Divergent impacts of air pollution on cardiovascular-kidney-metabolic progression: Comparative evidence from Chinese vs. British cohorts

Background: The association between air pollution and individual disease in cardiovascular-kidney-metabolic (CKM) syndrome is well-established. However, there is a lack of quantitative research on the impact of air pollution on CKM progression. Methods: Based on UK Biobank and Yinzhou cohort (China), we involved 44,369 (UK) and 4847 (China) Stage 1 population (characterized by excess or dysfunctional adiposity); 122,309 (UK) and 13,018 (China) Stage 2 population (diagnosed with metabolic diseases and/or chronic kidney disease). Markov models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for the impact air pollution on CKM progression across Stage 1, Stage 2, Stage 4 (cardiovascular diseases, CVDs), and death. Results: In Stage 1 population, air pollution was associated with higher risks of progression from Stage 1 to Stage 2 in both cohorts. In Yinzhou population, air pollution increased the risk of CKM progression from Stage 1 directly to Stage 4 and from Stage 2 to Stage 4. However, in UK Biobank, air pollution was associated with CKM-related mortality, particularly from Stage 2 to death and Stage 4 to death, with highest HRs 1.31 (1.08–1.59) and 1.17 (1.04–1.32), respectively. In Stage 2 population, similar patterns were observed, and paradoxically, non-overweight individuals exhibited higher risks of CVD onset and mortality when exposed to air pollution than overweight counterparts. Conclusion: Air pollution exposure markedly accelerates CKM progression, with distinct manifestations between China and the UK. These results emphasize the need for sustained reductions in pollutant concentrations, especially particulate matter in China.