For patients with type 2 diabetes, a combination of 2 antihypertensive drugs reduces the risk of kidney disease by about 20% even in patients who don’t have high blood pressure, according to a new study.
“This research demonstrated that lowering blood pressure with an ACE inhibitor/diuretic combination prevents kidney complications,” said author Vlado Perkovic, PhD, The George Institute for International Health, Sydney, Australia.
The post hoc analysis was based on the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) study, which included 11,140 patients with type 2 diabetes.
Patients were randomised to receive either a combination of perindopril and indapamide, or a placebo. Although most of the patients had hypertension, 20% had normal blood pressure (<130/80 mm Hg).
Researchers followed up with both groups an average of four years later to compare rates of kidney disease events, ranging from a drop in kidney function to kidney failure.
The rate of kidney disease was 21% lower for patients receiving the combination drug therapy compared with those in the placebo group. In some patients who previously had early signs of diabetes-related kidney disease, kidney function returned to normal during treatment with the antihypertensive drugs.
The drug combination reduced kidney disease events even in patients who did not initially have high blood pressure. The lower the blood pressure level, the lower the risk of kidney disease — even at blood pressure levels below the currently accepted normal.
Although more research is needed, these results raise the possibility that patients with type 2 diabetes should be considered for antihypertensive treatment even if they have normal blood pressure.
The study has some important limitations, including the fact that it was a post hoc analysis of a previous clinical trial. “Most of the findings related to early manifestations of kidney disease and the study was not large enough to assess the impact of the intervention directly on the risk of kidney failure,” said Dr. Perkovic. “We could not separate out the impact of the blood pressure-lowering combination used, or prove whether it had any effects beyond its blood pressure-lowering effects.”
April 2009 issue of the Journal of the American Society of Nephrology