Changes in Serum 25-hydroxycholecalciferol and Intact Parathyroid Hormone Status after Hip Fracture

The purpose of the study was to examine changes in the levels of serum 25-hydroxychole calciferol (25-OHD) and other biochemical markers in response to hip fracture. Serum 25-OHD, serum intact parathyroid hormone (intact PTH), serum N-terminal crosslinking telopeptide of type I collagen (NTx), and urine NTx were measured during a 6-month period after fracture in 11 patients with acute hip fracture. Bone mineral density (BMD) of the non-fractured hip was measured by dual-energy X-ray absorptiometry (DXA). Serum and urine were sampled at admission, on the day of surgery, and two weeks, four weeks, and either three months or six months after fracture. The mean change in the serum 25-OHD levels was less than ±10% after fracture. Intact PTH levels after three months were higher than those after two weeks or six months, and intact PTH after six months was higher than after two weeks, the mean change being ±20%. Urine NTx levels changed until four weeks after fracture, and individual differences were observed ; insufficient urine NTx data were obtained for analysis after four weeks, though the changes in the urine NTx level after four weeks were small. Changes in serum NTx were smaller than those in urine NTx and similarly showed no significant changes during the measurement period. In conclusion, serum 25-OHD did not show large changes during hip-fracture healing.