Parathyroidectomy may be better than calcimimetics at improving bone mineral density (BMD) and other parameters in primary hyperparathyroidism, researchers in New York say.
Dr. Rasa Zarnegar, senior author of a study reported online March 30th in Annals of Surgery, told Reuters Health by email, "More and more endocrinologists are relying on medication to fix surgical problems. What this study emphasizes is that given the minimal risk of this surgery in experienced hands the outcomes for patients, including bone gain, far outweigh those of medical management for this surgical disease."
Dr. Zarnegar and colleagues at New York Presbyterian Hospital-Weill Cornell Medical Center reviewed data on 17 patients who received calcimimetics and 17 who had parathyroidectomy (the control group). The authors say that all patients in the medical group qualified for surgical intervention but opted for medical treatment instead. All patients in both groups also had deficient vitamin D levels corrected as part of their treatment.
At one year, calcium levels had normalized in 70.6% of the medical patients and in everyone who had surgery. Corresponding proportions for BMD improvement at the femur were 18.8% and 58.8% and for the spine, 70.6% and 80.4%.
Parathyroid hormone (PTH) normalized in 35% of calcimimetic patients and in 76% of surgery patients. Regardless of treatment, normalization of PTH was associated with significant BMD improvement at the femur and spine.
Normalization of calcium without normalization of PTH did not affect BMD. "This observation," say the investigators, "suggests that calcium may be a confounder in BMD improvement and that the superior effects of surgery over calcimimetic treatment may ultimately be mediated by better control of PTH."
The investigators conclude that "parathyroidectomy results in greater normalization of serum calcium and PTH levels and significantly improves cortical BMD compared to calcimimetics."
In fact, lead researcher Dr. Xavier Keutgen told Reuters Health by email, "The superior effects of surgery over calcimimetics are likely related to a better normalization of PTH levels, not calcium levels. This finding may help develop novel non-surgical treatment strategies in the future."
The authors also point out that larger, prospective trials are needed to confirm these results and define the use of calcimimetic agents.