Accelerated bone loss in post-menopausal women with mild primary hyperparathyroidism.

OBJECTIVES: Osteopenia is regarded as an indication for parathyroidectomy in primary hyperparathyroidism. However, uncertainty exists as to the extent and degree of the skeletal effects in those with mild disease. We sought to determine whether mild primary hyperparathyroidism affects the rate of bone loss in postmenopausal women.
DESIGN: Prospective 2-year comparison of rates of bone loss throughout the skeleton in 17 post-menopausal women with untreated mild asymptomatic primary hyperparathyroidism, and 48 age-matched, eucalcaemic controls.
RESULTS: The women with primary hyperparathyroidism had a greater annual rate of loss of bone mineral density (BMD) of the total body (mean +/- SE, primary hyperparathyroidism -1.15 +/- 0.31%, controls -0.39 +/- 0.10%; P = 0.04) and its spine subregion (primary hyperparathyroidism -2.08 +/- 0.88%, controls 0.04 +/- 0.35%; P = 0.02). Lumbar spine BMD tended to decline in the primary hyperparathyroidism group (-0.35 +/- 0.33%) in contrast to the control group (+0.28 +/- 0.22%) (P = 0.10). There were no significant differences between the groups in rates of changes of BMD in the legs or the proximal femur. In the primary hyperparathyroidism group, the rate of total body bone loss in the eight women known at study entry to have had long-standing (> 5 years) primary hyperparathyroidism was -1.52 +/- 0.61%/year, similar to that of the whole group.
CONCLUSION: Primary hyperparathyroidism is associated with an increased rate of loss of total body bone mineral density in post-menopausal women. Prolonged disease duration is therefore likely to be associated with an increasing risk of osteopenia, such that skeletal surveillance and interventions designed to reduce bone loss should be considered.