Treating Kidney Disease

When we have healthy kidneys, little or no protein appears in the urine. But protein in the urine -- technically called proteinuria -- is an early sign that our diabetes has damaged the kidney's filters. It's a strong risk factor for kidney failure where the only treatment is dialysis.

A progression from diabetes to proteinuria to kidney failure is anything but inevitable. Each step can be a heads up for change.

Now, new studies show that a drug commonly used to treat problems of circulation can also decrease proteinuria. The drug is pentoxifylline, sold under the brand names of Pentoxil and Trental.

This drug works by reducing inflammation and by making red blood cells more flexible, improving circulation in our body's smallest blood vessels. The studies appeared in the September issue of the American Journal of Kidney Diseases, the official journal of the National Kidney Foundation.

In one study, lead by Dr. Brendan B. McCormick of the Kidney Research Centre in Ontario, Canada, researchers pooled data from 10 earlier studies into a meta-analysis of 476 people with diabetes and proteinuria. They found that pentoxifylline substantially reduced proteinuria -- especially among those with the highest level of protein in their urine.

In the other study, lead by Dr. Tun-Jun Tsai of the renal division of the National Taiwan University Hospital in Taipei, Taiwan, researchers analyzed how well pentoxifylline worked together with an ACE inhibitor, losartan. After one year on the two drugs the 85 people with advanced kidney disease had an average of 40 percent less proteinuria.

Until now ACE inhibitors, commonly prescribed for high blood pressure, have been the first choice of many doctors to protect the kidneys of those of us who have diabetes. But many of us -- myself included -- can't tolerate ACE inhibitors because of their side effects. And ACE inhibitors often become less effective as time goes on.

The authors of both studies are careful to say that confirmation of their findings will require further studies. But now we may have another tool, if and when we need it, to help us avoid one of the most serious of the complications of diabetes.