OBESE WOMEN - POSITIVE CORRELATION BETWEE N SERUM TESTOSTERONE AND INSULIN-RESISTANCE

Hyperinsulinemia and hyperandrogenemia are frequent in obese women. Th e aim of this study is to examine the relationship between the degree of insulin resistance and plasma androgens, and the role of android ob esity. We studied 16 obese (BMI = 39.3 +/- 1.6 kg/m2) premenopausal no n diabetic women (age = 28.2 +/- 1.4 years). The peripheral insulin se nsitivity was determined during an euglycemic insulin clamp study. Ser um total testosterone (TT), free testosterone (FT), androstenedione (A ) were measured in each women. We compared these results to those of 5 control subjects (BMI = 20 +/- 1 kg/m2). Insulin resistance was more severe in the obese women than in the control subjects : Vmax = 9.1 +/ - 0.5 mg/kg/mn vs 19.1 +/- 1.0 mg/kg/mn (p < 0.01) and Km = 152.2 +/- 13.9 muU/ml vs 42.6 +/- 5.8 muU/ml (p < 0.01). Significant positive co rrelations were demonstrated in the obese women between Km and both to tal testosterone (r = 0.74; p < 0.01) and free testosterone (r = 0.52; p < 0.05). There was no correlation between Km and Androstenedione. T he waist to hip ratio (WHR) differentiated two groups of age - and wei ght-matched obese women; Gr 1 : 10 upper body obese women (WHR = 0.90 +/- 0.10; BMI = 39.0 +/- 1.9 kg/m2); Gr 2: 6 lower body obese (WHR = 0 .77 +/- 0.02; BMI = 40.0 +/- 3.1 kg/m2. Insulin resistance was more se vere in the Gr 1: Km = 174 +/- 17 muU/ml, than in the Gr 2 : Km = 101 +/-8 muU/ml (p < 0.01). The upper body obese (Gr 1) had higher plasma androgens compared to the lower body obese women (Gr 2) : TT = 1.24 +/ - 0.12 ng/ml vs 0.69 +/- 0.05 (p < 0.01), FT = 5.8 +/- 0.55 pg/ ml vs 2.92 +/- 0.31 (p < 0.01), A = 3.51 +/- 0.39 ng/ ml vs 2.14 +/- 0.22 (p < 0.0 1). There was a positive correlation between WHR and Km (r: 0.5 5; p < 0.05). In conclusion, positive correlation was demonstrated bet ween testosteronemia and insulin resistance in obese women. Obese wome n with upper body segment obesity have more severe insulin resistance and are hyperandrogenic.