Efficacy of Strontium Ranelate in Combination with a D-Hormone Analog for the Treatment of Postmenopausal Osteoporosis

BACKGROUND Vitamin D supplements are recommended in individuals with vitamin D insufficiency and established osteoporosis to reduce risk of fracture and falling. Active vitamin D metabolites have been found to be more effective for fall prevention than native vitamin D. OBJECTIVES The aim of this study was to compare the efficacy of strontium ranelate in combination with alfacalcidol and strontium ranelate alone on bone mineral density (BMD) and fall risk in postmenopausal women with osteoporosis. METHODS A total of 48 women (mean age 62.4 years) with postmenopausal osteoporosis were randomized to strontium ranelate monotherapy 2 g/day (n = 16), strontium ranelate 2 g/day plus alfacalcidol 1 μg (n = 16) or control (n = 16) and followed for 6 months. All women received calcium and vitamin D3 supplements. BMD was measured at the lumbar spine and proximal femora at the beginning and end of therapy. Patients performed functional tests such as the "up and go" and chair rising tests to estimate risk of fall status. Biochemical markers of bone turnover were also assessed. RESULTS Statistically significant increases in BMD compared with baseline values and the control group were observed in both strontium ranelate treatment groups. Increases were also statistically significant in the strontium ranelate combination group compared with strontium ranelate alone. Strontium ranelate combination therapy for 6 months improved patients' ability to perform functional tests as well as increasing the number of women capable of performing the tests. No significant changes were observed in women receiving strontium ranelate monotherapy or in the control group. Serum levels of β-CrossLaps, a marker of bone resorption, were significantly reduced compared with control in both strontium ranelate groups. A significantly greater reduction was observed in the strontium ranelate combination group compared with strontium ranelate alone (24.0%; P = 0.008). Increases in type 1 procollagen total N-terminal propeptide (TP1NP), a marker of bone formation, reached statistical significance in both strontium ranelate groups compared with baseline. CONCLUSION Strontium ranelate and alfacalcidol combination therapy improves bone quality, fall risk and markers of bone turnover to a greater extent than strontium ranelate alone in patients with established osteoporosis.