Association between the efficacy of alendronate and serum level of vitamin D in patients with osteoporosis

Abstract

Objective To examine the association between vitamin D and alendronate response,and to investigate the proper vitamin D levels for the efficacy of alendronate treatment of osteoporosis.Methods In this retrospective study,559 post-menopausal women with osteoporosis were devided into two groups:non-responders and responders,based on the European Study of Forsteo (EUROFORS).Demographic and clinical data including mean 25-hydroxy vitamin D (25-OHD) levels between dual-energy X-ray absorptiometry (DEXA) scans were obtained.Mean 25-OHD levels were compared between responders and non-responders and multiple logistic regression analysis was performed to identify factors associated with non-response.Results There were 437 (75.5％) responsers to alendronate therapy and 142 (24.5％) non-responders.Responders with a mean serum 25-OHD level of (59.96 ±12.56) nmol/L,obtained a more favorable result than non-responders,whose serum 25-OHD level was (47.50 ±9.92) nmol/L (P＜0.01).25-OHD level was significantly associated with response.Conclusion Patients with a mean 25-OHD ≥50 nmol/L had a substantially greater likelihood of maintaining bisphosphonate response. Key words: Osteoporosis; Alendronate ; Biphosphonates ; Vitamin D