Primary hyperparathyroidism: Short-term changes in bone remodeling and bone mineral density following parathyroidectomy

Changes in bone remodeling and bone mineral density were observed during a period of 6 months after surgery in 24 patients with primary hyperparathyro idism (20 women and 4 men; age 54 +/- 12 years, range 26-69 years). All bon e markers declined significantly within the 6 month follow-up period, but t he time course for changes in renal N-terminal telopeptide of type 1 collag en (NTx) excretion differed from those of the other markers by a steep and significant reduction (p < 0.05) after less than 1 month. During the 6 mont h period, bone mineral density (BMD) increased significantly at all sites m easured (p < 0.05) apart from the femoral neck and the proximal and midfore arm, The greatest increase of 4.2% was observed in the trochanteric region (p < 0.001), The increase in BMD in spine, trochanteric, and intertrochante ric regions of the hip correlated inversely with baseline forearm BMD value s (p < 0.05). Baseline bone markers (serum alkaline phosphatase [AP], serum bone AP, serum pyridinoline crosslinked telopeptide of type 1 collagen, ur inary hydroxyproline, urinary osteocalcin), as well as baseline histomorpho metric indices of bone turnover (eroded and labeled surface, bone formation rate, activation frequency, and cortical porosity) were positively correla ted with changes in spinal BMD over 6 months (p < 0.05). It was concluded t hat, within 6 months after parathyroidectomy, patients with primary hyperpa rathyroidism obtain normalization of bone remodeling and a substantial incr ease in bone mineral density in regions rich in cancellous bone but no sign ificant changes in regions with predominantly cortical bone. (C) 1999 by El sevier Science Inc. All rights reserved.