Effect of fracture on bone turnover markers: a longitudinal study comparing marker levels before and after injury in 113 elderly women.

UNLABELLED

In this longitudinal, prospective, and population-based study (n = 1044), seven BTMs were assessed before and after trauma in 113 elderly women (85 with fractures). Markers were not altered in the immediate postfracture period but were clearly elevated during fracture repair. Recent fracture should thus be taken into account when markers are used in clinical practice.

INTRODUCTION

Fracture may influence the levels of bone turnover markers (BTM) and have implications for their use in clinical practice. In this longitudinal, prospective, and population-based study, we assessed prefracture levels of BTMs and compared them with postfracture levels of the same individuals immediately after fracture and during fracture repair. This is the first study in which the effect of fracture on bone markers has been evaluated with prefracture samples available.

MATERIALS AND METHODS

Serum and urine were collected at the emergency unit from 85 women (77.9 +/- 1.8 yr) who sustained a fracture after low-energy trauma and 28 controls (77.8 +/- 2.0 yr) with similar trauma but no fracture. All were participants of the Malmö OPRA study (n = 1044), and pretrauma samples were collected 1.05 +/- 0.85 yr before. Bone turnover was assessed by seven different BTMs reflecting different stages of bone metabolism {C-terminal cross-linked telopeptides of type I collagen [S-CTX], S-TRACP5b, N-terminal propeptides of type I collagen [S-PINP], serum osteocalcin (S-OC[1-49] and S-TotalOC), urinary deoxypyridinoline [U-DPD], and urinary osteocalcin [U-OC]}.

RESULTS

BTMs sampled within a few hours after fracture were not altered from preinjury levels. Both bone formation and bone resorption markers were, however, significantly increased 4 mo after fracture. The elevation was most pronounced after hip fracture. Bone turnover remained elevated up to 12 mo after fracture.

CONCLUSIONS

We believe this study extends our knowledge on the skeletal postfracture metabolic processes. In addition, it may provide a basis for future means to monitor pharmacological intervention promoting fracture healing.