Study of pituitary secretion in relation to retinopathy in patients with juvenile diabetes mellitus.

Fifteen juvenile diabetic patients with normal eye fundus, 6 with non proliferative retinopathy, 5 with proliferative retinopathy and 5 healthy control subjects were studied in order to investigate pituitary function in relation to diabetic retinopathy. ACTH values at 08(00) and 18(00), hPRL and TSh secretion in response to 200 microgram TRH i.v., and GH secretion in response to 500 mg oral L-dopa were evaluated. In all diabetic subjects, 08(00) ACTH levels were lower than in controls. Basal hPRL, TSH and GH values of the diabetics did not differ from those of the controls. No significant differences were found in hPRL levels in response to TRH, whereas significantly lower TSH responses were found in the diabetics. L-dopa caused a significantly different response of GH in the diabetic subjects compared to controls. There is thus a considerable derangement in pituitary hormone secretion in juvenile diabetics mellitus.