Bone loss in primary hyperparathyroidism.

X-ray images of the second metacarpals of 153 hyperparathyroid subjects were measured and an index of cortical bone was derived. Compared with normal standards, the cortical index was above the 50th percentile in only 17.8% of women and 13.6% of men. Comparing the mean index of hyperparathyroid subjects with the normal indices of each 10-year age group, it was found that the differences were highly significant and were the same for all age groups in each sex. In particular, the difference was not greater between older female hyperparathyroid and normal subjects than it was between younger female hyperparathyroid and normal subjects. It appears that bone involvement in the form of excessive cortical thinning is extremely common in hyperparathyroidism and that sex and age do not further influence its incidence or severity.