Risk factors for longitudinal bone loss in elderly men and women: The Framingham Osteoporosis Study

Few studies have evaluated risk factors for bone loss in elderly 7 women an d men. Thus, we examined risk factors for 4-year longitudinal change in bon e mineral density (BMD) at the hip, radius, and spine in elders. Eight hund red elderly women and men from the population-based Framingham Osteoporosis Study had BMD assessed in 1988-1989 and again in 1992-1993. BMD was measur ed at femoral neck, trochanter, Ward's area, radial shaft, ultradistal radi us, and lumbar spine using Lunar densitometers. We examined the relation of the following factors at baseline to percent BMD loss: age, weight, change in weight, height, smoking, caffeine, alcohol use, physical activity, seru m 25-OH vitamin D, calcium intake, and current estrogen replacement in wome n. Multivariate regression analyses were conducted with simultaneous adjust ment for all variables. Mean age at baseline was 74 years +/- 4.5 years (ra nge, 67-90 years). Average 4-year BMD loss for women (range, 3.4-4.8%) was greater than the loss for men (range, 0.2-3.6%) at all sites; however, BMD fell with age in both elderly women and elderly men. For women, lower basel ine weight, weight loss in interim, and greater alcohol use were associated with BMD loss. Women who gained weight during the interim gained BMD or ha d little change in BMD. For women, current estrogen users had less bone los s than nonusers; at: the femoral neck, nonusers lost up to 2.7% more BMD. F or men, lower baseline weight and weight loss also were associated with BMD loss. Men who smoked cigarettes at baseline lost more BMD at the trochante r site. Surprisingly, bone loss was not affected by caffeine, physical acti vity, serum 25-OH vitamin D, or calcium intake. Risk factors consistently a ssociated with bone loss in elders include female sex, thinness, and weight loss, while weight gain appears to protect against bone loss for both men and women. This population-based study suggests that current estrogen use m ay help to maintain bone in women, whereas current smoking was associated w ith bone loss in men. Even in the elderly years, potentially modifiable ris k factors, such as weight, estrogen use, and cigarette smoking are importan t components of bone health.