RELATIONSHIP BETWEEN VISCERAL FAT, STEROID-HORMONES AND INSULIN SENSITIVITY IN PREMENOPAUSAL OBESE WOMEN

Objectives. The relationships between visceral fat distribution, stero id hormones and peripheral insulin sensitivity were studied. Setting. All subjects were hospitalized in the Institute of Internal Medicine o f the University of Verona, Italy. Subjects. Nineteen fertile obese wo men were studied with ages ranging from 18 to 53 years and body mass i ndexes ranging from 27.3 to 48.4. Intervention. Body fat distribution was evaluated by waist-to-hip circumference ratio and by computed tomo graphy. The insulin tolerance test was used to evaluate peripheral ins ulin sensitivity. Glucose, insulin and C-peptide were measured in fast ing conditions and during glucose load; total and free plasma testoste rone and urinary cortisol excretion were also determined. Results. Sig nificant correlations emerged between visceral adipose tissue and fast ing glucose, insulin, and C-peptide. but not between visceral adipose tissue and total testosterone, free testosterone or urinary cortisol e xcretion. A negative correlation emerged between visceral adipose tiss ue and insulin sensitivity (r=-0.70; P<0.01). No significant correlati ons were found between insulin sensitivity and age, body weight, body mass index, total adipose tissue, subcutaneous adipose tissue or waist -to-hip ratio. Total testosterone correlated with body weight, subcuta neous adipose tissue and total adipose tissue. Free testosterone and u rinary cortisol excretion correlated positively with body weight, and negatively with age. No correlation was found between insulin sensitiv ity and total testosterone, free testosterone or urinary cortisol excr etion. The correlation between visceral adipose tissue and insulin sen sitivity remained significant even after adjusting for both age and th e body mass index. Conclusions. Our study shows that visceral fat is m ore closely associated with aberrations of insulin sensitivity than wi th obesity itself. Total testosterone, free testosterone and urinary c ortisol excretion in our subjects do not seem to be associated with su ch aberrations.