Changes in body composition and insulin resistance after parathyroidectomy for primary hyperparathyroidism: A pilot prospective case-control study.

BACKGROUND

Recent literature suggested that parathyroidectomy for primary hyperparathyroidism may improve metabolic outcomes. This prospective study compared body composition and insulin resistance changes in patients with primary hyperparathyroidism undergoing parathyroidectomy versus nonoperative management.

METHODS

Consecutive patients with primary hyperparathyroidism meeting indications for parathyroidectomy were prospectively recruited. Patients undergoing parathyroidectomy (surgery group) were compared with patients who declined surgery or were pending parathyroid localization imaging (nonsurgery group). Metabolic assessment comprised body composition measurements with bioelectrical impedance analysis and blood indices for the Homeostasis Model Assessment for Insulin Resistance score. The surgery group was assessed preoperatively, at postoperative 3 and 6 months; the nonsurgery group at baseline and 6 months.

RESULTS

Sixty-six patients were analyzed (surgery: n = 31; nonsurgery: n = 35). Forty-five (68.2%) were females; mean age was 63 years. Baseline demographics and body composition parameters were comparable. The surgery group had increased fat-free mass (median, 42.4 vs 43.6 kg; P = .048), muscle mass (39.9 vs 41 kg, P = .045), and skeletal muscle mass (24 vs 24.7 kg, P = .046) at 3 months postoperatively. The nonsurgery group had increased fat percentage (29.3% vs 31.6%, P = .018) and fat mass (16.6 vs 18.4 kg, P = .005) at 6 months. Comparing the 2 groups, the nonsurgery group had a greater increase in fat proportion (-0.1% vs 0.8%, P = .042) and fat mass (-1% vs 3.67%, P = .040) over 6 months. Six-month Homeostasis Model Assessment for Insulin Resistance changes between the 2 groups were statistically insignificant (-0.18 vs 0.07, P = .920).

CONCLUSION

Parathyroidectomy minimizes increase in fat mass in patients with primary hyperparathyroidism. By improving body composition, parathyroidectomy may reduce metabolic risk.