Dr. Krakauer asks whether our data support the thesis that primary hyperparathyroidism exerts differential skeletal effects according to the type of bone (cortical or trabecular). We emphasize that the principal conclusion of our report was that unadjusted bone mineral density was normal throughout the skeleton in postmenopausal women with mild primary hyperparathyroidism. Bone mineral density in the hyperparathyroid group tends to be slightly lower at predominantly cortical sites and slightly higher at predominantly trabecular sites; however, none of these trends is statistically significant, and larger studies are necessary to determine whether these trends are real. If present, any differences from normal values are small. Our results contrast with the substantial reduction in proximal forearm bone mineral density reported in most single-photon absorptiometry studies in patients with primary hyperparathyroidism [1]. These studies were probably subject to artefactual underestimation of bone mineral density by a failure to correct for increased soft-tissue adiposity over the measurement site in hyperparathyroid patients.

Because our data were compared with those from normal persons, it is unlikely that expressing them as a percentage of normal would influence our conclusions in any way.