Osteoporosis in men with hyperprolactinemic hypogonadism.

To ascertain the effects of chronic hyperprolactinemia and testosterone deficiency on skeletal integrity in men, we measured forearm bone density and hormone concentrations in 18 men aged 30 to 79 who had prolactin-secreting pituitary tumors. We also measured vertebral bone density in 12 of the men. Patients with hyperprolactinemia had significant decreases in both forearm (p less than 0.001) and vertebral bone density (p = 0.003) compared with age-matched controls. Cortical osteopenia was significantly related to the duration of hyperprolactinemia (p less than 0.01) but not to the absolute levels of prolactin or androgens. Seven patients had longitudinal follow-up measurements of forearm bone density. Normalization of serum levels of prolactin or testosterone was associated with an increase in forearm bone density (p less than 0.05). These data show that chronic hyperprolactinemia and testosterone deficiency in men have deleterious and previously unrecognized extragonadal effects that may be alleviated after normalization of hormone concentrations.