Effects of intensive blood pressure lowering on mortality and cardiovascular and renal outcomes in type 2 diabetic patients: A meta-analysis

Background Previous studies have demonstrated that intensive blood pressure (BP) lowering treatment reduces the risk of all-cause mortality and provides greater vascular protection for patients with hypertension. Whether intensive BP lowering treatment is associated with such benefits in patients with type 2 diabetes mellitus remain unknown. We aimed to clarify these benefits by method of meta-analysis. Methods The PubMed, EMBASE, Science Citation Index and Cochrane Library databases were searched to identify randomized controlled trials (RCT) that fulfilled study inclusion criteria. Two investigators independently extracted and summarized the relevant data of the included trials. Random-effects model was applied to calculate the estimates of all effect measures. Results We included 16 RCTs and our meta-analysis showed that intensive BP lowering treatment vs less intensive BP lowering treatment resulted in significant reductions in the all-cause mortality risk [relative risk (RR), 0.82; 95% CI, 0.70–0.96], major CV events (RR, 0.82; 95% CI, 0.73–0.92, MI (RR, 0.86; 95% CI, 0.77–0.96), stroke (RR, 0.72; 95% CI, 0.60–0.88, CV death (RR, 0.73; 95% CI, 0.58–0.92) and albuminuria progression (RR, 0.91 95% CI, 0.84–0.98). However, intensive BP lowering treatment had no clear effect on non-CV death (RR, 0.97; 95% CI, 0.79–1.20), heart failure (HF) (RR, 0.88; 95% CI, 0.71–1.08) or end-stage kidney disease (ESKD) (RR, 1.00; 95% CI, 0.75–1.33). Subgroup analysis showed that the reduction in all cause-mortality was consistent across most patient groups, and intensive BP lowering treatment had a clear benefit even in patients with systolic blood pressure lower than 140 mm Hg. However, the benefit differed in patients with different CV risk (≥10%: RR, 0.77, 95%CI, 0.64–0.91; <10%: RR, 1.04, 95%CI, 0.84–1.29; Phetero = 0.028). Conclusions Our data indicate that intensive BP lowering treatment provides greater benefits than less intensive treatment among patients with type 2 diabetes mellitus. Further studies are required to more clearly evaluate the benefits and harms of BP targets below those currently recommended with intensive BP lowering treatment.