24-Hour studies of prolactin and growth hormone levels in diabetic impotence.

Serum prolactin and growth hormone levels were measured hourly over 24 h in 8 insulin-treated diabetic males, 4 of whom were impotent. All patients showed normal sleep-related peaks of both hormones during the night. The mean 24-hour concentrations of prolactin and growth hormone were similar in patients with impotence (9.4 +/- 1.0 ng/ml and 3.8 +/- 0.4 microIU/ml, respectively) and without it (10.5 +/- 1.0 ng/ml and 4.7 +/- 1.1 microIU/ml, respectively). The mean prolactin and growth hormone concentration during the day time (7.00 a.m. to 7.00 p.m.) and the night time (7.00 p.m. to 7.00 a.m.) were also similar in patients with and without impotence. These results suggest that impotence in diabetic patients is not mediated by abnormalities of prolactin and growth hormone secretion.