National trends in osteoporosis in the general older population and postmenopausal women, to the COVID-19 pandemic by related factors, 2001-2021: a nationwide study in South Korea

Objective: Changes in the prevalence of osteoporosis, especially among the older population in South Korea, remain under-investigated, particularly during the COVID-19 pandemic. Thus, we aimed to analyze trends in osteoporosis and risk factors among Korean older adults, with a specific focus on the general population and postmenopausal women aged 50 years and above, spanning the period from 2001 to 2021. Methods: To estimate the prevalence and identify the determinants of osteoporosis, our study employed weighted complex sampling to ensure an accurate representation of menopausal status. We utilized linear and logistic regression to compute beta coefficients and evaluate associated factors. The weighted prevalence of osteoporosis by age, sex, menopausal status, socioeconomic status, and other sociodemographic variables was deduced from self-reporting. Results: This cross-sectional study utilized data from 38,341 older individuals in South Korea, collected through a nationwide survey. The overall sex distribution consisted of 21,836 (56.95%) females. The prevalence of osteoporosis in the general older population increased before the pandemic, as indicated by a β coefficient of 0.328 (95% CI, 0.061 to 0.596); however, it did not continue to increase significantly in the preceding pandemic years. The prevalence among menopausal women also increased, with a β coefficient of 0.912 (0.472 to 1.352) before the pandemic. However, the pandemic slowed the increase, as indicated by a βdiff of -1.90 (-3.31 to -0.49). Compared to the pre-pandemic, age of 80 years or above (ratio of wOR, 1.67; 95% CI, 1.29 to 2.16), higher income (1.29; 1.11 to 1.50), obesity (1.54; 1.05 to 2.27), and higher education (1.37; 1.15 to 1.63) stand out as influential factors increasing osteoporosis prevalence during the pandemic. Conclusions: Osteoporosis trends exhibited notable shifts during the study period within the COVID-19 pandemic. Further research is essential to monitor these trends and inform future healthcare strategies on the COVID-19 pandemic.