Associations between Markers of Glucose and Insulin Function and Cognitive Function in Healthy African American Elders

Abstract

Background Glucose and insulin are important moderators of cognitive function. African Americans have poorer glycemic control across the glycemic spectrum and are at increased risk for type 2 diabetes and poor cognitive health. It is unclear which glucoregulatory markers predict cognitive function in this at-risk population. The purpose of this study was to examine the association between cognitive function and common markers of glucoregulation in non-diabetic African Americans elders. Methods Thirty-four, community-dwelling African Americans, aged 50-75 years completed cognitive testing and blood collection as part of a health screening assessment. Cognitive outcomes were composite scores derived from neuropsychological tests of executive function and verbal memory. Linear regression was used to examine relationships between cognitive composite scores and fasting blood levels of glucose, insulin, and hemoglobin A1C, with adjustments for age, education, body mass index, and antihypertensive medication use. Results Fasting plasma glucose was negatively associated with executive function (β=−0.41, p=0.03). There was a trend of an association between fasting plasma glucose and verbal memory (β=−0.34, p=0.06). Fasting insulin and hemoglobin A1c were not associated with cognitive function. Conclusion High non-diabetic fasting glucose levels were associated with poorer executive function and verbal memory. These results provide preliminary support for proactive glucose control in older African Americans even before glycemic criteria for type 2 diabetes are met. Our findings suggests that high-normal FPG levels may represent an early red-flag to signify increased risk of cognitive impairment or decline.

Impaired fasting blood glucose is associated to cognitive impairment and cerebral atrophy in middle-aged non-human primates

“…The origin of cerebral atrophy in lemurs has been explored in previous studies and a relationship between atrophy and intracellular amyloid deposition has been suggested [ 33 ], but this study was based on few animals. In humans, IFG is related to poor cognitive performance and to atrophy of hippocampus [ 16 – 17 , 19 , 34 ]. We thus assessed whether these parameters could be linked to atrophy in lemurs and found that it is probably the main factor leading to pathologic hippocampal/ septal atrophy and the associated cognitive alterations in lemurs.…”

“…IFG is a largely developed condition in middle-age healthy human [ 16 – 17 , 19 , 34 ]. It is related to poor cognitive performance and to atrophy of hippocampus [ 16 – 17 , 19 , 34 ], and concomitant to neuroinflammatory changes dependent on brain stress and NF-Kb [ 36 ]. It is thus critical to further evaluate this condition.…”

Brain Diabetes: The New Type 3 Diabetes

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Elevated Fasting Plasma Glucose Is Associated With an Increased Risk of MCI: A Community-Based Cross-Sectional Study

“…Shuangling Xiu et al (13) found that the elderly (community-dwelling participants aged ≥ 55 years) with impaired fasting glucose (IFG) had a lower performance on the MMSE test compared with subjects who had normal blood glucose. Jeannine S Skinner et al (14) found that high non-diabetic fasting glucose levels were associated with poorer verbal memory and executive function. However, Sai Tian et al did not find a link between fasting glucose and cognitive impairment (15).…”

“…Jeannine S Skinner et al. ( 14 ) found that high non-diabetic fasting glucose levels were associated with poorer verbal memory and executive function. However, Sai Tian et al.…”