Abstract 14260: Mid-Life Vitamin D Levels Are Not Associated With 20-Year Cognitive Decline in Whites and Blacks: the Atherosclerosis Risk in Communities (ARIC) Study
Introduction: Prior studies, largely limited by short follow-up and the possibility of reverse causation, suggest that low vitamin D, measured by 25-hydroxyvitamin D [25(OH)D], is associated with cognitive decline. Less is known about the long-term associations of mid-life 25(OH)D levels with change in cognition among whites and blacks.
Hypothesis: We hypothesized that lower 25(OH)D would not be associated with greater decline in cognitive function over 20 years compared to higher 25(OH)D.
Methods: We conducted prospective (1990-1992 through 2011-2013) analyses of 13,044 ARIC participants with measured cognition and 25(OH)D at baseline. 25(OH)D was categorized as <20 ng/ml (deficient) versus ≥20 ng/ml. Cognition was measured by 3 tests at up to 3 time points (Delayed Word Recall, Digit Symbol Substitution, Word Fluency); these 3 tests were combined into global cognitive Z scores. Multiple imputation by chained equations were used to impute missing covariates and follow-up cognition data. Linear mixed-effects models adjusted for demographic, socioeconomic, and cardiovascular risk factors were used to estimate associations between 25(OH)D and 20-year global cognitive change. We formally tested for interaction by race.
Results: Mean age of participants was 57 years, 57% were female, 24% were black, and 32% had low 25(OH)D (<20 ng/mL). The adjusted average decline over a median of 20 years in global cognitive Z score was -0.75 (95% CI: -0.91, -0.60) among those with 25(OH)D <20 ng/ml and was -0.74 (95% CI: -0.88, -0.60) among those with 25(OH)D ≥20 ng/ml. The decline among those with 25(OH)D <20 ng/ml was not significantly greater than the decline among those with 25(OH)D ≥20 ng/ml (difference: -0.01 [95% CI: -0.06, 0.04]). Results did not differ by race (p-interaction=0.12) (Figure).
Conclusions: Our study did not find a significant association between lower 25(OH)D in mid-life with cognitive decline over 20 years, with no differences in this association by race.
Author Disclosures: A.L. Schneider: None. D. Zhao: None. P.L. Lutsey: None. R.F. Gottesman: None. A.R. Sharrett: None. A. Alonso: None. M. Gross: None. D. Knopman: None. T.H. Mosley: None. E. Selvin: None. E.D. Michos: Consultant/Advisory Board; Modest; Siemens Diagnostics.
- © 2016 by American Heart Association, Inc.