Urine May Give Sign of Mental Decline

Diabetes patients may be at risk of cognitive decline if protein persists in urine

(RxWiki News) Urine can tell us a lot about the health of a person. Doctors once tasted it for sweetness as a way to detect diabetes, and today, physicians use it to help diagnose a range of serious health problems.

Hundreds of years ago, doctors would actually ingest a bit of urine to diagnose diabetes because those with the disease would have extra sugar (glucose) in their urine. While blood tests have replaced the “taste test” as the prime method for diagnosing diabetes, urine exams remain important diagnostic tools in helping those with diabetes find life-threatening kidney and heart problems.

A new study has discovered that a simple urine test may help identify diabetes patients who are at risk of mental decline.

"Consider urine tests to detect possible kidney and heart problems."

Joshua Barzilay, MD, with the Division of Endocrinology at Kaiser Permanente and a professor at Emory School of Medicine in Atlanta, Georgia, collaborated with Lenore Launer, PhD, with the National Institute on Aging, and colleagues to evaluate if a protein excretion in the urine may predict cognitive decline in older adults with diabetes.

Up to about one-third of adults with diabetes between age 60 to 65 years old have a protein called albumin in their urine, according to Dr. Barzilay. The condition is called albuminuria.

Consistent albuminuria is a sign that the kidneys are damaged. High blood sugar from diabetes can overwork the kidneys. These organs filter waste products from the blood and rid the body of them through the urine. Protein is a useful substance that healthy kidneys do not normally filter from the body.

If tiny blood vessels in the kidneys become damaged, however, they start to leak useful protein into the urine.

Diabetes patients who control their blood sugar and blood pressure (often with blood pressure-lowering pills) may be able to avoid or delay kidney and heart disease.

Because albuminuria is a common condition among diabetes patients, doctors routinely check urine for this protein.

Dr. Barzilay told dailyRx News, “The presence of protein indicates leakiness in the small blood vessels of the kidney, but it may also suggest the presence of similar small blood vessel disease in the brain which can ultimately lead to increased risk of cognitive decline.”

For four to six years, Dr. Barzilay and his colleagues followed 2,977 diabetes patients with an average age of 62.

Participants were given three neuropsychological tests — one at the start of the study, a second at 20 months and a third at 40 months. They were tested on their information processing speed, verbal memory and executive function (a group of mental tasks that included organizing, strategizing, planning and setting goals).

Over four to five years, information processing speed in individuals with persistent albuminuria declined by a greater percentage than in participants without albuminuria.

Persistent and progressive albuminuria was linked with a greater than 5 percent decline in information processing speed scores. The condition, however, did not seem to affect verbal memory or executive function performance.

“Our finding was a subtle change in cognition; however, were this decline to continue over 10 to 15 years it could translate into noticeable cognitive decline by the age of 75 to 80 years, when cognitive impairment generally becomes clinically evident,” said Dr. Barzilay in a press release.

“Given how common albuminuria and diabetes are in the older population, these findings have a great deal of importance from a population point of view. Moreover, albuminuria is also common among older people with hypertension without diabetes,” he said.

The study was published on August 29 in the Clinical Journal of the American Society of Nephrology (CJASN). The work was funded by the National Institutes of Health and the National Institute on Aging.

Review Date: 
August 29, 2013