Determinants of Cognitive Change Over 1 Year in Older Adults With Type 1 Diabetes

Abstract

OBJECTIVE Older adults with type 1 diabetes (T1D) have a greater risk for cognitive decline, highlighting the need to identify risk factors for meaningful cognitive change using brief screening tools suitable for annual wellness examinations. RESEARCH DESIGN AND METHODS This study examined determinants of 1-year cognitive change in 74 older adults with T1D (mean age 70 ± 4 years; 47% female). Cognitive outcomes included the Montreal Cognitive Assessment (MoCA) and the Processing Speed Index (PSI) from the Wechsler Adult Intelligence Scale–Fourth Edition (WAIS-IV). Bivariate correlations and multiple regression analyses evaluated demographic, vascular, and diabetes-related predictors. RESULTS The mean MoCA change score was 0.1 (range −5 to 7; 23% with >1.73-point lower scores after 12 months), and the mean change on the WAIS-PSI was 2.5 (range −14 to 28). Greater MoCA decline was seen in participants with neuropathy (b = −1.19; SEb = 0.55; 95% CI −2.29 to −0.09; P = 0.04), partnered status (b = −1.15; SEb = 0.50; 95% CI −2.15 to −0.16; P = 0.02), and hypertension (b = −1.12; SEb = 0.50; 95% CI −2.13 to −0.12; P = 0.03), each reflecting an ∼1.1- to 1.2-point greater change relative to those without. Interval severe hypoglycemia (b = −6.73; SEb = 2.75; 95% CI −12.23 to −1.24; P = 0.02) and hypertension (b = −5.74; SEb = 2.02; 95% CI −9.77 to −1.70; P = 0.01) were associated with WAIS-IV PSI change scores. CONCLUSIONS Partnered status, older age, hypertension, neuropathy, and interval severe hypoglycemia predicted 1-year cognitive decline detectable with brief cognitive screening and processing speed measures, underscoring the importance of cognitive assessment and monitoring in older adults with T1D who present with these risk factors.