The diagnosis and prevalence of hypoprolactinemia in patients with panhypopituitarism and the effects on depression and sexual functions

Abstract

Purpose: We aimed to investigate the prevalence and the diagnostic criteria of hypoprolactinemia in patients with panhypopituitarism and the effects of hypoprolactinemia on depression and sexual functions.

Materials and methods: Forty-eight patients with panhypopituitarism and 20 healthy volunteers were included. Basal hormone levels were measured and a TRH stimulation test was performed. For the evaluation of sexual functions, questionnaries of Female Sexual Functional Index (FSFI) for females and International Erectile Functional Index for males were performed to the subjects. Depressive symptoms were evaluated by Beck Depression Envontory score (BDI-II).

Results: The peak PRL response to TRH stimulation test at 5th percentile in the control group was 18.6 ng/ml in males and 41.6 ng/ml in females and accepted as the cut-offs for sufficient response of PRL. Prolactin was insufficient in 42(87.5%) patients. A basal PRL level of ≤ 5.7 ng/ml in males and 7.11 ng/ml in females was 100% specific in predicting an inadequate response to TRH stimulation test with 80% and 70% sensitivity respectively. A basal PRL level of ≥ 8.5 ng/dl in males was 100% specific and 76% sensitive, and in females a level of ≥ 15.2 ng/dl was 96% specific and 66% sensitive in predicting an adequate response to TRH. PRL deficient patients with panhypopituitarism had higher depression scores compared to the controls, lower sexual function scores in males.

Conclusion: PRL deficiency is prevalent among individuals with panhypopituitarism, with the potential to result in elevated depression scores in both sexes and impaired sexual functions in males. A basal PRL level seems to be sufficient for the diagnosis of hypoprolactinemia in routine clinical practice.

Keywords: Depression; Hypopituitarism; Hypoprolactinemia; Prolactin; Sexual functions; TRH stimulation test.

Fig. 1

Etiology of panhypopituitarism. (1a) in the whole group. Pitutary surgery only (n: 15): Non-functioning pituitary adenoma (n:12) + Craniopharyngioma (n:1) + Meningioma (n:1) + Cushing disease (n:1) Pituitary surgery + RT (radiotherapy (n: 5): Non-functioning pituitary adenoma (n:2) + Craniopharyngioma (n:2) +  Sheehan syndrome (n:14) Empty Sella (n:5) Others (n: 9): Genetic diseases diagnosed in childhood (n:7) + Traumatic brain injury (n:1) + Meningitis (n:1). (1b) in patients with hypoprolactinemia. Pitutary surgery only (n:12) Non-functioning pituitary adenoma (n:10) + Craniopharyngioma (n:1) + Cushing’s disease (n:1) Pituitary surgery + radiotherapy (n:5): Non-functioning pituitary adenoma (n:2) + Craniopharyngioma (n:2) + Sheehan syndrome (n:14) Empty sella (n:5) Others (n:6): Genetic diseases diagnosed in childhood (n:5) + Traumatic brain injury (n:1). (1c) in patients without hypoprolactinemia. Pitutary surgery only (n: 3): Non-functioning pituitary adenoma (n:2) + Meningioma (n:1). Others (3): Genetic diseases diagnosed in childhood (n:2) + meningitis (n:1)

Fig. 2

ROC-curves of the peak PRL responses to TRH test in females and males

Fig. 3

Correlation of IGF-1 levels with AUC (PRL response) to TRH stimulation test (p:0.003, r:0.42)