Hip fracture protection by alendronate treatment in postmenopausal women with osteoporosis: a review of the literature

Osteoporosis most commonly affects postmenopausal women, placing them at a significant risk of fractures. In particular, hip fractures are an important cause of mortality and morbidity among postmenopausal women. Anti-resorptive therapies that produce greater decreases in bone turnover markers together with greater increases in bone mineral density (BMD) are associated with greater reductions in fracture risk, especially at sites primarily composed of cortical bone such as the hip. Thus, treatment with potent anti-resorptive drugs like alendronate is a strategy for preventing hip fractures in postmenopausal women with osteoporosis. The purpose of this paper is to discuss the efficacy of alendronate against hip fractures and the mechanism for this anti-fracture efficacy in postmenopausal women with osteoporosis. A meta-analysis of randomized controlled trials has shown that alendronate reduces the risk of hip fractures by 55% in postmenopausal women with osteoporosis. According to the analyses of the Fracture Intervention Trial, each 1 standard deviation reduction in a 1-year change in bone-specific alkaline phosphatase (BSAP) is associated with 39% fewer hip fractures in alendronate-treated postmenopausal women, and those with at least 30% reduction in BSAP have a 74% lower risk of hip fractures relative to those with less than 30%. Alendronate is effective in reducing the risk of hip fractures across a spectrum of ages. The mechanism for this anti-fracture efficacy has been clarified; alendronate strongly suppresses bone turnover and subsequently increases hip BMD, decreases cortical porosity, improves parameters of hip structure geometry (cortical thickness, cross-sectional area, section modulus, and buckling ratio), and produces more uniform mineralization (increases the mean degree of mineralization of bone) in cortical bone. A once-weekly regimen of alendronate administration provides better patient compliance and persistence with the treatment than the once-daily dosing regimen, leading to greater efficacy against hip fractures. Thus, the efficacy of alendronate against hip fractures has been confirmed in postmenopausal women with osteoporosis, especially with a once-weekly dosing regimen

A Radiographic Study on the Associations of Age and Prevalence of Vertebral Fractures with Abdominal Aortic Calcification in Japanese Postmenopausal Women and Men

The purpose of the present study was to determine the associations of age and history of non- and low-traumatic fractures with the severity of abdominal aortic calcification in Japanese postmenopausal women and men. Four hundred and one Japanese persons (24 men and 377 postmenopausal women, mean age: 73.8 years) for whom thoracic and lumbar spine radiographs had been obtained to evaluate their posture prior to patient participation in a fall-prevention exercise program were enrolled. The associations of sex, age, history of hip fracture, prevalence of vertebral fracture, and spondylosis grade (the Nathan degree) with the severity of abdominal aortic calcification (length of calcification, as evaluated according to the number of vertebral bodies) were analyzed. Nine subjects (2.2%) had a history of hip fracture, and 221 (55.1%) had at least one prevalent vertebral fracture. Two hundred and sixty-seven subjects (66.6%) had first-degree spondylosis. Age and the number of prevalent vertebral fractures, but not sex, history of hip fracture, or spondylosis grade, were significantly associated with the severity of abdominal aortic calcification. The present study confirmed that age and the number of vertebral fractures were associated with the severity of abdominal aortic calcification in Japanese postmenopausal women and men