Barry I. Freedman, M.D., reports that many relatives in these families have silent kidney diseases that can be treated at early stages, leading to slowed progression or prevention of future dialysis treatments or kidney transplants.
"Physicians caring for patients with chronic kidney disease should consider focusing screening efforts on high-risk family members in an attempt to slow the exponential growth rate of kidney failure," said Freedman, nephrology section head.
According to the National Institute of Diabetes and Digestive and Kidney Diseases, the rate of end stage kidney disease jumped from 219 persons per million in 1991 to 334 per million in 2000.
"Family members of individuals with chronic kidney disease also have an increased prevalence of high blood pressure, diabetes, excess protein in the urine, and undetected kidney disease," Freedman said. Excess protein in the urine is a sign that kidney disease is present and also a major risk factor for heart attack and stroke.
The study was based on dialysis patients in North Carolina, South Carolina and Georgia, which comprise End-Stage Renal Disease (ESRD) Network 6 of the Center for Medicare and Medicaid Services, one of 18 ESRD Networks in the United States. As of Dec. 31, 2003, Network 6 had 28,980 patients with end-stage kidney disease, the largest total among all 18 ESRD Networks and "accounting for approximately 7 percent of the U.S. population of individuals receiving renal replacement therapy," Freedman said.
The researchers from Wake Forest, Emory University and ESRD Network 6 undertook the largest study of its type ever performed, collecting family history information from 25,883 newly treated dialysis patients in the region. Of these, 5,901 (22.8 percent) had other close family members also with end-stage kidney failure on dialysis.
"This report demonstrated the strikingly high rates of familial clustering of the severest forms of kidney disease," he said. Patients with kidney disease due to diabetes were most likely to have close relatives with kidney disease, followed by those with kidney disease caused by high blood pressure.
Because of this clustering, "close relatives might be at increased risk for the presence of undetected chronic kidney disease or conditions that predispose to chronic kidney disease," Freedman said. "Periodically screening family members for chronic kidney disease and risk factors may be appropriate."
He said that chronic kidney disease has a long pre-clinical period, during which there are no symptoms, but when it can be easily diagnosed using blood and urine tests and treatment can be started.
"Primary care physicians need to be aware of this familial clustering and consider screening the close relatives of dialysis patients for silent kidney disease," said Freedman, who is the John H. Felts III, M.D., Professor of Internal Medicine and Head of the Section on Nephrology.
Besides Freedman, other researchers included Scott Satko, M.D., from Wake Forest, Nataliya Volkova, M.P.H., J. Michael Soucie, Ph.D., Claudine Jurkovitz, M.D., and William McClellan, M.D., of Emory University, and Jenna Krisher, B.S., of ESRD Network 6/The Southeastern Kidney Council Inc., in Raleigh.
Wake Forest University Baptist Medical Center is an academic health system comprised of North Carolina Baptist Hospital and Wake Forest University Health Sciences, which operates the university's School of Medicine. The system comprises 1,187 acute care, psychiatric, rehabilitation and long-term care beds and is consistently ranked as one of "America's Best Hospitals" by U.S. News & World Report.