The endocrine manifestations of hemochromatosis.

We have evaluated the endocrine changes in 10 male subjects with hemochromatosis. Two subjects initially had aplastic anemia, and the remainder had idiopathic hemochromatosis. Four of the ten patients had diabetes mellitus. Sexual dysfunction (impotence and/or decreased libido) was observed in 8 subjects. Six patients had subnormal testosterone levels; FSH levels were almost uniformly low, but LH concentrations were more variable. Only three patients had normal testosterone responses to hCG. Hypothyroidism, free T4 less than 0.9 ng/dl, was present in 4 subjects, and the etiology was heterogeneous. Basal prolactin levels were elevated in 2 patients and failed to respond adequately to TRH in 2 other patients. Growth hormone reserve was normal in all but 1 patient, and pituitary-adrenal reserve was normal in all but 1 patient. We conclude that disturbances in both pituitary and end-organ function are observed in hemochromatosis. These central and end-organ defects may exist alone or simultaneously. Hypogonadism is almost universal, and is a consequence of defective function of the hypothalamic-pituitary axis and/or primary Leydig cell disturbance. Other evidence of pituitary disturbance are observed but are rather uncommon.