SEX-SPECIFIC ACTION OF INSULIN TO ACUTELY INCREASE THE METABOLIC-CLEARANCE RATE OF DEHYDROEPIANDROSTERONE IN HUMANS

To test the hypothesis that insulin acutely enhances the metabolic cle arance rate (MCR) of dehydroepiandrosterone in humans, the effect of a short-term insulin infusion on the MCR of dehydroepiandrosterone was assessed in 10 men and 7 women. After an overnight fast, dehydroepiand rosterone was infused at 3.47 mu mol/h for 6.5 h. At 240 min, a hyperi nsulinemic-euglycemic clamp was begun by infusing insulin at 21.5 pmol /kg per min for 2.5 h. MCR of dehydroepiandrosterone was calculated at baseline (210-240 min) and during the insulin infusion (360-390 min). A control study was conducted at least 1 wk later, in which 0.45% sal ine was substituted for the hyperinsulinemic-euglycemic clamp. During the insulin clamp study, serum insulin rose from 34 +/- 2 to 1084 +/- 136 pmol/liter (P = 0.0001) in men and from 40 +/- 5 to 1357 +/- 175 p mol/liter (P = 0.0003) in women, while serum glucose remained constant in both groups. MCR of dehydroepiandrosterone rose in men during the insulin infusion from 2443 +/- 409 to 3599 +/- 500 liters/ 24 h (P = 0 .003), but did not change during the control saline infusion. In contr ast, MCR of dehydroepiandrosterone in women did not change in the insu lin damp study during insulin infusion (2526 +/- 495 liters/24 h at ba seline vs. 2442 +/- 491 liters/24 h during insulin infusion; P = 0.78) . These findings suggest that insulin acutely increases the MCR of deh ydroepiandrosterone in men but not in women.