A study reported in The New England Journal of Medicine (volume 358, page 2433) sheds light on a promising new approach that is effective for treating diabetic nephropathy (kidney disease) -- a complication of long-term diabetes.
About 30 to 40% of people with type 1 diabetes and 20% of those with type 2 diabetes eventually develop some kidney damage, though by no means do all of them go on to kidney failure. The damage occurs in tiny blood vessels throughout the kidneys, which act as filters to remove waste products from the bloodstream.
High blood pressure (hypertension) worsens kidney disease (nephropathy), so controlling hypertension is an essential part of managing diabetic nephropathy. For many people, existing antihypertensive drugs fail to slow kidney damage, but the new drug aliskiren (Tekturna) may offer much-needed additional protection.
Researchers randomized a group of 599 people with diabetes, hypertension, and kidney disease: Half took 150 mg of Tekturna daily for three months, then 300 mg a day for the next three months; the other half received placebos. All took the antihypertensive drug losartan (Cozaar) in addition to drugs to lower blood pressure.
Participants taking Tekturna had reduced proteinuria (loss of protein in the urine) -- a sign of failing kidneys -- by 20%, on average. In addition, almost 25% of the Tekturna takers had a 50% reduction in protein loss in urine, compared with 13% of the placebo group. Little difference in blood pressure was seen between the two groups.
Many common antihypertensive drugs work by interfering with angiotensin, a chemical that raises blood pressure by constricting blood vessels. Tekturna also blocks renin, the enzyme that produces angiotensin.
