Prevalence of and risk factors for non-alcoholic fatty liver disease in a non-obese Japanese population, 2011-2012

Nonalcoholic fatty liver disease in Asia: emerging perspectives

As in the West, nonalcoholic fatty liver disease (NAFLD) is the commonest chronic liver disease in Asia, with a prevalence higher than 40 % in some countries. The risk factors for NAFLD development are similar to those in Western countries, including increased body mass index, diabetes, insulin resistance, and metabolic syndrome. NAFLD in Asians is associated with different extrahepatic manifestations involving the cardiovascular, gastrointestinal, and renal systems. A considerable proportion of Asians with NAFLD are described as having "lean" NAFLD. Present in approximately 20 % of the Asian population, lean NAFLD is closely linked with insulin resistance, diabetes, and other metabolic complications, but its association with disease progression to nonalcoholic steatohepatitis and cirrhosis remains to be defined. There is emerging evidence of the interactions of NAFLD with hepatitis B virus and hepatitis C virus infection in Asia. Unlike in Western countries, NAFLD constitutes only a minority of cirrhosis and hepatocellular carcinoma cases in Asia. Possible explanations are the lower prevalence of obesity and the overwhelming problem of viral hepatitis in Asia. With aging of the obesity cohort in Asia, NAFLD-related liver complications are expected to increase.

Alcohol consumption and risk of fatty liver disease: a meta-analysis

BACKGROUND

Observational studies have shown inconsistent results regarding alcohol consumption and risk of fatty liver. We performed a meta-analysis of published literature to investigate the association between alcohol consumption and fatty liver disease (FLD).

METHODS

We searched Medline, Embase, Web of Science, and several Chinese databases, identifying studies that reported an association between alcohol consumption and the risk of FLD.

RESULTS

A total of 16 studies with 76,608 participants including 13 cross-sectional studies, two cross-sectional following longitudinal studies, and one cohort study met the inclusion criteria. For light to moderate alcohol consumption (LMAC), there was a 22.6% reduction in risk of FLD (odds ratio [OR] = 0.774, 95% confidence interval CI [0.695-0.862], P <0.001), and subgroup analysis showed that a greater reduction in risk of FLD was found in the female drinkers (30.2%) and the drinkers with BMI ≥25 kg/m2(31.3%) compared with the male drinkers (22.6%) and the drinkers with BMI <25 kg/m2(21.3%), respectively. For heavy alcohol consumption, there was no significant influence on risk of FLD (OR = 0.869, 95% CI [0.553-1.364], P = 0.541) in Japanese women, but there was a 33.7% reduction in risk of FLD (OR = 0.663, 95% CI [0.574-0.765], P < 0.001) in Japanese men and a significant increased risk of FLD (OR = 1.785, 95% CI [1.064-2.996], P = 0.028) in Germans.

CONCLUSION

LMAC is associated with a significant protective effect on FLD in the studied population, especially in the women and obese population. However, the effect of heavy alcohol consumption on FLD remains unclear due to limited studies and small sample sizes.

Characteristics of non-obese non-alcoholic fatty liver disease: Effect of genetic and environmental factors

AIM

There are a considerable number of patients with non-obese non-alcoholic fatty liver disease (NAFLD). However, the clinical characteristics of non-obese NAFLD is not fully understood. We investigated genetic and other clinical parameters in non-obese and obese NAFLD.

METHODS

The single nucleotide polymorphism rs738409 in the patatin-like phospholipase 3 gene (PNPLA3) was genotyped by the Invader assay in 540 NAFLD patients (134 non-obese and 406 obese) and 1012 control subjects (782 non-obese and 230 obese). All NAFLD patients underwent liver biopsy. Odds ratios were calculated by multiple logistic regression analysis using age, sex, body mass index (BMI), type 2 diabetes mellitus (T2DM) and rs738409 genotype as explanatory variables.

RESULTS

Non-obese NAFLD subjects had a higher rs738409 GG genotype than obese NAFLD. Multiple logistic regression analysis indicated that the odds ratios of T2DM and rs738409 GG genotype for NAFLD were higher in non-obese than in obese groups. In non-obese NAFLD, rs738409 GG genotype was associated with lobular inflammation, hepatocyte ballooning and NAFLD activity score. In obese NAFLD, BMI and T2DM but not rs738409 GG genotype were associated with severity of histology.

CONCLUSION

We demonstrated that the risk factors for the development and progression of NAFLD were different between non-obese and obese patients and that PNPLA3 rs738409 was strongly associated with the development and progression of non-obese NAFLD.

Increased risk of chronic liver disease in patients with bipolar disorder: A population-based study

OBJECTIVE

This study aimed to investigate the prevalence and incidence of chronic liver disease in patients with bipolar disorder.

METHODS

We used a random sample of 766,427 subjects aged ≥18 years from the National Health Research Institute database in the year 2005. Subjects with at least one primary diagnosis of bipolar disorder in 2005 were identified. Patients with a primary or secondary diagnosis of chronic liver disease were also defined. We compared the prevalence and associated factors of chronic liver disease between patients with bipolar disorder and the general population in 2005. We also compared the incidence of chronic liver disease in patients with bipolar disorder and the general population from 2006 to 2010.

RESULTS

The prevalence of chronic liver disease in patients with bipolar disorder (13.9%) was 2.68 times higher than that of the general population (5.8%) in 2005. The average annual incidence of chronic liver disease in patients with bipolar disorder from 2006 to 2010 was also higher than that of the general population (2.95% vs. 1.73%; risk ratio: 1.71; 95% confidence interval: 1.46-2.01).

CONCLUSIONS

Patients with bipolar disorder had a significantly higher prevalence and incidence of chronic liver disease than those in the general population, and younger patients with bipolar disorder have a much higher prevalence and incidence than those in the general population. Male sex, second-generation antipsychotic or antidepressant use, and hyperlipidemia were associated factors for chronic liver disease in patients with bipolar disorder.

Ethnicity matters: A Systematic Review and Meta-Analysis of the Non-Linear Relationship Between Alcohol Consumption and Prevalence and Incidence of Hepatic Steatosis

BACKGROUND

Fatty liver (hepatic steatosis) is one of the most common diseases globally, with increasing prevalence. The role of alcohol consumption in the development of hepatic steatosis has not been systematically examined.

METHODS

We searched Medline, Embase, and ProQuest Dissertations & Theses Global for original data on the relationship between alcohol consumption and hepatic steatosis measured by non-invasive imagery, excluding studies conducted in participants <18years, or subgroups related to viral and drug-induced liver disease. We identified 18 articles reporting adjusted data (Japan=11, other high-income countries=7). Random-effect categorical meta-analyses (<20g/day pure alcohol consumption vs non-drinkers) and dose-response meta-analyses for the whole range of alcohol consumption were conducted.

RESULTS

In total, 99,370 participants and 25,662 cases of hepatic steatosis were included. In Japan, low alcohol consumption was consistently associated with substantially reduced incidence and prevalence of hepatic steatosis compared to non-drinkers (RR for <20g pure alcohol/day=0.75, 95% CI: 0.71-0.79, I(2)=0%). No overall association was found in other countries (RR=1.05, 95% CI: 0.86-1.30, I(2)=84%). Dose-response analyses in Japan (up to 80g/day) showed an inverse relationship in men and a J-shape in women.

CONCLUSIONS

Alcohol consumption showed a complex association with hepatic steatosis with substantial differences by ethnicity and sex. Low alcohol consumption was beneficial in Japan with good epidemiological evidence, whereas there was no association in other countries. However, heterogeneity was large in countries other than Japan. More and higher quality research in diverse ethnic populations is needed to further clarify this relationship.

Lean NAFLD: An Underrecognized Outlier

Nonalcoholic fatty liver disease (NAFLD) is commonly diagnosed in obese or overweight individuals. However, lean individuals with NAFLD are not rare but represent one significant end of the phenotypic spectrum of NAFLD. Although initial observations between obese and lean NAFLD reveal some metabolic parallels, these associations vary widely given differences in study populations and metabolic parameters assessed. The role of body composition in risk assessment is significant and incompletely assessed during most clinical encounters. Recent multinational investigation reveals an increased mortality in lean individuals with NASH. Many aspects of lean NAFLD need further exploration including epidemiology, clinical risk assessment, histologic changes unique to lean NAFLD, genetic and pathophysiologic mechanisms predisposing at risk individuals, natural history and treatment strategies in this underrecognized population.

Nonalcoholic fatty liver disease severity is associated with the ratios of total cholesterol and triglycerides to high-density lipoprotein cholesterol

BACKGROUND

Limited data support the notion that lipid ratios are risk factors for nonalcoholic fatty liver disease (NAFLD). We evaluated the association between lipid ratios and NAFLD.

METHODS

This was a large population, cross-sectional, retrospective study. Data on NAFLD severity, blood pressure, fasting glucose, total cholesterol (TC), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) levels were obtained from 44,767 examinees at single health checkup center. The enrollees were stratified into four subgroups based on their TC/HDL-C and TG/HDL-C ratios. We used multivariate analyses to evaluate the odds between lipid ratios and NAFLD.

RESULTS

The prevalence rate of fatty liver in this study was 53.76%. In the baseline subgroup with the lowest TC/HDL-C and TG/HDL-C ratios, the prevalence of NAFLD, hypertension, and diabetes was lower than that of the other three subgroups. Patients with higher lipid ratios had a significantly greater risk for advanced NAFLD.

CONCLUSIONS

Adults with high TC/HDL-C or TG/HDL-C ratios, or both, have a greater risk for NAFLD, especially advanced NAFLD.

Neck circumference as an independent indicator to non-alcoholic fatty liver disease in non-obese men

Background

To investigate the relationship of the neck circumference (NC) with non-alcoholic fatty liver disease (NAFLD) in non-obese Chinese population.

Methods

Our data were obtained from a cross-sectional survey on the prevalence of metabolic diseases and risk factors in East China in 2014. Subjects with a BMI ≥ 18.5 kg/m² and < 25 kg/m² were considered normal weight. A total of 2668 participants aged 18–89 were identified for analysis. Anthropometric indices, biochemical parameters, clinical characteristics and abdominal ultrasound were measured. Independent predictors of NAFLD were identified by multiple logistic regressions.

Results

The overall prevalence of NAFLD was 10.94 % in this study population and men had a higher prevalence than women (19.89 % vs 7.48 %, P < 0.01). The mean NC was greater in NAFLD subjects compared with other groups in both genders (P < 0.01). NC was correlated to BMI, waist circumference, hip circumference, systolic blood pressure, diastolic blood pressure, insulin, HOMA-IR, triglycerides and ALT, regardless of sex. In the highest quartile of NC levels in men but not in women, the risks were substantially higher for NAFLD [odds ratio 2.18, (95 % confidence interval 1.16–4.13)] (P < 0.001 for trend) after adjusting for potential confounding factors.

Conclusion

NC was an independent indicator for NAFLD in normal weighted men.

Cholesterol induces lipoprotein lipase expression in a tree shrew (Tupaia belangeri chinensis) model of non-alcoholic fatty liver disease

Animal models are indispensible to investigate the pathogenesis and treatments of non-alcoholic fatty liver diseases (NAFLD). Altered cholesterol metabolism has been implicated into the pathogenesis of NAFLD. Here, using high fat, cholesterol and cholate diet (HFHC), we generated a novel tree shrew (Tupaia belangeri chinensis) model of NAFLD, which displayed dyslipidemia with increased levels of plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-c) and high density lipoprotein-cholesterol (HDL-c), but decreased level of triglycerides (TG). Liver histopathology and genes expression indicated that HFHC diet successfully induced liver steatosis to inflammation and fibrosis progressively within 10 weeks. Moreover, HFHC induced the transcriptional expression of lipoprotein lipase (lpl) in the liver, but repressed the expression of LDL receptor, and the endogenous synthesis pathway and excretion of cholesterol. Notably, Poloxamer 407 (P-407) inhibition of LPL improved the severity of steatosis and reduced inflammation. These results illustrated that LPL plays an important role in cholesterol metabolism in NAFLD, and the tree shrew may be a valuable animal model for further research into NAFLD.

Biphasic effect of alcohol intake on the development of fatty liver disease

BACKGROUND

Fatty liver is an important clinical feature not only in alcoholic and non-alcoholic fatty liver diseases, but in other chronic liver diseases as well. Our aim was to elucidate the effect and relationship between habitual alcohol intake and obesity in the development of fatty liver disease.

METHODS

We enrolled 8,029 subjects undergoing abdominal ultrasonography with general medical examinations, and analyzed the factors associated with fatty liver based on daily alcohol intake, body mass index (BMI), and waist circumference.

RESULTS

For fatty liver, BMI, waist circumference, total cholesterol, triglycerides, and fasting plasma glucose were significant and independent risk factors. Heavy alcohol intake (50 g/day) was a significant risk factor for fatty liver in women (odds ratio [OR], 3.35). Analysis based on the presence or absence of obesity revealed that moderate alcohol intake was a significant negative risk factor for fatty liver in both male and female obese (BMI ≥25 kg/m(2)) subjects (OR, 0.74 for non-obese and 0.39 for obese patients, respectively). Heavy alcohol intake was also a significant negative risk factor in obese males (0.62). In contrast, heavy alcohol intake was a risk factor in non-obese males (OR, 1.29) and in all females (OR, 2.22 for non-obese and 6.6 for obese patients, respectively).

CONCLUSIONS

The influence of alcohol intake on fatty liver differed depending on the level of alcohol consumption, gender, and the presence of obesity, and showed biphasic effects.

The Impact of PNPLA3 rs738409 Genetic Polymorphism and Weight Gain ≥10 kg after Age 20 on Non-Alcoholic Fatty Liver Disease in Non-Obese Japanese Individuals

Non-alcoholic fatty liver disease (NAFLD) in non-obese individuals is inadequately elucidated. We aim to investigate the impact of known genetic polymorphisms on NAFLD and the interaction between genetic risks and weight gain on NAFLD in obese and non-obese Japanese individuals. A total of 1164 participants who received health checkups were included. Participants with excessive alcohol consumption, with viral hepatitis or other inappropriate cases were excluded. Fatty liver was diagnosed by ultrasonography. Participants with a body mass index (BMI) of <18.5 kg/m2, 18.5-22.9 kg/m2, 23.0-24.9 kg/m2 and ≥25 kg/m2 were classified underweight, normal weight, overweight and obese, respectively. Self-administered questionnaire for lifestyle was assessed and a total of 8 previously reported genetic polymorphisms were chosen and examined. In all, 824 subjects were enrolled. The overall prevalence of NAFLD was 33.0%: 0% in underweight, 15.3% in normal weight, 41.1% in overweight and 71.7% in obese individuals. The prevalence of NAFLD is more affected by the G allele of patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 in normal weight (odds ratio (OR) 3.52; 95%-CI: 1.42-8.71; P = 0.0063) and in overweight individuals (OR 2.60; 95%-CI: 1.14-5.91; P = 0.0225) than in obese individuals (not significant). Moreover, the G allele of PNPLA3 rs738409 and weight gain ≥10 kg after age 20 had a joint effect on the risk of NAFLD in the normal weight (OR 12.00; 95% CI: 3.71-38.79; P = 3.3×10-5) and the overweight individuals (OR 13.40; 95% CI: 2.92-61.36; P = 0.0008). The G allele of PNPLA3 rs738409 is a prominent risk factor for NAFLD and the interaction between the PNPLA3 rs738409 and weight gain ≥10 kg after age 20 plays a crucial role in the pathogenesis of NAFLD, especially in non-obese Japanese individuals.

Somatotipo, fatores de risco e razão cintura-estatura em indivíduos fisicamente ativos

INTRODUÇÃO: A relação entre o tipo físico e o risco cardiovascular vem sendo estudada em diversas populações do mundo. No Brasil, estudos que avaliam esta relação são escassos, principalmente quando se trata de indivíduos que praticam atividades físicas. Objetivo: Analisar a relação do somatotipo com fatores de risco cardiovascular e razão cintura-estatura (RCEst) em praticantes de atividade física.MÉTODOS: Trata-se de uma pesquisa descritiva com delineamento transversal. A amostra foi constituída por 280 sujeitos, usuários da pista de Cooper da Universidade Federal de Pernambuco, na cidade de Recife, PE, Brasil. Para identificação do nível de atividade física, utilizou-se a versão curta do International Physical Activity Questionnaire(IPAQ). Os indivíduos classificados como muito ativos, ativos ou irregularmente ativos A ou B, foram incluídos na amostra. Excluíram-se os sujeitos inativos fisicamente. O somatotipo foi estimado através do protocolo antropométrico de Carter e Heath (1990). Determinaram-se como fatores de risco cardiovascular o tabagismo, o consumo de bebida alcoólica e a pressão arterial (PA). Empregou-se a estatística descritiva para caracterização da amostra, em seguida, utilizou-se a Análise de Variância Multivariada (MANOVA), com nível de significância de p < 0,05.RESULTADOS: Não foi identificada relação significativa para as variáveis tabagismo e consumo de bebida alcoólica. Na análise da PA (Pillai's trace = 0,082; F = 8,187; p < 0,05) e da RCEst (Pillai's trace = 0,298; F = 39,081; p < 0,05), verificou-se significância estatística com o somatotipo.CONCLUSÃO: O tipo físico foi positivo e significativamente relacionado com a PA e com a RCEst, demonstrando que esse indicador antropométrico pode ser utilizado para predizer precocemente o risco de desenvolvimento de doenças cardiovasculares.

S100A9: A Potential Biomarker for the Progression of Non-Alcoholic Fatty Liver Disease and the Diagnosis of Non-Alcoholic Steatohepatitis

Non-alcoholic fatty liver (NAFL) has the potential to progress to non-alcoholic steatohepatitis (NASH) or to promote type 2 diabetes mellitus (T2DM). However, NASH and T2DM do not always develop coordinately. Additionally, there are no definite noninvasive methods for NASH diagnosis currently. We established rat models of NAFL, NASH, and NAFL + T2DM to recapitulate different phenotypes associated with non-alcoholic fatty liver disease (NAFLD) and its progression. Histologic features of rat livers were scored according to criteria established by the Nonalcoholic Steatohepatitis Clinical Research Network. Microarray was performed to assess gene expression changes in rat livers. We find that gene expression of s100a9 was higher in NAFL group compared with control, and was increased in NASH groups and decreased in NAFL + T2DM group compared with NAFL. In contrast, srebf1, tbx21, and gimap4 only showed limited discriminating abilities in different groups. There is a significant positive correlation between serum levels of S100A9 and NAFLD Activity Score (NAS), the severity of hepatic steatosis, and lobular inflammation (r = 0.80, 0.64 and 0.86, P < 0.001). These findings suggest that S100A9 may be extremely useful in the diagnosis of NASH (AUROC: 0.947, CI: 0.845-1.049). Additionally, serum S100A9 levels displayed a strong correlation with ALT, AST and TBil (r = 0.81, 0.89 and 0.91, P < 0.001) but a weak correlation with FBG, HOMA-IR, TG, and TC (r = -0.41, -0.40, 0.47 and 0.49, P < 0.05). Conclusions: The results we provide here suggest that S100A9 may be useful as a biomarker for the hepatic and metabolic progression of NAFLD and the non-invasive diagnosis of NASH.

Evaluation of the fatty liver index as a predictor for the development of diabetes among insurance beneficiaries with prediabetes

Aims/Introduction

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in developed countries, and it was required to monitor patients with prediabetes. However, there have been few reports establishing the risk for diabetes mellitus (DM) among patients with prediabetes. The purpose of the present study was to evaluate the effect of NAFLD on the progression of DM among insurance beneficiaries with prediabetes, using data from specific health check-ups and the fatty liver index (FLI).

Materials and Methods

We used a retrospective cohort study that enrolled 967 insurance beneficiaries with prediabetes who had rarely drunk or could not drink alcohol, or whose alcohol consumption was <19 g/day from two health insurance societies. We divided insurance beneficiaries into FLI <30, intermediates FLIs and FLI ≥60, and compared the incidence rate of DM among the groups after 3 years' follow up, using multiple logistic regression models.

Results

During 3 years' follow up, progression of diabetes was seen in 65 men (11.5%) and 24 women (6.0%). Logistic regression analyses showed that those with NAFLD had significantly higher risks of developing DM; this was the case in both men (odds ratio 2.68, 95% confidential interval 1.29–5.56) and women (odds ratio 10.35, 95% confidential interval 3.22–33.31).

Conclusions

Among insurance beneficiaries with prediabetes, those with NAFLD had a significantly higher risk of DM than those without NAFLD. The FLI might be useful for detecting individuals who have an especially higher risk for DM, and developing more effective guidance for delivering healthcare services in Japan.