Serum betatrophin concentrations are significantly increased in overweight but not in obese or type 2 diabetic individuals

Abstract

Objective In this study, circulating serum betatrophin levels were quantitated and their relationships with insulin resistance (IR) and other metabolic parameters in Chinese subjects with varying degrees of obesity and glucose tolerance were examined. Methods Serum betatrophin levels were determined using ELISA in 60 subjects with normal glucose tolerance (NGT: 17 lean, 23 overweight, and 20 obese subjects) and 56 subjects with type 2 diabetes mellitus (T2DM: 14 lean, 23 overweight, and 19 obese subjects). The associations of serum betatrophin levels with adiposity, glucose, lipid profile, and hepatic enzyme parameters were studied. Results Serum betatrophin concentrations were significantly higher in overweight subjects in both the NGT and T2DM groups; however, no significant difference between lean and obese participants was observed. No significant difference was found between males and females or between NGT and T2DM subjects. Serum betatrophin concentrations correlated positively with fasting insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR), γ-glutamyl transpeptidase (γ-GT), and alanine aminotransferase (ALT) in all subjects. Serum betatrophin concentrations showed an independent association with γ-GT and HOMA-IR. Conclusions Serum betatrophin levels were significantly increased in overweight individuals but not in individuals with obesity or T2DM. Serum betatrophin concentrations were significantly associated with IR, but not with lipid profiles, glucose homeostasis, or diabetes.