Background: There is an ongoing controversy regarding how to take care of patients with mild primary hyperparathyroidism (PHPT) and how to grade their disease activity in terms of bone parameters. This prospective and randomized study was undertaken to evaluate skeletal effects of delayed surgical treatment in such patients.
Methods: Fifty patients with mild PHPT (serum calcium, 2.55 to 2.95 mmol/L; 10.2 to 11.8 mg/dL) were randomized to parathyroidectomy either at diagnosis or 1 year later. Hip and spine bone mineral density (BMD, determined by dual energy x-ray absorptiometry), bone alkaline phosphatase in serum, osteocalcin and beta-CrossLaps in plasma, and calcium in urine were measured in all patients at inclusion in the study and 1 and 2 years later.
Results: The skeletal effects of mild PHPT varied with anatomy and time of exposure. Parathyroidectomy decreased all biochemical bone markers ( P < .0001) and increased lumbar spine BMD ( P < .05) equally in both groups, even in patients without overt osteoporosis, whereas hip BMD was increased ( P < .05) in the early intervention group only.
Conclusion: Prolonged exposure to mild and seemingly stable PHPT is a risk factor for hip fractures, which adds to other reasons for surgical treatment of this condition without delay regardless of serum calcium levels.