The Randomized Olmesartan and Diabetes Microalbuminuria Prevention Study

The ROADMAP trial, or Randomized Olmesartan and Diabetes Microalbuminuria Prevention study, was conducted from 2004 to 2009 by clinical researchers in the United States, Germany, Japan, Poland, France, the Netherlands, Spain, and England. The investigators examined and followed nearly 4500 type 2 diabetes patients at 262 collaborating treatment centers in 19 European countries over the course of an average of 3.2 years (maximum follow up approximately 6 years). Their goal was to see the effect of the anti-hypertensive medication olmesartan on the prevention of microalbuminuria. It was the first large-scale trial of its kind.

Microalbuminuria and diabetes

Microalbuminuria is the presence of albumin, a type of protein, in the urine. It is indicative of kidney damage, representing the early stages of diabetic kidney disease or failure, but it is also a recognized risk factor for cardiovascular disease in diabetes patients. Diabetics are at particular risk of renal (i.e. kidney) complications because of scarring that occurs to the kidney’s filtration units over time in the presence of high blood glucose and increased blood pressure.

Olmesartan and hypertension

Olmesartanis used to treat hypertension, congestive heart failure, and diabetic nephropathy. It is an angiotensin II receptor antagonist, part of a class of drugs known as ARBs (angiotensin receptor blockers). ARBs block the actions of a member of the renin-angiotensin system, angiotensin II, the over-activity of which is one pathway leading to high blood pressure. These drugs, including olmesartan, lower blood pressure by preventing blood vessel contraction.

ROADMAP trial design

The study was a double-blind, randomized intervention trial to determine the safety and efficacy of treating diabetic patients with olmesartan medoxomil (40 mg daily) compared to placebo. Patients were followed up every 3 months for the occurrence of microalbuminuria as well as cardiovascular and renal problems. Full information about the exact primary and secondary endpoints, as well as the inclusion and exclusion criteria for patient enrollment, is available from the clinical trials database.

ROADMAP study findings

The initial findings of the study were presented at the American Society of Hypertension meeting in 2009. The full analysis of the study findings was published in the New England Journal of Medicine in March 2011 (read the ROADMAP study). The researchers found that some patients needed a second anti-hypertensive agent (that did not act via the renin-angiotensin system) to control blood pressure, but that the experimental group of type 2 diabetics receiving olmesartan had a significantly later onset of microalbuminuria, though nearly the same number in the experimental and placebo groups went on to develop the disorder. However, among patients with coronary artery disease, olmesartan resulted in more cardiovascular-related deaths. This potential risk factor should be investigated in additional studies, but the published work concluded the phase III trial, and in 2010 the FDA ruled that the benefits of the drug outweigh the risks.

Conflict of interest note: The trial was funded by Japanese pharmaceutical corporation Daiichi Sankyo. Sankyo markets olmesartan as Benicar.