To evaluate the effects of oral salmon calcitonin (sCT) on Lequesne's algofunctional index scores and on biomarkers of joint metabolism in knee osteoarthritis.
In this randomized, double-blind trial, patients received either placebo (n = 18), 0.5 mg of sCT (n = 17), or 1 mg of sCT (n = 18) daily for 84 days. Biomarkers included C-telopeptide of type II collagen (CTX-II), type II collagen neoepitope C2C, collagenases (matrix metalloproteinase 1 [MMP-1], MMP-8, and MMP-13), stromelysin (MMP-3), tissue inhibitors of metalloproteinases 1 and 2, and hyaluronan. Statistical analysis included nonparametric tests.
A total of 41 patients completed the study (13 in the group receiving 0.5 mg of sCT and 14 in each of the other 2 other groups). Although, on day 84, patients in both the placebo group and the group receiving 1 mg of sCT exhibited a similar significant decrease in pain scores, a significant reduction in the function score was observed only in the 2 sCT groups. On day 84, there was no significant decrease in biomarker levels in the placebo group, whereas significant reductions in the levels of both MMP-3 and hyaluronan were observed in the 2 sCT groups. The group of patients receiving 1 mg of sCT exhibited significant decreases in the levels of CTX-II, C2C, and MMP-13.
By improving functional disability and by reducing levels of biomarkers that are thought to be predictive of joint space narrowing (and thus cartilage loss), oral sCT at a dose of 1 mg might be a useful pharmacologic agent in human knee OA.