Abstract MP05: Mid-Life Vitamin D Levels are Not Associated with Cognition and Dementia Risk in Whites and Blacks: the Atherosclerosis Risk in Communities (ARIC) Study
Introduction: Recent studies, mainly performed in elderly whites, suggest that vitamin D, measured by 25-hydroxyvitamin D [25(OH)D], is important for cognition. Less is known about the association of 25(OH)D measured in mid-life with cognition and dementia risk in whites and blacks.
Hypothesis: We hypothesized that lower concentrations of 25(OH)D would be associated cross-sectionally with lower cognitive test scores and prospectively with greater decline in cognitive test scores and with increased risk of dementia.
Methods: We conducted cross-sectional (1993-1995), change (1993-1995 to 2004-2006), and prospective (follow-up through 2010) analyses of 1,652 participants in the ARIC Brain Ancillary Study with measured 25(OH)D (1993-1995). 25(OH)D was analyzed in race-specific tertiles and continuously. Cognition was measured by 3 tests: Delayed Word Recall (DWR), Digit Symbol Substitution (DSS), and Word Fluency (WF). Dementia was defined by hospitalization ICD-9 codes. Adjusted race-stratified linear regression and Cox proportional hazards models were used.
Results: Mean age of participants was 62 years, 60% were female, and 48% were black. Mean 25(OH)D was higher in whites than blacks (25.5 versus 17.3 ng/ml, p<0.05). Over a median of 16.6 years, there were 145 incident hospitalized dementia cases. In prospective analyses, lower levels of 25(OH)D trended towards an association with increased dementia risk in whites and in blacks, but these results were not statistically significant (lowest versus highest tertile: whites, HR: 1.32 [95% CI: 0.69, 2.55]; blacks, HR: 1.53 [95% CI: 0.84, 2.79]) (Figure).
Conclusion: In contrast to prior studies performed in elderly populations, our study did not find significant associations between lower levels of 25(OH)D in mid-life with lower cognitive test scores at baseline, change in score over time, or increased dementia risk.
Author Disclosures: A.L. Schneider: None. P.L. Lutsey: None. A. Alonso: None. R.F. Gottesman: None. A.R. Sharrett: None. K.A. Carson: None. W.S. Post: None. D.S. Knopman: None. T.H. Mosley: None. E.D. Michos: None.
- © 2014 by American Heart Association, Inc.