Longitudinal change in bone mineral density among adults aged 55 years and older using the healthy aging longitudinal study in Taiwan (Halst)

[[abstract]]Objective: To describe the change in BMD over 6 y among adults aged 55 y and older by sex and osteoporosis status. Methods: Participants included the cohort of healthy adults from HALST having BMD measurements at baseline and at follow-up (follow-up duration (mean±SD): 6.1±0.5 y). BMD of lumbar spine (L1-L4) was measured using DXA by operators following standardized procedures at 4 sites in HALST. Osteoporosis status at baseline was defined by a BMD T-score as osteoporosis (T-score ≤ -2.5), osteopenia (-2.5 < T-score < -1), or normal status (T-score ≥ -1). Longitudinal BMD change was calculated as the percent change between the baseline BMD and the follow-up BMD. A 3% BMD change has been considered as the least significant change (LSC) at the lumbar spine to be of potential clinical significance beyond measurement imprecision. Results: Among the 1508 participants with BMD measurements at baseline and follow-up; at baseline, 52% (n=782) were women, 62% (n=932) aged 65 y and older, 14% (n=215) had osteoporosis, 33% (n=500) had osteopenia, and 3% (n=47) had a recent history of an antiosteoporotic medication. At 6 y of follow-up, the largest BMD reduction had occurred among women aged between 55-65 y (-3.1%, 95%CI: -3.8%, -2.4%) (Figure). For all other healthy aging adults, there were no changes in BMD beyond the LSC of 3%. Conclusion: Among healthy adults in Taiwan aged 55 y and older, women aged 55-65, soon after menopause, experienced the most significant BMD loss in lumbar spine in a 6-y observation period. These women may benefit most from potential interventions to reduce bone loss and risk of developing osteoporosis. For the other healthy adults, men aged 55 y and older and women aged 65 y and older, who have relatively stable measurements of BMD over 6 y, a one-time DXA screening appears adequate to identify those at high risk for an osteoporotic fracture