[Association between long-term blood pressure change and the incidence of cardiovascular diseases: a population-based...

Objective: To explore the association between long-term changes in blood pressure (BP) levels and the incidence of cardiovascular diseases (CVD). Methods: A total of 5 752 participants, who participated baseline examination in 1992-1993 and re-examination in 2007, were followed up till December 31, 2013 according to the study protocol of the Chinese Multi-provincial Cohort Study. Participants were stratified by baseline BP and re-examination BP and cross-combined into 9 subgroups. The 20-year incidence of acute cardiovascular events, acute coronary heart disease (CHD) and acute stroke events were analyzed and association between disease incidence and 15-year changes in BP were determined using the competing risk regression model. Results: (1) There were 523 CVD events (170 CHD, 373 stroke) during the 20 years follow up. The number of participants with baseline systolic blood pressure (SBP)/diastolic blood pressure (DBP) of <130/80 mmHg (1 mmHg=0.133 kPa), 130-139/80-89 mmHg, and hypertension were 2 892 (50.3%), 1 328 (23.1%) and 1 532 (26.6%), respectively. (2) Among participants with baseline SBP of 130-139 mmHg or DBP of 80-89 mmHg, 870 (65.5%) progressed to hypertension and 279 (21.0%) maintained at the same stratum over a 15-year follow up period. (3) After adjustment for age, sex, body mass index, smoking status, diabetes, total cholesterol, and high-density lipoprotein cholesterol at baseline, participants maintained SBP/DBP at 130-139/80-89 mmHg had a higher risk of developing acute cardiovascular events, CHD and stroke with the hazard ratios (HR) and 95% confidence interval (95%CI) of 2.04 (1.16, 3.57), 3.29 (1.30, 8.35) and 1.63 (0.80, 3.33), compared with those who maintained their SBP < 130 mmHg and DBP <80 mmHg. Participants whose BP increased from 130-139/80-89 mmHg to hypertension over the follow up period had 2.81-fold (1.84, 4.29), 3.17-fold (1.43, 7.03) and 2.71-fold (1.65, 4.44) higher risk for the incidence of acute cardiovascular events, CHD, and stroke, respectively, compared with participants who maintained their SBP <130 mmHg and DBP <80 mmHg. Conclusions: Participants with SBP/DBP of 130-139/80-89 mmHg have a high long-term risk for progression to hypertension. Sustained exposure to SBP/DBP of 130-139/80-89 mmHg or higher increases the risk of CVD incidence, and our results highlight the importance of early prevention for participants with this BP stratum.