关键词: 糖尿病, 2型, 超重, 瘦素, 肿瘤坏死因子&alpha

Abstract: ［Abstract］ Objective To investigate the effect of low carbohydrate diet intervention on the methylation of leptin gene and tumor necrosis factor-α gene(TNF-α) in overweight patients with diabetes mellitus type 2(T2DM).
Methods One hundred and twenty  overweight patients with T2DM, were randomly divided into observation group and control group with 60 cases in each group. The observation group was given low-carbohydrate diet and the control group was given daily diet. The levels of fasting plasma glucose(FPG), fasting insulin(FINS), homeostasis model assessment(HOMA-IR), hemoglobin A1c(HbA1c), total cholesterol(TC), triglyceride(TG), high-density lipoprotein cholesterol(HDL-C), low-density lipoprotein cholesterol(LDL-C), body mass index(BMI), waist circumference(WC), Diabetes Distress Scale(DDS), Audit of Diabetes-dependent Quality of Life(ADQoL), serum concentrations of leptin and TNF-α, the methylation rates of leptin gene and TNF-α gene were observed before and after treatment.
Results The levels of FPG, FINS, HOMA-IR and HbA1c after treatment were significantly decreased than those before treatment in both groups(P＜0.05). After treatment, the levels of FPG, FINS, HOMA-IR and HbA1c in observation group were significantly lower than those in control group(P＜0.05). In observation group, the levels of TC and TG after treatment were significantly decreased and HDL-C after treatment was significantly increased than those before treatment(P＜0.05). After treatment, TC and TG concentration in observation group were significantly lower and HDL-C concentration in observation group were significantly higher than those in control group after treatment(P＜0.05). In observation group, the levels of BMI, WC and DDS score were significantly lower and ADQoL score was significantly higher than those before treatment(P＜0.05). In observation group, the levels of BMI, WC and DDS score after treatment were significantly lower and HDL-C concentration was much higher than those in control group after treatment(P＜0.05). The methylation rates of leptin gene and TNF-α gene after treatment were significantly increased and the serum concentration of leptin and TNF-α after treatment were decreased significantly than those before treatment in both groups(P＜0.05), and those changes in observation group were more significant than those in control group, with the higher methylation rates of leptin gene and TNF-α gene, the lower serum concentration of leptin and TNF-α in observation group than those in control group(P＜0.05).
Conclusion The diet intervention with low carbohydrate has significant curative effect on overweight type 2 diabetes, which can alleviate the disorder of carbohydrate and lipid metabolism, and it may be related to the methylation of leptin gene and TNF-α gene.

Key words: diabetes mellitus, type 2, overweight, leptin, tumor necrosis factor-α