Diabetes, disability, and dementia risk: Results from the Hispanic Established Populations for the Epidemiologic Studies of the Elderly (H-EPESE)

Ethnic and Racial Disparities in the Association between Type II Diabetes Mellitus and Dementia

Evidence in the literature suggests an association between Type 2 Diabetes Mellitus (T2DM) and dementia, but this relationship has not been studied in the most recently available nationally representative datasets. This retrospective, observational, cross-sectional study of adults (60+ years of age) seeks to investigate this association across racial and ethnic groups in the most recently available National Ambulatory Medical Care Survey (NAMCS) datasets. A multivariable logistic regression model is employed to investigate the association between T2DM and the diagnosis of dementia and assess disparities in racial and ethnic groups, while controlling for available covariates of interest. The analysis found no evidence of a relationship between T2DM and dementia even after adjusting for available covariates of interest (OR 1.13, 95% CI = 0.81-1.57). However, evidence of differences in the proportion with dementia was observed between ethnicities and race groups. Hispanic/Latinos were found to have more than double the odds of dementia compared to Non-Hispanic/Latinos (OR 2.08, 95% CI = 1.05-4.14), while the Other race group had 74% lower odds of dementia compared to the White race group (OR 0.26, 95% CI = 0.10-0.64). This study suggests that disparities in the risk of dementia remain for ethnic/racial groups. As minority populations continue to grow, educational and preventative measures for both diabetes and dementia are vital public health priorities. Perceptions of cognitive impairment, its association with T2DM, and the interventions needed to address the deficits may vary by culture and ethnic background; therefore, specific characteristics relevant to these populations should be further evaluated.

Sex Differences in Cognition Across Aging

Sex and gender differences are seen in cognitive disturbances in a variety of neurological and psychiatry diseases. Men are more likely to have cognitive symptoms in schizophrenia whereas women are more likely to have more severe cognitive symptoms with major depressive disorder and Alzheimer's disease. Thus, it is important to understand sex and gender differences in underlying cognitive abilities with and without disease. Sex differences are noted in performance across various cognitive domains - with males typically outperforming females in spatial tasks and females typically outperforming males in verbal tasks. Furthermore, there are striking sex differences in brain networks that are activated during cognitive tasks and in learning strategies. Although rarely studied, there are also sex differences in the trajectory of cognitive aging. It is important to pay attention to these sex differences as they inform researchers of potential differences in resilience to age-related cognitive decline and underlying mechanisms for both healthy and pathological cognitive aging, depending on sex. We review literature on the progressive neurodegenerative disorder, Alzheimer's disease, as an example of pathological cognitive aging in which human females show greater lifetime risk, neuropathology, and cognitive impairment, compared to human males. Not surprisingly, the relationships between sex and cognition, cognitive aging, and Alzheimer's disease are nuanced and multifaceted. As such, this chapter will end with a discussion of lifestyle factors, like education and diet, as modifiable factors that can alter cognitive aging by sex. Understanding how cognition changes across age and contributing factors, like sex differences, will be essential to improving care for older adults.