By Amir Khan

Millions of people in Canada are unaware that they have chronic kidney disease, even when it progresses into the later stages, according to a study published today in the Canadian Medical Association Journal.

Researchers found that 12.5 percent of Canadian adults have chronic kidney disease, but only 5 percent of them have been diagnosed — which could be resulting in millions of preventable deaths, and adding billions of dollars to healthcare costs. In addition, researchers said, the numbers seen in the study mirror those that previous studies have shown in the United States, indicating that the problem isn’t unique to Canada. Approximately 10 percent of Americans have kidney disease, according to the U.S. Centers for Disease Control and Prevention.

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“Chronic kidney disease has been identified as a risk factor for death and cardiovascular-related morbidity and is a substantial burden on the health care system,” the researchers, led by Paul Arora MSc, a researcher with the Centre for Global Health Research in Toronto, wrote in the study. “Hemodialysis costs the Canadian health care system about $60,000 per patient per year of treatment.”

Researchers came up with the 12.5 percent number by extrapolating data on blood and urine samples from 3.689 people between the ages of 18 and 79. They found that a total of 2.9 million Canadians have kidney disease. Much of the diagnosis disconnect was credited to the fact that more than 70 percent of the people who probably have kidney disease did not have hypertension or diabetes, risk factors for the disease.

Chronic kidney disease symptoms include less-frequent urination, trouble sleeping and loss of appetite — symptoms that could indicate a number of conditions. Kidney function is typically tested in people with diabetes or hypertension, since they are at a higher risk, but for people who are not at high risk, testing is not routine, researchers said.

“Because most of these people did not have diabetes or hypertension, conditions most likely to prompt screening for kidney dysfunction, they may be easily missed based on current practices,” the researchers wrote in the study.

Many people aren’t diagnosed until kidney disease progresses to stage 4, the second to last stage, said Brian Radbill, MD, a nephrologist with Mount Sinai Hospital in New York City. By that time, it’s usually too late to treat.

People with early-stage kidney disease often don’t show any symptoms, which is also sometime true of people with later stage disease, said Dr. Radbill.

“When patients are diagnosed at an advanced stage, they are shocked to hear that they need to start thinking about a kidney transplant because they usually feel fine,” he said. More than 16,000 Americans received a kidney transplant in 2009, according to the U.S. Department of Health and Human Services, and the number is steadily increasing.

Instead of waiting for symptoms to appear, Radbill added, it would be better to focus on people who are risk for kidney disease, such as those who are obese, have high cholesterol or have a family history of the disease, and urge them to get screened.

“Any blood test will be able to tell if you have kidney disease,” he said, adding that there is no special test needed to diagnose chronic kidney disease.

Chronic kidney disease is typically treated by fixing the underlying condition, such as diabetes or hypertension. But for people who don’t have an underlying condition, being diagnosed early means they may be able to avoid a kidney transplant, Radbill explained. When caught early, the progression of the disease can be slowed with medications, such as ACE inhibitors.

“Catching it early means you can institute strategies to slow the progression,” he said. “It doesn’t mean you will be able to cure it, but you can treat it easier.”

Millions Have Chronic Kidney Disease But Don’t Know It, Study Finds” originally appeared on Everyday Health.