Major sign of kidney and heart damage often ignored: proteinuria
Many patients with too much protein in their urine - the earliest sign of kidney damage and a risk factor for heart disease - go untreated, according to new findings presented at the National Kidney Foundation's 2014 Spring Clinical Meetings.
The study, in hospitalized patients, also found that 41 percent of patients with this condition, called proteinuria, reported taking a common type of over-the-counter pain medication called non-steroidal anti-inflammatory drugs (NSAIDs), which can worsen kidney function.
"This gives us a huge opportunity to intervene and prevent kidney damage and cardiovascular mortality in patients that have chronic kidney disease," Vishesh Kumar, MD, a resident at Albany Medical College in Albany, New York, who led the new study, said. Proteinuria can be easily and effectively treated with several medications, including angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), spironolactone, diltiazem or verapamil, he noted. "It's very common and it's easy to fix," Dr. Kumar said. "And it's being ignored."
Dr. Kumar decided to conduct the study after noticing that many patients admitted to general medical floors of his hospital through the emergency room had proteinuria. To investigate how common proteinuria was, Dr. Kumar and colleagues at Albany Medical College and St. James Hospital in Chicago looked at 298 patients admitted to both hospitals. Forty percent had proteinuria on routine urinalysis. But just 37 percent of those with proteinuria were being treated for it. One third of the patients with proteinuria had hypertension, only 43 percent of whom were receiving treatment with an anti-proteinuric antihypertensive drug.
The finding that many patients with proteinuria were taking NSAIDs also represents a "huge opportunity" for intervention, Dr. Kumar said.
"We were very surprised by the findings," he said. "We've known for years that ACE inhibitors and ARBs slow the progression of kidney damage, but we were surprised by the fact that over 60 percent of the patients we looked at with confirmed proteinuria were not taking any of these drugs. We can have a major impact on reducing proteinuria in these patients."
Testing for proteinuria is very simple, explained Thomas Manley, director of scientific activities at the National Kidney Foundation, and involves placing a dipstick in a urine sample, and then performing a second test for confirmation. "The solution for this problem can be just as simple as recognizing the problem," he said.
"Chronic kidney disease is typically asymptomatic until the late stages; however, simple, inexpensive tests can be done to determine if you have kidney disease," said Manley. "Consistent with a number of other recent studies, these investigators found that kidney disease is often undetected, which means patients won't begin therapies that have been shown to slow the progression of kidney disease."
People in the following categories are at risk - those with diabetes, high blood pressure, family history of kidney failure or age over 60 - and should be tested, according to the National Kidney Foundation.