Cumulative exposure to elevated blood pressure better predicts cardiovascular disease risk in rural Chinese adults

BACKGROUND: Traditional risk estimations for cardiovascular disease (CVD) are based on current blood pressure (BP); however, whether cumulative exposure to elevated BP among rural individuals has additional prognostic value is unclear. We aimed to validate the association of cumulative BP with CVD occurrence and assess the prognostic value of cumulative BP in CVD risk prediction. METHODS: A total of 13,057 participants who underwent three examinations from 2004 to 2010 were included in this rural epidemiological study and followed up until 2017. Cumulative BP was defined as the sum of the product of the average BP values between consecutive examinations and the time interval for each pair of successive tests prior to the follow-up period. CVD incidents that occurred during the follow-up period were noted and verified by qualified researchers. We used multivariate Cox models to assess the association of cumulative BP with CVD risk. The receiver operating characteristic curve was constructed to determine the predictive differentiation of single baseline BP measurements and cumulative BP values for CVD outcomes. RESULTS: During the follow-up period, 1,312 participants underwent CVD incidents. We found that cumulative systolic BP (hazard ratio = 1.334, 95% confidence interval: 1.245, 1.430) and cumulative diastolic BP (hazard ratio = 1.253, 95% confidence interval: 1.168, 1.343) were associated with CVD incidence above and beyond that of the current BP. These stronger associations persisted for stroke, myocardial infarction, and CVD mortality. The area under the curve for the model increased significantly (p < 0.001) from 0.735 (0.720, 0.750) to 0.742 (0.728, 0.757) when integrating cumulative systolic BP instead of baseline systolic BP. CONCLUSION: Cumulative BP in Chinese rural adults showed a stronger association with CVD incidence than that of current BP. Furthermore, cumulative BP slightly improved the predictive performance for CVD. Our findings underline the incremental predictive value of cumulative BP in CVD risk assessment among Chinese rural adults.