Impact of treatments for osteoporosis on cartilage biomarkers in humans.

The rationale to target bone for treating osteoarthritis (OA) relies on the known cross-talk between subchondral bone and cartilage and the demonstration that subchondral bone resorption occurs at an early stage in the development of OA. Therefore, the possible OA disease-modifying effects of bone antiresorptive agents are of interest. This paper aims to review the published data on the effect of estrogens, selective estrogen receptor modulators, calcitonin, strontium ranelate, and bisphosphonates on cartilage biomarkers levels used as surrogate endpoints in clinical trials. Except for findings for tibolone, most observations indicated that these antiresorptive therapies decreased the urinary levels of CTX-II, a biomarker of type II collagen degradation. These data, which should be cautiously interpreted, suggest that these drugs might favorably affect cartilage homeostasis.