Effects of Alfacalcidol on Back Extensor Strength Gained Through Back Extensor Exercise in Postmenopausal Women with Osteoporosis

Hara S, Kishimoto KN, Okuno H, Tanaka M, Saito H, Oizumi A, Itoi E: Effects of alfacalcidol on back extensor strength gained through back extensor exercise in postmenopausal women with osteoporosis. Am J Phys Med Rehabil 2013;92:101-110. Objective: The aim of this study was to investigate the additive effect of the active form of vitamin D-3 on the gain in back extensor strength through a back extensor exercise. Design: A total of 107 postmenopausal women with osteoporosis were randomly divided into two groups: the D-3 group and the control group. Both groups were treated with calcium and alendronate and undertook the back extensor exercise. Alfacalcidol was prescribed only to the D-3 group. Results: There was no significant difference in the demographic data between the two groups. Ninety-four participants who completed a 4-mo intervention were subjected to per-protocol analysis. There was no significant difference in the improvement in back extensor strength between two the groups (P = 0.349). All subjects were further categorized into two subgroups by age. In the older subgroup (>= 68 yrs), no significant difference was found in the improvement in back extensor strength (P = 0.316). In the younger subgroup (<68 yrs), the back extensor strength in the D-3 group was significantly more improved than in the control group (P = 0.034). Conclusions: The results of this study suggest that the administration of the active form of vitamin D-3 enhances the beneficial effects of the back extensor exercise in patients younger than those in their late 60s.