Lower baseline value and greater decline in BMD as independent risk factors for mortality in community dwelling elderly

Skeleton plays diverse roles via crosstalk between others, thus it is conceivable that lower BMD per se may reflect negative influences on health status and threats to life independent of fracture events. We investigated investigate the association between BMD and mortality, and to examine whether the rate of bone loss can predict future mortality in an elderly population. This study was conducted as a part of the Korean Longitudinal Study on Health and Aging, a community-based prospective study of Korean people aged 65 years and older that began in 2005. A total of 648 people (318 men and 330 women) were included. Dual energy X-ray absorptiometry were conducted at baseline and at 5 years. Mortality data were collected until the date of death or the last follow-up in December 2014. Osteoporosis in all skeletal sites significantly related to increased risk of mortality in men and women, but the associations were stronger for BMD in the femur neck and total hip than in the lumbar spine. A multivariable Cox proportional-hazards model showed that baseline BMD level was a significant independent predictor of increased all-cause mortality for all three skeletal sites in men, and for lumbar spine and total hip in women. Furthermore, faster bone loss of BMDs, as shown by the decline in BMD in the lumbar spine, femur neck, and total hip, was significantly related to increased risk of mortality after adjusting for all covariates in men. Faster BMD loss at femur neck was also related to the increased risks of mortality in women. Conclusively, both a lower baseline values and greater decline in BMD were associated with excess morality in community-dwelling elderly population; there associations were stronger in men than in women. This study emphasizes the importance of skeletal health for healthy aging, revealing lower bone mass and faster bone loss may be markers of poorer health that are driving excess mortality.