Combination antihypertensive can delay early sign of kidney disease, trial shows

One of the most common complications of type 2 (adult onset) diabetes is a type of kidney disease known as diabetic nephropathy, a condition where the kidneys become less and less efficient in eliminating toxins from the body in the urine.

A recent study has demonstrated that a combination of trandolapril, an angiotensin-converting enzyme (ACE) inhibitor, and verapamil, a calcium channel blocker, reduced the incidence of protein in the urine or microalbuminuria, an early indicator of kidney disease, compared with placebo (sugar pill).

The Bergamo Nephrologic Diabetes Complication Trial (BENEDICT), published in the New England Journal of Medicine, examined the effects of various combinations of the ACE inhibitor trandolapril and the nondihydropyridine calcium channel blocker verapamil during the onset of microalbuminuria in more than 1,200 patients with type 2 diabetes and hypertension for about three and a half years.

In addition, the study noted that the trandolapril/verapamil combination helped patients reduce blood pressure with fewer additional medications. Blood pressure reduction is also important to reduce the risk of kidney and cardiovascular diseases like heart attack and stroke.

The BENEDICT study results underscore the potential role of combination antihypertensive medicine in delaying the onset of microalbuminuria, which is an important treatment goal for individuals with hypertension and diabetes.

"Independent of blood pressure, the study showed that the combination of trandolapril and verapamil was able to reduce the incidence of kidney disease in the high risk diabetic hypertensive patients who, for all intents and purposes, have normal kidney function," said Dr. Loewe Go, a consultant at the Heart Institute of St. Luke’s Medical Center.

"Doctors do not have to wait for the early signs of kidney disease before treating patients with the right combination of drugs," Go said.

"The results of the BENEDICT trial are important because they support the role of an ACE inhibitor when used alone or as part of a combination such as trandolapril/verapamil to treat high blood pressure and reduce an early indicator of kidney and cardiovascular disease," said Dr. George Bakris, vice chairman of the Department of Preventive Medicine of Rush University Medical Center, Chicago.

By 2030, there will be about 370 million people worldwide with type 2 diabetes and approximately one-third of them will develop nephropathy and require dialysis therapy.

About 10,000 Filipinos suffer from end-stage renal disease each year, according to data from the National Kidney and Transplant Institute. More than half of the cases are due to diabetes and hypertension.

The trandolapril/verapamil combination in a fixed dose combination will soon be available as a prescription medicine.