Long-term effects of ambient PM2.5 on hypertension in multi-ethnic population from Sichuan province, China: a study based on 2013 and 2018 health service surveys

Abstract Background Hypertension, a major risk factor of many sever chronic diseases and leading cause of global disease burden, is reported associated with exposure to PM2.5. China’s high PM2.5 pollution level has become a major public health issue. However, existing studies from China on the effect of PM2.5 exposure on hypertension have got inconsistent results with very limited investigation into the multi-ethnic people. This study adds multi-ethnic evidence from Sichuan Province, southwestern China, and assesses ethnic differences of PM2.5 exposure effect on hypertension. Methods We pooled large cross-sectional data from two surveys conducted in Sichuan province in 2013 and 2018 to exam the effect of long-term exposure to PM2.5 on prevalence of hypertension in adults aged 30 years old and above. Community-specified annual PM2.5 concentration was estimated using satellite data. Logistic regression was applied to examine the association between long-term exposure to PM2.5 and hypertension prevalence in the whole population, specific ethnic populations and population (including Han and ethnic minority people) living in same areas. Results 31462 participants with an average age of 56 years old were included. The average exposure concentration was 32.8 µg/m3. The proportions of the Han, the Tibetan, the Yi, and other ethnic people were 89.2%, 7.3%, 3.2%, and 0.3%, respectively. The adjusted odds ratio (OR) was 1.08 (95% CI, 1.04–1.12) for a 10 µg/m3 PM2.5 concentration increment for the whole population. The adjusted ORs for the Han, the Tibetan, and the Yi were 1.08 (95% CI, 1.04–1.12), 0.03 (95% CI, 0.00-0.27), and 1.75 (95% CI, 1.28–2.38) for a 10 µg/m3 PM2.5 concentration increment, respectively. Stratification analysis found stronger associations in participants with chronic diseases and Yi minority population. Conclusion Long-term exposure to PM2.5 may increase the risk of hypertension prevalence in Chinese multi-ethnic adults. Stronger associations were found in people with chronic disease and Yi minority group.