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An Ounce of Prevention for Kidney Disease

By Christine Grillo

As a Hopkins medical student in the 1980s, Josef Coresh saw a number of patients so debilitated by advanced stages of kidney and heart disease that he decided to devote himself to prevention. Mentored by Michael J. Klag, a pioneering kidney disease epidemiologist and now dean of the School, Coresh shifted the focus of his work to the epidemiology of chronic kidney disease (CKD). At the time, there were very few epidemiologists studying CKD, and some of his studies of the earlier stages of the disease were met with criticism.

With chronic kidney disease, patients undergo loss of kidney function over time. The symptoms of intermediate kidney loss are subtle—hypertension, anemia, bone disease and weight loss—and often they go unrecognized and undiagnosed. If the kidney disease advances to its end stage, in which 90 percent of kidney function is lost and they fail to filter blood adequately, dialysis or transplantation is the only means for staying alive.

By Coresh's estimate, more than 20 million Americans have chronic kidney disease, but only 1 in 10 people has been diagnosed. Recently Coresh, professor of Epidemiology, was selected to chair the U.S. Renal Data Survey (USRDS) scientific advisory committee. The USRDS tracks the number of dialysis and kidney transplantation patients over time, documenting their treatment and complications. According to the survey's data, end-stage renal disease has more than doubled since 1991, to over 472,000 patients, and projections show it continuing to rise, perhaps doubling again in the next decade. (Coresh documents the increase in "Prevalence of Chronic Kidney Disease in the United States," published November 7, 2007, in JAMA.) "Where we are today with chronic kidney disease," says Coresh, "is where hypertension was in the '70s."

We know that optimizing hypertension and diabetes treatments is critical to preventing CKD or its advancement. So why the increased prevalence of CKD? We have increasing data that the rise in obesity and diabetes is responsible in part. Also, more Americans are living longer, and more people are surviving heart attacks to experience end-organ failure, including heart and kidney failure.

If Coresh, MD, PhD, MHS '92, can promote earlier detection, providers will know to test for CKD more regularly. And they'll prescribe kidney-sensitive treatments for their patients, especially older adults and those who are likely to receive treatments and medication that can injure already compromised kidneys.

"Recognition is the big thing," says Coresh. "People know if they have hypertension, people know if they have diabetes—but they don't know if they have compromised kidney function." There is an unrecognized pool of people with CKD. His goal is to close the gap between the diagnosed few and the undiagnosed millions.