Depressed prolactin levels in diabetic women with anovulation

The circulating levels of prolactin (PRL), luteinizing hormone (LH), follicle stimulating hormone (FSH) and estradiol-17 beta were determined by radioimmunoassay in 76 normal healthy women in the follicular phase of the menstrual cycle, 54 consecutive anovulatory non-diabetic women and 20 consecutive diabetic women with anovulation. An elevated plasma PRL concentration was found in 1/20 (5%) of the diabetic women and in 17/54 (32%) of the non-diabetic anovulatory women (p less than 0.05). Plasma concentrations of estradiol-17 beta and gonadotropins in diabetics did not differ (p greater than 0.05) from those found in non-diabetic women with anovulation. Diabetic women with secondary amenorrhea had significantly (p less than 0.05) lower plasma concentrations of PRL and estradiol-17 beta than non-diabetic women with amenorrhea and normal controls. Furthermore, this group of diabetic women had lower median plasma LH concentrations than the non-diabetics with secondary amenorrhea and normal controls, but this difference was not significant (p greater than 0.05). These data indicate that diabetic patients with anovulation have hypothalamic and/or pituitary defects. Furthermore, the low prolactin and LH levels despite a low estradiol-17 beta concentration may suggest an increased hypothalamic dopamine activity in patients with diabetes mellitus and secondary amenorrhea.