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.