Give your kidneys a break: lose some weight

(Agencies)
Updated: 2009-09-18 09:02

NEW YORK - Shedding some excess weight through diet, exercise or surgery may help obese adults with kidney disease ward off further decline in kidney function, research hints.

The kidneys filter waste products from the blood and excrete them in the urine. When damaged, their ability to perform these vital functions is reduced.

More than a third of US adults are either overweight or obese, putting them at increased risk for kidney trouble, not to mention heart trouble and diabetes. Weight loss has been shown to improve control of diabetes, lower blood pressure and cholesterol levels, and reduce the effects of heart disease.

To see if losing weight might also help protect the kidneys, Dr. Sankar Navaneethan, from Ohio's Cleveland Clinic, and colleagues pooled data from 13 studies that examined the impact on kidney function of weight loss achieved through diet, exercise, or surgery. They report their findings in an upcoming issue of the Clinical Journal of the American Society Nephrology.

The researchers found that, in obese adults with kidney disease, losing weight through diet and exercise reduced one hallmark of kidney damage - namely, excess excretion of protein in the urine - what doctors call "proteinuria."

Diet- and exercise-induced weight loss may also prevent additional decline in kidney function in obese adults with kidney disease, the researchers found.

Weight loss achieved through surgery, on the other hand, seems to help normalize the rate at which the kidneys filter waste products in obese adults with abnormally high filtration rates - a well-known risk factor for the development of kidney disease.

Currently more than 20 million Americans have chronic kidney disease and it's estimated that by 2015 there will be more than 700,000 people with the most advanced form of kidney disease known as end-stage renal disease or ESRD.

"The health care costs that are associated with this increase are staggering," Navaneethan and colleagues note.

In obese adults, weight loss may offer real benefits in terms of the kidneys, in addition to the heart-related benefits of shedding excess pounds, they conclude.