Relationship of androgens to insulin resistance and chronic inflammation in morbidly obese premenopausal women: Studies before and after vertical banded gastroplasty

Background: Morbid obesity is associated with insulin resistance (IR), type 2 diabetes, lipid abnormalities, and hypertension. The association of obesity with increased androgen production and low concentrations of sex hormone-binding globulin (SHBG) in women has been demonstrated as well as a strong association of androgens with markers of inflammation such as high-sensitive C-reactive protein (hsCRP). Because weight loss results in a significant decrease in cardiovascular risk factors, IR and inflammation, we questioned a possible interrelationship between androgens, IR and inflammation in a prospective study with 43 morbidly obese female patients undergoing bariatric surgery. Methods: SHBG, dehydroepiandrosterone-sulfate (DHEA-S), and insulin were measured by ELISA, cortisol by fluorescence polarization immunoassay, androstendione by RIA, and testosterone by electrochemiluminescence immunoassay. The free androgen index (FAI) was calculated as the total testosterone/SHBG ratio. High sensitivity assays were used to obtain concentrations of fasting hsCRP, Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha). Results: Weight loss resulted in a significant increase in SHBG (17 12 vs 70 30 nmol/l, P < 0.0001). Serum concentrations of androstendione, total testosterone, DHEA-S and the FAI decreased significantly (2.05 +/- 0.78 vs 1.40 +/- 0.54 ng/ml, P < 0.0001; 1.88 +/- 0.84 vs 1.16 +/- 0.57 nmol/L, P < 0.0001; 1.72 +/- 0.86 vs 1.49 +/- 0.78 mu g/ml, P < 0.01; 0.15 +/- 0.10 vs 0.02 +/- 0.01, P < 0.0001; respectively). Preoperatively and postoperatively, no association between androgens and IR, chronic subclinical inflammation and lipid parameters could be observed. Conclusion: Massive weight loss induced by bariatric surgery is associated with a significant reduction of androgen concentrations but not related to the concomitant decline of chronic inflammation, IR, glucose and lipid abnormalities in premenopausal morbidly obese women.