The influence of multiple air pollutants on sarcopenia progression: a multi-state analysis in a prospective cohort

BACKGROUND: Air pollution's influence on sarcopenia progression remains insufficiently studied. METHODS: Using the UK Biobank cohort, we included 50381 participants initially free of probable sarcopenia and sarcopenia. Exposures to PM2.5, PM10, PM2.5-10, NO2, and NOx for each transition stage were estimated at each participant's residential addresses using data from the UK's department. Parametric g-computation was applied to estimate cumulative risks under hypothetical pollution reduction scenarios. Multistate models were used to examine associations between air pollution and sarcopenia progression. RESULTS: During 8.98 years (median), 4445 (8.8%) participants developed probable sarcopenia; 17 (0.4%) progressed to sarcopenia. Parametric g-computation estimated that a simultaneous 10% reduction in all 4 pollutants would decrease the 15-year cumulative risk (risk ratio [RR] = 0.93; risk difference [RD] = -2.21). In multistate models, PM2.5 increased risks of probable sarcopenia (hazard ratio [HR]: 1.06; 95% confidence interval [CI]: 1.02-1.10), sarcopenia (HR: 1.18; 95% CI: 1.04-1.34), baseline to death (HR: 1.11; 95% CI: 1.02-1.20,) and probable sarcopenia to death (HR: 1.24; 95% CI: 1.04-1.50). NO2 showed similar associations: probable sarcopenia (HR: 1.06; 95% CI: 1.02-1.10), sarcopenia (HR: 1.23; 95% CI: 1.09-1.39), baseline to death (HR: 1.10; 95% CI: 1.01-1.19), and probable sarcopenia to death (HR: 1.23; 95% CI: 1.01-1.50). NOx increased risks for probable sarcopenia (HR: 1.06; 95% CI: 1.03-1.09), sarcopenia (HR: 1.15; 95% CI: 1.04-1.26), and probable sarcopenia to death (HR: 1.22; 95% CI: 1.04-1.43). Stratified analyses indicated effect modification by sex, household income, and body mass index (BMI). CONCLUSIONS: These findings highlight the critical role of clean air in preventing and delaying sarcopenia progression, especially in vulnerable populations.