A review of renal, cardiovascular and mortality endpoints in antihypertensive trials in diabetic patients

Renal disease is highly prevalent in people with type 2 diabetes, and co-existence with hypertension increases the risk of cardiac events and mortality. Despite many large randomized trials, controversies remain regarding optimal antihypertensive therapy in diabetic patients, including whether some classes of antihypertensive drugs have specific renal protective properties, and the relationships between renal, cardiovascular and mortality endpoints. In this article, we review landmark antihypertensive drug trials from the last two decades in patient populations composed, or including substantial proportions, of patients with type 2 diabetes. Several points emerge. Firstly, treatment effects can vary widely among different renal, cardiovascular and mortality endpoints. Secondly, combinations of antihypertensive drugs vary in their ability to prevent major renal and cardiovascular events, even if they produce similar reductions in blood pressure. Thirdly, simply adding further antihypertensive drugs may not improve outcomes, even if it produces further reductions in blood pressure. In most trials, a reduction in microalbuminuria was associated with evidence of renal protection, but further evidence is needed relating changes in proteinuria with cardiovascular risk. The study that aligns best with the current reappraisal of ESH guidelines, with regard to blood pressure goals, use of an adequate combination and simultaneously protecting the kidney and the cardiovascular system, is the ADVANCE study.