SEVERITY AND REVERSIBILITY OF AXIAL BONE LOSS IN PRIMARY HYPERPARATHYROIDISM - POSTOPERATIVE BONE-MINERAL DENSITY IN 10 PATIENTS

This study was designed to evaluate axial bone mineral density changes associated with primary hyperparathyroidism before and after parathyroidectomy. Twenty patients who had removal of a parathyroid adenoma were studied. Mean age was 64 +/- 8 years. Bone mineral density was measured preoperatively in all 20 patients and at least 12 months postoperatively in 10 patients. Measurement sites were the lumbar spine (n=20), femoral neck (n=6), and/or whole body (n=6). Preoperatively, mean bone mineral density was decreased at all measurement sites as compared with normal age- and sex-specific values (mean z-score -1 for the lumbar spine and femoral neck and -1.6 for the whole body). Lumbar bone mineral density increased post-operatively in all patients. Bone gain was most marked during the first six months after surgery. Twelve months after surgery, mean lumbar bone mineral density increase was 10.5 +/- 10.2% (n=10). However reversal of bone loss after surgery was incomplete (z-score at the lumbar spine -0.92 DS +/- 1.04 12 months after surgery).