Total and high-molecular-weight adiponectin levels and prediction of insulin resistance

Adiponectin is a peptide secreted by adipocytes; its reduction is associated with obesity-related disorders, including insulin resistance (IR). The study analysed levels of total adiponectin and its high-molecular-weight (HMW) oligomer in a group of metabolically healthy adults and in patients with type 2 diabetes mellitus (T2DM) to evaluate these levels as potential predictors of the presence of IR. The study comprised 269 metabolically healthy adults and 300 patients with T2DM. Anthropometric and bio-chemical indices were measured, including total and HMW adiponectin levels; the Homeostatic Model Assessment of IR (HOMA-IR) index was calculated, and logistic regression analysis was used to predict the presence of IR. In healthy individuals, both total and HMW adiponectin levels were significantly higher than in diabetic patients. Total and HMW adiponectin levels were moderately correlated with the HOMA-IR index. Logistic regression analysis showed that increased levels of both total adiponectin (odds ratio [OR] 0.598, 95% confidence interval [CI] 0.483-0.723) and the HMW form (OR 0.360, 95% CI 0.242-0.511) are protective factors for the development of IR. The cut-off levels were 4.22 mg/L for total adiponectin and 2.75 mg/L for HMW adiponectin. The results are valid for middle-aged European adults. Adiponectin levels below the indicated cut-offs may predict a potential risk for the development of IR.