Association between Thyroid Function and Nonalcoholic Fatty Liver Disease in Euthyroid Type 2 Diabetes Patients.

Bin Huang,Shandong Ye,Shengju Yang

doi:10.1155/2020/6538208

Bin Huang, Shandong Ye + Show 1 more

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https://doi.org/10.1155/2020/6538208

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Abstract

Thyroid function and type 2 diabetes mellitus (T2DM) are both associated with increased risks of adverse clinical outcomes in nonalcoholic fatty liver disease (NAFLD). Our study is aimed at evaluating the association between thyroid function and NAFLD in T2DM patients with normal thyroid function (euthyroid) and analyzing the potential effects of metformin on the pathological process. Overall, 369 T2DM patients were enrolled between July 2017 and September 2018 and stratified into NAFLD and non-NAFLD groups. Data on age, gender, body mass index (BMI, kg/m2), metformin use, and basal metabolic rate (BMR) were obtained from participants' records. All patients were tested for biochemical markers, indexes of glucose metabolism, lipid metabolism, bone metabolism, and thyroid function at baseline. Multivariate analyses detected increased odds of NAFLD among individuals with T2DM per unit increase in their BMI and free triiodothyronine (FT3) and thyroid stimulating hormone (TSH); the odds ratios (OR) were 1.25, 3.02, and 1.58, respectively (all p < 0.05). Positive correlations were detected between alanine aminotransferase (ALT) and FT3 (r = 0.221, p = 0.010), and negative correlations were noted between TSH and BMR (r = −0.618, p < 0.001) and between BMR and FT3 (r = −0.452, p < 0.001) in T2DM subjects with NAFLD. A significant difference in serum FT3 (t = 2.468, p = 0.0167) and TSH (t = 2.658, p = 0.010) levels was found between obese individuals with NAFLD who used and did not use metformin. The pathological mechanism of T2DM complicated by NAFLD in euthyroid patients may be associated with insulin resistance and a thyroid hormone resistance-like manifestation, i.e., relevant hypothyroidism. Metformin can potentially decrease the double-resistance situation, especially in obese individuals.

Highlights

Type 2 diabetes mellitus (T2DM), one of the largest epidemics the world has confronted, is often implicated in multiple organ dysfunctions, including liver, kidney, and cardiovascular diseases [1]
All patients were tested for biochemical markers of liver function: alanine transaminase (ALT) and aspartate transaminase (AST); kidney function: creatinine (Cr), estimated glomerular filtration rate, calcium (Ca2+), and phosphorus (P); glucose metabolism: fasting blood glucose (FBG), fasting insulin (Fins), fasting c peptide (FCP), hemoglobin A1c (HbA1c), and homeostatic model assessment-insulin resistance (HOMA-IR); lipid metabolism: triglycerides (TG), total cholesterol (TC), lowdensity lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c); bone metabolism: osteocalcin, type I procollagen peptide, β-CrossLaps, and 25hydroxyvitamin D (25-OHD); and thyroid function: free triiodothyronine (FT3, normal range: 3.28-6.47 pmol/L), free thyroxine (FT4, normal range: 7.90-19.05 pmol/L), and thyroid stimulating hormone (TSH), FT3/FT4 ratio at baseline
There were no significant differences in sex, Cr, estimated glomerular filtration rate (eGFR), P, FPG, HbA1c, HOMA-IR, HDL-c, and FT4 between the two groups (Table 1)

Summary

Introduction

Type 2 diabetes mellitus (T2DM), one of the largest epidemics the world has confronted, is often implicated in multiple organ dysfunctions, including liver, kidney, and cardiovascular diseases [1]. The incidence of nonalcoholic fatty liver disease (NAFLD) in patients with T2DM is very high, and these patients have an increased risk of adverse clinical outcomes and death [3]. Existing clinical practice guidelines for NAFLD management do not provide specific recommendations for the therapy of T2DM patients with NAFLD. It is well known that thyroid hormones have a significant effect on hepatic lipid metabolism [4]. Hypothyroidisminduced NAFLD has generally been attributed to interruptions in thyroid hormone (TH) signals, leading to reduced utilization of lipids by the liver [5]. Subclinical hypothyroidism, even in the upper range of normal serum thyroid stimulating hormone (TSH) concentrations, has been found to be associated with NAFLD in a dose-dependent way [6]. A study involving 20,289 euthyroid individuals with suspected NAFLD showed higher levels of the thyroid hormones free triiodothyronine (FT3) and TSH compared with individuals without NAFLD and confirmed the existence of a thyroid

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