Does non-malignant hypertension cause renal insufficiency? Evidence-based perspective.

While it is clear that malignant hypertension damages the kidneys, the question of whether non-malignant hypertension actually causes renal insufficiency remains controversial. A recent meta-analysis of 10 randomized controlled trials of antihypertensive drug therapy showed that patients randomized to antihypertensive therapy (or more-intensive therapy) did not show a significant reduction in their risk of developing renal dysfunction (relative risk, 0.97; 95% confidence interval, 0.78-1.21; P=0.77). A review of the totality of the evidence shows that there is relatively weak support for the thesis that non-malignant hypertension itself is an important de-novo cause (initiator) of renal insufficiency (as opposed to being a promoter of existing renal disease, which is a well established fact). Failure to evaluate the possibility that pre-existing renal disease could explain any observed association between elevated blood pressure and subsequent loss of renal function is an important limitation of published studies.