Total and regional bone mineral content in primary hyperparathyroidism: sex differences

Changes in cortical and trabecular bone mass occurring in primary hyperparathyroidism are the subject of controversy. We measured the total and regional bone mass in a group of patients and controls and analyzed the observed changes with respect to sex and other characteristics. Parathormone, serum calcium, serum phosphorus, tubular resorption of phosphates, alkaline phosphatase, and tartrate-resistant acid phosphatase differed significantly (p < 0.001 for all) between patients and controls. All the patients had significantly less total and regional bone mass; the regional bone mass of the arms did not differ. When analyzed according to sex, we found that women had a significant reduction in bone mass in all the zones studied (p < 0.001), whereas men had a significant decrease in bone mass only in the head (p < 0.025). Our findings show that hyperparathyroidism is accompanied by a loss of bone mass except in the arms, and that predominantly both cortical bone (legs, pelvis and skull) and trabecular bone (trunk) are affected. This means that the skeleton suffers generalized bone loss and a significant reduction in total body calcium content. Although we did not study many men, their bone involvement was less intense, and there was a clear difference between the sexes in this respect.