| Abstract: | Objectives: This study aims to predict the longitudinal transition of osteoporosis status among adults aged 55 years and older. Material and Methods: Bone mineral density (BMD) was assessed using dual-energy X-ray absorptiometry at baseline and a follow-up visit in the Healthy Aging Longitudinal Study in Taiwan (HALST). Osteoporosis status was categorized based on the lower BMD T-score between lumbar spine (L1 – L4) and femur neck as severe osteoporosis (T-score ≤ -3), osteoporosis (-3 < T-score ≤ -2.5), osteopenia (-2.5 < T-score <-1), or normal status (T-score ≥ -1). Baseline characteristics included sex, age, body mass index, education level, smoking and drinking status, frailty status, and serum vitamin D concentration. A four-state semi-Markov model was employed to predict longitudinal tran- sitions of osteoporosis status for participants by their osteoporosis status at baseline. Re- sults: Among the 3,681 participants with one BMD measurement at baseline, 51.4% were women (n=1,893). Moreover, 49.9% of women (n=945) had osteopenia, 11.4% (n=215) had osteoporosis, and 16.0% (n=302) had severe osteoporosis. Correspondingly, among men (n=1,788), 38.3% (n=684) had osteopenia, 4.2% (n=75) had osteoporosis, and 2.6% (n=47) had severe osteoporosis. After an average of 6 years of follow-up, a notable proportion of participants experienced transitions in osteoporosis status. Among women (n=767), 12.1% (n=44) progressed from osteopenia to osteoporosis, 2.2% (n=8) from osteopenia to severe osteoporosis, and 38.2% (n=29) from osteoporosis to severe osteoporosis. Corresponding- ly, among men (n=728), 7.4% (n=20) transitioned from osteopenia to osteoporosis, 1.1% (n=3) from osteopenia to severe osteoporosis, and 30.4% (n=7) from osteoporosis to se- vere osteoporosis. Adjusting for various factors, women participants over 75 years old, frail women, and those with insufficient vitamin D levels revealed higher transition probabilities to severe status (osteopenia, osteoporosis, or severe osteoporosis) (Figure). Conclusions: In middle-aged and older Taiwanese adults, transition probabilities between different osteoporosis statuses varied by sex, age group, frailty status, and serum vitamin D concentration. These findings suggest the potential for targeted health promotion strategies based on current osteoporosis status and individualized risk factors, particularly, among women, older adults, frail individuals, and people with insufficient vitamin D levels. |
