Visit-to-visit variability of blood pressure and risk of macrovascular and microvascular complications in patients with type 2 diabetes: A Chinese primary-care cohort study

BackgroundWe evaluated the effects of visit-to-visit variability of systolic blood pressure (SBP) and diastolic blood pressure (DBP) on macrovascular and microvascular complications among patients with type 2 diabetes. MethodsA total of 11 043 patients with type 2 diabetes from primary healthcare institutions between January 2010 and June 2020 were included. The visit-to-visit blood pressure variability was calculated using three metrics: SD, coefficient of variation (CV), and average real variability (ARV), obtained over a 12-month measurement period. The associations of visit-to-visit blood pressure variability with macrovascular and microvascular complications were evaluated using multivariate-adjusted Cox proportional hazards models, and hazard ratio (HR) with 95% confidence interval (CI) were reported. ResultsThere were 330 macrovascular events and 542 microvascular events. Compared to those for participants with the lowest quartile of SD of SBP and DBP, increased risks were observed in patients with the highest quartile of SD of SBP and DBP for macrovascular complications (SD-SBP: HR = 1.78, 95% CI: 1.24-2.57; SD-DBP: HR = 2.20, 95% CI: 1.50-3.25) and microvascular complications (SD-SBP: HR = 1.85, 95% CI: 1.39-2.46; SD-DBP: HR = 1.82, 95% CI: 1.36-2.44). CV and ARV of SBP and DBP also had statistically significant associations with macrovascular and microvascular complications. The optimal variability of blood pressure target was SD of SBP <6.45 mm Hg and SD of DBP <4.81 mm Hg. ConclusionsVisit-to-visit blood pressure variability may be a potential predictor for macrovascular and microvascular complications in patients with type 2 diabetes.