National, regional and provincial prevalence of carotid atherosclerosis and carotid plaque in Chinese adults: an updated systematic review and modelling analysis

Background: Carotid atherosclerosis (CAS), a major contributor to cardiovascular morbidity in China, exhibits substantial geographic disparities that remain unquantified at the provincial level. We aimed to provide updated national, regional, and provincial prevalence of CAS or carotid plaque (CP) among Chinese adults aged 30-79 years. Methods: We searched CNKI, Wanfang, China Science and Technology Journal Database (VIP), PubMed, Embase, and MEDLINE for articles published after 2010 that reported on the prevalence of CAS or CP in the general Chinese population. We used a multilevel mixed-effects meta-regression model to estimate the national age- and sex-specific prevalence of CAS and CP. We assessed the relationships of associated factors with CAS and CP using random-effects meta-analysis. The pooled odds ratios were then incorporated into 'associated factor-based' model, alongside provincial-level associated factor data, to estimate national case numbers across provinces. Results: Based on data from 82 articles, we estimated the overall prevalences of CAS and CP to be 36.35% (95% confidence interval (CI) = 29.74-43.44) and 26.27% (95% CI = 23.17-29.59), respectively. We noted associations between high prevalence and advancing age, with males having a higher prevalence across the whole age spectrum compared to females. A total of 320.25 million (95% CI = 262.03-382.72) and 231.48 million (95% CI = 204.19-260.70) population aged 30-79 years were affected by CAS and CP in mainland China. Current smoking, hypertension, and diabetes were associated with CAS and CP, with dyslipidaemia only associated with CP. Northeast China recorded the highest prevalence of CAS (39.31%; 95% CI = 32.25-46.81) and CP (28.56%; 95% CI = 25.21-32.13) in 2020. Sichuan Province had the highest prevalence of both CAS (42.14%; 95% CI = 34.79-49.92) and CP (30.77%; 95% CI = 27.26-34.50), while Tibet showed the lowest (CAS: 26.80%; 95% CI = 21.35-32.92; CP: 18.74%; 95% CI = 16.33-21.39). Conclusions: CAS and CP are highly prevalent in China, with substantial age trends, sex differences, and regional disparities. Targeted prevention strategies and evidence-based resource allocation are needed to manage the high burden of CAS and CP and their associated factors. Registration: PROSPERO: CRD420251033132.