Missing Urine Tests Increases Risk for Chronic Kidney Disease

August 23, 2021 - Johns Hopkins Bloomberg School of Public Health researchers found that despite people with hypertension or diabetes having an increased risk of chronic kidney disease, individuals are typically not given a urine test to screen for the disease.

Researchers analyzed data on almost four million hypertension and diabetes patients around the world. Through the study, the team discovered that only about 4 percent of those with hypertension and 35 percent of those with diabetes had been screened for chronic kidney disease with an albuminuria test, a standard measure of protein in the urine.

“These results highlight the need to widen albuminuria testing for early detection of chronic kidney diseases—especially now that we have new and more effective treatments that could benefit these patients,” study first author Jung-Im Shin, MD, said in a press release.

Study senior author Josef Coresh, MD, added, “We’re really missing a huge number of chronic kidney disease cases that should be detected and treated, and apart from all the other downsides of letting it go untreated, there is the fact that COVID-19 outcomes are often much worse for people with kidney disease.”

According to the Centers for Disease Control and Prevention (CDC), about 37 million US adults have chronic kidney disease, although many remain unaware. Chronic kidney disease can easily go undetected, especially in the early stages. However, the disease often progresses undiagnosed to the point that kidney failure is unavoidable.

Testing for abnormally high protein levels in urine, a sign of kidney damage, is a trusted method of detecting potential chronic kidney disease. The clinically performed test is called the ACR test, which measures the level of albumin in a urine sample.

Medical associations recommend frequent ACR testing for people with diabetes. Patients with ACR levels of at least 30 mg/g, the threshold of albuminuria and a potential sign of early chronic kidney disease, be given medications to protect the kidneys.

Researchers believe that ACR testing in individuals with hypertension, another condition strongly associated with chronic kidney disease, would yield similar benefits for patients.

“There are new treatments for patients with albuminuria, including a class of drugs called SGLT2 inhibitors, which appear to be quite effective in protecting the kidneys as well as the cardiovascular system,” Shin, who is also an assistant professor in the Department of Epidemiology at the Bloomberg School said.

“Our findings suggest that albuminuria screening should be used much more often for detecting chronic kidney disease early, so that patients can benefit from earlier treatment.”

To determine how often patients with diabetes and hypertension were given ACR urine tests to detect albuminuria, researchers analyzed datasets including medical records for a total of 1,344,594 adults with diabetes and 2,334,461 adults who had hypertension but not diabetes.

The researchers found that only 4.1 percent of the hypertension patients and 35.1 percent of the diabetes patients have an ACR test done during the dataset’s two-year time window, even though the high-risk patients given the test showed high rates of albuminuria.

“We estimate that the number of patients with undetected ACR ≥30 mg/g was far greater than the number of detected cases—almost 20 times greater among the hypertension patients,” Coresh said.

By administering the test to high-risk patients such as those with hypertension or diabetes, providers can engage in chronic kidney disease prevention.