Regaining BMD after parathyroidectomy
Hyperparathyroidism was discussed in Newsletter #14 on this site. As mentioned, this can be another cause of osteoporosis, and its treatment is often surgical to remove the offending parathyroid gland(s) that over produce parathyroid hormone. What wasn't mentioned in the discussion was what happens to the bone mineral density (BMD) after the surgery. A member of the Linking Up group recently was treated for hyperparathyroidism by surgical removal of his parathyroid glands and asked members of the group if he would need to take one of the approved osteoporosis medications as his physician had suggested. In order to help this member find an answer to his question, I decided to research this issue. The following is the result of that research.
Calcif Tissue Int. 2003 Jul;73(1):44-8, Short- and long-term changes in bone mineral density of the lumbar spine after parathyroidectomy in patients with primary hyperparathyroidism. Lumachi F and others. PMID: 14506953. This study evaluated the one- and two-year change in lumbar spine bone mineral density (LS-BMD) after parathyroidectomy in men (14), premenopausal women (12) and postmenopausal women (36). The authors noted that, "At 2-year follow-up the LS-BMD improved by 13.0%, 11.5%, and 11.7% in Groups A, B, and C, respectively (P=NS)."
J Clin Endocrinol Metab. 2000 May;85(5):1901-7, Prediction of bone mass change after parathyroidectomy in patients with primary hyperparathyroidism. Nakaoka D and others. PMID: 10843172. This was a complex study evaluating the Consensus Development Conference of the NIH proposed guidelines for parathyroid surgery (PTX). I will disregard that element of the study instead concentrating on the increase in BMD in those patients who had parathyroid surgery during the study. The study evaluated both the lumbar spine and radial (lower arm bone) BMD using dual-energy X-ray absorptiometry (DXA) and single photon absorptiometry, respectively. The authors found, "Average annual percent increases in lumbar and radial BMD after PTX were 12.2 +/- 1.4% and 11.6 +/- 1.6% (mean +/- SEM), respectively, and those net increases were 0.0803 +- 0.0008 and 0.0484 +/- 0.0006 g/cm2, respectively.
Editor's comments. In addition to the above studies, PMID: 10671948, and PMID: 12412794 also describe improvements in BMD that occur post-parathyroidectomy without any other treatment such as approved osteoporosis medications. It thus appears that BMD will increase after removal of the parathyroid glands without the addition of any medications that are normally taken by individuals to treat osteoporosis. This would appear to be a simple cause and effect relationship. Thus, the cause of the osteoporosis is the over production of the parathyroid glands. Once that cause is removed, the effect will be an improvement in BMD. Although the various approved osteoporosis medications are relatively safe with few side effects, the are not totally risk-free. They should thus be taken only if improvement would not be expected otherwise--not the case after parathyroidectomy. Thus post-parathyroidectomy patients should discuss the studies I've mentioned above with their physicians if those care providers recommend an approved osteoporosis medication in addition to the surgical removal of the parathyroids.