Serum osteocalcin in primary hyperparathyroidism: short-term effect of surgery.

This study has been carried out in order to evaluate both serum osteocalcin levels in primary hyperparathyroidism and their changes following surgery. Twenty-one consecutive patients were studied (12 females and 9 males, aged 46 +/- 17 years). Preoperatively, a better correlation was found between serum osteocalcin and serum alkaline phosphatase activity (r = 0.79, p less than 0.001) than between serum osteocalcin and the 24-hour urinary hydroxyproline/creatine ratio (r = 0.55, p less than 0.05). Following the surgical removal of hyperfunctioning parathyroid tissue, a modest but significant decrease was observed in the serum levels of osteocalcin; this reached a nadir during the 1st or 2nd day after the removal of the adenoma. The mean levels then tended to rise, so that the values measured on the 7th day after parathyroidectomy (12.4 +/- 2.5 ng/ml) were not significantly different in respect to basal values (13.6 +/- 2.7 ng/ml). A parallel pattern was also noted as concerns the serum alkaline phosphatase activity. On the contrary, mean values of serum immunoreactive parathyroid hormone (243 +/- 78 vs. 58 +/- 11 pmol/l; p less than 0.02) and serum calcium (12.4 +/- 0.5 vs. 9.2 +/- 0.3 mg/dl; p less than 0.01) were significantly reduced and mean values of serum phosphorus (2.4 +/- 0.2 vs. 3.1 +/- 0.2 mg/dl; p less than 0.001) significantly higher in comparison to basal values.(ABSTRACT TRUNCATED AT 250 WORDS)