Effects of blood pressure on renal and cardiovascular outcomes in Asian patients with type 2 diabetes and overt nephropathy: a post hoc analysis (ORIENT-blood pressure)

BACKGROUND: Blood pressure (BP) control may have different effects on cardiovascular (CV) and renal outcomes in diabetes. We examined the impact of systolic BP (SBP) on renal and CV outcomes in a post hoc analysis in the Olmesartan Reducing Incidence of Endstage Renal Disease in Diabetic Nephropathy Trial. METHODS: We stratified mean follow-up SBP into three categories (≤130, 131–140 and >140 mmHg) and used a Cox regression model to estimate the hazard ratio (HR, 95% confidence interval) for the outcomes. The composite renal outcome was doubling of serum creatinine, end-stage renal disease and all-cause death. The composite CV outcome included CV death, nonfatal stroke, nonfatal myocardial infarction, hospitalization for unstable angina or heart failure, revascularization and lower extremity amputation. We also compared the slope of estimated glomerular filtration rate (eGFR) in all three groups. RESULTS: After a mean follow-up period of 3.2 years, the follow-up SBP was linearly associated with risk of renal outcomes in all 566 patients. In patients with heavy proteinuria (≥1 g/gCr), a follow-up SBP > 130 mmHg was associated with an HR of 2.33 (1.62–3.36) for renal outcomes with referent to SBP ≤ 130 mmHg. In patients without history of CV disease, a follow-up SBP > 140 mmHg was associated with an HR of 2.04 (1.23–3.40) for CV outcomes with referent to SBP < 140 mmHg. The median (interquartile range) slopes of eGFR were −3.27 (−6.90, −1.63), −4.53 (−8.08, −2.29) and −7.13 (−10.90, −3.99) dL/mg/year in patients with SBP ≤ 130, 131–140 and > 140 mmHg, respectively (P = 0.008 between ≤130 and 131–140, P < 0.001 between ≤ 130 and > 140 mmHg). CONCLUSION: In Asian type 2 diabetic patients with chronic kidney disease and heavy proteinuria, reduction of SBP ≤ 130 mmHg was associated with greater renoprotection than cardioprotection. However, our results emphasize the need to individualize BP targets in type 2 diabetes.