Serum omentin level and related factors in obese and type 2 diabetic patients

Abstract

Objective To assay the serum omentin level in obese and newly diagnosed type 2 diabetes mellitus (T2DM) patients and investigate the relations hip between serum omentin level and body fat parameters, glucose and lipid metabolism and insulin resistance index (IR) etc. Methods 143 Shanghainese, 74 males and 69 females, aged 20-69, underwent evaluation of body mass index (BMI),waist circumference (W), hip circumference (H), and waist hip ratio (WHR). 69 patients with T2DM were divided into 2 subgroups: normal weight (T2DM-NW) subgroup (n=36, with BMI＜25 kg/m2) and overweight/obese (T2DM-OW/OB) subgroup (n=8, with BMI≥25 kg/m2). 74 patients with normal glucose regulation (NGR) were subdivided into 2 subgroups : normal weight (NGR-NW) subgroup (n=36,with BMI＜25 kg/m2) and overweight/obese (NGR-OW) subgroup (n=38, with BMI≥25 kg/m2). The level of fasting serum omentin was measured by ELISA. Blood glucose, HbAle, lipids, and insulin levels were also measured. Insulin sensitivity was assessed by HOMA-IR. Results After age and sex adjusted,the serum omentin level of the T2DM group was (17.5±5.8)μg/L , siguificandy lower than that of the NGR group [ (20.0±7.6)μg,/L, P＜0.05 ] ; the serum omentin level of the overweight/obese subjects was ( 16.8±6.0)μg/L, significantly lower than that of the NW subjects [ (20.7±7.2 μg/L, P＜0.01 ]. The serum omentin level of the T2DM -OW/OB subgroup was significantly lower than that of the NGR-OW/OB group (P＜0.05). Partial correlation analysis showed that the serum omentin was negatively correlated to waist W, WHR, natural logarithm of HOMA-insulin resistance indexes [In(HOMA-IR)], triglycerides (TG), BMI,fasting serum insulin (FINS), and 2 hour OGTT glucose (2 hPG) (r=-0.329, -0.313,-0.301, -0.299, -0.298, -0. 240, and -0.166 respectively,P＜0.01 or P＜0.05), and positively correlated to high density lipoprotein- cholesterol (HDL-C) (r=0.400, P＜0.01). Multiple linear regression showed that HDL-C, W and in (HOMA-IR) were independent variables of omentin. Conelusion The serum omentin level is low in the obese and type 2 diabetes mellitus subjects, and is correlated with obese indexes, insulin resistance and lipid metabolism. Serum omentin may directly contribute to the underlying pathophysiology of insulin resistance syndrome. Key words: Obesity; Diabetes mellitus,type 2 ; Omentin