Relationship Between Uncontrolled Diabetes and Cognition in Mexican American Elders

Hypothesis: Diabetes affects approximately 29.1 million Americans with Mexican Americans being twice as likely to be diagnosed with diabetes. Diabetes is considered a modifiable risk factor for Alzheimer’s disease and cognitive decline. Several studies have shown a link between diabetes and an increased risk of the progression from mild cognitive impairment to Alzheimer’s disease. Although diabetes’ role in cognition is an emerging topic, the majority of research examining diabetes and cognition has focused on non-Hispanic populations. The purpose of this research was to examine the impact of diabetic control on cognition in Mexican Americans. This study was designed to evaluate differences in cognition among controlled and uncontrolled diabetics without cognitive impairment. Past research analyzing the effects of glycemic control on cognition have shown that adults with normal cognition and high HbA1c performed worse on memory and cognition tests than their lower HbA1c counterparts. Methods: Data were obtained from 171 Mexican American participants with diabetes (61 uncontrolled; 110 controlled) enrolled in the Health and Aging Brain among Latino Elders (HABLE) study, a longitudinal study of cognition in elderly Mexican Americans. All participants were classified as having normal cognition. Uncontrolled diabetes was defined as HbA1C levels 9 or greater. Fasting venous blood was drawn from study participants to obtain HbA1C levels and measure long term glycemic control. Cognition level was determined by participant performance on multiple neuropsychological tests evaluating numerous domains of memory: visuospatial, attention, immediate memory, delayed memory and executive function. Results: Independent t tests were conducted to compare cognition among controlled and uncontrolled diabetics. Uncontrolled diabetics performed worse on WMS digit span t(167)=2.1, p Conclusions: Uncontrolled diabetes was associated with poorer performance in the areas of attention and executive functioning among cognitively normal Mexican Americans. No differences were found in immediate and delayed memory, and visuospatial scores. Ongoing work will determine if these links are associated with neuroimaging and other biomarker signatures that may identify those Mexican Americans at greatest risk for cognitive loss associated with poor diabetic control.