health-related quality of life was reported.

CONCLUSION

The current study underlines the plausibility and potential of an 8 week individualised web-based exercise program in NAFLD. Clinical trial number: NCT02526732.

NAFLD and Extra-Hepatic Comorbidities: Current Evidence on a Multi-Organ Metabolic Syndrome

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide and its incidence is definitely increasing. NAFLD is a metabolic disease with extensive multi-organ involvement, whose extra-hepatic manifestations include type 2 diabetes mellitus, cardiovascular disease, obstructive sleep apnea, chronic kidney disease, osteoporosis, and polycystic ovarian syndrome. Recently, further evidence has given attention to pathological correlations not strictly related to metabolic disease, also incorporating in this broad spectrum of systemic involvement hypothyroidism, psoriasis, male sexual dysfunction, periodontitis, and urolithiasis. The most common cause of mortality in NAFLD is represented by cardiovascular disease, followed by liver-related complications. Therefore, clinicians should learn to screen and initiate treatment for these extra-hepatic manifestations, in order to provide appropriate multidisciplinary assessments and rigorous surveillance. This review evaluates the current evidence regarding extra-hepatic associations of NAFLD, focusing on the pathogenic hypothesis and the clinical implications.

Nonalcoholic fatty liver disease and alcoholic liver disease: metabolic diseases with systemic manifestations

The progression of liver disease is portrayed by several common, overarching signs and symptoms. Classically, these include findings such as spider angiomata, jaundice, palmar erythema, and as cirrhosis decompensates, ascites, variceal hemorrhage (VH), hepatic encephalopathy (HE), and hepatocellular carcinoma (HCC). Aside from these universal hallmarks among cirrhotics, patients with nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) harbor their own distinct systemic associations and manifestations. NAFLD is tightly linked to metabolic syndrome, which appears to be a driving force for a multitude of comorbidities, such as insulin resistance, cardiovascular disease, chronic kidney disease (CKD), obstructive sleep apnea (OSA), as well as increased malignancy risk. ALD also maintains a variety of comorbidities congruent with systemic effects of chronic alcohol use. These findings are highlighted by cardiovascular conditions, neuronal damage, myopathy, nutritional deficiencies, chronic pancreatitis, in addition to increased malignancy risk. While a general, guideline-driven management for all cirrhotic patients remains imperative for minimizing risk of complications, a tailored treatment strategy is useful for patients with NAFLD and ALD who entertain their own constellation of unique systemic manifestations.

Development of liver surface nodularity quantification program and its clinical application in nonalcoholic fatty liver disease

The liver morphological changes in relation to fibrosis stage in nonalcoholic fatty liver disease (NAFLD) have not yet been clearly understood. This study was to develop a liver surface nodularity (LSN) quantification program and to compare the fibrosis grades in simple steatosis (SS) and nonalcoholic steatohepatitis (NASH). Thirty subjects (7 normal controls [NC], 12 SS and 11 NASH) were studied. LSN quantification procedure was bias correction, boundary detection, segmentation and LSN measurement. LSN scores among three groups and fibrosis grades compared using Kruskal–Wallis H test. Diagnostic accuracy was determined by calculating the area under the receiver operating characteristics (ROC) curve. Mean LSN scores were NC 1.30 ± 0.09, SS 1.54 ± 0.21 and NASH 1.59 ± 0.23 (p = 0.008). Mean LSN scores according to fibrosis grade (F) were F0 1.30 ± 0.09, F1 1.45 ± 0.17 and F2&F3 1.67 ± 0.20 (p = 0.001). The mean LSN score in F2&F3 is significantly higher than that in F1 (p = 0.019). The AUROC curve to distinguish F1 and F2&F3 was 0.788 (95% CI 0.595–0.981, p = 0.019) at a cut-off LSN score greater than 1.48, and its diagnostic accuracy had 0.833 sensitivity and 0.727 specificity. This study developed LSN program and its clinical application demonstrated that the quantitative LSN scores can help to differentially diagnose fibrosis stage in NAFLD.

From NASH to HCC: current concepts and future challenges

Caloric excess and sedentary lifestyle have led to a global epidemic of obesity and metabolic syndrome. The hepatic consequence of metabolic syndrome and obesity, nonalcoholic fatty liver disease (NAFLD), is estimated to affect up to one-third of the adult population in many developed and developing countries. This spectrum of liver disease ranges from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. Owing to the high prevalence of NAFLD, especially in industrialized countries but also worldwide, and the consequent burden of progressive liver disease, there is mounting epidemiological evidence that NAFLD has rapidly become a leading aetiology underlying many cases of hepatocellular carcinoma (HCC). In this Review, we discuss NAFLD-associated HCC, including its epidemiology, the key features of the hepatic NAFLD microenvironment (for instance, adaptive and innate immune responses) that promote hepatocarcinogenesis and the management of HCC in patients with obesity and associated metabolic comorbidities. The challenges and future directions of research will also be discussed, including clinically relevant biomarkers for early detection, treatment stratification and monitoring as well as approaches to therapies for both prevention and treatment in those at risk or presenting with NAFLD-associated HCC.

A Comprehensive Review of Patient-reported Outcomes in Patients With Chronic Liver Diseases

Chronic liver disease (CLD) is a global health problem with chronic viral hepatitis, alcohol-related liver disease, and nonalcoholic fatty liver disease being important causes of mortality. Besides its clinical burden, patients with CLD also suffer from impairment of their health-related quality of life and other patient-reported outcomes (PRO). In this context, a combination of both clinical and PROs will allow assessment of the comprehensive burden of liver disease on patients. PROs cannot be observed directly and must be assessed by validated questionnaires or tools. Various tools have been developed to accurately measure PROs in patients with CLD, including generic and disease-specific questionnaires such as Short Form-36, Chronic Liver Disease Questionnaire and its subtypes. It is important to note that PRO instruments can be used to appreciate the impact of the natural history of CLD or of treatment on patients' experiences. This review summarizes PRO assessment in different types of liver disease and different tools useful to investigators and clinicians who are interested in this aspect of patients' experience.

The influence of dietary fatty acids on liver fat content and metabolism

Non-alcoholic fatty liver disease encompasses a spectrum of conditions from hepatic steatosis through to cirrhosis; obesity is a known risk factor. The liver plays a major role in regulating fatty acid metabolism and perturbations in intrahepatic processes have potential to impact on metabolic health. It remains unclear why intra-hepatocellular fat starts to accumulate, but it likely involves an imbalance between fatty acid delivery to the liver, fatty acid synthesis and oxidation within the liver and TAG export from the liver. As man spends the majority of the day in a postprandial rather than postabsorptive state, dietary fatty acid intake should be taken into consideration when investigating why intra-hepatic fat starts to accumulate. This review will discuss the impact of the quantity and quality of dietary fatty acids on liver fat accumulation and metabolism, along with some of the potential mechanisms involved. Studies investigating the role of dietary fat in liver fat accumulation, although surprisingly limited, have clearly demonstrated that it is total energy intake, rather than fat intake per se, that is a key mediator of liver fat content; hyperenergetic diets increase liver fat whilst hypoenergetic diets decrease liver fat content irrespective of total fat content. Moreover, there is now, albeit limited evidence emerging to suggest the composition of dietary fat may also play a role in liver fat accumulation, with diets enriched in saturated fat appearing to increase liver fat content to a greater extent when compared with diets enriched in unsaturated fats.

Web-Based Exercise as an Effective Complementary Treatment for Patients With Nonalcoholic Fatty Liver Disease: Intervention Study

Background

Physical inactivity is a major risk factor for nonalcoholic fatty liver disease (NAFLD). Exercise-based prevention interventions for improving cardiorespiratory fitness are a recommended complementary treatment for NAFLD. Achievement of minimally effective physical activity to improve cardiorespiratory fitness among patients typically involves high personal and financial expenses in face-to-face settings. We designed an eHealth approach for patients with NAFLD to improve the cardiorespiratory fitness and report the first results of the HELP (Hepatic Inflammation and Physical Performance in Patients With NASH [nonalcoholic steatohepatitis]) study.

Objective

We aimed to assess the effectiveness of an 8-week, tailored, Web-based exercise intervention for cardiorespiratory fitness improvement, expressed as peak oxygen uptake (peak volume of oxygen [VO_2peak]), in patients with histologically confirmed NAFLD.

Methods

In a 24-month period, 44 patients were enrolled into an 8-week, prospective, single-arm study with 12 weeks of follow-up. After a medical examination and performance diagnostics, a sports therapist introduced the patients to a Web-based platform for individualized training support. Regular individual patient feedback was provided to systematically adapt the weekly exercise schedule, which allowed us to monitor and ensure patient adherence to strength and endurance training and optimize the step-wise progressive exercise load. Exercise progression was based on an a priori algorithm that considered the subjective rate for both perceived exhaustion and general physical discomfort. The VO_2peak was assessed at baseline and at the end of the study by spiroergometry.

Results

A total of 43 patients completed the intervention with no adverse events. The VO_2peak increased significantly by 2.4 mL/kg/min (8.8%; 95% confidence interval [CI]: 1.48-3.27; P<.001) accompanied by a reduction of 1.0 kg in a body weight (95% CI: 0.33-1.58; P=.004) and 1.3 kg in body fat mass (95% CI: 0.27-2.27; P=.01). In an exploratory analysis, step-wise logistic regression analysis revealed low body fat and VO_2peak at baseline and the total minutes of endurance training during the intervention as main contributors to a positive change in VO_2peak. Our predictive model indicated that the average patient with NAFLD needed 223 min for stabilization of VO_2peak and 628 min for average improvement in VO_2peak. However, in patients with a VO_2peak approximately 20% higher than the average VO_2peak, 628 min were only sufficient to stabilize the VO_2peak and >40% reduction in the average fat mass would be required to achieve an average outcome.

Conclusions

This is the first study to show that patients with NAFLD can be effectively supported by a Web-based approach, which can increase the VO_2peak to a similar extent as face-to-face interventions. Patients with low body fat and low VO_2peak benefited the most from our intervention. In terms of future treatment strategies, NAFLD patients with high body fat may particularly benefit from body-fat reduction through a strict nutritional intervention, subsequently enabling a more effective exercise intervention.

Trial Registration

ClinicalTrials.gov NCT02526732; https://clinicaltrials.gov/ct2/show/NCT02526732 (Archived by WebCite at http://www.webcitation.org/74pXhXXfq)

International Registered Report Identifier (IRRID)

RR2-10.2196/resprot.8607

A systematic review of the present and future of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the Western world. Ongoing research has furthered our understanding of NAFLD, the nature of progression of this disease, and its impact on morbidity and mortality. An active form of NAFLD is non-alcoholic steatohepatitis (NASH); it is the most severe subtype, without any current recommended therapies, according to the European Medicines Agency. The development of new therapies presents challenges, notably due to the slow progression of NASH and the clinically relevant endpoints.

Correlating new data with effective treatment regimens is an emerging challenge, which will increase our understanding of the factors affecting the NAFLD course. This can enable more appropriate non-invasive prognostic assessments, which can focus on specifically at-risk NAFLD populations for tailored individual treatment. This review article aims to highlight the current developments in the field of NAFLD: pathogenesis, epidemiology, diagnosis, clinical features, and available treatment, including novel targets and therapies.

Short-term decreased physical activity with increased sedentary behaviour causes metabolic derangements and altered body composition: effects in individuals with and without a first-degree relative with type 2 diabetes

AIMS/HYPOTHESIS

Low physical activity levels and sedentary behaviour are associated with obesity, insulin resistance and type 2 diabetes. We investigated the effects of a short-term reduction in physical activity with increased sedentary behaviour on metabolic profiles and body composition, comparing the effects in individuals with first-degree relatives with type 2 diabetes (FDR+ve) vs those without (FDR-ve).

METHODS

Forty-five habitually active participants (16 FDR+ve [10 female, 6 male] and 29 FDR-ve [18 female, 11 male]; age 36 ± 14 years) were assessed at baseline, after 14 days of step reduction and 14 days after resuming normal activity. We determined physical activity (using a SenseWear armband), cardiorespiratory fitness ([Formula: see text]), body composition (dual-energy x-ray absorptiometry/magnetic resonance spectroscopy) and multi-organ insulin sensitivity (OGTT) at each time point. Statistical analysis was performed using a two-factor between-groups ANCOVA, with data presented as mean ± SD or (95% CI).

RESULTS

There were no significant between-group differences in physical activity either at baseline or following step reduction. During the step-reduction phase, average daily step count decreased by 10,285 steps (95% CI 9389, 11,182; p < 0.001), a reduction of 81 ± 8%, increasing sedentary time by 223 min/day (151, 295; p < 0.001). Pooling data from both groups, following step reduction there was a significant decrease in whole-body insulin sensitivity (Matsuda index) (p < 0.001), muscle insulin sensitivity index (p < 0.001), cardiorespiratory fitness (p = 0.002) and lower limb lean mass (p = 0.004). Further, there was a significant increase in total body fat (p < 0.001), liver fat (p = 0.001) and LDL-cholesterol (p = 0.013), with a borderline significant increase in NEFA AUC during the OGTT (p = 0.050). Four significant between-group differences were apparent: following step reduction, FDR+ve participants accumulated 1.5% more android fat (0.4, 2.6; p = 0.008) and increased triacylglycerol by 0.3 mmol/l (0.1, 0.6; p = 0.044). After resuming normal activity, FDR+ve participants engaged in lower amounts of vigorous activity (p = 0.006) and had lower muscle insulin sensitivity (p = 0.023). All other changes were reversed with no significant between-group differences.

CONCLUSIONS/INTERPRETATION

A short-term reduction in physical activity with increased sedentary behaviour leads to a reversible reduction in multi-organ insulin sensitivity and cardiorespiratory fitness, with concomitant increases in central and liver fat and dyslipidaemia. The effects are broadly similar in FDR+ve and FDR-ve individuals. Public health recommendations promoting physical activity should incorporate advice to avoid periods of sedentary behaviour.

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)

Exercise might prevent cirrhosis in overweight and obese adults

BACKGROUND & AIMS

Exercise in overweight patients with liver disease has improved liver enzymes, insulin levels and quality of life. Scientific evidence is incomplete regarding the role of exercise in the prevention of cirrhosis. We investigated the effect of exercise on the occurrence of cirrhosis in obese and overweight adults.

METHODS

Exercise was assessed using the 2012 Adult Preventive Medical Service dataset while cirrhosis was identified using the National Health Insurance Research Database. All participants were aged 40 years and older. Unconditional logistic regression was used to estimate the odds ratios for cirrhosis.

RESULTS

Overall, 1586 overweight and 1525 obese adults were identified with cirrhosis. Weekly exercise >150 min was significantly protective for cirrhosis in obese men and women. However, exercise <150 min/wk was significantly protective only in men compared to women. For weekly exercise >150 mins, the odds ratio for cirrhosis in obese men and women was 0.701 (95% CI: 0.584-0.841) and 0.736 (95% CI: 0.562-0.964) respectively. The adjusted odds ratios in overweight men and women were 0.734 (95% CI: 0.622-0.866) and 0.503 (CI: 0.37-0.684). For weekly exercise <150 min/wk, overweight and obese men had odds ratios of 0.879 (CI: 0.0.788-0.98) and 0.874 (CI: 0.782-0.977) compared to 0.918 (95% CI: 0.778-1.083) and 0.916 (95% CI: 0.780-1.075) in overweight and obese women respectively.

CONCLUSIONS

Moderate exercise might significantly prevent obese and overweight adults from developing cirrhosis. The benefits appear to be greater for persons who exceed the minimum recommendations of 150 min/wk.

Global burden of NAFLD and NASH: trends, predictions, risk factors and prevention

NAFLD is one of the most important causes of liver disease worldwide and will probably emerge as the leading cause of end-stage liver disease in the coming decades, with the disease affecting both adults and children. The epidemiology and demographic characteristics of NAFLD vary worldwide, usually parallel to the prevalence of obesity, but a substantial proportion of patients are lean. The large number of patients with NAFLD with potential for progressive liver disease creates challenges for screening, as the diagnosis of NASH necessitates invasive liver biopsy. Furthermore, individuals with NAFLD have a high frequency of metabolic comorbidities and could place a growing strain on health-care systems from their need for management. While awaiting the development effective therapies, this disease warrants the attention of primary care physicians, specialists and health policy makers.

Ideal cardiovascular health and liver enzyme levels in European adolescents; the HELENA study

There is an increasing interest for the role of liver enzymes as predictors of non-liver-related morbidity and mortality. The American Heart Association (AHA) described the ideal cardiovascular health concept as a score of seven cardiovascular health behaviors and factors that can be used to monitor and predict ideal cardiovascular health over time. This study aimed to examine the association of the ideal cardiovascular health (ICH), as defined by the AHA, with liver enzyme levels in European adolescents. A total of 637 adolescents (54.6% females), aged 14.6 ± 1.2 years from nine European countries participated in this cross-sectional study. Blood levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase were measured and the AST/ALT ratio calculated. Ideal cardiovascular health was defined as meeting ideal levels of the following components: four behaviors (smoking, body mass index, physical activity, and diet) and three factors (total cholesterol, blood pressure, and glucose). A higher number of ideal cardiovascular health behaviors, factors, and ideal cardiovascular health index were associated with lower ALT (P < 0.05, P < 0.001, and P < 0.001, respectively) and gamma-glutamyltransferase (P < 0.001, P < 0.01, and P < 0.001, respectively) levels. Similarly, a higher number of ideal cardiovascular health behaviors (P < 0.01), factors (P < 0.01), and ideal cardiovascular health index (P < 0.001) were associated with a higher aspartate aminotransferase to alanine aminotransferase ratio. These findings reinforce the usefulness of the ICH index as an instrument to identify target individuals and promote cardiovascular health in adolescents, and it also extends these observations to the liver manifestation of the metabolic syndrome.

Physical activity and sedentary behavior can modulate the effect of the PNPLA3 variant on childhood NAFLD: a case-control study in a Chinese population

Background

The patatin like phospholipase containing domain 3 gene (PNPLA3) rs738409 C > G polymorphism, one of the most important gene polymorphisms involved in hepatic steatosis, has been reported to interact with different nutrients and dietary patterns on Non-Alcoholic Fatty Liver Disease (NAFLD), but no studies have focused on its interaction with physical activity or sedentary behavior. Therefore, this study aims at determining whether physical activity or sedentary behavior could modulate the effect of the PNPLA3 variant on childhood NAFLD.

Methods

A case-control study was conducted including 1027 Chinese children aged 7–18 years old (162 children with NAFLD and 865 children without). The anthropometric measurements, liver ultrasound examination, questionnaires and genotyping of the PNPLA3 rs738409 polymorphism were performed.

Results

Stratified analyses showed that the proportions of NAFLD increased with the G-allele number only in children who did not have enough physical activity (physical activity < 1 h/d) (OR 3.05, 95% CI 1.82–5.12, P < 0.001), and in children with a sedentary lifestyle (sedentary behavior ≥ 2 h/d) (OR 3.41, 95% CI 1.88–6.18, P < 0.001). Significant interactions on childhood NAFLD were found between the G-allele number in the PNPLA3 rs738409 polymorphism and behaviors, including physical activity (P = 0.001), sedentary behavior (P = 0.010) and the combination of physical activity and sedentary behavior (P < 0.001).

Conclusion

This is the first study to report the interaction between the PNPLA3 rs738409 polymorphism and physical activity or sedentary behavior on NAFLD, providing new clues on the function of the PNPLA3 gene, which will also be useful for future risk assessment and personalized treatment of NAFLD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-016-0352-9) contains supplementary material, which is available to authorized users.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Associations between sitting time and non-alcoholic fatty liver diseases in Chinese male workers: a cross-sectional study

OBJECTIVES

Various studies have revealed a close association between sedentary behaviour and metabolic diseases, yet the association between sedentary time and non-alcoholic fatty liver disease (NAFLD) remains unclear. In this study, we investigated the association between sitting time and NAFLD in a Chinese male population and explored its underlying mechanism.

STUDY DESIGN

A cross-sectional study.

SETTING

Chongqing, China.

PARTICIPANTS

Our study included 2054 male participants; all of the participants were of Han nationality.

PRIMARY OUTCOME MEASURES

Sitting time was assessed using a self-reported questionnaire concerning the time devoted to sitting behaviour. Various clinical and demographic biomarkers were measured. Logistic regression analyses were used to investigate the ORs and the 95% CIs between sitting time and NAFLD.

RESULTS

We found a higher proportion of NAFLD across the tertiles of sitting time (p trend=0.003). Multivariate linear regression analyses showed sitting time independently correlated with homoeostasis model assessment for insulin resistance (HOMA-IR), alanine aminotransferase, γ-glutamyl transpeptidase, body mass index, triglyceride and the high-sensitive C reactive protein (hsCRP) (all p<0.05). Further logistic regression analyses showed that longer sitting time (>7.1 hours/day) was associated with a higher prevalence of NAFLD (OR 1.09; 95% CI (1.04 to 1.67)) after adjusting for confounders. However, this association was insignificant after further adjusting for hsCRP (OR 1.03; 95% CI (0.92 to 1.84)).

CONCLUSIONS

Sitting time was positively associated with the prevalence of NAFLD, and this association might be affected by inflammation.

Reduction of sitting time has a positive effect on the decrease of insulin resistance in patients with non-alcoholic fatty liver disease

Introduction

Non-alcoholic fatty liver disease (NAFLD) affects a large part of the human population. One of the major environmental factors associated with the risk of NAFLD is the lack of physical activity.

Aim

To compare the level of physical activity and the insulin resistance in NAFLD patients.

Material and methods

Thirty patients with NAFLD underwent a six-month dietary intervention based on the principles of classical dietetics. Data about diet and physical activity was based on 72-hour nutrition diaries and International Physical Activity Questionnaire (IPAQ). Standard blood biochemical analyses were carried out before and after diet at the University Hospital Laboratory.

Results

The study showed that total physical activity and physical activity in leisure time are negatively correlated with insulin resistance (HOMA-IR) (p < 0.05). Insulin (p < 0.05), body weight (p < 0.05), and waist-hip ratio (WHR) (p < 0.05) were also negatively correlated with physical activity in free time. In addition, we noticed a positive correlation between sitting time and the risk of insulin resistance, in the case of HOMA-IR and insulin concentration (p < 0.05).

Conclusions

Dietary intervention and a physical activity plan are important factors in the treatment of non-alcoholic fatty liver disease. Taking regular exercise increases insulin sensitivity and prevents further development of the disease. It seems that diet and physical activity are not the only one risk factors of NAFLD. Our study reveals that the reduction of sitting time has a positive effect on the level of insulin and it reduces insulin resistance in patients with NAFLD.

Survival effects of physical activity on mortality among persons with liver disease

Physical activity is protective of premature mortality and those with liver disease are at an increased risk of early mortality. It is thus plausible to suggest that physical activity may have survival benefits among those with liver disease, but this has yet to be investigated. In a national sample, we examine the prospective association of objectively-measured physical activity on all-cause mortality among those with liver disease. Data from the 2003-2006 National Health and Nutrition Examination Survey (with follow-up through 2011) were evaluated (analyzed in 2015). Physical activity was assessed via accelerometry over 7 days. Liver disease was assessed via self-report of physician diagnosis. Covariates included age, gender, race-ethnicity, serum cotinine, income-to-poverty ratio, C-reactive protein, cholesterol medication use, blood pressure medication use, alcohol behavior, self-reported liver disease status, serum alanine aminotransferase (ALT), serum gamma-glutamyltransferase (GGT) and comorbid illness. The sample included 162 adults who self-reported a physician-diagnosis of liver disease. The unweighted median follow-up period was 80.0 months (IQR = 68-91; SD = 18.0). In the sample, 12,815 person-months occurred with a mortality incidence rate of 1.09 deaths per 1000 person-months. After adjustments, for every 10 min/day increase in moderate-to-vigorous physical activity (MVPA), participants had an 89% reduced risk of all-cause mortality (HRadjusted = 0.11; 95% CI: 0.02-0.47; P = 0.004). There was no evidence of moderation by alcohol behavior, ALT, GGT or Hepatitis C virus status. These findings demonstrate that modest increases in MVPA may have survival benefits among those with a self-reported liver condition.

Targeting Lifestyle Behavior Change in Adults with NAFLD During a 20-min Consultation: Summary of the Dietary and Exercise Literature

Non-alcoholic fatty liver disease (NAFLD) is largely linked to poor diet, lack of physical activity/exercise, and being overweight. In the absence of approved pharmaceutical agents, lifestyle modification, encompassing dietary change and increased physical activity/exercise to initiate weight loss, is the recommended therapy for NAFLD. Despite this, the use of lifestyle therapy within clinical settings is lacking with limited guidance available about what it should involve, how it should be delivered, and whether it can be feasibly delivered as part of standard care. This paper highlights the evidence for the use of lifestyle modification in NAFLD. While there is evidence to support use of behavioral strategies to support lifestyle behavior change in other clinical populations, these are yet to be assessed in people with NAFLD. However, there is sufficient evidence to suggest that behavioral intervention targeting diet and physical activity to promote weight loss in general is effective and a number of practical strategies are presented on how this could be achieved.

Objectively Quantified Physical Activity and Sedentary Behavior in Predicting Visceral Adiposity and Liver Fat

Objective. Epidemiologic studies suggest an inverse relationship between nonalcoholic fatty liver disease (NAFLD), visceral adipose tissue (VAT), and self-reported physical activity levels. However, subjective measurements can be inaccurate and prone to reporter bias. We investigated whether objectively quantified physical activity levels predicted liver fat and VAT in overweight/obese adults. Methods. Habitual physical activity was measured by triaxial accelerometry for four days (n = 82). Time spent in sedentary behavior (MET < 1.6) and light (MET 1.6 < 3), moderate (MET 3 < 6), and vigorous (MET 6 < 9) physical activity was quantified. Magnetic resonance imaging and spectroscopy were used to quantify visceral and liver fat. Bivariate correlations and hierarchical multiple regression analyses were performed. Results. There were no associations between physical activity or sedentary behavior and liver lipid. Sedentary behavior and moderate and vigorous physical activity accounted for just 3% of variance for VAT (p = 0.14) and 0.003% for liver fat (p = 0.96). Higher levels of VAT were associated with time spent in moderate activity (r = 0.294, p = 0.007), but there was no association with sedentary behavior. Known risk factors for obesity-related NAFLD accounted for 62% and 40% of variance in VAT and liver fat, respectively (p < 0.01). Conclusion. Objectively measured levels of habitual physical activity and sedentary behavior did not influence VAT or liver fat.

Assessment of Diet and Physical Activity in Paediatric Non-Alcoholic Fatty Liver Disease Patients: A United Kingdom Case Control Study

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children, with prevalence rising alongside childhood obesity rates. This study aimed to characterise the habitual diet and activity behaviours of children with NAFLD compared to obese children without liver disease in the United Kingdom (UK). Twenty-four biopsy-proven paediatric NAFLD cases and eight obese controls without biochemical or radiological evidence of NAFLD completed a 24-h dietary recall, a Physical Activity Questionnaire (PAQ), a Dutch Eating Behavior Questionnaire (DEBQ) and a 7-day food and activity diary (FAD), in conjunction with wearing a pedometer. Groups were well matched for age and gender. Obese children had higher BMI z-scores (p = 0.006) and BMI centiles (p = 0.002) than participants with NAFLD. After adjusting for multiple hypotheses testing and controlling for differences in BMI, no differences in macro- or micronutrient intake were observed as assessed using either 24-h recall or 7-day FAD (p > 0.001). Under-reporting was prevalent (NAFLD 75%, Obese Control 87%: p = 0.15). Restrained eating behaviours were significantly higher in the NAFLD group (p = 0.005), who also recorded more steps per day than the obese controls (p = 0.01). In conclusion, this is the first study to assess dietary and activity patterns in a UK paediatric NAFLD population. Only a minority of cases and controls were meeting current dietary and physical activity recommendations. Our findings do not support development of specific dietary/ physical activity guidelines for children with NAFLD; promoting adherence with current general paediatric recommendations for health should remain the focus of clinical management.

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.

Nonalcoholic fatty liver disease and decreased bone mineral density: is there a link?

PURPOSE

Liver diseases are associated with decreased bone mineral density (BMD) and evidence suggests that nonalcoholic fatty liver disease (NAFLD) affects several extra-hepatic organs, interacting with the regulation of multiple endocrine and metabolic pathways. This review focuses on the rapidly expanding body of evidence that supports a strong association between NAFLD and the risk of decreased BMD, expression of low bone mass (osteoporosis), or reduced mineralization (osteomalacia).

METHODS

We identified studies by searching PubMed for original articles published in English through March 2015 using the keywords "nonalcoholic fatty liver disease" or "fatty liver" combined with "bone mineral density", "osteoporosis", or "osteomalacia".

RESULTS

Recent cross-sectional and case-control studies involving both adults and children have consistently shown that patients with NAFLD exhibit a greater prevalence of decreased BMD compared with age-, sex-, and body mass index-matched healthy controls. Accumulating clinical and experimental evidence suggests that NAFLD may contribute to the pathophysiology of low BMD, possibly through the direct contribution of NAFLD to whole-body and hepatic insulin resistance and/or the systemic release of multiple pro-inflammatory, pro-coagulant, and pro-fibrogenic mediators.

CONCLUSIONS

Although more research is needed before firm conclusions can be drawn, it appears that there is a non-chance, statistical association between NAFLD and low BMD. This finding argues for more careful monitoring and evaluation of BMD among patients with NAFLD. The potential contribution of NAFLD itself to the development and progression of decreased BMD warrants further study.