Dehydroepiandrosterone (DHEA) ameliorates the insulin sensitivity in older rats

To evaluate whether dehydroepiandrosterone (DHEA) ameliorates the decreased insulin sensitivity in older rats, hyperinsulinemic euglycemic clamp studies were performed in rats of various age groups previously treated with DHEA. The glucose metabolic clearance rate (MCR) of the control rats showed a gradual decline with the advancing ages (MCR = 13.05 - 0.027*age (days), r2=0.683, p < 0.01, n = 18). The glucose MCR of the DHEA-treated rats also showed a gradual decline with the aging process (MCR = 12.67 - 0.011*age (days), r2=0.429, p < 0.01, n = 18). However, the MCR of the DHEA-treated rats were significantly higher than that of control rats. As glucose MCR is a parameter which indicates the insulin sensitivity in various tissues, especially in muscles and body composition, was not changed after the injection of DHEA, DHEA is considered to work on muscles to increase insulin sensitivity.