Age-Specific Associations Between Systolic Blood Pressure and Cardiovascular Disease: A 10-Year Diabetes Mellitus Cohort Study

Background The relationship between systolic blood pressure (SBP) and cardiovascular disease (CVD) among patients with diabetes mellitus remains unclear. The study aimed to explore age-specific associations betweenSBPandCVD. Methods and Results A population-based retrospective cohort study was conducted on 180 492 Chinese adults with type 2 diabetes mellitus in 2008-2010, with follow-up to 2017. Age-specific associations (<50, 50-59, 60-69, and 70-79 years) between the averageSBPin the previous 2 years andCVDrisk were assessed by adjusted Cox proportional hazards regression with age-specific regression dilution ratios and patient characteristics stratified by subgroups. During a median follow-up of 9.3 years (1.5 million person-years), 32 545 patients developed aCVD, with an incidence rate of 23.4 per 1000 person-years. A positive and log-linear association betweenSBPandCVDrisk was observed among the 4 age groups without evidence of a threshold down to 120 mm Hg, but the magnitude ofSBPeffect onCVDattenuated with increased age. TheCVDrisk in the age group <50 years was approximate to 22% higher than the age group 70 to 79 years (hazard ratio [HR], 1.33 [95%CI, 1.26-1.41] versusHR, 1.09 [95%CI, 1.07-1.11]). Each 10-mm Hg higherSBPwas associated with 12% (HR, 1.12 [95%CI, 1.10-1.13]), 11% (HR, 1.11 [95%CI, 1.10-1.13]), and 20% (HR, 1.20 [95%CI, 1.17-1.22]) higher risk of all compositeCVDevents, individualCVD, andCVDmortality, respectively. Conclusions There is a significant log-linear relationship between baselineSBPand the risk ofCVDamong patients with diabetes mellitus in China. The risk increases from anSBPof 120 mm Hg onward. Age influences this relationship significantly, with younger patients (<50 years) having a greater risk ofCVDfor a similar rise inSBPas compared with those who are older. These findings suggest that differential target blood pressures stratified by age maybe useful.