Cognition in Non-Demented Diabetic Older Adults

Abstract

Evidence links diabetes mellitus to cognitive impairment and increased risk of Alzheimer's disease (AD) and suggests that insulin therapy improves cognition. With an increasing percentage of the US elderly population at high risk for diabetes and AD, the evidence of an association between diabetes and poor cognition in non-demented elderly may have implications for diagnosis, prevention and treatment of cognitive decline including AD. In our study, we hypothesized that diabetic elders with normal cognition would demonstrate poorer cognitive outcomes than non-diabetic elders and that diabetic elders receiving diabetes treatment would demonstrate better outcomes than those not receiving treatment. Data were evaluated from the National Alzheimer's Coordinating Center's Uniform Data Set (UDS). The UDS consists of clinical and neuropsychological assessments of a sample of elderly research subjects recruited from thirty-one Alzheimer's Disease Centers nationwide. The UDS provides a unique opportunity to study cognition in a nationally recruited sample with structured neuropsychological tests. We examined the impact of diabetes and diabetes treatment on cognitive measures in 3421 elderly research subjects from 2005-2007 with normal cognition. We performed linear regression analyses to compare cognitive scores between diabetic subjects and non-diabetic subjects. Diabetic subjects had lower scores than non-diabetic subjects including attention, psychomotor function and executive function, but no differences in memory or semantic memory language. There was no association between diabetes treatment and cognitive scores. These subtle but significant cognitive deficits in diabetic subjects compared to non-diabetic subjects may contribute to difficulty with compliance with complex diabetes medication regimens. A specific role of diabetes as a risk for cognitive impairment will require longitudinal study.

Impact of type 2 diabetes mellitus on short term and working memory

“…[9] Nandipati et al in their study "Cognition in nondemented diabetic older adults" on 314 diabetic patients and normal subjects showed that cognitive functioning was significantly lower in diabetic subjects compared to nondiabetics with P = 0.01. [10] In the present study, all five memory tests scores were significantly decreased in diabetic patients (P < 0.001) when compared to normal subjects. The decrease in the scores in diabetes patients was may be due to hyperglycemia, [11] vascular disease, [12] hypoglycemia, [12] insulin resistance, [13] and amyloid deposition.…”

Blast Exposure, White Matter Integrity, and Cognitive Function in Iraq and Afghanistan Combat Veterans

“…An overall composite score was calculated by averaging the three domain scores. This approach to calculating domain and composite scores has been used by our group and others (45, 46) in studies evaluating cognitive functioning in mildly-impaired cohorts.…”

Executive Function in Adults With Type 2 Diabetes

“…In addition, other factors such as type of T2DM therapy and alcoholism have been proposed to affect the T2DM-EF association and were not included as moderators in this meta-analysis because of the limited number of studies reporting these sample characteristics. In the few studies examining the effect of medication, insulin therapy has been associated with a larger association of T2DM and EF than oral antihyperglycemics or diet therapy alone (40,49,53). It is therefore possible that medication type, and not T2DM duration, is significant in moderating the effect of T2DM on EF.…”