Temporal trends and climate association with Perthes disease in a nationwide cohort of military draft eligible male population

A retrospective, nationwide, population-based study was conducted to evaluate the correlation between climate change and Legg–Calvé–Perthes disease (LCPD) in young adult males in South Korea. Open repository data from the Military Manpower Administration were retrospectively collected to measure the prevalence and 95% confidence intervals (CI) of LCPD, along with the year (between 2013 and 2022) and region in South Korea. Meteorological factors were evaluated using the Korea Meteorological Administration’s National Climate Data Centre. Spearman’s correlation analysis and a simple distributed linear model (DLM) were used to assess the correlations between the prevalence of LCPD in the male population and meteorological factors. The prevalence of LCPD significantly correlated with temperature ( r = 0.73, p = 0.017). Moreover, the prevalence of LCPD with incongruency was significantly correlated with carbon dioxide (CO 2 ) concentration ( r = 0.93, p < 0.001), particle matter 10 μm (µg/m 3 ), defined as a coarse particle ( r =-0.89, p = 0.001), particle matter 2.5 μm (µg/m 3 ), defined as a fine particle ( r =−0.80, p = 0.017), sulfur dioxide ( r =−0.85, p = 0.002), nitrogen dioxide ( r =−0.92, p < 0.001), and ozone (O 3 ) ( r = 0.88, p < 0.001). Despite this global warming trend, special attention is required to understand the complex interplay between the progression of LCPD and climate change.