The influence of insulin resistance in the occurence of non-alcoholic fatty liver disease among first degree relatives of type 2 diabetes

First-degree family history of diabetes is associated with nonalcoholic fatty liver disease independent of glucose metabolic status

BACKGROUND

The first-degree relatives of patients with diabetes (FDRs) share a common genetic background with patients with diabetes. Insulin resistance is recognized as a common contributor to diabetes and nonalcoholic fatty liver disease (NAFLD). The present study aimed to investigate the association between a first-degree family history of diabetes (FHD) and NAFLD and the influence of glucose metabolic status.

METHODS

The present work analyzed a part of the baseline data of the REACTION study conducted in a community population. A total of 11,162 participants with an average age of 55.57 ± 9.66 years were enrolled, including 9870 non-FDRs and 1292 FDRs. First-degree FHD was defined as at least one patient with diabetes among parents, siblings or children. The fatty liver index (FLI) was calculated to identify NAFLD.

RESULTS

The proportions of subjects without NAFLD, with intermediate FLI, and with NAFLD differed significantly between non-FDRs and FDRs (P < 0.001). FLI was one of the metabolic factors independently associated with first-degree FHD (P = 0.006). Multivariate variance analysis revealed positive associations of first-degree FHD and glucose metabolic status (both P < 0.001) with FLI, which were independent of each other (P for interaction = 0.182). Multiple stepwise linear regression analysis identified that first-degree FHD was independently and positively associated with FLI in men, premenopausal women, and postmenopausal women (all P < 0.05).

CONCLUSION

A first-degree FHD was an independent risk factor for NAFLD. Regardless of the status of glucose metabolism, FDRs were more susceptible to NAFLD.

Elevated TPOAb is a Strong Predictor of Autoimmune Development in Patients of Type 2 Diabetes Mellitus and Non-Alcoholic Fatty Liver Disease: A Case-Control Study

OBJECTIVE

The aim of this study was to assess the prevalence of thyroid autoimmunity in T2DM with NAFLD, furthermore explore the relationship between elevated TPOAb titer and the severity of NAFLD.

METHODS

A total of 400 patients with T2DM were divided into two groups according to NAFLD. Thyroid function and other metabolic indicators were measured.

RESULTS

There were more TPOAb-positive patients in both groups, and the prevalence of TPOAb positive was significantly different in two groups (17% vs 6.9%, p< 0.01). FT4 was significantly lower in patients with T2DM with NAFLD (median FT4 0.89 vs 1.08, p < 0.001), while TSH was increased (median TSH 2.85 vs 2.28, p < 0.05). In patients with T2DM with NAFLD, the proportion of women in the thyroid autoimmune-positive group was significantly higher than the negative (71.1% vs 46%, p < 0.01). Similarly, thyroid autoimmune-positive T2DM and NAFLD patients had lower FT4 levels (median FT4 0.59 vs 0.92, p < 0.001), higher TSH levels (median TSH 3.65 vs 2.67, p < 0.001), and much higher TPOAb/TGAb (median TPOAb/TGAb 6.8 vs 1.46, p < 0.001). The increase of TPOAb was significantly correlated with the severity of fatty liver. HbA1c, TC, TG, TSH, TPOAb/TGAb and severity of fatty liver were risk factors of thyroid autoimmunity.

CONCLUSION

Autoimmune thyroid disease is more common in patients with T2DM complicated with NAFLD. Elevated TPOAb titer is closely related to fatty liver, suggesting that elevated TPOAb titer is a predictor of autoimmune development in T2DM with NAFLD.

Effect of Saxagliptin, a Dipeptidyl Peptidase 4 Inhibitor, on Non-Alcoholic Fatty Liver Disease

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) represents a broad spectrum of chronic liver disease characterized by aberrant accumulation of triglycerides (TG) in hepatocytes without excessive alcohol consumption. Hepatic lipotoxicity derived from overaccumulation of free fatty acids is considered as one of the typical hallmarks of NAFLD. Insulin resistance (IR) and chronic inflammation are widely recognized as the key etiological factors associated with NAFLD. Dipeptidyl peptidase 4 inhibitor (DPP4i) is a novel pharmacological agent extensively applied in the treatment of Type 2 Diabetes Mellitus (T2DM) for decades which also have a liver protective effect.

METHODS

In order to invest the therapeutic efficiency and underlying mechanism of DPP4i saxagliptin, we used high-fat diet (HFD) and streptozotocin-induced NAFLD treated with saxagliptin. Biochemical, histomorphological, genetic and protein expression of related pathways were investigated.

RESULTS

Fasting blood glucose (FBG), TG, total cholesterol (TC), and low-density lipoprotein cholesterin significantly increased in NAFLD group, which also exhibited severe steatosis. Other remarkable findings were hyperinsulinemia, increased DPP4, PTP-1B and TNF-α level and decreased GLP-1, ACOX-1, CPT-1A expression, concomitant with liver DPP4 expression enhancement and serum DPP4 elevation. These undesirable consequences were alleviated by saxagliptin to a certain degree.

CONCLUSION

DPP4i saxagliptin improves NAFLD by ameliorating IR, inflammation, downregulation of hepatic DPP4 and sDPP4, as well as subsequent steatosis. The elevation of hepatic DPP4 and sDPP4 and succedent post-treatment decrease suggested that DPP4 may involve in the development of NAFLD. The anti-lipotoxic effect of DPP4i may involve the activation of CPT1A and ACOX1 related β-oxidation signaling pathway suppression of TNF-α mediated inflammatory and PTP-1B. The results covered in this article showed that saxagliptin affects many aspects of the pathological characteristics of NAFLD, suggesting that DPP4i saxagliptin may offer a novel therapeutic option for NAFLD.