Effect of intensive blood pressure on the progression of non-diabetic chronic kidney disease at varying degrees of proteinuria

The ideal blood pressure (BP) target for renoprotection is uncertain in patients with non-diabetic chronic kidney disease (CKD), especially considering the influence exerted by pre-existing proteinuria. In this pooled analysis of landmark trials, we coalesced individual data from 5001 such subjects randomized to intensive versus standard BP targets. We employed multivariable regression to evaluate the relationship between follow-up systolic blood pressure (SBP) and diastolic blood pressure (DBP) on CKD progression (defined as glomerular filtration rate decline by 50% or end-stage renal disease), focusing on the potential for effect modification by baseline proteinuria or albuminuria. The median follow-up was 3.2 years. We found that SBP rather than DBP was the primary predictor of renal outcomes. The optimal SBP target was 110-129 mm Hg. We observed a strong interaction between SBP and proteinuria such that lower SBP ranges were significantly linked with progressively lower CKD risk in grade A3 albuminuria or ≥0.5-1 g/day proteinuria (relative to SBP 110-119 mm Hg, the adjusted HR for SBP 120-129 mm Hg, 130-139 mm Hg, and 140-149 mm Hg was 1.5, 2.3, and 3.3, respectively; all p<0.05). In grade A2 microalbuminuria or proteinuria near 0.5 g/day, a non-significant but possible connection was seen between tighter BP and decreased CKD (aforementioned HRs all <2; all p>0.05), while in grade A1 albuminuria or proteinuria <0.2 g/day no significant association was apparent (HRs all <1.5; all p>0.1). We conclude that in non-diabetic CKD, stricter BP targets <130 mm Hg may help limit CKD progression as proteinuria rises.