Comparing cognitive function in white Mexican & non-Hispanic white Americans with/without diabetes

Objectives
An association between type-2 diabetes mellitus and cognitive decline is well known. Additionally, type 2 diabetes is known to be more physically burdensome for minorities. However, the combined impact of both ethnicity and diabetes on cognition is still not clear.

Methods
Data from the 2014 Health and Retirement Study (HRS) was used in this study to compare the cognitive functioning of non-Hispanic White (n = 10,658) and White Mexican/Mexican American (n = 847) individuals, age 50+ years, with or without type 2 diabetes. Cognitive functioning was measured by a composite of three constructs (serial 7 s, immediate, delayed recall). Ethnic groups and diabetes status were examined concerning cognitive functioning.

Results
A Multivariate Analysis of Covariance (MANCOVA) indicated significant main effects for ethnicity (F(3,11,496) = 11.15, p < .001) and diabetes status (F(3,11,496) = 3.15, p < .024), with Mexican Americans and those with diabetes exhibiting worse cognitive performance than non-Hispanic Whites and individuals without diabetes. There were significant effects for all covariates. A step-wise multiple regression indicated that education, age, depression, ethnicity and diabetes status accounted for a combined 28.4% variance in the cognitive performance composite.

Conclusions
Results found that education contributes significantly to variation of cognitive performance. The impact of education could be related to various possibilities. However, the impact of health literacy is a likely component, which has a positive relationship with level of education. Individuals with higher health literacy are more conscientious in health actions (e.g., exhibit regular self-care, glucose monitoring, and foot care). Therefore, the study results indicate it is likely that the duration of diabetes, and diabetes management (e.g., effective control of blood glucose, blood pressure, and lipids), contributing to cognitive decline. Cognitive screening at routine doctor visits is encouraged, particularly for Mexican/Mexican Americans, as the current study found support for ethnic minority vulnerability to the negative impacts of diabetes.