Aldosterone in panhypopitutarism: dynamic studies and therapeutic effects in Sheehan's syndrome

Abstract

Abstract. To appreciate the aldosterone secretion status in panhypopituitarism, the steroid response to stimulation was studied in a homogeneous group of 20 female patients presenting with global hypopituitarism. Specific effects of glucocorticoid and thyroid hormone deficiencies were also assessed by studying the same patients before and after cortisol (F) and cortisol plus thyroid hormone (F + T) substitution. The patients were submitted to two stimulation tests before and after each treatment: the orthostasis test (O-T) and the furosemide test (Furo-T). The results obtained in the 3 situations were compared, each patient serving as her own control. Comparison was also established with the results obtained in healthy women serving as control group. Basal plasma aldosterone levels in the untreated patients were not significantly different from those of the control group (5.43 ± 0.51 vs 7.16 ±0.80 ng/100 ml, mean ± sem). They were significantly lower after F (3.91 ± 0.42) and F + T substitution (3.31 ± 0.23) than those of untreated patients and controls. Response to both stimulations was blunted in the untreated patients (O-T: 14.10 ± 2.81; Furo-T: 9.78 ± 1.35) as compared to the control group (O-T: 26.46 ± 4.67; Furo-T: 23.96 ± 3.30). F treatment did not improve the response to either tests, (O-T: 11.42 ± 2.55; Furo-T: 10.32 ± 1.23). F + T treatment normalized the orthostasis response (20.83 ± 3.59) and increased the response to furosemide which remained, however, lower (15.28 ± 1.83) than in the control group. These results are in favour of a minor role of the pituitary in the regulation of aldosterone secretion. They emphasize the role of thyroid hormones which may act partly directly, partly through their effect on renin secretion.