POSSIBLE ALTERED DOPAMINERGIC MODULATION OF PITUITARY-FUNCTION IN NORMAL-MENSTRUATING WOMEN WITH INSULIN DEPENDENT DIABETES-MELLITUS (IDDM)

To assess whether a possible altered dopamine activity in normal-menstruating diabetic patients may influence the pituitary hormone secretion, the basal serum concentrations of Prl [prolactin], LH [luteinizing hormone] and FSH were measured in 28 patients with insulin dependent diabetes mellitus (IDDM) and in 55 normal-menstruating women at day 3-6 of the menstrual cycle. In addition basal levels of estradiol-17.beta., TSH, thyroxine (T4), triiodothyronine (T3) and resin-T3 uptake (RTeU) were determined in 17 patients with IDDM and in 17 controls. The responses of FSH, LH, Prl, GH [growth hormone] and TSH to metoclopramide (MTC) administration (10 mg i.v.) were studied in 17 patients and 17 controls. In 10 patients with IDDM and 8 controls the short-term variations in pituitary hormones and blood glucose concentration were evaluated. Patients with IDDM had significantly lower basal levels of Prl (P < 0.01) and TSH (P < 0.05) and significantly (P < 0.05) higher basal levels of GH than normal women. No significant (P > 0.05) differences were found regarding basal serum concentrations of FSH, LH, estradiol, T4, T3 and RT3U. During the 3 h period the mean coefficient of variation of Prl, FSH, LH and GH was not significantly (P > 0.05) different between diabetic patients and controls. Both groups responded significantly (P < 0.01) in Prl and TSH to MTC but the TSH response was significantly (P < 0.05) lower in patients with IDDM. The Prl response to MTC was not significantly (P > 0.05) different within the 2 groups. None of the groups responded significantly (P > 0.05) in GH or gonadotropins to MTC. No significant correlations (P > 0.05) were found between parameters of diabetes regulation and basal or stimulated hormone concentrations. although, the interpretation of the results may be controversial it is suggested that the hormonal changes in normal-menstruating women with IDDM are to some extent compatible with a raised central dopaminergic activity.