Hypoadiponectemia is associated with metabolic syndrome in patients with type 2 diabetes

Adipose tissue-expressed adiponectin levels are inversely related to the degree of adiposity, and a reduction in adiponectin serum levels is accompanied by insulin resistance. The aim of this study was to evaluate the relationship between serum adiponectin concentration and metabolic syndrome (MetS) in patients with type 2 diabetes mellitus (DM). Fasting blood samples were obtained from 150 volunteers with type 2 DM. MetS and its components were defined according to diagnostic criteria from the International Diabetes Federation. Serum adiponectin concentrations were measured using a commercially available enzyme-linked immunosorbent assay. Among the 150 patients with type 2 DM, 102 (68.0%) had MetS. Female gender (P = 0.007), hypertension (P = 0.005), systolic blood pressure (P < 0.001), diastolic blood pressure (DBP, P < 0.001), waist circumference (P < 0.001), body weight (P < 0.001), body mass index (BMI, P < 0.001), fasting glucose (P = 0.035), triglyceride (TG) level (P < 0.001), glycated hemoglobin level (HbA1c, P = 0.020), insulin level (P < 0.001), and homeostasis model assessment of insulin resistance (HOMA-IR, P < 0.001) were higher in DM patients who had MetS, whereas high-density lipoprotein cholesterol (HDL-C) concentrations (P < 0.001) and adiponectin levels (P < 0.001) were lower. Univariate linear analysis revealed that logarithmically transformed age (log-age, r = 0.279; P = 0.001) and HDL-C (r = 0.246; P = 0.002) positively correlated, whereas height (r = -0.183; P = 0.025), body weight (r = -0.282; P < 0.001), BMI (r = -0.237; P = 0.004), waist circumference (r = -0.249; P = 0.002), DBP (r = 0.252; P = 0.002), log-TG (r = 0.255; P = 0.002), log-insulin (r = -0.298; P < 0.001), and log-HOMA-IR (r = 0.288; P < 0.001) negatively correlated with serum adiponectin levels in patients with type 2 DM. Multivariate forward stepwise linear regression analysis revealed that log-age (adjusted R² change = 0.069; P < 0.001) positively correlated, whereas log-insulin (adjusted R² change = 0.182; P = 0.002) and HDL-C (adjusted R² change = 0.037; P = 0.006) negatively correlated with serum adiponectin levels in patients with type 2 DM. This study showed that lower serum adiponectin levels were positively associated with MetS in patients with type 2 DM and significantly positively related to age but negatively related to serum insulin and HDL-C levels in these subjects.