Effect of Achieved Systolic Blood Pressure on Cardiovascular Outcomes in Patients With Type 2 Diabetes: A Population-Based Retrospective Cohort Study

Abstract

OBJECTIVE: The objective of this study was to compare the incidence of cardiovascular disease (CVD) among patients with type 2 diabetes mellitus (T2DM) with treated hypertension who achieved systolic blood pressures (SBPs) of <120, <130, and <140 mmHg after an increase in their antihypertensive regimen. RESEARCH DESIGN AND METHODS: A retrospective cohort study was conducted on 28,014 primary care adult patients with T2DM with no prior diagnosis of CVD and who achieved SBP readings <140 mmHg after an increase in the number of antihypertensive medications prescribed. Using an extension of propensity score matching, a total of 2,079, 10,851, and 15,084 matched patients with achieved SBP measurements of <120, <130, and <140 mmHg were identified. The association between achieved SBP and incident CVD were evaluated using Cox regressions. Subgroup analyses were conducted by stratifying patients' baseline characteristics. RESULTS: Over a median follow-up period of 4.8 years, the incidence of CVD in patients with achieved SBP measures of <120, <130, and <140 mmHg were 318 (15.3%; incidence rate [IR] 34.3/1,000 person-years [PY]), 992 (9.1%; IR 20.4/1,000 PY), and 1,635 (10.8%; IR 21.4/1,000 PY). Achieved SBP <120 mmHg was associated with a higher risk of CVD compared with achieved SBP <130 mmHg (hazard ratio [HR] 1.75 [95% CI 1.53, 2.00]) and achieved SBP <140 mmHg (HR 1.67 [95% CI 1.46, 1.90]). There was a significant reduction in CVD risk in patients <65 years (HR 0.81 [95% CI 0.69, 0.96]) but no difference for other patients, including patients ≥65 years, who achieved SBP <130 mmHg when compared with the group that achieved SBP <140 mmHg. CONCLUSIONS: Our findings support a SBP treatment target of 140 mmHg and suspect no risk reduction attenuation on CVD for lower SBP targets (<120 or <130 mmHg) for most patients with uncomplicated T2DM. A randomized control trial is still needed to confirm these findings.