Decline of body weight with aging is a major risk factor for frailty, osteoporosis and fracture, suggesting that treatment for osteoporosis may affect body composition. Recently, we have shown that 5-year treatment with raloxifene prevented age-related weight loss, suggesting some other drugs for osteoporosis may also prevent a decrease in body weight with aging. The present study aimed to identify the relationship between bisphosphonate treatment and body composition markers. We measured bone mineral density (BMD), body composition, and bone remodeling markers in 551 Japanese postmenopausal women with bisphosphonate treatment, which included risedronate or alendronate treatment (BP-treatment group; N = 193) and without treatment by any osteoporosis drug (no-treatment group; N = 358) for 4-7 years (mean observation periods; 5.5 years) and analyzed the relationship of these with BMD, body mass index (BMI), body weight, and biochemical markers. The mean (SD) age of the participants was 68.6 (9.8) years in the BP-treatment group and 63.7 (10.6) years in the no-treatment group. Percent changes in body weight and BMI were significantly different between the BP-treatment and no-treatment groups (P < 0.01 and P < 0.01, respectively). In multiple linear regression analysis, bisphosphonate treatment was a significant independent determinant of percent changes in body weight and BMI (P < 0.01 and P = 0.01, respectively). Long-term use of bisphosphonates prevented reductions in BMI and body weight, usually observed in elderly women. Our results suggest that bisphosphonate treatment not only reduces the risk for incident osteoporotic fractures but also for frailty in the elderly.
Keywords: Bisphosphonates; Body mass index; Body weight; Long-term treatment.