The Effects of Alendronate and Calcitonin on Cytokines in Postmenopausal Osteoporosis: A 6-Month Randomized and Controlled Study

The present study was designed to determine if levels of serum cytokines, such as interleukin (IL)-1β, IL-2, IL-2r, IL-6, IL-6r, IL-8, IL-10, and TNF-α are different in osteoporotic and non-osteoporotic postmenopausal women, and to evaluate the effects of calcitonin and alendronate therapies over a six month period on serum cytokine levels in postmenopausal osteoporotic women.

Serum levels of IL-2, TNF-α and IL-8 were found to be significantly higher (p < 0.05), and serum IL-10, and IL-6r significantly lower in the calcitonin (N=60) and the alendronate (N=60) treatment groups than in the control group (N=50) (p < 0.05). But, no significant difference was apparent between the calcitonin and alendronate treated groups before treatment. Statistically significant changes occurred in patients, with respect to the levels of serum IL-6r, and IL-8 after one month (p < 0.05), in IL-2r, IL-6r, IL-8, IL-10 after three months, and in IL-1β, IL-6r, IL-8, IL-10 and TNF-α after six months of calcitonin therapy (p < 0.05). No significant difference was observed in IL-6r after one month, in IL-8 and IL-10 after three months, and in TNF-α after six months in the calcitonin treated group and in the control group, whereas these parameters were significantly different at baseline. In the alendronate treated group, statistically significant changes occurred in the levels of serum IL-1α and IL-6 after three months, and in IL-1β, IL-6, IL-6r and TNF-α after six months (p < 0.05). No significant difference was observed in IL-6r after one month, in IL-10 after three months or in TNF-α after six months between the alendronate treatment group and the control group, whereas these parameters were significantly different at baseline.

In conclusion, we suggest that; 1) not only IL-1, IL-6, TNF-α and IL-11 but also IL-2, IL-8 and IL-10 may have roles in the etiopathogenesis of osteoporosis, 2) calcitonin therapy have a more distinct influence on serum levels of some cytokines and have an earlier effect than alendronate therapy (especially upon IL-2r, IL-8, and IL-10). Nevertheless, further longitudinal studies are needed to identify the cytokines involved in the pathogenesis of postmenopausal osteoporosis and to evaluate the influence of different treatments on these cytokines.