Are Lower Blood Pressure Targets Beneficial in Chronic Kidney Disease?

Intensive blood pressure reduction slows the progression of chronic kidney disease (CKD), but only in patients with proteinuria, suggests a meta-analysis in the Canadian Medical Association Journal.

A systematic review identified 11 randomized trials in which CKD patients were assigned to different blood pressure reduction targets. A meta-analysis included data on more than 9000 patients; blood pressure targets in the intervention groups varied widely. Outcomes of interest were a composite of doubling of serum creatinine level and a 50 percent decline in GFR, and the progression of ESRD.

Intensive blood pressure reduction was associated with a lower rate of both renal outcomes: hazard ratio 0.82 for the composite outcome and 0.79 for ESRD. However, there was a significant modifying effect of proteinuria. The reduction in kidney failure was significant only in patients with proteinuria at baseline: hazard ratio 0.73.

The effect on renal outcomes also appeared stronger in studies with lower markers of trial quality. The rates of cardiovascular events, all-cause mortality, and severe adverse events were similar between the intervention and usual care groups.

The current CKD guidelines recommend a blood pressure target of less than 130/80 mm Hg, but the strength of evidence behind this recommendation has been questioned. The new meta-analysis finds a reduced risk of kidney failure events with intensive blood pressure lowering, but mainly in patients with baseline proteinuria. Further study would be needed to show a similar protective effect in CKD patients without proteinuria [Lv J, et al. Effects of intensive blood pressure lowering on the progression of chronic kidney disease: a systematic review and meta-analysis. CMAJ 2013; 185:949–957].