Steroids in Adult Men With Type 1 Diabetes

Abstract

OBJECTIVE—To compare steroids and their associations in men with type 1 diabetes and healthy control subjects. RESEARCH DESIGN AND METHODS—We studied 52 adult men with type 1 diabetes without microvascular complications, compared with 53 control subjects matched for age and BMI. Steroids and their binding globulins were assessed in a single venous blood sample and a 24-h urine sample. RESULTS—In adult men with type 1 diabetes, total testosterone did not differ from healthy control subjects, but sex hormone–binding globulin (SHBG) (42 [14–83] vs. 26 [9–117] nmol/l, P < 0.001), cortisol-binding globulin (CBG; 0.87 ± 0.17 vs. 0.73 ± 0.10 nmol/l, P < 0.001), and cortisol levels (0.46 ± 0.16 vs. 0.39 ± 0.14 nmol/l, P < 0.01) were higher. The free testosterone index was lower (60 [17–139] vs. 82 [24–200], P < 0.001), and the calculated free testosterone was slightly lower (497 [115] vs. 542 [130], P < 0.064), but the pituitary-gonadal axis was not obviously affected in type 1 diabetes. The calculated free serum cortisol was not different, and 24-h urinary free cortisol excretion was lower in type 1 diabetes (121 [42–365] vs. 161 [55–284] nmol/24 h, P < 0.009). Testosterone was mainly associated with SHBG. Estimated portal insulin was a contributer to SHBG in control subjects but not in type 1 diabetes. Cortisol was associated with CBG. HbA1c contributed to CBG in men with diabetes but not in control subjects, whereas estimated portal insulin did not contribute. CONCLUSIONS—Adult men with fairly controlled type 1 diabetes without complications who are treated with subcutaneous insulin have a tendency to hypogonadism, as reflected by lower free testosterone levels in the presence of similar total testosterone levels and higher SHBG levels.