Strontium ranelate and risk of vertebral fractures in frail osteoporotic women

AimTherapies to treat osteoporosis remain underutilized and minimally evaluated in frail elderly patients. Our study determined and compared the risk of vertebral fractures in frail, intermediate and robust older patients being treated with strontium ranelate vs. placebo.MethodsData were obtained from the SOTI (Spinal Osteoporosis Therapeutic Intervention) and TROPOS (Treatment Of Peripheral Osteoporosis) studies which randomized participants to receive either strontium ranelate or placebo over 3 years. Frail, intermediate and robust patients were identified using adapted Fried's criteria. Analyses were performed according to the intention-to-treat principle utilizing 1- and 3-year study follow-up data.Results2346 robust, 2472 intermediate and 264 frail women were identified. At 3 years, the risk for vertebral fractures was reduced by 30% (Relative Risk [RR], 0.70; 95% confidence interval [CI], 0.57-0.86) in the robust, by 45% (RR, 0.55; 95%CI, 0.46-0.67) in the intermediate and by 58% (RR, 0.42; 95%CI, 0.24-0.74) in the frail patients compared to those assigned to placebo (p < 0.01 for all three groups; p = 0.11 for trend). Risk of vertebral fracture was significantly reduced within 1 year in all three groups. Numbers of subjects needed to be treated to prevent one new vertebral fracture over 3 years were 13, 9 and 5 in the robust, intermediate and frail groups, respectively. Adverse event profiles and medication compliance were similar across the 3 groups.ConclusionsThe imperative to treat osteoporosis appears to be greatest in frail patients since similar relative risk reductions would avert more fractures in frail than in non-frail elderly patients.