Associations Between Diabetes and Cognitive Function in Socioeconomically Diverse African American and White Men and Women

Race and sex differences in the association between lifespan glycemic status and midlife cognitive function: the Bogalusa heart study

Introduction

Glycemic markers throughout life are associated with increased risk of midlife cognitive decline, yet it is unclear whether these associations differ by race and sex.

Methods

This study used cross-sectional analysis of prospectively maintained cohort. 1,295 participants in the Bogalusa Heart Study, a biracial epidemiological cohort located in a micropolitan area core setting, provided fasting plasma insulin (FPI) and glucose (FPG) biannually from 1973 to 2016. Memory, executive function (EF), attention, working memory (WM), and global cognition (GC), collected 2013-2016. Glycemic markers (i.e., FPG, FPI, and HOMA-IR) averaged within lifespan epochs (≤ 20 years, childhood/adolescence (C/A); 21-40 years, early adulthood (EA); and 40-58 years, midlife). Linear regression models were analyzed for each epoch and separate models were analyzed with sex and race, education as a covariate.

Results

Sample was 59% women, 34% African American (AA). Among women, higher C/A FPG was associated with poorer memory and poorer GC. Higher EA FPG was associated with poorer WM. Among men, higher EA HOMA-IR was associated with worse attention. Higher C/A HOMA-IR and FPI were associated with better memory, as was higher EA FPI. Among AA, higher C/A FPG was associated with worse attention, EF, and GC. Higher EA HOMA-IR was associated with worse attention. Higher midlife FPI and C/A HOMA-IR were associated with worse WM and EF among White Americans (WAs).

Discussion

Markers indicative of hyperglycemia at different epochs were associated with worse midlife cognition in women, AAs, and WAs; but not in men. Differences in the relationship between lifespan glycemic exposures and midlife cognition could reflect broader health disparities.

Explanatory role of sociodemographic, clinical, behavioral, and social factors on cognitive decline in older adults with diabetes

BACKGROUND

The aim of the study was to examine the explanatory role of sociodemographic, clinical, behavioral, and social factors on racial/ethnic differences in cognitive decline among adults with diabetes.

METHODS

Adults aged 50+ years with diabetes from the Health and Retirement Survey were assessed for cognitive function (normal, mild cognitive impairment [MCI], and dementia). Generalized estimating equation (GEE) logistic regression models were used to account for repeating measures over time. Models were adjusted for sociodemographic (gender, age, education, household income and assets), behavioral (smoking), clinical (ie. comorbidities, body mass index), and social (social support, loneliness, social participation, perceived constraints and perceived mastery on personal control) factors.

RESULTS

Unadjusted models showed non-Hispanic Blacks (NHB) and Hispanics were significantly more likely to progress from normal cognition to dementia (NHB OR: 2.99, 95%CI 2.35-3.81; Hispanic OR: 3.55, 95%CI 2.77-4.56), and normal cognition to MCI (NHB OR = 2.45, 95%CI 2.14-2.82; Hispanic OR = 2.49, 95%CI 2.13-2.90) compared to non-Hispanic Whites (NHW). Unadjusted models for the transition from mild cognitive decline to dementia showed Hispanics were more likely than NHW to progress (OR = 1.43, 95%CI 1.11-1.84). After adjusting for sociodemographic, clinical/behavioral, and social measures, NHB were 3.75 times more likely (95%CI 2.52-5.56) than NHW to reach dementia from normal cognition. NHB were 2.87 times more likely (95%CI 2.37-3.48) than NHW to reach MCI from normal. Hispanics were 1.72 times more likely (95%CI 1.17-2.52) than NHW to reach dementia from MCI.

CONCLUSION

Clinical/behavioral and social factors did not explain racial/ethnic disparities. Racial/ethnic disparities are less evident from MCI to dementia, emphasizing preventative measures/interventions before cognitive impairment onset are important.

Racial/Ethnic Disparities in Young Adulthood and Midlife Cardiovascular Risk Factors and Late-life Cognitive Domains: The Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study

BACKGROUND

Midlife cardiovascular risk factors (CVRF) increase dementia risk. Less is known about whether CVRF identified before midlife impact late-life cognition in diverse populations.

METHODS

Linear regression models examined hypertension, hyperlipidemia, and overweight/obesity at ages 30 to 59 with late-life executive function, semantic memory, verbal episodic memory, and global cognition in a cohort of Asians, blacks, Latinos, and whites (n=1127; mean age=75.8, range=65 to 98). Models adjusted for age at CVRF, age at cognitive assessment, sex, race/ethnicity, participant education, and parental education.

RESULTS

Overall, 34% had 1 CVRF at ages 30 to 59; 19% had 2+. Blacks (26%) and Latinos (23%) were more likely to have 2+ CVRF than Asians (14%) or whites (13%). Having 2+ CVRF was associated with lower global cognition [β=-0.33; 95% confidence interval (CI)=-0.45, -0.21], executive function (β=-0.26; 95% CI=-0.39, -0.13), verbal episodic memory (β=-0.34; 95% CI=-0.48, -0.20), and semantic memory (β=-0.20; 95% CI=-0.33, -0.07). Interaction by age (P=0.06) indicated overweight/obesity was negatively associated with executive function at ages 30 to 39 but not at ages 40 to 59. Race/ethnic-specific effects showed disparities in CVRF prevalence impact population disparities in late-life cognition.

CONCLUSION

Being overweight/obese in early adulthood and having 2+ CVRF in early adulthood/midlife are modifiable targets to redress racial/ethnic disparities in cognitive impairment and dementia.

The Contribution of Kidney Disease to Cognitive Impairment in Patients with Type 2 Diabetes

PURPOSE OF REVIEW

This review focuses on the relationships between diabetes, cognitive impairment, and the contribution of kidney disease.

RECENT FINDINGS

We review the independent contributions of parameters of kidney disease, including albuminuria, glomerular filtration, bone/mineral metabolism, and vitamin D synthesis, on cognitive performance in patients with diabetes. Potential pathophysiologic mechanisms underlying these associations are discussed highlighting gaps in existing knowledge. Finally, effects of the dialysis procedure on the brain and cognitive performance are considered. Emphasis is placed on novel non-invasive screening tools with the potential to preserve cerebral perfusion during hemodialysis and limit cognitive decline in patients with diabetic ESKD. Patients with type 2 diabetes and advanced chronic kidney disease suffer a higher prevalence of cognitive impairment. This is particularly true in patients with diabetes and end-stage kidney disease (ESKD).

Dementia and Cognitive Impairment Among U.S. Veterans With a History of MDD or PTSD: A Retrospective Cohort Study Based on Sex and Race

Objective: The aim of this study was to examine major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) diagnosed at age < 55 as predictors, and sex and race as potential moderators, of dementia and other forms of cognitive impairment. Method: Veterans (N = 4,800) aged ⩾ 56 years were grouped by psychiatric history, sex, and race. Hierarchical and stepwise regression were employed to determine significant predictors. Results: MDD and PTSD were associated with almost double the risk for developing dementia or cognitive impairment at age ⩾ 56. Sex, as a moderator, had small effects whereas race increased the risk almost twofold for Black veterans, given the presence of MDD history. Discussion: MDD and PTSD act as significant risk factors for dementia and other forms of cognitive impairment, and Black veterans, given a history of MDD, may be at an increased risk. An important endeavor for future research is to examine how this risk may vary across dementia subtypes and related conditions.

Type 2 diabetes and cognitive dysfunction in minorities: a review of the literature

OBJECTIVES

The purpose of this review was to summarize the current status of knowledge regarding cognitive dysfunction and diabetes in minorities. Literature on the interaction of cognitive dysfunction and diabetes was analyzed to (a) examine the number and characteristics of studies in minority populations; (b) identify tests used to assess cognitive function in diabetes; (c) consider the impact of diabetes on cognitive function; and (d) assess the moderators of the association between diabetes and cognitive function.

DESIGN

A literature review and thematic analysis was conducted. Studies were mapped to describe their design, target population, instruments used, and the physiologic, psychosocial, and socioeconomic findings related to cognitive function and diabetes. Twelve studies met the inclusion criteria.

RESULTS

Hispanics were studied more than any other ethnic group. Rates and degree of cognitive dysfunction were more prevalent in minorities than non-Hispanic whites. Overall, 28 different tests were administered to evaluate cognitive function. There was some variation among findings regarding the relationship of cognitive function and diabetes. Risk for cognitive decline was associated with the diagnosis of diabetes alone, regardless of whether the diabetes was treated or untreated. Higher rates of discrimination were associated with greater cognitive decline Conclusion: Given the context of minority health, there is a potential for higher negative health impact due to the increased prevalence of diabetes and cognitive dysfunction and other related health disparities. Reduction of physiological risk factors for diabetes, consistency in assessment, as well as elimination of structural barriers such as access to care should be helpful in decreasing the incidence of both diabetes and cognitive decline. More research is needed to determine whether the observed differences are modifiable and to identify factors involved in the interaction of diabetes and cognitive decline-not only physiological factors, but factors related to socioeconomic status and quality of life.

Things Are Changing so Fast: Integrative Technology for Preserving Cognitive Health and Community History

Background and Objectives

Multimodal interventions are increasingly targeting multiple cognitive decline risk factors. However, technology remains mostly adjunctive, largely prioritizes age relevancy over cultural relevancy, and often targets individual health without lasting, community-wide deliverables. Meanwhile, African Americans remain overburdened by cognitive risk factors yet underrepresented in cognitive health and technology studies. The Sharing History through Active Reminiscence and Photo-imagery (SHARP) program increases physical, social, and cognitive activity within a culturally meaningful context that produces community deliverables-an oral history archive and cognitive health education.

Design and Methods

The SHARP application was tested with 19 African Americans ≥55 years, aiming for an easy, integrative, and culturally meaningful experience. The application guided triads in walks 3 times weekly for 6 months in Portland, Oregon's historically Black neighborhoods; local historical images prompted recorded conversational reminiscence. Focus groups evaluated factors influencing technology acceptance-attitudes about technology, usefulness, usability, and relevance to integrating program goals. Thematic analysis guided qualitative interpretation.

Results

Technology acceptance was influenced by group learning, paper-copy replicas for reluctant users, ease of navigation, usefulness for integrating and engaging in health behaviors, relevance to integrating individual benefit and the community priority of preserving history amidst gentrification, and flexibility in how the community uses deliverables. Perceived community benefits sustained acceptance despite intermittent technology failure.

Discussion and Implications

We offer applicable considerations for brain health technology design, implementation, and deliverables that integrate modalities, age, and cultural relevance, and individual and community benefit for more meaningful, and thus more motivated community engagement.

Perceived cognitive deficits are associated with diabetes self-management in a multiethnic sample

Background

People with diabetes have almost twice the risk of developing cognitive impairment or dementia as do those without diabetes, and about half of older adults with diabetes will become functionally disabled or cognitively impaired. But diabetes requires complex self-management: patients must learn about the implications of their disease; manage their diets, physical activity, and medication; and monitor their blood glucose. Difficulties with cognition can hinder these activities.

Methods

The purpose of this study was to explore perceptions of cognitive ability in a multiethnic sample of persons with type 2 diabetes (T2DM). One hundred twenty participants completed surveys assessing perceived memory, executive function, diabetes self-management, and quality of life. Scores on the surveys were examined along with hemoglobin A1C levels and demographics.

Results

Scores for executive function were positively associated with self-reports of dietary adherence and blood glucose monitoring. Perceived memory ability was a significant predictor of quality of life, and executive function was a significant predictor of A1C.

Conclusions

Patients’ perceptions of their cognitive difficulties may assist health care providers in detection of patients’ deficiencies in performing diabetes self-management tasks. The relationships between cognitive difficulties and self-management found in this descriptive study suggest that research on the processes leading to cognitive changes in T2DM is needed, as are studies on how those processes affect diabetes self-management.

New directions for diabetes prevention and management in behavioral medicine

Accelerating diabetes rates have resulted in a global public health epidemic. Lifestyle change is a cornerstone of care, yet regimen demands may result in adherence difficulties. Distress, depression, and other psychosocial concerns are higher in those with diabetes. While interventions, such as the Diabetes Prevention Program appear to be effective, further research is needed to support the translation of interventions to prevent diabetes. Studies assessing optimal approaches to promoting effective decision making, coping and adherence are needed. More information is needed to evaluate the influence and potential of emerging technologies on intervention delivery and quality of life in children and adults with diabetes. Theoretically informed, interdisciplinary studies that consider ecological models are needed to develop a roadmap for policies and diabetes management recommendations. Reduction of diabetes-related health disparities is a critical area for future studies. Behavioral medicine scientists and practitioners are poised to address these and other proposed future research directions to advance diabetes prevention and management.

Challenges and Considerations Related to Studying Dementia in Blacks/African Americans

Blacks/African Americans have been reported to be ∼2-4 times more likely to develop clinical Alzheimer's disease (AD) compared to Whites. Unfortunately, study design challenges (e.g., recruitment bias), racism, mistrust of healthcare providers and biomedical researchers, confounders related to socioeconomic status, and other sources of bias are often ignored when interpreting differences in human subjects categorized by race. Failure to account for these factors can lead to misinterpretation of results, reification of race as biology, discrimination, and missed or delayed diagnoses. Here we provide a selected historical background, discuss challenges, present opportunities, and suggest considerations for studying health outcomes among racial/ethnic groups. We encourage neuroscientists to consider shifting away from using biologic determination to interpret data, and work instead toward a paradigm of incorporating both biological and socio-environmental factors known to affect health outcomes with the goal of understanding and improving dementia treatments for Blacks/African Americans and other underserved populations.

Cognitive decline following incident and preexisting diabetes mellitus in a population sample

OBJECTIVE

To examine if incident and preexisting diabetes mellitus (DM) were associated with cognitive decline among African Americans (AAs) and European Americans (EAs).

METHODS

Based on a prospective study of 7,740 older adults (mean age 72.3 years, 64% AA, 63% female), DM was ascertained by hypoglycemic medication use and Medicare claims during physician or hospital visits, and cognition by performance on a brief battery for executive functioning, episodic memory, and Mini-Mental State Examination (MMSE). Decline in composite and individual tests among those with incident DM, with preexisting DM, and without DM was studied using a linear mixed effects model with and without change point.

RESULTS

At baseline, 737 (15%) AAs and 269 (10%) EAs had preexisting DM. Another 721 (17%) AAs and 289 (12%) EAs had incident DM in old age. Following incident DM, cognitive decline increased by 36% among AAs and by 40% among EAs compared to those without DM. No significant difference was observed between AAs and EAs (p = 0.64). However, cognitive decline increased by 17% among AAs with preexisting DM compared to those without DM, but no increased decline was observed among EAs with preexisting DM. In secondary analyses, faster decline in executive functioning and episodic memory was observed following incident DM.

CONCLUSIONS

In old age, faster cognitive decline was present among AAs and EAs following incident DM, compared to cognitive decline prior to DM, and among those without DM. This underscores the need for stronger prevention and control of DM in old age.

Diabetes, Obesity, and the Brain: New Developments in Biobehavioral Medicine

Diabetes and obesity, two major public health concerns, are associated with increased risk for problems in multiple organ systems, including the central nervous system. The adverse effects of diabetes and obesity on cognitive functioning are increasingly well recognized. This special issue of Psychosomatic Medicine features the latest research linking diabetes, obesity, and brain structure, function, and metabolism and follows a special meeting on this topic organized by the American Psychosomatic Society in October 2013. Evidence for the increased prevalence of diabetes and obesity is reviewed as it relates to cognitive decline. These articles indicate that the age of onset of Type 1 diabetes may be relevant to future cognitive function and that disease duration of Type 2 diabetes and sociocultural factors are related to cognitive decline during the aging process. The hypothalamus and other neural circuits, notably the dopaminergic system that underlies feeding and reward-related aspects of food intake, are among the key factors involved in obesity. Research on the associations between obesity and cognitive function is described using the positive effects of weight reduction following bariatric surgery or behavioral methods. This special issue concludes with a conceptual framework for linking obesity and diabetes with accelerated cognitive decline as related to the aging process. The collection of articles highlights the importance of using a life span perspective to understand the influence of both Type 1 and Type 2 diabetes on brain metabolism, function, and structure. Moreover, these studies show that distressing environmental circumstances can adversely influence neurocognitive dysfunction associated with obesity and diabetes.