Abstract
Osteocalcin (bone gla-protein) is a low-molecular-weight vitamin K-dependent protein which is a sensitive and specific marker of bone turnover. To determine whether serum osteocalcin is a useful indicator for parathyroidectomy in patients with RHP, we measured serum osteocalcin levels (normal<6.5ng/ml), and compared them with patient symptoms, X-ray findings and biochemical data. Thirty seven RHP patients who were followed up for more than six months after parathyroidectomy were studied. All patients underwent total parathyroidectomy and parathyroid autotransplantation. Controls consisted of 46 non-operated patients undergoing chronic maintenance hemodialysis for more than three years. Serum osteocalcin levels were markedly increased in 37 patients with parathyroidectomy, ranging from 4.2ng/ml to 645ng/ml, with a mean value of 278.8±159.8 (M±SD)ng/ml versus 65.0±85.2ng/ml in the 46 controls (non-operated patients) (p<0.001). Patients with high osteocalcin levels had severe bone pain and X-ray findings of severe osteotis fibrosa. Serum osteocalcin was found to be significantly (p<0.001) correlated with both serum ALP and m-PTH. The total mean weight of the parathyroid tumors resected was 2, 152±1, 368mg (M±SD), ranging from 200mg to 5, 600mg, and was significantly (r=0.656, p<0.001) correlated with the osteocalcin level. These results suggest that osteocalcin measurement is a sensitive method for detecting increased bone turnover and is possibly useful as an indication for parathyroidectomy in patients with RHP.
