Blood pressure and cardiovascular morbidity risk in type 2 diabetes with hypertension over a decade of follow-up: evidence for J-shaped phenomenon.

There is still debate on whether the relationship between blood pressure (BP) and risk of cardiovascular diseases (CVD) in patients with type 2 diabetes (T2D) is linear or not. Since these cardio-metabolic disturbances share interrelated complex pathogenic mechanisms, we aimed to assess the relationship of baseline systolic (SBP)/diastolic pressures with CVD and coronary heart disease (CHD) events in a cohort of Iranians with T2D during a median follow-up of 8.8 years. Of all 1009 eligible participants with T2D with a mean (s.d.) age of 54.4 (11.6) years and free of CVD at baseline, we primarily focused on 260 participants undergoing anti-hypertensive treatment. Multivariate Cox proportional hazard models were used to evaluate hazard ratios (HR) of BP categories for CVD and CHD events. Also, multivariable regression modelling was applied to obtain their risk curve. We detected a J-shaped phenomenon between the continuous baseline BP and risk of CVD events. Considering 130⩽SBP<140 mm Hg as reference, a SBP ⩾140 mm Hg was associated with increased CVD (HR [95% confidence interval (CI)]: 2.43 [1.23-4.82]) and CHD (HR [95% CI]: 2.05 [1.02-4.13]) risk. However, a SBP⩽120 mm Hg in those with drug-treated hypertension also showed higher risk for CVD (HR [95% CI]: 2.80 [1.24-6.34]) and CHD events (HR [95% CI]: 2.39 [1.03-5.57]). Our findings revealed that the risk for macrovascular morbidity events was inversely associated with BP reduction below the level of 120/80 mm Hg for those with diabetes. People with diabetes might benefit from a BP management to a moderate range of 120/80-140/90 mm Hg for CVD risk reduction.