Surgery lowers risk of fracture in primary hyperparathyroidism

Patients with primary hyperparathyroidism are at increased risk of fractures, but surgery appears to be protective, according to a study.

The study included 5,009 patients who had surgery for primary hyperparathyroidism from the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery and 14,983 matched population controls. Researchers cross-linked data with Statistics Sweden and the National Board of Health and Welfare.

Patients were followed for 49,522 person-years preoperatively and 29,322 person-years postoperatively. Controls, on the other hand, were followed for 148,319 and 86,423 person-years, respectively.

During a median observation period of 15.7 years, any fracture and fragility fracture occurred more frequently among patients than controls prior to surgery (incidence rate ratio [IRR], 1.27, 95 percent confidence interval [CI], 1.11–1.46), with the highest incidence recorded in the year immediately preceding surgery. Postoperatively, fracture incidence was similar among patients and controls.

Fracture incidence showed no association with preoperative total calcium, multiglandular disease, adenoma on histology, or adenoma weight. This finding persisted in an analysis that excluded patients and controls who were prescribed drugs affecting bone metabolism.

The lack of association between calcium and fracture incidence might be explained by the fact that patients with biochemically more severe disease, manifested as symptomatic hypercalcemia, were more likely to be diagnosed and undergo surgery within a shorter time frame. This could indicate that patients were diagnosed and referred to surgery in an earlier, milder, course of disease.