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

Insulin Resistance, Non-Alcoholic Fatty Liver Disease and Type 2 Diabetes Mellitus: Clinical and Experimental Perspective

It has been generally accepted that insulin resistance (IR) and reduced insulin secretory capacity are the basic pathogenesis of type 2 diabetes mellitus (T2DM). In addition to genetic factors, the persistence of systemic inflammation caused by obesity and the associated threat of lipotoxicity increase the risk of T2DM. In particular, the main cause of IR is obesity and subjects with T2DM have a higher body mass index (BMI) than normal subjects according to recent studies. The prevalence of T2DM with IR has increased with increasing BMI during the past three decades. According to recent studies, homeostatic model assessment of IR was increased compared to that of the 1990s. Rising prevalence of obesity in Korea have contributed to the development of IR, non-alcoholic fatty liver disease and T2DM and cutting this vicious cycle is important. My colleagues and I have investigated this pathogenic mechanism on this theme through clinical and experimental studies over 20 years and herein, I would like to summarize some of our studies with deep gratitude for receiving the prestigious 2023 Sulwon Award.

Liver steatosis as a predictor of incident diabetes in adults: a prospective evaluation in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Increasing epidemiological evidence suggests a bidirectional relationship between non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes, and that NAFLD may precede and/or promote the development of diabetes. This study aimed to investigate whether liver steatosis is associated with the incidence of diabetes in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). The ELSA-Brasil is an occupational cohort study of active or retired civil servants, aged 35-74 years, in six capital cities in Brazil. We excluded participants with diabetes at baseline, those who reported excessive alcohol consumption or with missing information on relevant covariates, and those with self-referred hepatitis or cirrhosis. In total, 8,166 individuals participated, and the mean duration of follow-up was 3.8 years. The Cox proportional regression model was used to estimate the adjusted hazard ratio (HR) for the associations. Abdominal ultrasonography was used to detect liver steatosis. In the follow-up period, the cumulative incidence of diabetes was 5.25% in the whole sample, 7.83% and 3.88% in the groups with and without hepatic steatosis, respectively (p < 0.001). Compared to those without steatosis, individuals with hepatic steatosis had an increased risk of developing diabetes (HR = 1.31; 95%CI: 1.09-1.56) after adjustment for potential confounders, including body mass index (BMI). Hepatic steatosis was an independent predictor of incident diabetes in the ELSA-Brasil cohort study. Physicians should encourage changes in lifestyle and screen for diabetes in patients with fatty liver.

Cardiovascular risk, fatty liver disease, glucose and insulin curve among prediabetes phenotypes in Peruvian population

Aims

To describe the cardiovascular risks, fatty liver disease, and glucose and insulin curve among prediabetes phenotypes (PPh) in Peruvian population.

Methods

A study was carried out using a secondary database of a series of patients with identified risk factors for diabetes mellitus type 2 in one clinic in Lima, Peru. Patients were divided according with the OGTT in impaired glucose 2h or IGT(Pph1), impaired fasting glucose or IFG(Pph3) or both(Pph2).

Results

259 patients were identified for analysis, 149 of whom had normal OGTT, 94 had prediabetes (36.3%), and 16 diabetes (6.2%). We found that 37(39.4%), 37(39.4%) and 20(21.2%) presented Pph1, Pph-2 and Pph-3 respectively. Most of the cardiovascular risks and hepatic function comparison showed no difference in our study sample groups. However, we found that Pph2 showed significantly higher abnormalities in HDL-c, triglycerides, hepatic steatosis, and HOMA-IR compared with normal OGTT group (p < 0.05). Interestingly, this difference was not seen with the other phenotypes. Also, hepatic steatosis was higher in Pph2 compared to Pph3 (p < 0.05). HOMA-IR was high in Phenotype 2 compared with Phenotype 1. Regarding hepatic steatosis, this was high in all prediabetes phenotypes, however we found this to be of statistical significance in Pph2 compared to Pph3 (p < 0.01).

Conclusions

In general, prediabetes phenotypes show a similar association with cardiovascular risk factors and hepatic steatosis, however, Pph2 show more differences in specific comparisons. We believe that this study is a starting point for further investigation to understand prediabetes in Peruvian population and be able to improve disease risk stratification.

Environmental toxicant-induced maladaptive mitochondrial changes: A potential unifying mechanism in fatty liver disease?

Occupational and environmental exposures to industrial chemicals are well known to cause hepatotoxicity and liver injury. However, despite extensive evidence showing that exposure can lead to disease, current research approaches and regulatory policies fail to address the possibility that subtle changes caused by low level exposure to chemicals may also enhance preexisting conditions. In recent years, the conceptual understanding of the contribution of environmental chemicals to liver disease has progressed significantly. Mitochondria are often target of toxicity of environmental toxicants resulting in multisystem disorders involving different cells, tissues, and organs. Here, we review persistent maladaptive changes to mitochondria in response to environmental toxicant exposure as a mechanism of hepatotoxicity. With better understanding of the mechanism(s) and risk factors that mediate the initiation and progression of toxicant-induced liver disease, rational targeted therapy can be developed to better predict risk, as well as to treat or prevent this disease.

Association Between Diabetes Mellitus and All-Cause and Cardiovascular Mortality Among Individuals With Ultrasound-Defined Non-Alcoholic Fatty Liver Disease

OBJECTIVE

The influence of diabetes on mortality among patients with non-alcoholic fatty liver disease (NAFLD) in the general population has not been extensively studied. This study aimed to determine the relationship between diabetes and all-cause and cardiovascular mortality in patients with hepatic ultrasound-confirmed NAFLD using data from the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994.

METHODS

Data from 4,037 adult individuals with NAFLD from the NHANES III and mortality outcomes linked to National Death Index records through December 31, 2015, were included. Cox proportional hazards models were used to calculate the hazard ratio (HR) and corresponding 95% CI for mortality from all causes and cardiovascular disease after adjusting for multiple variables.

RESULTS

Among 4,037 subjects with NAFLD (55.9% female), 483 had diabetes at baseline. During a median follow-up of 22.1 years, 1,517 (11.5%) died, including 332 (8.22%) from cardiovascular causes. Diabetes was associated with increased all-cause (HR 3.02 [95% CI 2.67-3.41]) and cardiovascular (HR 3.36 [95% CI 2.61-4.32]) mortality in an unadjusted multivariable Cox regression model. The association remained statistically significant after adjusting for a range of potential confounders (HR 2.20 [95% CI 1.90-2.55] for all-cause mortality and HR 2.47 [95% CI 1.81-3.37] for cardiovascular mortality). An additional stratified analysis did not reveal significantly altered results.

CONCLUSION

Diabetes was associated with all-cause and cardiovascular mortality in patients with NAFLD. This link could be further characterized in future studies assessing the degree of glycemic control and its relationship with mortality in patients with diabetes and NAFLD.

Prevalence, clinical characteristics, risk factors, and indicators for lean Chinese adults with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic diseases in the world. Nowadays, the percentage of non-obese or lean patients with NAFLD is increasing. NAFLD in non-obese populations, especially the lean subgroup with a normal waist circumference (WC), might lead to more problems than obese individuals, as these individuals may not visit clinics for NAFLD diagnosis or ignore the diagnosis of NAFLD. If the precise characteristics of these populations, especially the lean subgroup, are identified, the clinicians would be able to provide more appropriate advice and treatment to these populations.

AIM

To investigate the prevalence, clinical characteristics, risk factors, and possible indicators for NAFLD in lean Chinese adults with a normal WC.

METHODS

People without diabetes mellitus or significant alcohol consumption who underwent routine health examinations were included. Their fatty liver index (FLI), abdominal ultrasonography results, and controlled attenuation parameter were all assessed. Genotyping for single-nucleotide polymorphisms associated with NAFLD was performed in another small group consisting of biopsy-proven NAFLD subjects and healthy controls.

RESULTS

A total of 2715 subjects who underwent routine health examinations were included in the study. Among 810 lean participants with a normal WC, 142 (17.5%) fulfilled the diagnostic criteria for NAFLD. Waist-height ratio, hemoglobin, platelets, and triglycerides were significant factors associated with the presence of NAFLD in these participants. The appropriate cut-off value of the FLI score in screening for NAFLD in the lean subjects with a normal WC was 25.15, which had a 77.8% sensitivity and 75.9% specificity. There was no significant difference in the single-nucleotide polymorphisms in the SIRT1, APOC3, PNPLA3, AGTR1, and PPARGC1A genes between lean subjects with and without NAFLD (P < 0.05).

CONCLUSION

NAFLD is not uncommon in lean Chinese adults even with a normal WC. Metabolic factors, rather than genetic factors, may play important roles in the development of NAFLD in this population. A lower cut-off value of the FLI score in screening for NAFLD should be used for lean Chinese adults with a normal WC.

Comparative Effects and Mechanisms of Chitosan and Its Derivatives on Hypercholesterolemia in High-Fat Diet-Fed Rats

The present study investigated and compared the effects of different molecular weights of chitosan (high molecular weight chitosan (HC) and low molecular weight chitosan (LC)) and its derivatives (chitosan oligosaccharide (CO)) on cholesterol regulation in high-fat (HF) diet-fed rats. A diet supplementation of 5% HC, 5% LC, or 5% CO for 8 weeks showed hypocholesterolemic potential in HF diet-fed rats. Unexpectedly, a 5% CO-supplemented diet exerted hepatic damage, producing increased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and tumor necrosis factor-alpha (TNF-α). The supplementation of HC and LC, unlike CO, significantly decreased the hepatic total cholesterol (TC) levels and increased the fecal TC levels in HF diet-fed rats. The hepatic protein expression of the peroxisome proliferator-activated receptor-α (PPARα) in the HF diet-fed rats was markedly decreased, which could be significantly reversed by both HC and LC, but not CO, supplementation. Unlike the supplementation of CO, both HC and LC supplementation could effectively reverse the HF-inhibited/induced gene expressions of the low-density lipoprotein receptor (LDLR) and cholesterol 7α-hydroxylase (CYP7A1), respectively. The upregulated intestinal acyl-CoA cholesterol acyltransferase 2 (ACAT2) protein expression in HF diet-fed rats could be reversed by HC and LC, but not CO, supplementation. Taken together, a supplementation of 5% CO in HF diet-fed rats may exert liver damage via a higher hepatic cholesterol accumulation and a higher intestinal cholesterol uptake. Both HC and LC effectively ameliorated the hypercholesterolemia and regulated cholesterol homeostasis via the activation and inhibition of hepatic (AMPKα and PPARα) and intestinal (ACAT2) cholesterol-modulators, respectively, as well as the modulation of downstream signals (LDLR and CYP7A1).

Nonalcoholic Fatty Liver Disease and Diabetes: An Epidemiological Perspective

Nonalcoholic fatty liver disease (NAFLD) is thought to stem from the body's inability to store excess energy in adipocytes; as such, it is commonly viewed as the hepatic manifestation of metabolic syndrome. The pathogenesis of NAFLD involves ectopic fat accumulation, which also takes place in the liver, muscle and visceral fat. NAFLD is rapidly becoming more widespread in Korea, with an estimated prevalence of 30% in adults. Type 2 diabetes mellitus (T2DM) and NAFLD share insulin resistance as a common pathophysiological mechanism, and each of these two diseases affects the development of the other. Recent studies have suggested that NAFLD is often present as a comorbidity in T2DM patients. The mutual interrelationship between these conditions is shown by findings suggesting that T2DM can exacerbate NAFLD by promoting progression to nonalcoholic hepatosteatosis or fibrosis, while NAFLD causes the natural course of diabetic complications to worsen in T2DM patients. It remains unknown whether one disease is the cause of the other or vice versa. In this review, I would like to discuss current epidemiological data on the associations between NAFLD and T2DM, and how each disease affects the course of the other.

Improvement of Nonalcoholic Fatty Liver Disease Reduces the Risk of Type 2 Diabetes Mellitus

BACKGROUND/AIMS

Little evidence is available about the effect of change in nonalcoholic fatty liver disease (NAFLD) status on risk of diabetes mellitus (DM) development. In this study, we tried to analyze the DM risk according to change in NAFLD status over time.

METHODS

Among a total of 10,141 individuals for whom routine healthcare assessment was performed, 2,726 subjects were selected according to the inclusion/exclusion criteria. NAFLD status change was determined by using serial abdominal ultrasonography and fatty liver index (FLI) during the follow-up period.

RESULTS

Subjects were categorized according to change in NAFLD status as follows: 670 subjects in the persistent NAFLD group, 155 subjects in the resolved NAFLD group, 498 subjects in the incident NAFLD group, and 1,403 subjects in the no NAFLD group. Multivariate Cox regression analysis revealed that incident NAFLD (hazard ratio [HR], 1.94; 95% confidence interval [CI], 1.08 to 3.50; p=0.026) and persistent NAFLD (HR, 3.59; 95% CI, 2.05 to 6.27; p<0.001) were independent risk factors for predicting DM development, whereas the risk with resolved NAFLD was not significantly different from that with no NAFLD. FLI could reproduce the results acquired by ultrasonography.

CONCLUSIONS

This study demonstrated that future DM risk could be influenced by changes in NAFLD status over time. Resolution of NAFLD could reduce the risk of future DM development, while the development of new NAFLD could increase the risk of DM development.

Nonalcoholic Fatty Liver Disease in Diabetes. Part I: Epidemiology and Diagnosis

Nonalcoholic fatty liver disease (NAFLD) and diabetes are common metabolic disorders whose prevalence rates are expected to rise worldwide, corresponding to aging and increasingly obese populations. Compared to the general population (around 25%), 50% to 70% of people with diabetes have NAFLD, and NAFLD severity (including fibrosis) tends to be worsened by the presence of diabetes. NAFLD is considered an emerging risk factor for type 2 diabetes mellitus and a contributor to the development of chronic diabetes-related complications. This reciprocal relationship demonstrates the importance of confirming suspected NAFLD in patients with diabetes. Due to the invasive nature of liver biopsy to assess NAFLD status, various alternative non-invasive modalities have been developed and validated. Here, we summarized the epidemiology of NAFLD in patients with diabetes and reviewed currently available imaging modalities and biomarker-based prediction models for their ability to detect liver steatosis and/or fibrosis.

Lean non-alcoholic fatty liver disease patients had comparable total caloric, carbohydrate, protein, fat, iron, sleep duration and overtime work as obese non-alcoholic fatty liver disease patients

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial disease that involves a complex interaction between genetics, diet, and lifestyle. Although closely related with obese subjects, it is also common in lean humans. This study aimed to characterize the diet and lifestyle of lean and obese NAFLD patients in China.

METHODS

To characterize the diet and lifestyle of lean and obese NAFLD patients, we conducted a matched case-control study that included 351 Chinese adults. General characteristics, dietary intake, and lifestyle were gathered by using a valid and reliable dietary questionnaire. We compared the dietary intake and lifestyle between lean and obese NAFLD patients.

RESULTS

All NAFLD patients had more total caloric, calorigenic nutrients (carbohydrate, fat, and protein), grain, potato, fruit, and iron with higher levels of waist circumference and overtime work but shorter sleep duration than their corresponding controls. Particularly, lean NAFLD patients consumed comparable total caloric, calorigenic nutrients, iron, sleep duration, and overtime work as obese NAFLD patients, though they consumed lower levels of grain, potato, and fruit (lean NAFLD patients vs. obese NAFLD patients: mean ± SD, g/day grain: 291.8 ± 83.8, 365.2 ± 89.0; potato: 63.5 ± 33.1, 80.4 ± 37.6; fruit: 324.3 ± 148.4, 414.0 ± 220.4; P < 0.0001).

CONCLUSION

Non-alcoholic fatty liver disease patients had higher total caloric, calorigenic nutrients, grain, potato, fruit, iron, and overtime work but shorter sleep duration. Lean NAFLD patients had comparable total caloric, calorigenic nutrients, iron, sleep duration, and overtime work as obese NAFLD patients. These features could be used to the nutritional education and therapeutic guidance for lean NAFLD patients in the future.

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.

Burden of non-alcoholic fatty liver disease in Australia

Non-alcoholic fatty liver disease (NAFLD) is the commonest cause of chronic liver disease in the Australian population, although precise estimates of prevalence are lacking. NAFLD may progress to liver fibrosis, cirrhosis, decompensated liver disease, and liver cancer and is becoming an increasingly common indication for liver transplantation in Australia and New Zealand. There is an extrahepatic burden of NAFLD extending beyond the liver, which is manifested by an increased risk of developing cardiovascular disease, diabetes, and chronic renal impairment, all of which are common causes of morbidity in the Australian population. Early recognition of those patients at high risk of developing advanced liver disease is essential in order to target those who will benefit from intensive lifestyle modification. In this review, we present data on the epidemiology of NAFLD within Australia, its associated health burden in terms of hepatic and extrahepatic complications, common clinical presentations, and indications for treatment. We also propose a research agenda that highlights knowledge needed to improve diagnosis and management specific to the Australian context.

Nonalcoholic fatty liver disease as a sentinel marker for the development of diabetes mellitus in non-obese subjects

BACKGROUND

Non alcoholic fatty liver disease (NAFLD) is associated with substantial cardiometabolic morbidity.

AIMS

We evaluated the long-term extrahepatic complications of NAFLD and sought to evaluate NAFLD in non-obese subjects.

METHODS

A total of 2920 participants were retrospectively selected from a health check-up center in 2000, and followed through to December 2010. NAFLD was diagnosed using ultrasonography. Subjects were stratified according to body mass index, NAFLD, and metabolic syndrome.

RESULTS

The prevalence of non-obese NAFLD subjects and metabolically unhealthy non-obese subjects was 14.4% and 8.7%, respectively. In the multivariate analysis, non-obese NAFLD subjects had a significantly higher risk for diabetes mellitus (DM; HR 2.69, 95% CI 1.72-4.20, P < 0.001); no increase was observed for hypertension or cardiovascular disease. Metabolically unhealthy non-obese subjects had a significantly higher risk for hypertension (HR 2.75, 95% CI 2.02-3.74, P < 0.001), DM (HR 5.72, 95% CI 3.68-8.89, P < 0.001), and cardiovascular disease (HR 2.93, 95% CI 1.53-5.63, P = 0.001). Subgroup analysis of non-obese subjects showed that NAFLD, without metabolic syndrome, conferred a higher risk for DM (HR 3.60, 95% CI 2.03-6.39, P < 0.001).

CONCLUSION

Non-obese subjects with NAFLD are at a higher risk for DM independent of metabolic syndrome.

Analyses of risk factors for polycystic ovary syndrome complicated with non-alcoholic fatty liver disease

The risk factors related to polycystic ovary syndrome (PCOS) patients complicated with non-alcoholic fatty liver disease (NAFLD) were investigated. A total of 188 PCOS patients treated in Shengli Oilfield Central Hospital (Dongying, China) from February 2014 to February 2015 were retrospectively analyzed as PCOS group, and PCOS group was further divided into NAFLD group and non-NAFLD (N-NAFLD) group according to the liver B ultrasound. In the same time-period, 65 healthy people were selected as normal control group. The differences of clinical, biochemical and metabolic indexes were compared. The levels of luteinizing hormone (LH), LH/follicle stimulating hormone (FSH), testosterone (T), free androgen index (FAI), fasting insulin (FINS) and homeostasis model assessment of insulin resistance (HOMA-IR) index in PCOS group were higher than those in normal control group, but the sex hormone binding globulin (SHBG) level was lower than that in normal control group (P<0.05); there were no statistically significant differences in comparisons of age, body mass index (BMI), waist-hip ratio (WHR), FSH, dehydroepiandrosterone sulfate (DHEAs) and fasting blood glucose (FBG) between the two groups (P>0.05). The prevalence rate of NAFLD in PCOS group (44.68%) was significantly higher than that in control group (24.62%) (P<0.05). The proportion of NAFLD in PCOS patients in obesity group (63.51%) was significantly higher than that in non-obesity group (15.79%) (P<0.05). In PCOS group, NAFLD patients had more obvious metabolic abnormalities [high BMI, WHR, FBG, FINS, HOMA-IR index, total cholesterol (TC) and triglyceride (TG), and low high-density lipoprotein HDL and SHBG] and androgen excess compared with those in N-NAFLD patients (P<0.05). The levels of LH, LH/FSH, FINS and HOMA-IR index in PCOS group complicated with NAFLD were higher than those in control group complicated with NAFLD (P<0.05), but the differences in age, BMI, WHR, FSH and FBG levels were not statistically significant between the two groups (P>0.05). HOMA-IR index, BMI, WHR and TG were independent risk factors for PCOS complicated with NAFLD (P<0.05).

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.

Nonalcoholic Fatty Liver Disease and Risk of Incident Type 2 Diabetes: A Meta-analysis

OBJECTIVE

Several studies have explored the impact of nonalcoholic fatty liver disease (NAFLD) on risk of incident type 2 diabetes. However, the extent to which NAFLD may confer risk of incident diabetes remains uncertain. We performed a meta-analysis of relevant studies to quantify the magnitude of the association between NAFLD and risk of incident diabetes.

RESEARCH DESIGN AND METHODS

We collected data using PubMed, Scopus, and Web of Science from January 2000 to July 2017. We included only large (n ≥500) observational studies with a follow-up duration of at least 1 year in which NAFLD was diagnosed on imaging methods. Eligible studies were selected according to predefined keywords and clinical outcomes. Data from selected studies were extracted, and meta-analysis was performed using random-effects modeling.

RESULTS

A total of 19 observational studies with 296,439 individuals (30.1% with NAFLD) and nearly 16,000 cases of incident diabetes over a median of 5 years were included in the final analysis. Patients with NAFLD had a greater risk of incident diabetes than those without NAFLD (random-effects hazard ratio [HR] 2.22, 95% CI 1.84-2.60; I² = 79.2%). Patients with more "severe" NAFLD were also more likely to develop incident diabetes; this risk increased across the ultrasonographic scores of steatosis (n = 3 studies), but it appeared to be even greater among NAFLD patients with advanced high NAFLD fibrosis score (n = 1 study; random-effects HR 4.74, 95% CI 3.54-5.94). Sensitivity analyses did not alter these findings. Funnel plot and Egger test did not reveal significant publication bias. Study limitations included high heterogeneity, varying degrees of confounder adjustment across individual studies, and lack of studies using liver biopsy.

CONCLUSIONS

NAFLD is significantly associated with a twofold increased risk of incident diabetes. However, the observational design of the eligible studies does not allow for proving causality.

Non-alcoholic fatty liver disease and its relationship with cardiovascular disease and other extrahepatic diseases

Key physiological functions of the liver, including glucose and lipid metabolism, become disturbed in the setting of non-alcoholic fatty liver disease (NAFLD) and may be associated with a systemic inflammatory 'milieu' initiated in part by liver-secreted cytokines and molecules. Consequently, the pathophysiological effects of NAFLD extend beyond the liver with a large body of clinical evidence demonstrating NAFLD to be independently associated with both prevalent and incident cardiovascular disease (CVD), chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). The magnitude of risk of developing these extrahepatic diseases parallels the underlying severity of NAFLD, such that patients with non-alcoholic steatohepatitis (NASH) appear to be at greater risk of incident CVD, CKD and T2DM than those with simple steatosis. Other modifiers of risk may include genetic variants (eg, patatin-like phospholipase domain-containing 3 and trans-membrane 6 superfamily member 2 polymorphisms), visceral adipose tissue accumulation, dietary intake and the gut microbiome. Emerging data also suggest that NAFLD may be a risk factor for colonic neoplasia and reduced bone mineral density, especially among men. Importantly, improvement/resolution of NAFLD is associated with a reduced incidence of T2DM and improved kidney function, adding weight to causality and suggesting liver focused treatments may reduce risk of extrahepatic complications. Awareness of these associations is important for the clinicians such that CVD risk factor management, screening for T2DM and CKD are part of the routine management of patients with NAFLD.

Nonalcoholic fatty liver disease: cause or consequence of type 2 diabetes?

Growing epidemiological evidence suggests that nonalcoholic fatty liver disease (NAFLD) is an early predictor of and determinant for the development of type 2 diabetes and other features of the metabolic syndrome. This finding may have important clinical implications for the diagnosis, prevention and treatment of type 2 diabetes and its chronic complications. However, given the complex and bi-directional relationships between NAFLD, insulin resistance and chronic hyperglycaemia, it is extremely difficult to distinguish whether NAFLD is a cause or a consequence of insulin resistance and type 2 diabetes. Indeed, at the molecular level, hepatic lipogenesis and hepatic glucose production depend on differentially regulated branches of the insulin signalling pathway. Furthermore, genetic studies suggest that excess hepatic fat is associated with progressive liver disease, but does not always increase the risk of incident type 2 diabetes. Here, we will briefly review the epidemiological, pathophysiological and molecular evidence linking NAFLD to the development of type 2 diabetes. We will also discuss some recent genetic and therapeutic advances that seem to challenge a causal role of NAFLD in the pathogenesis type 2 diabetes, and propose a working hypothesis to explain this apparent conundrum. In conclusion, progressive liver disease and type 2 diabetes are divergent though inter-related consequences of insulin resistance and the metabolic syndrome.

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.

Extrahepatic Complications of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is an important cause of liver disease that is often associated with the metabolic syndrome. There is a growing awareness that extrahepatic complications occur in individuals with NAFLD, especially an increased risk of cardiovascular disease. Development of diabetes mellitus, chronic kidney disease, colorectal cancer, and endocrinopathies has been linked to NAFLD. This article reviews the extrahepatic complications affecting individuals with NAFLD and the pathogenesis underlying their development.

Risk of type 2 diabetes in patients with non-alcoholic fatty liver disease: Causal association or epiphenomenon?

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver diseases worldwide, causing considerable liver-related mortality and morbidity. Over the last 10years, it has also become increasingly evident that NAFLD is a multisystem disease, affecting many extra-hepatic organ systems and interacting with the regulation of multiple metabolic pathways. NAFLD is potentially involved in the aetiology and pathogenesis of type 2 diabetes via its direct contribution to hepatic/peripheral insulin resistance and the systemic release of multiple hepatokines that may adversely affect glucose metabolism and insulin action. In this updated review, we discuss the rapidly expanding body of clinical and epidemiological evidence that supports a strong link between NAFLD and the risk of developing type 2 diabetes. We also briefly examine the conventional and the more innovative pharmacological approaches for the treatment of NAFLD that may influence the risk of developing type 2 diabetes.

Physiology and pathophysiology of liver lipid metabolism

Liver lipid metabolism and its modulation are involved in many pathologic conditions, such as obesity, non-alcoholic fatty liver disease, diabetes mellitus, atherosclerosis and cardiovascular disease. Metabolic disorders seem to share a similar background of low-grade chronic inflammation, even if the pathophysiological mechanisms leading to tissue and organ damage have not been completely clarified yet. The accumulation of neutral lipids in the liver is now recognized as a beneficial and protective mechanism; on the other hand, lipoperoxidation is involved in the development and progression of non-alcoholic steatohepatitis. The role of the gut microbiota in liver lipid metabolism has been the object of recent scientific investigations. It is likely that the gut microbiota is involved in a complex metabolic modulation and the translocation of gut microflora may also contribute to maintaining the low-grade inflammatory status of metabolic syndrome. Therefore, lipid metabolism pathology has vague limits and complex mechanisms, and the knowledge of these is essential to guide diagnostic and therapeutic decisions.

Association Between Change in Serum Aminotransferase and Mortality: A Nationwide Cohort Study in Korea

There is little information on how the change in serum aminotransferase affects mortality. We investigated the association between changes in serum aminotransferase levels and mortality from all causes, cardiovascular disease (CVD), and liver disease.Three percent of men from the Korean National Health Insurance database were sampled randomly at the end of 2002. After excluding patients with cancer, CVD, CVD risk factors, or liver disease, those who participated in 2 consecutive rounds of the national health screening examination were included (n = 68,431). The primary outcome was CVD mortality. Secondary outcomes were liver disease mortality and all-cause mortality. Change in metabolic profiles was analyzed based on changes in liver enzyme levels. Elevated levels of serum aminotransferase were associated with CVD, liver disease, and all-cause mortality. Men who had sustained elevation of serum aminotransferase during 2 subsequent liver enzyme tests showed a significantly higher risk of CVD mortality (adjusted hazard ratio [aHR] 1.95; 95% confidence interval [CI] 1.07-3.56, 2.29; 1.27-4.12) than the sustained normal group. In contrast, the normalization group (aHR 1.52, 95% CI 0.82-2.81 for aspartate aminotransferase [AST]; aHR 1.35, 95% CI 0.70-2.61 for alanine aminotransferase [ALT]) and the new elevation group (aHR 1.27, 0.66-2.44 for AST; aHR 0.99, 95% CI 0.49-2.20 for ALT) were not different from the sustained normal group in CVD mortality.Individuals with serum aminotransferase elevation, particularly when sustained, are at higher risk of mortality, and should receive appropriate medical attention.

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.

Non-alcoholic fatty liver disease predicts type 2 diabetes mellitus, but not prediabetes, in Xi'an, China: a five-year cohort study

BACKGROUND & AIMS

Emerging studies have focused the association between non-alcoholic fatty liver disease (NAFLD) and the risk of type 2 diabetes mellitus (T2DM) but the results were inconsistent. In addition, few studies have put focus on the association between NAFLD and the risk of prediabetes. We aimed to investigate whether NAFLD diagnosed by ultrasonography could predict the risk of future T2DM and prediabetes in Chinese population.

METHODS

The population-based cohort study held in Xi'an, Northwestern China, was based on China National Diabetes and Metabolic Disorders Survey. During a follow-up of 5 years, 508 healthy subjects were included as study sample. NAFLD was determined by abdominal ultrasonography. T2DM and prediabetes were diagnosed based on oral glucose tolerance test.

RESULTS

Of 508 subjects, 97 (19.1%) were diagnosed as NAFLD and 411 (80.9%) were as non-NAFLD; 20 (3.9%) developed diabetes and 85 (16.7%) developed prediabetes during follow-up. The incidence of diabetes and prediabetes in the NAFLD group was 20.6 and 51.6 per 1000 person-years, respectively, whereas that in non-NAFLD group was 4.9 and 29.2 per 1000 person-years respectively. Cox proportional hazard regression showed that the multivariable-adjusted relative risk (RR) of T2DM and prediabetes in the NAFLD group was 4.462 [95% confidence interval (CI): 1.855-10.734, P < 0.001] and 1.642 (95% CI: 0.965-2.793, P = 0.067), respectively, compared with non-NAFLD group.

CONCLUSIONS

Non-alcoholic fatty liver disease was a significant predictor for future diabetes, but not for prediabetes, in Xi'an, China. More cohort studies are needed to confirm our findings.

Independent Association Between Improvement of Nonalcoholic Fatty Liver Disease and Reduced Incidence of Type 2 Diabetes

OBJECTIVE

Only a few studies have evaluated the long-term effects of nonalcoholic fatty liver disease (NAFLD) on type 2 diabetes mellitus (T2DM), and none have examined whether NAFLD improvement reduces T2DM incidence. We investigated the association between NAFLD improvement and T2DM incidence.

RESEARCH DESIGN AND METHODS

Between 2000 and 2012, 4,604 participants who underwent a health check twice with >10 years between were enrolled. Exclusion criteria were positive hepatitis B surface antigen, positive hepatitis C antibody, ethanol intake >20 g/day, and diabetes. The 3,074 eligible participants were divided into an NAFLD group (n = 728) and a non-NAFLD group (n = 2,346) according to ultrasonography-detected fatty liver. The NAFLD group was categorized into an improved group (n = 110) and a sustained NAFLD group (n = 618) based on fatty liver disappearance at the second visit. Incident T2DM odds ratios (ORs) were estimated by logistic regression models adjusted for age, sex, BMI, impaired fasting glucose, family history of diabetes, dyslipidemia, hypertension, and physical exercise.

RESULTS

T2DM occurred in 117 participants (16.1%) in the NAFLD group and 72 (3.1%) in the non-NAFLD group. NAFLD at baseline was associated with T2DM incidence (multivariate OR 2.37 [95% CI 1.60-3.52]). T2DM occurred in 7 participants (6.4%) in the improved group and in 110 (17.8%) in the sustained NAFLD group. NAFLD improvement was associated with reduced T2DM incidence (multivariate OR 0.27 [95% CI 0.12-0.61]).

CONCLUSIONS

NAFLD improvement is associated with T2DM incidence reduction.

Association between the Fatty Liver Index and Risk of Type 2 Diabetes in the EPIC-Potsdam Study

The fatty liver index (FLI) predicts fatty liver by using BMI, waist circumference, γ-glutamyltransferase and triglycerides. We investigated the association between the FLI and the risk of type 2 diabetes and evaluated to what extent single FLI components contribute to the diabetes risk. We analysed a case-cohort study (random sub-cohort: 1922; incident cases: 563) nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study. The proportion of exposure effect (PEE) explained by single FLI components was evaluated and effect decomposition using inverse probability weighting (IPW) was applied. Women and men with a FLI ≥60 compared to those with a FLI <30 had a multivariable-adjusted Hazard Ratio (HR) of 17.6; 95% confidence interval (CI) 11.1-28.0 and HR: 10.9; 95% CI 6.22-19.2, respectively. Adjustment for BMI or waist circumference attenuated this association in men [PEE_BMI (95% CI) = 53.8% (43.9%-65.8%); PEE_waist (95% CI) = 54.8% (44.2%-68.8%)]. In women, adjustment for waist circumference attenuated the association to a lesser degree than in men [PEE_waist (95% CI) = 31.1%; (21.9%-43.1%)] while BMI had no appreciable effect [PEE_BMI (95% CI) = 11.0% (2.68%-21.0%)]. γ-glutamyltransferase and triglycerides showed only a small attenuation in women [PEE_GGT(95% CI) = 3.11% (-0.72%-4.48%); PEE_TG (95% CI) = 6.36% (3.81%-9.92%)] and in men [PEE_GGT = 0%; PEE_TG (95% CI) = 6.23% (2.03%-11.8%)]. In women, the total effect was decomposed into a direct effect and 4 indirect effects (HR_BMI = 1.10; HR_waist = 1.28; HR_GGT = 0.97 and HR_TG = 1.03). In men, the 4 indirect effects were HR_BMI = 1.25; HR_waist = 1.29; HR_GGT = 0.97 and HR_TG = 0.99. These data suggest that the FLI, as a proxy for fatty liver, is associated with risk of type 2 diabetes. This association is only partly explained by standard estimates of overall and abdominal body fatness, particularly among women.

Lean-non-alcoholic fatty liver disease increases risk for metabolic disorders in a normal weight Chinese population

AIM: To study the prevalence and clinical biochemical, blood cell and metabolic features of lean-non-alcoholic fatty liver disease (lean-NAFLD) and its association with other diseases.

METHODS: Demographic, biochemical and blood examinations were conducted in all the subjects in this study. We classified the subjects into four groups according to their weight and NAFLD status: lean-control, lean-NAFLD [body mass index (BMI) < 24 kg/m²], overweight-obese control and overweight-obese NAFLD. One-way analysis of variance (ANOVA) was used to compare the means of continuous variables (age, BMI, blood pressure, glucose, lipid, insulin, liver enzymes and blood cell counts) and the χ² test was used to compare the differences in frequency of categorical variables (sex, education, physical activity, smoking, alcohol consumption and prevalence of hypertension, hyperlipidemia, diabetes, metabolic syndrome central obesity and obesity). Both univariate and multivariate logistic regression models were adopted to calculate odds ratios (ORs) and predict hyperlipidemia, hypertension, diabetes and metabolic syndrome when we respectively set all controls, lean-control and overweight-obese-control as references. In multivariate logistic regression models, we adjusted potential confounding factors, including age, sex, smoking, alcohol consumption and physical activity.

RESULTS: The prevalence of NAFLD was very high in China. NAFLD patients were older, had a higher BMI, waist circumference, blood pressure, fasting blood glucose, insulin, blood lipid, liver enzymes and uric acid than the controls. Although lean-NAFLD patients had lower BMI and waist circumstance, they had significantly higher visceral adiposity index than overweight-obese controls. Lean-NAFLD patients had comparable triglyceride, cholesterin and low-density lipoprotein cholesterin to overweight-obese NAFLD patients. In blood cell examination, both lean and overweight-obese NAFLD was companied by higher white blood cell count, red blood cell count, hemoglobin and hematocrit value. All NAFLD patients were at risk of hyperlipidemia, hypertension, diabetes and metabolic syndrome (MetS). Lean-NAFLD was more strongly associated with diabetes (OR = 2.47, 95%CI: 1.14-5.35), hypertension (OR = 1.72, 95%CI: 1.00-2.96) and MetS (OR = 3.19, 95%CI: 1.17-4.05) than overweight-obese-NAFLD (only OR for MetS was meaningful: OR = 1.89, 95%CI: 1.29-2.77). NAFLD patients were more likely to have central obesity (OR = 1.97, 95%CI: 1.38-2.80), especially in lean groups (OR = 2.17, 95%CI: 1.17-4.05).

CONCLUSION: Lean-NAFLD has unique results in demographic, biochemical and blood examinations, and adds significant risk for diabetes, hypertension and MetS in lean individuals.

Non-alcoholic fatty liver disease as a cause and a consequence of metabolic syndrome

Metabolic syndrome is a cluster of metabolic abnormalities that identifies people at risk of diabetes and cardiovascular disease, whereas non-alcoholic fatty liver disease (NAFLD) is defined as a disorder with excess fat in the liver due to non-alcoholic causes. Two key components of metabolic syndrome, glucose and triglycerides, are overproduced by the fatty liver. The liver is therefore a key determinant of metabolic abnormalities. The prevalence of both metabolic syndrome and NAFLD increases with obesity. Other acquired causes for both disorders include excessive intake of simple sugars and physical inactivity. Both disorders predict type 2 diabetes, cardiovascular disease, non-alcoholic steatohepatitis (NASH), and hepatocellular carcinoma. Because metabolic syndrome can be defined in many different ways, NAFLD might be a more direct predictor of these diseases. Half of people with NAFLD carry at least one variant (G) allele at rs738409 in the PNPLA3 gene, which is associated with high liver fat content. Steatosis in PNPLA3-associated NAFLD is not accompanied by features of metabolic syndrome. All forms of NAFLD increase the risk of NASH, cirrhosis, and hepatocellular carcinoma.

Non-alcoholic fatty liver disease in obese adults: clinical aspects and current management strategies

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder whose prevalence is strongly linked to the current epidemic of obesity in many western countries. The prevalence of NAFLD is two to four times higher in populations with pre-existing metabolic comorbidities than in the general population. The diagnosis of primary NAFLD involves establishing the presence of hepatic steatosis or steatohepatitis by imaging or histology, along with establishing the non-alcoholic nature of the disease process and excluding competing aetiologies for hepatic steatosis. Among the indirect serum biomarkers, the NAFLD fibrosis score can help to identify patients with NAFLD and with higher likelihood of having fibrosis or cirrhosis. A liver biopsy should be considered in NAFLD patients at increased risk for steatohepatitis/advanced fibrosis and in cases where a liver biopsy is necessary to exclude co-existing chronic liver diseases and other aetiologies for hepatic steatosis. The treatment and management recommendations for obesity-associated NAFLD are aimed towards weight reduction. The currently available interventions employed to promote weight loss and improve the metabolic responses in NAFLD include lifestyle modification, pharmacotherapy and bariatric surgery.

Non-alcoholic fatty liver disease and diabetes: From physiopathological interplay to diagnosis and treatment

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent in patients with diabetes mellitus and increasing evidence suggests that patients with type 2 diabetes are at a particularly high risk for developing the progressive forms of NAFLD, non-alcoholic steatohepatitis and associated advanced liver fibrosis. Moreover, diabetes is an independent risk factor for NAFLD progression, and for hepatocellular carcinoma development and liver-related mortality in prospective studies. Notwithstanding, patients with NAFLD have an elevated prevalence of prediabetes. Recent studies have shown that NAFLD presence predicts the development of type 2 diabetes. Diabetes and NAFLD have mutual pathogenetic mechanisms and it is possible that genetic and environmental factors interact with metabolic derangements to accelerate NAFLD progression in diabetic patients. The diagnosis of the more advanced stages of NAFLD in diabetic patients shares the same challenges as in non-diabetic patients and it includes imaging and serological methods, although histopathological evaluation is still considered the gold standard diagnostic method. An effective established treatment is not yet available for patients with steatohepatitis and fibrosis and randomized clinical trials including only diabetic patients are lacking. We sought to outline the published data including epidemiology, pathogenesis, diagnosis and treatment of NAFLD in diabetic patients, in order to better understand the interplay between these two prevalent diseases and identify the gaps that still need to be fulfilled in the management of NAFLD in patients with diabetes mellitus.

Non-alcoholic fatty liver disease: a diabetologist's perspective

In the recent years, non-alcoholic fatty liver disease (NAFLD) has emerged as the commonest cause of chronic liver disease in the developed world. The global epidemic of obesity secondary to physical inactivity and adverse food habits accounts for the alarming rise in NAFLD. Metabolic syndrome plays a major role in the pathogenesis of both NAFLD and type 2 diabetes mellitus (T2DM). Whilst most cases of NAFLD remain asymptomatic with only hepatic steatosis, about 30 % progress to non-alcoholic steatohepatitis with chronic liver inflammation that can lead on to fibrosis, cirrhosis, liver failure, and hepatocellular carcinoma. Because of the similar pathogenesis shared between T2DM and NAFLD, T2DM occurs as an important complication in many cases of NAFLD, and many cases of T2DM are further complicated by NAFLD. Rapid progression and increased complications of the individual diseases is the end result of this dual coexistence. Diagnosis of NAFLD relies upon hepatic imaging, serum biochemical markers, and liver biopsy. As in T2DM, the most important management option for patients with NAFLD is lifestyle changes targeted at weight reduction. Other treatment options include insulin sensitizers (metformin and pioglitazone), vitamin E, incretin mimetics, omega-3 fatty acids, cholesterol lowering agents, orlistat, and bariatric surgery. The clinical spectrum, patho-physiological features and therapeutic options of NAFLD share many things in common with T2DM and therefore, this review is to highlight the diabetologist's perspective of the disease.

Severe asymptomatic non-alcoholic fatty liver disease in routine diabetes care; a multi-disciplinary team approach to diagnosis and management

OBJECTIVES

To prospectively use a non-invasive algorithm to identify asymptomatic, advanced non-alcoholic fatty liver disease (NAFLD) in a secondary care diabetes clinic and to determine the short-term effect of a multi-disciplinary team (MDT) approach in a liver clinic.

RESEARCH DESIGN AND METHODS

NAFLD Fibrosis Score (NFS) was calculated in 64 asymptomatic patients with type 2 diabetes. Advanced fibrosis was identified using transient elastography and confirmed with liver biopsy. In a subsequent retrospective study, 95 patients newly referred to the NAFLD MDT clinic were investigated and the impact of the MDT approach assessed.

RESULTS

25/64 (39.0%) of patients with diabetes had a low NFS (<-1.455). 39/64 (61.0%) patients had a high or indeterminate NFS and were referred for review in the NAFLD MDT clinic, of which 23/39 attended for assessment. 19/23 (82.6%) were diagnosed with NAFLD, of which 6/19 (31.6%) patients had a positive transient elastography (≥8 kPa). Liver biopsy confirmed advanced fibrosis in 5/6 cases, with moderate fibrosis in 1 case. In the retrospective study, 65/95 (68.4%) new referrals to the NAFLD MDT clinic had a diagnosis of NAFLD. Over a median 98 days (IQR 70-182) follow-up, there was a significant improvement in weight (-0.8 kg; P = 0.024), total cholesterol (-0.2 mmol/L; P = 0.044), ALT (alanine transmaminase, -12.5 IU/L; P < 0.001) and GGT (gammu-glutamyl transferase, -13.0 IU/L; P < 0.0001). 7/28 (25%) of patients with diabetes achieved >5% weight loss.

CONCLUSIONS

A significant proportion of asymptomatic patients attending type 2 diabetes clinics have undiagnosed advanced NAFLD fibrosis. An MDT approach to NAFLD results in short-term improvements in metabolic and liver parameters.

Non-alcoholic fatty liver disease in common endocrine disorders

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of disease spanning from simple benign steatosis to steatohepatitis with fibrosis and scarring that can eventually lead to cirrhosis. Its prevalence is rising rapidly and is developing into the leading indication for liver transplantation worldwide. Abnormalities in endocrine axes have been associated with NALFD, including hypogonadism, hypothyroidism, GH deficiency and hypercortisolaemia. In some instances, correction of the endocrine defects has been shown to have a beneficial impact. While in patients with type 2 diabetes the association with NAFLD is well established and recognised, there is a more limited appreciation of the condition among common endocrine diseases presenting with hormonal excess or deficiency. In this review, we examine the published data that have suggested a mechanistic link between endocrine abnormalities and NAFLD and summarise the clinical data endorsing these observations.

Interaction of type 2 diabetes and nonalcoholic fatty liver disease

Evauation of: Kasturiratne A, Weerasinghe S, Dassanayake A et al. Influence of non-alcoholic fatty liver disease on the development of diabetes mellitus. J. Gastroenterol. Hepatol. 28(1), 142-147 (2013). It has been a few decades that Type 2 diabetes has been clearly linked to the development and progression of nonalcoholic fatty liver disease (NAFLD). In a recent study reported by Kastuiratne et al., the reverse scenario is also reported. In this study, a cohort of Sri Lankan adults were evaluated for NAFLD by ultrasound and for the presence of Type 2 diabetes. Those without diabetes at baseline were followed prospectively for 3 years and assessed for incident diabetes. On multivariate analysis, after adjustment for a number of factors (age, impaired fasting glucose, BMI, waist circumference, elevated ALT, family history of diabetes and presence of hypertension and hyperlipidemia), NAFLD was the only predictor of incident diabetes in those with and without impaired fasting glucose at baseline. This study adds to the growing evidence connecting NAFLD to Type 2 diabetes and highlights the importance of its recognition in an effort to target those at the highest risk of diabetes for lifestyle and pharmacologic intervention.

Elevated liver enzymes in individuals with undiagnosed diabetes in the U.S

OBJECTIVE

We investigated the association of diabetes diagnosis and medication type with liver injury in individuals with clinical diabetes.

METHODS

We analyzed 2426 patients with clinical diabetes in the National Health and Nutrition Examination Survey conducted from 1999 to 2008. Elevated alanine transaminase (ALT) and aspartate transaminase (AST) levels were used as markers of liver injury. Participants were categorized into one of three categories: 1) clinical diabetes without physician's diagnosis or diabetes medication; 2) diagnosed diabetes without diabetes medication; or 3) diagnosed diabetes with diabetes medication, further divided by classes of diabetes medications prescribed. We conducted logistic regression analysis to examine the relationship between diabetes diagnosis and medication type and elevated ALT and AST, adjusting for race/ethnicity, education, health insurance status, BMI category, alcohol consumption, physical activity, antihyperlipidemic agents, glycohemoglobin, C-reactive protein, viral hepatitis and liver disease.

RESULTS

Participants with undiagnosed diabetes were more likely to have elevated ALT and AST levels (OR=1.82, 95% CI 1.47, 2.42; OR=1.99, 95% CI 1.46, 2.71, respectively). In contrast, there was no association between specific diabetes medication (i.e., sulfonylureas, biguanides/thiazolidinediones) and elevated ALT or AST levels among the treated. Our findings were confirmed in sensitivity analyses employing a lower threshold for ALT, and excluding individuals with viral hepatitis or liver disease.

CONCLUSION

We found that undiagnosed diabetes is associated with liver injury, compared to diagnosed diabetes with treatment. The effect of diabetes treatment on liver injury in individuals with diabetes remains uncertain.