Plasma adiponectin in overweight, nondiabetic individuals with or without insulin resistance

Aim: Adiponectin is a protein produced exclusively by adipocytes with putative insulin‐sensitizing and anti‐atherogenic properties. This cross‐sectional study investigated the relationship between plasma adiponectin and a range of anthropometric, glycaemic, lipid and inflammatory parameters in overweight and obese subjects expressing characteristics of the metabolic syndrome. Methods: Subjects were selected for the study from a clinical database, if they were non‐diabetic, overweight [body mass index (BMI) > 25] and had features of the metabolic syndrome. The subjects were grouped according to BMI (25–30, 31–35 and >35 kg/m2) and then stratified for insulin resistance [homeostasis model assessment (HOMA) %S]. One hundred and ninety‐seven patients (109 males and 88 females) were selected for the study by taking an equal number with the highest and lowest HOMA indices from each of the three BMI groups. Plasma adiponectin concentration was measured in duplicate by radioimmunoassay, and the relationship between these levels and the other parameters was investigated using correlation and multiple linear regression analyses. Results: Plasma adiponectin concentration was higher in females than males (median 10.3 vs. 7.1 µg/ml, p