Plasma SFRP5 levels are decreased in Chinese subjects with obesity and type 2 diabetes and negatively correlated with parameters of insulin resistance

Aims: To detect plasma secreted frizzled-related protein (SFRP) 5 levels in Chinese healthy, obese and type 2 diabetes mellitus (T2DM) subjects and to investigate the relationships between plasma SFRP5 levels and body fat parameters, insulin resistance, glucolipid metabolism and inflammation. Methods: Eighty-nine subjects with normal glucose tolerance (NGT) and 87 subjects with T2DM were enrolled in this study. NGT and T2DM groups were divided into normal weight (NW) and obese (OB) subgroups separately. Anthropometric parameters such as body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) were examined. Plasma levels of SFRP5, IL-6, glucose, serum lipid, glycated hemoglobin (HbA(1C)) and fasting insulin (FINS) levels were measured. Insulin resistance index (IR) was assessed by homeostasis model assessment (HOMA). Results: Plasma SFRP5 levels were lower in T2DM group than in NGT group. The levels of plasma SFRP5 in subjects with obesity were also lower than those in subjects with NW in both NGT and T2DM groups. T2DM-OB subgroup had lower plasma SFRP5 levels than that in NGT-OB subgroup. Plasma SFRP5 levels were negatively correlated with BMI, WC, WHR, fasting plasma glucose, HbA1C, triglyceride (TG), FINS, HOMA-IR and IL-6. Multiple stepwise regression analysis showed that HOMA-IR, BMI and TG were independently related with plasma SFRP5 levels. Conclusions: Plasma levels of SFRP5 were decreased in Chinese obese and T2DM subjects. SFRP5 was an independent factor affecting glucolipid metabolism, inflammation and IR. It may play an important role in the pathogenesis of obesity and T2DM. (C) 2012 Elsevier Ireland Ltd. All rights reserved.