Pituitary Function in Patients with Hereditary Haemochromatosis

Abstract

Haemochromatosis may impair the function of endocrine organs, amongst others the pituitary gland. It was the aim of this study to determine pituitary function in adult patients with genetically defined hereditary haemochromatosis in a prospective diagnostic study using a standardised stimulation test. Therefore, 22 patients (7 females, 15 males; age at diagnosis of haemochromatosis 48.1 ± 7.9 years; age at study inclusion 50.7 ± 7.7 years) with genetically defined hereditary haemochromatosis were investigated by a combined pituitary stimulation test (CRH, GHRH/arginine, GnRH, TRH). In 11 patients (50% of the study population; 2 females, 9 males), pituitary insufficiencies were detected [isolated corticotrophic insufficiency (peak cortisol < 181.25 μg/l/500 nmol/l) n=10 (2 females, 8 males); combined corticotrophic and borderline gonadotrophic insufficiency (basal testosterone 2.4-3.0 μg/l without basal LH-elevation) in 1 male]. Somatotrophic pituitary insufficiencies were not found. IFG-1 concentrations below -2 standard deviations in 7 patients (32%) may be attributed to impaired hepatic IGF-1 synthesis. Hypopituitarism, particularly corticotrophic insufficiency, seems to be prevalent in a considerable number of middle-aged patients with hereditary haemochromatosis. Despite normal somatotrophic function, low IGF-1 serum concentrations may be found in a subgroup of haemochromatosis patients.