Effect of nonalcoholic Fatty liver disease on the development of type 2 diabetes in nonobese, nondiabetic korean men

Genetic and Lifestyle Risk Factors of Metabolic Dysfunction-Associated Fatty Liver Disease and Its Relationship with Premature Coronary Artery Disease: A Study on the Pars Cohort

BACKGROUND

The main objective of this study is to identify the risk factors of metabolic dysfunction-associated fatty liver disease (MAFLD) in coronary artery disease (CAD) patients.

METHODS

The present retrospective cohort study is part of the Pars Cohort Study (PCS). The participants were categorized as having MAFLD or not. The pattern of independent variables in patients was compared with those who did not have MAFLD. All variables were retained in the multivariable logistic regression model.

RESULTS

Totally, 1862 participants with CAD were enrolled in this study. MAFLD was diagnosed in 647 (40.1%) participants. Gender, diabetes, hypertension, tobacco, opium, alcohol, age, weight, waist circumference, cholesterol, HDL, triglyceride, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were significantly different in MAFLD and non-MAFLD patients. Also, the results of multivariable logistic regression show male gender (OR=0.651, 95% CI: 0.470‒0.902, P value=0.01) and opium consumption (OR=0.563, 95% CI: 0.328‒0.968, P value<0.001) to be negative risk factors of MAFLD occurrence in CAD patients. Having diabetes (OR=2.414, 95% CI: 1.740-3.349, P value<0.001), high waist circumference (OR=1.078, 95% CI: 1.055‒1.102, P value<0.01), high triglyceride (OR=1.005, 95% CI: 1.001‒1.008, P value=0.006), and high ALT (OR=1.039, 95% CI: 1.026‒1.051, P value<0.01) were positive risk factors of MAFLD in CAD patients.

CONCLUSION

Our study found that consuming opium decreases the likelihood of MAFLD in CAD patients, since these patients have decreased appetite and lower body mass index (BMI). On the other hand, female gender, having diabetes, high waist circumference, high triglyceride levels, and high ALT levels increase the probability of MAFLD in CAD patients.

Long-chain saturated fatty acids and its interaction with insulin resistance and the risk of nonalcoholic fatty liver disease in type 2 diabetes in Chinese

INTRODUCTION

This study aimed to explore relationships between long-chain saturated fatty acids (LSFAs) and nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes (T2D); and whether insulin action had an interactive effect with LSFAs on NAFLD progression.

METHODS

From April 2018 to April 2019, we extracted the electronic medical records of 481 patients with T2D who meet the inclusion and exclusion criteria from the Second Affiliated Hospital of Dalian Medical University. Ultrasound was used to estimate NAFLD at admission. Logistic regression analysis were used to estimate odds ratios (OR) and 95% confidence intervals (CI). The additive interaction was carried out to estimate interactions between LSFAs and insulin resistance (IR) in NAFLD patients with T2D.

RESULTS

Myristic acid (14:0) and palmitic acid (16:0) were positively associated with the risk of NAFLD (OR for myristic acid (14:0): 7.516, 3.557-15.882 and OR for palmitic acid (16:0): 4.071, 1.987-8.343, respectively). After adjustment for traditional risk factors, these associations were slightly attenuated but still highly significant. Co-presence of myristic acid (14:0)>72.83 μmol/L and IR>4.89 greatly increased OR of NAFLD to 9.691 (4.113-22.833). Similarly, co-presence of palmitic acid (16:0)>3745.43μmol/L and IR>4.89 greatly increased OR of NAFLD to 6.518(2.860-14.854). However, stearic acid (18:0) and risk of NAFLD have no association. Moreover, there was no association between very-long-chain SFAs (VLSFAs) and risk of NAFLD.

DISCUSSION

Myristic acid (14:0) and palmitic acid (16:0) were positively associated with the risk of NAFLD in T2D patients in China. High IR amplified the effect of high myristic acid (14:0) and high palmitic acid (16:0) on NAFLD.

Determinants of hyperglucagonemia in pediatric non-alcoholic fatty liver disease

OBJECTIVE

Over the years, non-alcoholic fatty liver (NAFLD) disease has progressed to become the most frequent chronic liver disease in children and adolescents. The full pathology is not yet known, but disease progression leads to cirrhosis and hepatocellular carcinoma. Risk factors included hypercaloric diet, obesity, insulin resistance and genetics. Hyperglucagonemia appears to be a pathophysiological consequence of hepatic steatosis, thus, the hypothesis of the study is that hepatic fat accumulation leads to increased insulin resistance and impaired glucagon metabolism leading to hyperglucagonemia in pediatric NAFLD.

METHODS

132 children and adolescents between 10 and 18 years, with varying degrees of obesity, were included in the study. Using Magnetic Resonance Imaging (MRI) average liver fat was determined, and patients were stratified as NAFLD (>5% liver fat content) and non-NAFLD (<5%). All patients underwent a standardized oral glucose tolerance test (OGTT). Additionally, anthropometric parameters (height, weight, BMI, waist circumference, hip circumference) such as lab data including lipid profile (triglycerides, HDL, LDL), liver function parameters (ALT, AST), uric acid, glucose metabolism (fasting insulin and glucagon, HbA1c, glucose 120 min) and indices evaluating insulin resistance (HIRI, SPISE, HOMA-IR, WBISI) were measured.

RESULTS

Children and adolescents with NAFLD had significantly higher fasting glucagon values compared to the non-NAFLD cohort (p=0.0079). In the NAFLD cohort univariate analysis of fasting glucagon was associated with BMI-SDS (p<0.01), visceral adipose tissue volume (VAT) (p<0.001), average liver fat content (p<0.001), fasting insulin concentration (p<0.001), triglycerides (p<0.001) and HDL (p=0.034). This correlation equally applied to all insulin indices HOMA-IR, WBISI, HIRI (all p<0.001) and SPISE (p<0.002). Multivariate analysis (R² adjusted 0.509) for the same subgroup identified HIRI (p=0.003) and VAT volume (p=0.017) as the best predictors for hyperglucagonemia. Average liver fat content is predictive in pediatric overweight and obesity but not NAFLD.

CONCLUSIONS

Children and adolescents with NAFLD have significantly higher fasting plasma glucagon values, which were best predicted by hepatic insulin resistance and visceral adipose tissue, but not average liver fat content.

The interaction between the gut microbiota and dietary carbohydrates in nonalcoholic fatty liver disease

Imbalance between fat production and consumption causes various metabolic disorders. Nonalcoholic fatty liver disease (NAFLD), one such pathology, is characterized by abnormally increased fat synthesis and subsequent fat accumulation in hepatocytes1,2. While often comorbid with obesity and insulin resistance, this disease can also be found in lean individuals, suggesting specific metabolic dysfunction2. NAFLD has become one of the most prevalent liver diseases in adults worldwide, but its incidence in both children and adolescents has also markedly increased in developed nations3,4. Progression of this disease into nonalcoholic steatohepatitis (NASH), cirrhosis, liver failure, and hepatocellular carcinoma in combination with its widespread incidence thus makes NAFLD and its related pathologies a significant public health concern. Here, we review our understanding of the roles of dietary carbohydrates (glucose, fructose, and fibers) and the gut microbiota, which provides essential carbon sources for hepatic fat synthesis during the development of NAFLD.

Reduction of fatty liver in rats by nicotinamide via the regeneration of the methionine cycle and the inhibition of aldehyde oxidase

Nonalcoholic fatty liver disease, which has been rapidly increasing in the world in recent years, is roughly classified into nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis. This study was based on our previous reports that stated that the combination treatment of N1-methylnicotinamide (MNA) and hydralazine (HYD) improves fatty liver in NAFL model rats. This finding was attributed to the MNA metabolism inhibition by HYD, which is a strong inhibitor of aldehyde oxidase (AO); this results in an increase in hepatic MNA and improved fatty liver. We hypothesized that orally administered nicotinamide (NAM), which is the precursor of MNA and is a form of niacin, would be efficiently metabolized by nicotinamide N-methyltransferase in the presence of exogenous S-adenosylmethionine (SAM) in NAFL rats. To address this issue, NAFL model rats were orally administered with NAM, SAM, and/or HYD. As a result, liver triglyceride (TG) and lipid droplet levels were barely altered by the administration of NAM, SAM, NAM+SAM, or NAM+HYD. By contrast, the triple combination of NAM+SAM+HYD significantly reduced hepatic TG and lipid droplet levels and significantly increased hepatic MNA levels. These findings indicated that the combination of exogenous SAM with AO inhibitors, such as HYD, has beneficial effects for improving fatty liver with NAM.

Prevalence and Profile of Nonalcoholic Fatty Liver Disease in Lean Adults: Systematic Review and Meta-Analysis

Data on prevalence and profile of nonalcoholic fatty liver disease (NAFLD) among individuals who are lean (normal body mass index) is unclear. Published data from studies comparing lean with obese NAFLD or with healthy subjects on prevalence, comorbidities, liver chemistry and histology, and metabolic/inflammatory markers were analyzed. Data were reported as odds ratio and 95% confidence interval for categorical variables and difference of means for continuous variables. Analysis of 53 studies on 65,029 subjects with NAFLD (38,084 lean) and 249,544 healthy subjects showed a prevalence of lean NAFLD at 11.2% in the general population. Among individuals with NAFLD, the prevalence of lean NAFLD was 25.3%. Lean NAFLD versus healthy subjects had higher odds for abnormalities on metabolic profile, including metabolic syndrome and its components, renal and liver function, and patatin‐like phospholipase domain‐containing protein 3 (PNPLA3) G allele; and inflammatory profile, including uric acid and C‐reactive protein. The abnormalities were less severe among lean versus obese NAFLD on metabolic syndrome with its components, renal and liver chemistry, liver stiffness measurement, PNPLA3 and transmembrane 6 superfamily member 2 polymorphisms, and uric acid levels as markers of inflammation. Lean NAFLD had less severe histologic findings, including hepatocyte ballooning, lobular inflammation, NAFLD activity score, and fibrosis stage. Limited data also showed worse outcomes between obese versus lean NAFLD. Conclusion: Lean NAFLD is a distinct entity with metabolic, biochemical, and inflammatory abnormalities compared to healthy subjects and a more favorable profile, including liver histology of steatohepatitis and fibrosis stage, compared to obese NAFLD. We suggest that prospective multicenter studies examine long‐term hepatic and extrahepatic outcomes in individuals with lean NAFLD.

Fat and Sugar-A Dangerous Duet. A Comparative Review on Metabolic Remodeling in Rodent Models of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common disease in Western society and ranges from steatosis to steatohepatitis to end-stage liver disease such as cirrhosis and hepatocellular carcinoma. The molecular mechanisms that are involved in the progression of steatosis to more severe liver damage in patients are not fully understood. A deeper investigation of NAFLD pathogenesis is possible due to the many different animal models developed recently. In this review, we present a comparative overview of the most common dietary NAFLD rodent models with respect to their metabolic phenotype and morphological manifestation. Moreover, we describe similarities and controversies concerning the effect of NAFLD-inducing diets on mitochondria as well as mitochondria-derived oxidative stress in the progression of NAFLD.

Ultrasound-Diagnosed Nonalcoholic Fatty Liver Disease Independently Predicts a Higher Risk of Developing Diabetes Mellitus in Nonoverweight Individuals

RATIONALE AND OBJECTIVES

This study was aimed to evaluate the independent value of ultrasound-diagnosed nonalcoholic fatty liver disease (us-NAFLD), as a surrogate imaging marker of the pathologic entity of NAFLD, in predicting incident diabetes mellitus (DM) in nonoverweight individuals.

MATERIALS AND METHODS

A total of 10,064 participants who had a body mass index <23 kg/m² were included in this retrospective cohort study. us-NAFLD was diagnosed using abdominal ultrasound. All participants were divided into subgroups according to the presence or absence of us-NAFLD and metabolic syndrome (MS).

RESULTS

Over a mean follow-up of 6.0 years, 125 participants (1.2%) developed DM. The incidence rates of DM were 1.0% in participants without us-NAFLD, 6.2% in participants with us-NAFLD, 1.1% in participants without MS, and 13.2% in participants with MS. The adjusted hazard ratios for incident DM were 2.52 (95% confidence interval:1.58-4.03) for us-NAFLD and 2.64 (95% confidence interval:1.54-4.54) for MS.

CONCLUSION

This study demonstrates that us-NAFLD has an independent value in predicting incident DM in non-overweight individuals.

Nonalcoholic Fatty Liver Disease and Risk of Diabetes: A Prospective Study in China

OBJECTIVE

We aimed to investigate whether liver steatosis severity affects the risk of developing diabetes in a large cohort study.

METHODS

We prospectively examined the association in 41,650 Chinese adults with negative hepatitis-B surface antigen who were free of alcohol consumption, diabetes, and liver cirrhosis at baseline. Cox proportional models were used to estimate the risk of diabetes after a mean of 3.6 years of follow-up. Nonalcoholic fatty liver disease (NAFLD) was assessed with hepatic ultrasonography. Elevated alanine transaminase (ALT) was defined as ALT concentrations >19 and >30 U/L in females and males, respectively. Diabetes was defined as a fasting glucose ³7.0 mmol/L or treatment with hypoglycemic medication.

RESULTS

Liver steatosis severity was significantly associated with higher risks of developing diabetes (adjusted hazard ratio [HR] for severe vs. without NAFLD = 2.66, 95% confidence interval [CI]: 2.17-3.25, P-trend<.001) and impaired fasting glucose (fasting glucose between 5.6 and 6.9 mmol/L, adjusted HR = 1.36, 95% CI: 1.16-1.59, P-trend<.001), as well as a faster increase rate of fasting glucose concentrations ( P-trend<.001), during 3.6 years of follow-up. Elevated ALT was also associated with incident diabetes (HR = 1.12, 95% CI: 1.02-1.22), adjusting for NAFLD and other covariates.

CONCLUSION

We observed a dose-response relationship between liver steatosis severity and increased diabetes risk, and ALT may predict incident diabetes independently of NAFLD.

ABBREVIATIONS

ALT = alanine transaminase; BP = blood pressure; CI = confidence interval; HCV = hepatitis C virus; HR = hazard ratio; IFG = impaired fasting glucose; NAFLD = nonalcoholic fatty liver disease; ULN = upper limit of normal.

Liver Enzymes, Fatty Liver and Type 2 Diabetes Mellitus in a Jinchang Cohort: A Prospective Study in Adults

OBJECTIVES

It is unclear whether liver enzymes or the interactions of various liver enzymes is a predictor of type 2 diabetes mellitus (T2DM), which is independent of fatty liver.

METHODS

A total of 48,001 subjects participated in baseline examinations. Among the subjects, 33,355 were followed for an average of 2.2 years. Cox proportional hazard models were used to examine the adjusted associations of AST, GGT and ALT with T2DM.

RESULTS

The cumulative incidence of T2DM was 8.05% to 9.02% for fatty liver and 2.25% to 4.10% for non-fatty liver, both showing statistically significant differences. Compared with the normal liver enzyme levels in the group with fatty liver, the adjusted incident hazard ratios in T2DM were: ALT 1.23 (95% CI 1.10 to 1.50); AST 1.30 (95% CI 1.07-1.59); and GGT 1.34 (95% CI 1.08 to 1.65). In addition, compared with the normal liver enzyme levels in the group with non-fatty liver, the adjusted incident hazard ratios in type 2 diabetes were: ALT 1.27 (95% CI 1.02 to 1.59); AST 1.33 (95% CI 1.02 to 1.59); and GGT 1.53 (95% CI 1.19 to 1.98). There are significant interactions of T2DM hazard ratios between GGT and ALT and between GGT and AST in addition to ALT and AST.

CONCLUSIONS

Our results suggest that the incidence of T2DM in the group with fatty liver is significantly higher than that in the normal population, and the rise of serum AST, GGT and ALT levels are risk factors independent of fatty liver for the development of T2DM after adjusting for confounding factors.

Laboratory parameters in lean NAFLD: comparison of subjects with lean NAFLD with obese subjects without hepatic steatosis

Objective

Search for meaningful laboratory and anthropometric parameters in lean non-alcoholic fatty liver disease (lean NAFLD) in the general population. Out of 2445 subjects in a random population sample, we compared those who had a body mass index (BMI) < 25 and a fatty liver [lean NAFLD (LN), n = 5] with obese subjects who had a BMI > 30 but no fatty liver [non-NAFLD (NN), n = 27] in a follow-up examination. Ultrasonic, anthropometric and laboratory parameters were collected.

Results

There were significant differences (p < 0.05) between the LN and the NN groups with respect to serum ferritin (199.2 ± 72.1 LN vs 106.0 ± 89.6 NN), haemoglobin (14.9 ± 0.8 LN vs 13.5 ± 1.2 NN), haematocrit (0.438 ± 0.019 LN vs 0.407 ± 0.035 NN) and Mean corpuscular haemoglobin concentration (34 ± 0.6 LN vs 33.2 ± 0.8 NN). Significantly lower values of soluble transferrin receptor were measured in the LN group (2.8 ± 0.4 LN vs 3.8 ± 1.5 NN). In both groups, the measured HOMA-IR index (homeostatic model assessment of insulin resistance index) (2.3; normal range ≤ 1) was abnormal. Mean cholesterol (6.2 ± 1.4 LN and 5.6 ± 1.1 NN) and low-density lipoprotein levels (3.8 ± 1.0 LN 3.4 ± 0.9 NN) were above the upper limit of normal in both groups, as was the mean triglycerides level in the LN group (2.6 ± 2.0). In summary, there are differences in parameters of iron and fat metabolism between subjects with LN and overweight subjects without fatty liver infiltration.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3212-1) contains supplementary material, which is available to authorized users.

Histologic Scores for Fat and Fibrosis Associate With Development of Type 2 Diabetes in Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is a strong risk factor for development of type 2 diabetes, but little is known about how long-term NAFLD or its histologic features affect risk. We aimed to investigate the cumulative incidence of type 2 diabetes in patients with NAFLD and to identify histologic factors that affect risk of diabetes.

METHODS

We performed a retrospective study of 396 patients in Sweden diagnosed with NAFLD by biopsy analysis from 1971 through 2009 who did not have type 2 diabetes at baseline. Data on development of type 2 diabetes were collected from patient charts and national registers. Patients were categorized into groups with fibrosis stages 0-2 (n = 357) or stages 3-4 (n = 39). Hazard ratios of histologic parameters for type 2 diabetes development were calculated separately in a multivariate Cox regression model adjusted for sex, age, body mass index, and serum levels of triglycerides greater than 150 mg/dL.

RESULTS

During a mean follow-up period of 18.4 years (range, 0-41 years), 132 individuals (33%) developed type 2 diabetes. A significantly higher proportion of patients with fibrosis stages 3-4 (51.2%) developed type 2 diabetes than patients with fibrosis stages 0-2 (31.3%) (P = .02). For patients with fibrosis stages 0-2, fat score associated independently with development of type 2 diabetes (adjusted hazard ratio, 1.34; 95% confidence interval, 1.03-1.74; P = .03). No histologic factors associated with development of diabetes in patients with fibrosis stages 3-4. Presence of nonalcoholic steatohepatitis was not associated with development of type 2 diabetes.

CONCLUSIONS

In a retrospective study we found a higher proportion of patients with fibrosis stages 3-4 to develop type 2 diabetes than patients with fibrosis stages 0-2. In patients with fibrosis stages 0-2, fat score associates with risk of type 2 diabetes.

Systematic review with meta-analysis: risk factors for non-alcoholic fatty liver disease suggest a shared altered metabolic and cardiovascular profile between lean and obese patients

BACKGROUND

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is closely associated with the co-occurrence of multiple pathological conditions characterising the metabolic syndrome (MetS), obesity in particular. However, NAFLD also develops in lean subjects, whose risk factors remain poorly defined.

METHODS

We performed a meta-analysis of 15 studies, along with the data pertaining to our own population (n=336 patients). Data from lean (n=1966) and obese (n=5938) patients with NAFLD were analysed; lean (n=9946) and obese (n=6027) subjects without NAFLD served as controls.

RESULTS

Relative to the lean non-NAFLD controls, lean patients with NAFLD were older (3.79±0.72 years, P=1.36×10^-6 ) and exhibited the entire spectrum of the MetS risk factors. Specifically, they had a significant (P=10^-10 ) increase in plasma glucose levels (6.44±1.12 mg/dL) and HOMA-IR (0.52±0.094-unit increment), blood lipids (triglycerides: 48.37±3.6, P=10^-10 and total cholesterol: 7.04±3.8, mg/dL, P=4.2×10^-7 ), systolic (5.64±0.7) and diastolic (3.37±0.9) blood pressure (mm Hg), P=10^-10 , and waist circumference (5.88±0.4 cm, P=10^-10 ); values denote difference in means±SE. Nevertheless, the overall alterations in the obese group were much more severe when compared to lean subjects, regardless of the presence of NAFLD. Meta-regression suggested that NAFLD is a modifier of the level of blood lipids.

CONCLUSION

Lean and obese patients with NAFLD share a common altered metabolic and cardiovascular profile. The former, while having normal body weight, showed excess of abdominal adipose tissue as well as other MetS features.

Non-alcoholic fatty liver disease with and without metabolic syndrome: Different long-term outcomes

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS) are both shown to increase the risk of cardiovascular diseases and type 2 diabetes. However, there is a great overlap between these two diseases. The present study was aimed to examine the cardiovascular and metabolic prognosis of non-alcoholic fatty liver disease with and without metabolic syndrome.

METHODS

Middle-aged subjects (n=958) were divided into four subgroups, those with NAFLD and MetS, those with NAFLD or MetS, and healthy controls. The baseline characteristics of the subgroups were analyzed. The follow-up time for cardiovascular events was about 16years. After approximately 21years the cardiac ultrasound and laboratory parameters were re-analyzed and new type 2 diabetes cases were recorded.

RESULTS

Those with both diseases were at the greatest risk for cardiovascular events (p<0.001). Compared to healthy controls, only those with MetS, with or without NAFLD, were at increased risk for the development of type 2 diabetes (p<0.001) and for an increase in left ventricular mass index (p=0.001 and p=0.005, respectively). The cardiovascular and metabolic risk in subjects with NAFLD only was quite similar to that in healthy controls. The I148M variant of the patatin-like phospholipase domain-containing 3 gene (PNPLA3 polymorphism) was most present in those with NAFLD only (p=0.008).

CONCLUSIONS

NAFLD with MetS implies a considerable risk for cardiovascular diseases, type 2 diabetes and the increase of left ventricular mass index whereas NAFLD without MetS does not.

Non-alcoholic fatty liver disease and diabetes

Non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2DM) are common conditions that regularly co-exist and can act synergistically to drive adverse outcomes. The presence of both NAFLD and T2DM increases the likelihood of the development of complications of diabetes (including both macro- and micro- vascular complications) as well as augmenting the risk of more severe NAFLD, including cirrhosis, hepatocellular carcinoma and death. The mainstay of NAFLD management is currently to reduce modifiable metabolic risk. Achieving good glycaemic control and optimising weight loss are pivotal to restricting disease progression. Once cirrhosis has developed, it is necessary to screen for complications and minimise the risk of hepatic decompensation. Therapeutic disease modifying options for patients with NAFLD are currently limited. When diabetes and NAFLD co-exist, there are published data that can help inform the clinician as to the most appropriate oral hypoglycaemic agent or injectable therapy that may improve NAFLD, however most of these data are drawn from observations in retrospective series and there is a paucity of well-designed randomised double blind placebo controlled studies with gold-standard end-points. Furthermore, given the heterogeneity of inclusion criteria and primary outcomes, as well as duration of follow-up, it is difficult to draw robust conclusions that are applicable across the entire spectrum of NAFLD and diabetes. In this review, we have summarised and critically evaluated the available data, with the aim of helping to inform the reader as to the most pertinent issues when managing patients with co-existent NAFLD and T2DM.

Normal weight dyslipidemia: Is it all about the liver?

OBJECTIVE

The liver coordinates lipid metabolism and may play a vital role in the development of dyslipidemia, even in the absence of obesity. Normal weight dyslipidemia (NWD) and patients with nonalcoholic fatty liver disease (NAFLD) who do not have obesity constitute a unique subset of individuals characterized by dyslipidemia and metabolic deterioration. This review examined the available literature on the role of the liver in dyslipidemia and the metabolic characteristics of patients with NAFLD who do not have obesity.

METHODS

PubMed was searched using the following keywords: nonobese, dyslipidemia, NAFLD, NWD, liver, and metabolically obese/unhealthy normal weight. Additionally, article bibliographies were screened, and relevant citations were retrieved. Studies were excluded if they had not measured relevant biomarkers of dyslipidemia.

RESULTS

NWD and NAFLD without obesity share a similar abnormal metabolic profile. When compared with patients with NAFLD who have obesity, the metabolic abnormalities of NAFLD without obesity are similar or less severe. Furthermore, hepatic lesions develop independent of obesity, and the extent of dyslipidemia seems comparable.

CONCLUSIONS

NAFLD may impair hepatic lipid handling, causing faulty lipid homeostasis, and serves as a likely starting point for initiation and propagation of dyslipidemia along with associated comorbidities in patients without obesity.

The impact of non-alcoholic fatty liver disease on incident type 2 diabetes mellitus in non-overweight individuals

BACKGROUND & AIMS

The aim of this study was to evaluate the impact of non-alcoholic fatty liver disease (NAFLD) on incident type 2 diabetes mellitus (T2DM) in non-overweight individuals with NAFLD.

METHODS

A population-based retrospective cohort study of 4629 participants who were enrolled in a health check-up programme for more than 10 years. A standardized questionnaire and abdominal ultrasonography were used to diagnose NAFLD. A cut-off point of BMI 23 kg/m(2) was used to define overweight (≥23.0 kg/m(2)) or non-overweight (<23.0 kg/m(2)). The primary outcome was incident T2DM.

RESULTS

Over a mean follow-up of 12.8 years, 351 participants (7.6%) developed T2DM. The incidence rate of T2DM was 3.2% in the non-overweight without NAFLD group, 14.4% in the non-overweight with NAFLD group, 8.0% in the overweight without NAFLD group and 26.4% in the overweight with NAFLD group. The adjusted hazard ratios for incident T2DM compared with the non-overweight without NAFLD group were as follows: 3.59 (95% CI: 2.14-5.76) in the non-overweight with NAFLD group, 1.99 (95% CI: 1.47-2.69) in the overweight without NAFLD group and 6.77 (95% CI: 5.17-8.91) in the overweight with NAFLD group. The adjusted hazard ratio in the non-overweight with NAFLD group was significantly higher than that in the overweight without NAFLD group or that in the non-overweight without NAFLD group.

CONCLUSIONS

Non-overweight individuals with NAFLD had a high risk of incident T2DM. Diagnosis of NAFLD is important in non-overweight individuals, and therefore it might be necessary to follow their health conditions on a long-term basis after detection of NAFLD.

Usefulness of the controlled attenuation parameter for detecting liver steatosis in health checkup examinees

Background/Aims

The controlled attenuation parameter (CAP) implemented in FibroScan^® is reported to be a non-invasive means of detecting steatosis (>10% steatosis). We aimed to evaluate the usefulness of CAP in detecting steatosis among health checkup examinees and to assess its correlation with ultrasonography (US).

Methods

Consecutive CAP results were retrospectively collected. A total of 280 subjects were included.

Results

Fatty liver was detected in 119 subjects (42.5%) by US, whereas it was detected in 160 subjects (57.1%) by the CAP. The numbers of subjects with S0:S1:S2:S3 steatosis according to the CAP value were 120:59:58:43, respectively. The mean CAP values were 203.34±28.39 dB/m for S0, 248.83±6.14 dB/m for S1, 274.33±8.53 dB/m for S2, and 322.35±22.20 dB/m for S3. CAP values were correlated with body weight (r=0.404, p<0.001), body mass index (r=0.445, p<0.001), and the fatty liver grade by US (r=0.472, p<0.001). Among the 161 subjects with normal US findings, steatosis was detected in 65 subjects (40.4%) using the CAP.

Conclusions

The CAP seems to be useful for detecting very low-grade hepatic steatosis in health checkup examinees. Its role in predicting subjects with a risk of metabolic derangement needs to be evaluated.

Comparison of effects of obesity and non-alcoholic fatty liver disease on incidence of type 2 diabetes mellitus

AIM: To compare and analyze the effects of obesity and non-alcoholic fatty liver disease (NAFLD) on the incidence of type 2 diabetes mellitus (T2DM) in Chinese subjects.

METHODS: In 2008, a population of 4847 subjects was randomly sampled from 17 medical units for enrollment in this cohort study. Baseline information was obtained via a questionnaire on general information, physical examination (height, weight, and blood pressure), laboratory tests (triglycerides, total cholesterol, fasting blood glucose, alanine aminotransferase (ALT), uric acid, and creatinine), B-mode ultrasound, and ECG screening. The incidence of T2DM after four years of follow-up was calculated. Numeric variable data was tested for normality, with the data expressed as mean ± SD. Kaplan-Meier analysis was performed to calculate the cumulative incidence. The Cox proportional hazards model was used to analyze the relative risk (RR) of different body mass index (BMI) levels and NAFLD on T2DM, as well as analyzing the RR adjusted for age, sex, blood pressure, lipids, transaminases, uric acid, and creatinine.

RESULTS: A total of 4736 (97.71%) subjects completed 4-year follow-up, with a median follow-up time of 3.85 years, totaling 17223 person-years. 380 subjects were diagnosed with T2DM, with a cumulative incidence of 8.0%. The cumulative incidence of T2DM in the NAFLD and control groups was 17.4% vs 4.1% (P < 0.001), respectively, while the incidence in overweight and obese subjects was 11.0% vs 15.8% (P < 0.001), respectively. The incidence of T2DM increased with an increase in baseline BMI. Cox regression analysis showed that the risk of T2DM in the NAFLD group (RR = 4.492, 95%CI: 3.640-5.542) after adjustment for age, sex, blood pressure, lipids, ALT, uric acid, and creatinine was 3.367 (2.367-4.266), while the value (RR, 95%CI) in overweight and obese subjects after adjustment for age, sex, BMI, blood pressure, lipids and other factors was 1.274 (0.997-1.629) and 1.554 (1.140-2.091), respectively. Stratification of three BMI levels (BMI < 24 kg/m², 24 kg/m²≤ BMI < 28 kg/m², BMI ≥ 28 kg/m²) showed that the risk of T2DM in the NAFLD group was significantly higher than that in the control group (RR = 3.860, 4.049 and 3.823, respectively).

CONCLUSION: Compared with BMI, NAFLD could be better at forecasting the risk of T2DM in Chinese subjects, and may be a high risk factor for T2DM, independent of overweight/obesity.

Serum ferritin is associated with non-alcoholic fatty liver disease and decreased Β-cell function in non-diabetic men and women

AIMS

We sought to determine whether NAFLD is associated with poorer β-cell function and if any β-cell dysfunction is associated with abnormal markers of iron or inflammation.

METHODS

This was a cross-sectional study of 15 non-diabetic adults with NAFLD and 15 non-diabetic age and BMI-matched controls. Insulin sensitivity was measured by isotope-labeled hyperinsulinemic-euglycemic clamps and β-cell function by both oral (OGTT) and intravenous glucose tolerance tests. Liver and abdominal fat composition was evaluated by CT scan. Fasting serum levels of ferritin, transferrin-iron saturation, IL-6, TNFα and hsCRP were measured.

RESULTS

Compared to controls, subjects with NAFLD had lower hepatic and systemic insulin sensitivity and β-cell function was decreased as measured by the oral disposition index. Fasting serum ferritin and transferrin-iron saturation were higher in NAFLD and were positively associated with liver fat. Serum ferritin was negatively associated with β-cell function measured by both oral and intravenous tests, but was not associated with insulin sensitivity. IL-6, TNFα and hsCRP did not differ between groups and did not correlate with serum ferritin, liver fat or measures of β-cell function.

CONCLUSIONS

These findings support a potential pathophysiological link between iron metabolism, liver fat and diabetes risk.

Obesity as the common soil of non-alcoholic fatty liver disease and diabetes: Role of adipokines

Non‐alcoholic fatty liver disease (NAFLD) describes a spectrum of liver conditions from simple steatosis, steatohepatitis to end‐stage liver disease. The prevalence of NAFLD has been on the rise in many parts of the world, including Asia, and NAFLD is now the liver disease associated with the highest mortality, consequent to the increased risk of cardiovascular diseases and hepatocellular carcinoma. Whereas NAFLD is an independent risk factor for type 2 diabetes, increased hepatic and peripheral insulin resistance contribute to the pathogenesis of both NAFLD and diabetes, which are associated with enhanced cardiovascular risk. Studies in humans and animal models have suggested obesity as the common link of these two diseases, likely mediated by adipose tissue inflammation and dysregulated adipokine production in obesity. In the present review, we discuss recent advances in our understanding of the role of several novel adipokines (adiponectin, adipocyte fatty acid binding protein and fibroblast growth factor‐21) in the pathophysiology of NAFLD and diabetes, as well as their use as potential biomarkers and therapeutic targets for dysglycemia in NAFLD patients.

Increased risk of type 2 diabetes in subjects with both elevated liver enzymes and ultrasonographically diagnosed nonalcoholic fatty liver disease: a 4-year longitudinal study

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is reported to contribute to the development of type 2 diabetes (T2DM). We aimed to compare the risk for development of T2DM among the four groups of NAFLD status divided by the combined assessment of liver enzyme and ultrasonographic steatosis in a retrospective cohort of Korean subjects.

METHODS

This study included 7,849 individuals without diabetes who underwent annual health check-ups for 5 consecutive years. Based on the presence or absence of fatty liver on ultrasound and serum alanine aminotransferase (ALT) values at baseline, subjects were classified into controls, an increased ALT group without steatosis, a steatosis group with normal ALT, and a group with both steatosis and elevated ALT (combined abnormality).

RESULTS

During a 4-year period, the incidence of diabetes was 3.5% in the control group, 4.6% in the increased ALT group, 7.3% in the steatosis group, and 11.8% in the combined abnormality group. The hazard ratio (HR) (95% confidence interval [CI]) of incident diabetes was increased in the elevated ALT group, the steatosis group, and the combined abnormality group in a stepwise fashion. Subjects with combined abnormality group had a significantly increased HR of 1.64 (1.27-2.13) even after multivariate adjustment.

CONCLUSIONS

NAFLD subjects with both elevated ALT and ultrasonographic steatosis have significantly increased risk for future diabetes development.