Finding that about one in 10 adult Americans suffer from chronic kidney disease, researchers have called upon patients and doctors to look for early signs so they can prevent potentially fatal complications.
Researchers from the Johns Hopkins Bloomberg School of Public Health said doctors should be attuned to the early signs, which can be gleaned from routine blood and urine tests. Early treatment can stave off heart attacks or the need for dialysis or kidney transplants.
"At the early stages, there are a number of measures that can slow the progression of kidney diseases and possibly improve quality of life and decrease the risk of heart attacks," said Dr. Josef Coresh, lead author of a study that appears in this month's American Journal of Kidney Disease.
Such measures include better nutrition and medications to control hypertension and diabetes, two conditions that trigger and complicate kidney disease. Overweight patients can also try to lose weight because obesity is a major factor behind the epidemic of diabetes.
Researchers based their estimate that 11 percent of the adult population suffers from kidney disease - ranging from mild to severe - on blood and urine samples supplied by 15,625 people participating in a national health survey.
Coresh said the high rate can be explained in part by the epidemic of diabetes and the aging of the population. The risk of kidney disease is known to increase with age.
"It's a combination of things, but I'm not sure we understand it completely," he said. "It's not clear that kidney function has to decrease with age."
An impaired kidney loses its ability to filter toxins from the blood. The study found that about 4 percent of adults, about 8 million people, have less than half the normal kidney function of a young adult. This low level is thought to be present in about one out of five Americans older than 65.
Coresh said the study gives the first solid estimate of how common the disease is in the United States.
But public health experts have been aware that the disease has been on the rise in part because of the steady increase in people needing dialysis or kidney transplants. Three years ago, about 340,000 patients needed dialysis or a transplant. The number is expected to increase to 651,000 by 2010.
The National Institutes of Health recently launched an educational program aimed at increasing awareness of the problem. Also, the National Kidney Foundation released clinical guidelines last year aimed at helping doctors recognize the disease in its early stages.