TESTOSTERONE TREATMENT IN ADOLESCENTS WITH DELAYED PUBERTY: EFFECTS ON LEAN BODY MASS, INSULIN SENSITIVITY AND INSULIN CLEARANCE. †490

Cross-sectional studies from our and other laboratories have demonstrated that puberty is characterized by insulin resistance compared with prepuberty and adulthood. It has been postulated that pubertal elevations in growth hormone levels play a major role. The present study was undertaken to assess the effects of low-dose testosterone therapy in patients with constitutional delay of puberty (CD). 6 males with CD, age 15.2±0.4 yrs, and Tanner I pubertal staging were treated with 50 mg testosterone enanthate (T) IM q 2 weeks for 4 months. Pre T and 1 week post last injection they underwent a hyperinsulinemic-euglycemic clamp (40mu/m²/min), to assess insulin stimulated glucose metabolism (Rd), metabolic clearance rate of insulin(MCRI), and insulin sensitivity (IS). Indirect calorimetry was used to measure substrate oxidation rates. Body composition was evaluated by H₂¹⁸ O dilution principle. (FFM: fat free mass, GOX: glucose oxidation, NOXGD: nonoxidative glucose disposal). Table

Table 1

In summary, 4 months of low-dose testosterone in CD led to 18% increase in lean body mass and 30% decrease in% body fat. Post testosterone, though glucose metabolism decreased during hyperinsulinemia, insulin sensitivity did not change because of lower plasma insulin levels secondary to increased clearance of insulin.