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 betweenSBP andCVD .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 averageSBP in the previous 2 years andCVD risk 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 betweenSBP andCVD risk was observed among the 4 age groups without evidence of a threshold down to 120 mm Hg, but the magnitude ofSBP effect onCVD attenuated with increased age. TheCVD risk in the age group <50 years was ≈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 higherSBP was 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 compositeCVD events, individualCVD , andCVD mortality, respectively.Conclusions There is a significant log‐linear relationship between baselineSBP and the risk ofCVD among patients with diabetes mellitus in China. The risk increases from anSBP of 120 mm Hg onward. Age influences this relationship significantly, with younger patients (<50 years) having a greater risk ofCVD for a similar rise inSBP as compared with those who are older. These findings suggest that differential target blood pressures stratified by age maybe useful.