Introduction: Hypoglycemia and cognitive impairment are major problems in older adults with diabetes. It is unknown whether persons with prior hypoglycemia have distinct patterns of cognitive impairment compared to persons without hypoglycemia.
Hypothesis: Compared to older adults with diabetes and no history of hypoglycemia, persons with prior hypoglycemia will have worse cognitive performance across all domains, but particularly in the executive function domain.
Methods: We conducted a cross-sectional analysis of older adults with diagnosed diabetes using data from the ARIC study (2011-2013). Participants completed eight cognitive tests that measured three domains: memory, language, and executive function. Cognitive impairment in each domain was defined as having at least one test score lower than 1.5 standard deviations below age-, race-, and education-specific norms. We identified prior severe hypoglycemic events through 2012 with ICD-9 codes from hospitalizations and emergency department visits. We used Poisson regression with robust standard errors to generate prevalence ratios (PR) adjusted for demographic and clinical characteristics.
Results: Among 1,867 adults with diagnosed diabetes: mean age 76 years, 56% female, 32% black, and 3% with prior hypoglycemia. In persons with prior hypoglycemia, 50% had cognitive impairment in at least one domain, compared to 43% in persons without prior hypoglycemia (p=0.24). After adjustment, persons with prior hypoglycemia were more likely to have worse performance in executive function (PR=1.73; 95% CI: 1.14-2.64) and language (PR=1.78; 95% CI: 1.08-2.93) but not memory (PR=1.19; 95% CI: 0.81-1.76) (Figure).
Conclusions: Persons with prior severe hypoglycemia are a unique subset of older adults with diabetes with greater cognitive deficits in the domains of executive function and language. Their cognitive impairment presents challenges for the management of their diabetes and the prevention of additional hypoglycemic episodes and cognitive decline.