Effects of pronounced weight loss on adiponectin oligomer composition and metabolic parameters

Objective: Adiponectin is an adipocytokine secreted into circulation in three isoforms. The aim of the study was to investigate changes of adiponectin isoforms during profound weight loss and its relation to anthropomorphometric and metabolic parameters. Research Methods and Procedures: Thirteen severely obese female subjects were examined before and 1 year after surgical treatment. Total adiponectin was determined by radioimmunosorbent assay, and oligomer composition was detected by nondenaturing Western blot. Results: BMI decreased substantially (p < 0.001), which was associated with an increase of total adiponectin from 12.9 +/- 5.9 to 14.3 +/- 6.1 mu g/mL (p = 0.055). Medium molecular weight (MMW) adiponectin increased from 7.5 +/- 3.6 to 9.1 +/- 4.1 mu g/mL (p = 0.009), whereas high (HMW) and low molecular weight adiponectin remained unchanged. Delta values of total adiponectin correlated significantly with Delta values of anthropometric parameters. Similar correlations were found for Delta values of MMW (Delta weight: r(2) = 0.4132, p = 0.0178; Delta BMI: r(2) = 0.3319, p = 0.0393; Delta fat mass: r(2) = 0.5202, p = 0.0054). Discussion: Thus, profound weight loss was associated with an increase in total adiponectin, which was mainly and consistently caused by increases in MMW adiponectin (p = 0.009). These changes result in a shift from low molecular weight to MMW and HMW adiponectin isoforms, which may be related to improvements in both anthropometric and metabolic parameters.