[Bone tissue in patients with hyperprolactinemic hypogonadism]

Sixteen women with hyperprolactinemia were examined for Ca metabolism, osseous metabolism, mineral saturation of bone tissue in the thoracic portion of the spine and radius. Lowered mineral saturation of the thoracic vertebrae was detected in 69% of the examinees, that of the distal segment of the radius in 44%. Reduction of the mineral saturation of the spine was in negative correlation with the blood prolactin level and length of amenorrhea. No changes in the bone resorption biochemistry or Ca metabolism were detected. A marked reduction of blood osteocalcin level that reflects osteoblast function was detected, its blood concentration being in negative correlation with prolactin level. No relationships between mineral saturation of bone tissue, prolactin, and osteocalcin, on the one hand, and blood estradiol level, on the other, were observed. These data suggest that osteopathy in hyperprolactinemic hypogonadism is due to reduced bone formation and not to reduced estradiol production.