Epidemiology and Natural History of Non-alcoholic Fatty Liver Disease

Controlled attenuation parameter is correlated with actual hepatic fat content in patients with non-alcoholic fatty liver disease with none-to-mild obesity and liver fibrosis

AIM

Non-invasive steatosis-quantifying methods are required for non-alcoholic fatty liver disease (NAFLD) patients in order to monitor disease severity and assess therapeutic efficacy. Controlled attenuation parameter (CAP) evaluated with vibration-controlled transient elastography can predict the presence of steatosis, but its application to absolute hepatic fat quantitation remains unclear. The aim of this st\udy was to examine whether CAP is correlated with real hepatic fat content in NAFLD patients.

METHODS

Eighty-two NAFLD patients who had undergone percutaneous liver biopsy were enrolled. CAP was measured using FibroScan(®) just before liver biopsy. The percentage of fat droplet area to hepatocyte area in biopsied specimen was determined morphometrically using computerized optical image analyzing system. The correlation between CAP and liver histology was examined.

RESULTS

CAP showed an excellent correlation with actual liver fat percentage in the NAFLD patients with body mass index (BMI) of less than 28 kg/m(2) (r = 0.579, P < 0.0001), especially less than 25 kg/m(2) (r = 0.708, P < 0.01), but the meaningful correlation disappeared in the patients with BMI of 28 kg/m(2) or more. In the patients with BMI of less than 28 kg/m(2) , CAP quantitativeness was affected by the presence of stage 2-4 fibrosis, but not the presence of hepatocyte ballooning and severity of lobular inflammation.

CONCLUSION

CAP may be a promising tool for quantifying hepatic fat content in NAFLD patients with none-to-mild obesity and liver fibrosis. Further improvement of CAP performance is needed for the NAFLD patients with BMI of more than 28 kg/m(2) or significant hepatic fibrosis.

Assessment of health utilities and quality of life in patients with non-alcoholic fatty liver disease

Background

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease associated with increased liver-related mortality. Additionally, NAFLD could potentially impair health-related quality of life. Although an approved treatment for NAFLD does not exist, a number of new drugs for treatment of NAFLD are being developed. As the efficacy and safety of these regimens are being established, their cost-effectiveness, which requires the use of quality of life metrics and health utility scores to quality-adjusted outcomes, must also be assessed. The aim of this study was to report quality of life and health utilities in patients with NAFLD with and without cirrhosis for future use.

Methods

Patients with NAFLD were seen in an outpatient clinic setting. Each patient had extensive clinical data and completed the Short Form-36 (SF-36 V.1) questionnaire. The SF-6D health utility scores were calculated.

Results

There were 89 patients with the spectrum of NAFLD completed the SF-36 questionnaire: 59 with non-cirrhotic NAFLD and 30 with cirrhosis. Patients with NAFLD had significantly lower quality of life and health utility scores than the general population (all p<0.0001). Furthermore, patients with cirrhosis had lower quality of life and utility scores than non-cirrhotic NAFLD patients: SF-6D 0.660±0.107 in non-cirrhotic NAFLD vs 0.551±0.138 in cirrhotic NAFLD (p=0.0003).

Conclusions

Health utilities and quality of life scores are impaired in patients with cirrhotic NAFLD. These values should be used in cost-effectiveness analysis of the upcoming treatment regimens for advanced NAFLD.

Non-alcoholic fatty liver disease and dyslipidemia: An update

Non-alcoholic fatty liver (NAFLD) is the most common liver disease worldwide, progressing from simple steatosis to necroinflammation and fibrosis (leading to non-alcoholic steatohepatitis, NASH), and in some cases to cirrhosis and hepatocellular carcinoma. Inflammation, oxidative stress and insulin resistance are involved in NAFLD development and progression. NAFLD has been associated with several cardiovascular (CV) risk factors including obesity, dyslipidemia, hyperglycemia, hypertension and smoking. NAFLD is also characterized by atherogenic dyslipidemia, postprandial lipemia and high-density lipoprotein (HDL) dysfunction. Most importantly, NAFLD patients have an increased risk for both liver and CV disease (CVD) morbidity and mortality. In this narrative review, the associations between NAFLD, dyslipidemia and vascular disease in NAFLD patients are discussed. NAFLD treatment is also reviewed with a focus on lipid-lowering drugs. Finally, future perspectives in terms of both NAFLD diagnostic biomarkers and therapeutic targets are considered.

Effectiveness of exercise in hepatic fat mobilization in non-alcoholic fatty liver disease: Systematic review

AIM: To investigate the efficacy of exercise interventions on hepatic fat mobilization in non-alcoholic fatty liver disease (NAFLD) patients.

METHODS: Ovid-Medline, PubMed, EMBASE and Cochrane database were searched for randomized trials and prospective cohort studies in adults aged ≥ 18 which investigated the effects of at least 8 wk of exercise only or combination with diet on NAFLD from 2010 to 2016. The search terms used to identify articles, in which exercise was clearly described by type, duration, intensity and frequency were: “NASH”, “NAFLD”, “non-alcoholic steatohepatitis”, “non-alcoholic fatty liver disease”, “fat”, “steatosis”, “diet”, “exercise”, “MR spectroscopy” and “liver biopsy”. NAFLD diagnosis, as well as the outcome measures, was confirmed by either hydrogen-magnetic resonance spectroscopy (H-MRS) or biopsy. Trials that included dietary interventions along with exercise were accepted if they met all criteria.

RESULTS: Eight studies met selection criteria (6 with exercise only, 2 with diet and exercise with a total of 433 adult participants). Training interventions ranged between 8 and 48 wk in duration with a prescribed exercise frequency of 3 to 7 d per week, at intensities between 45% and 75% of VO₂ peak. The most commonly used imaging modality was H-MRS and one study utilized biopsy. The effect of intervention on fat mobilization was 30.2% in the exercise only group and 49.8% in diet and exercise group. There was no difference between aerobic and resistance exercise intervention, although only one study compared the two interventions. The beneficial effects of exercise on intrahepatic triglyceride (IHTG) were seen even in the absence of significant weight loss. Although combining an exercise program with dietary interventions augmented the reduction in IHTG, as well as improved measures of glucose control and/or insulin sensitivity, exercise only significantly decreased hepatic lipid contents.

CONCLUSION: Prescribed exercise in subjects with NAFLD reduces IHTG independent of dietary intervention. Diet and exercise was more effective than exercise alone in reducing IHTG.

Contribution of Alcoholic and Nonalcoholic Fatty Liver Disease to the Burden of Liver-Related Morbidity and Mortality

Nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are common causes of chronic liver disease. NAFLD is associated with obesity and metabolic syndrome whereas ALD is associated with excessive alcohol consumption. Both diseases can progress to cirrhosis, hepatocellular carcinoma, and liver-related death. A higher proportion of patients with NAFLD die from cardiovascular disorders than patients with ALD, whereas a higher proportion of patients with ALD die from liver disease. NAFLD and ALD each are associated with significant morbidity, impairment to health-related quality of life, and economic costs to society.

Epidemiology of Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis in the United States and the Rest of the World

Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease with increasing prevalence, which can progress to cirrhosis and liver failure. Because of the obesity epidemic and increasing prevalence of metabolic syndrome, NAFLD and its progressive form, nonalcoholic steatohepatitis, are seen more commonly in different parts of the world. This article reviews the worldwide epidemiology of NAFLD and nonalcoholic steatohepatitis. The PubMed database was used to identify studies related to epidemiology of NAFLD in the adult population. It is estimated that the epidemic of obesity will continue to fuel the burden of NAFLD and its long-term complications.

Editor-in-Chief's welcome to Hepatology, Medicine and Policy

Hepatology, Medicine and Policy (HMAP), a new open-access peer-reviewed journal, is making its debut at a time when the hepatitis field is seeing great progress but still has far to go. The World Health Organization and many countries have shown increasing interest in viral hepatitis in recent years, helping to foster a stronger response to this group of diseases. Meanwhile, alcohol-associated cirrhosis and alcohol-associated liver cancer continue to take a heavy toll worldwide, as does non-alcoholic fatty liver disease. The lack of a unified strategic response to viral hepatitis and other liver diseases is the impetus for launching HMAP, which will publish policy, public health and social science articles alongside clinical science articles. It will encourage submissions in diverse domains such as disease prevention and management, epidemiology, economics, health behavior, health service delivery, ethics, human rights, and the role of laws, policies and clinical guidelines in shaping health initiatives. The current attention to powerful new hepatitis C treatments presents a strategic opportunity to more comprehensively address the full constellation of biomedical and social issues relating to liver health. HMAP is committed to publishing research and policy articles that help to drive forward this broader agenda.

Hepatic manifestations of women with polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) have a higher prevalence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) than the general population. The link between NAFLD/NASH and PCOS is not just a coincidence. Indeed, both of these disorders comprise common risk factors, including central obesity, insulin resistance, chronic low-grade inflammation, and hyperandrogenemia. The characteristics of hyperandrogenemia in women with PCOS include elevated total and free testosterone levels and low sex hormone-binding globulin levels and are reported to be associated with NAFLD and elevated liver enzymes; however, not all elevated androgen levels in women with PCOS have the same adverse effects on the liver. With the exception of weight loss and encouraging exercise in obese women, few evidence-based effective treatments target NAFLD/NASH in women with PCOS. Selective antiandrogens and insulin sensitizers might be beneficial in treating NAFLD/NASH in women with PCOS, but further elucidation is needed.

Relevance of low testosterone to non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a condition where there is excess accumulation of triglycerides in the liver in the absence of excess alcohol consumption. It ranges from simple steatosis to non-alcoholic steatohepatitis (NASH), which can progress to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). NAFLD, one of the most common causes of chronic liver disease in Western populations, is the hepatic component of the metabolic syndrome (MetS) and is associated with increased visceral adipose tissue (VAT), insulin resistance, and dyslipidemia. Studies have also shown that testosterone deficiency is associated with increased VAT and insulin resistance in males while hyperandrogenemia has been associated with increased risk of insulin resistance and VAT in females. Thus, the aims of this review are to discuss the available experimental and epidemiological data evaluating the association between testosterone and NAFLD, to discuss the potential clinical relevance of these data, and to identify gaps in the literature.