ELEVATED LEVELS OF SEX-HORMONES AND SEX-HORMONE BINDING GLOBULIN IN MALE-PATIENTS WITH INSULIN-DEPENDENT DIABETES-MELLITUS - EFFECT OF IMPROVED BLOOD-GLUCOSE REGULATION

In a prospective study we have measured serum levels of sex hormone-bi nding globulin (SHBG), androgens, oestrogens and gonadotropins in 20 m ale IDDM patients with the aim of evaluating the effect of improved gl ycaemic control on these levels and to compare the IDDM patients with an age- and weight-matched healthy non-diabetic control group. The pat ients were chosen from the male IDDM patients attending the outpatient clinic at the Department of Endocrinology, Odense University Hospital . Glycaemic control was optimized by a trained diabetologist according to the patients' measurements of home blood glucose concentrations an d reported hypoglycaemic episodes during a three month period. Prior t o regulation the patients, compared to healthy control subjects, had s ignificantly higher serum levels of oestrone (0.29+/-0.02 vs 0.16+/-0. 01 nmol/l (Mean+/-SEM), p<0.01), 17 beta-oestradiol (0.12+/-0.01 vs 0. 08+/-0.01 nmol/l, p<0.01), dihydrotestosterone (4.20+/-0.18 vs 1.66+/- 0.09 nmol/l, p<0.01), total testosterone (20.7+/-0.9 vs 17.8+/-1.1 nmo l/l, p<0.05) and SHBG (42.3+/-2.9 vs 15.5+/-3.5 nmol/l, p<0.05), while the calculated free-testosterone was lower (0.34+/-0.02 vs 0.40+/-0.0 2 nmol/l, p=0.068). After regulation, the patients obtained significan tly lower levels of glycosylated haemoglobin (10.4+/-0.3 vs 8.9+/-0.2% , p<0.005) and serum fructosamine (1.50+/-0.05 vs 1.34+/-0.04 nmol/l, p<0.005) on a higher 24 hour insulin dose (52.7+/-4.4 vs 59.2+/-4.6 IU /24h, p<0.005). Levels of free-testosterone (0.41+/-0.04 nmol/l), oest rone (0.33+/-0.03 nmol/l), oestradiol (0.14+/-0.01 nmol/l), Delta 4-an drostenedione (4.44+/-0.43 vs 3.85+/-0.42 nmol/l), and prolactin (249/-24 vs 200+/-19 mIU/l) increased compared to values obtained before r egulation (all p<0.05). We conclude that SHBG, testosterone, dihydrote stosterone and oestrogen levels are increased in male IDDM patients. H igh SHBG levels tend to keep the free fractions of sex hormones within normal limits. During improvement of glycaemic control with insulin, levels of free-testosterone and its bioprecursors and metabolites rise . This may partly be due to the increased daily insulin dose and/or to the improvement in glycaemic control itself.