Persistent Urinary Albumin May Indicate Risk for Cognitive Decline in Type II Diabetics
The chronic presence of albumin in the urine (albuminuria) of individuals with type II diabetes has been linked to a gradual decline in their ability to process information (i.e., cognitive decline).
Investigators at Kaiser Permanente of Georgia/Emory School of Medicine (Duluth, GA, USA) determined the level of albumin in urine samples obtained from participants in the Action to Control Cardiovascular Risk in Diabetes Memory in Diabetes Study. This study comprised 2,977 individuals with mean age 62.5 years who had been recruited from August 2003 to December 2005 and then followed through June 2009. The purpose of the study was to examine the association of intensive versus standard glucose control on cognitive function. Participants underwent three neuropsychologic tests at baseline, 20 months, and 40 months. Tests included information processing speed, verbal memory, and executive function. Urine albumin measurements were carried out in parallel with the memory tests.
Results revealed that participants with albuminuria at baseline and follow-up (persistent albuminuria) and participants with albuminuria at follow-up but none at baseline (progressive albuminuria) had greater percentage declines on information processing speed than participants without albuminuria at baseline and at follow-up (no albuminuria). Persistent albuminuria and progressive albuminuria were associated with about a 5% decline in information processing speed scores but not with verbal memory or executive function performance.
Senior author Dr. Joshua Barzilay, an endocrinologist at Kaiser Permanente, said, “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. 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.”
The study was published in the August 29, 2013, online edition of the Clinical Journal of the American Society of Nephrology.