Association of air pollution with frailty and sarcopenia among middle-aged and older adults: a systematic review and meta-analysis

Background: The current evidence regarding the impact of air pollution on frailty and sarcopenia is inconsistent. This study aimed to synthesize evidence on the overall association of air pollution with frailty and sarcopenia risk among middle-aged and older adults. Methods: We thoroughly searched three online databases, including Pubmed, Embase, and Web of Science, for relevant publications up to January 11, 2025. Studies evaluating the associations of indoor and outdoor air pollution with frailty and sarcopenia risk were included. Adjusted Odds Ratios (OR) with 95 % confidence intervals (CI) were computed using random-effects or fixed-effects meta-analysis. I2 statistic and Q-test were used to test for heterogeneity. Results: The study identified 38 articles. Per 10 mu g/m3 increment of exposure to PM2.5, PM2.5-10, O3, and NO2 was respectively associated with 23.6 % (OR: 1.236, 95 % CI: 1.116-1.368), 17.9 % (OR: 1.179, 95 % CI: 1.126-1.234), 16.4 % (OR: 1.164, 95 % CI: 1.067-1.271), and 7.8 % (OR: 1.078, 95 % CI: 1.037-1.121) increased risk of frailty. Solid fuel use was linked to frailty measured by frailty index (OR: 1.252, 95 % CI: 1.113-1.409) and frailty measured by frailty phenotype (OR: 1.249, 95 % CI: 1.090-1.431). Each 10 mu g/m3 increment of exposure to PM2.5 (OR: 1.519, 95 % CI: 1.019-2.263) and NO2 (OR: 1.109, 95 % CI: 1.092-1.127) increased the risk of sarcopenia. Conclusions: Exposure to PM2.5, PM2.5-10, O3, NO2, and solid fuel increased frailty risk; PM2.5, NO2, and solid fuel exposure elevated the sarcopenia risk among middle-aged and older participants. These results support the implementation of sustained environmental policies to prevent frailty and sarcopenia.