Bone mineral density 5 years after parathyroidectomy in hemodialysis patients with secondary hyperparathyroidism

Whether bone mineral density (BMD) is improved at 5 years after parathyroidectomy (PTx) for secondary hyperparathyroidism (SHPT) remains unknown.

To investigate BMD after PTx by dual energy X-ray absorptiometry (DXA).

BMD was measured at the distal 1/3 of the radius (non-shunt side) and at the lumbar supine (L2-L4, lateral view) before and 5 years after PTx in 35 hemodialysis patients who had undergone surgery from April 1994 to May 2004. The data were analyzed retrospectively.

Intact PTH decreased significantly from 1,100 ± 530 (range: 446 - 2,300) pg/ ml before PTx to 75 ± 68 (2 - 251) pg/ml at 5 years after PTx (p < 0.01). Before PTx, the radial BMD and lumbar BMD were both decreased -3.3 ± 1.9 SD and -1.3 ± 2.4 SD compared with the corresponding normal mean T-score, respectively. Radial BMD increased significantly from 0.522 ± 0.113 g/cm2 before PTx to 0.545 ± 0.114 g/cm2 (p = 0.01) at 5 years after PTx, while the T-score improved to -2.8 ± 2.0 SD. In contrast, lumbar BMD showed no significant change between before (0.734 ± 0.202 g/cm2) and 5 years after PTx (0.746 ± 0.199 g/cm2), and neither did the T-score (-1.1 ± 2.3 SD). None of the patients suffered any fractures during follow up.

These findings indicate that maintaining iPTH at < 300 pg/ml for 5 years after PTx results in an increase of radial BMD in SHPT patients with preoperative BMD levels in the osteoporosis range (below -2.5 SD) according to the WHO, as well as stabilizing lumbar BMD.