Glycemic Control, Cognitive Aging, and Impairment Among Diverse Hispanics/Latinos: Study of Latinos-Investigation of Neurocognitive Aging (Hispanic Community Health Study/Study of Latinos).

OBJECTIVE: Hispanics/Latinos in the United States have the highest prevalence of undiagnosed and untreated diabetes and are at increased risk for cognitive impairment. In this study, we examine glycemic control in relation to cognitive aging and impairment in a large prospective cohort of middle-aged and older Hispanics/Latinos of diverse heritages.

RESEARCH DESIGN AND METHODS: Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) is a Hispanic Community Health Study/Study of Latinos (HCHS/SOL) ancillary study. HCHS/SOL is a multisite (Bronx, NY; Chicago, IL; Miami, FL; and San Diego, CA), probability sampled prospective cohort study. SOL-INCA enrolled 6,377 diverse Hispanics/Latinos age 50 years and older (2016-2018). The primary outcomes were cognitive function, 7-year cognitive decline and mild cognitive impairment (MCI). The primary glycemia exposure variables were measured from fasting blood samples collected at HCHS/SOL visit 1 (2008-2011).

RESULTS: Visit 1 mean age was 56.5 years ± 8.2 SD, and the average glycosylated hemoglobin A1C (HbA1c) was 6.12% (43.5 ± 14.6 mmol/mol). After covariates adjustment, higher HbA1c was associated with accelerated 7-year global (b = -0.045; 95% CI = -0.070; -0.021; in z-score units) and executive cognitive decline, and a higher prevalence of MCI (odds ratio = 1.20; 95% CI = 1.11;1.29).

CONCLUSIONS: Elevated HbA1c levels were associated with 7-year executive cognitive decline and increased MCI risk among diverse middle-aged and older Hispanics/Latinos. Our findings indicate that poor glycemic control in midlife may pose significant risks for cognitive decline and MCI later in life among Hispanics/Latinos of diverse heritages.