Abstract
Background :Results of prospective studies examining the association between 25 hydroxyvitamin D (25[OH]D) levels and cognitive decline have been inconsistent. We tested the hypothesis that lower 25(OH)D levels are associated with a greater likelihood of cognitive impairment and risk of cognitive decline.Methods :The study is a cross-sectional and longitudinal analysis of a prospective cohort of 6,257 community-dwelling elderly women followed for 4 years. Global cognitive function was measured by the Modified Mini-Mental State Examination and executive function was measured by Trail Making Test Part B (Trails B). Cognitive impairment at baseline was defined as a score >1.5 SD below the sample mean; cognitive decline was defined as decline from baseline to follow-up >1 SD from mean change in score. Results :Women with very low vitamin D levels had an increased odds of global cognitive impairment at baseline: odds ratio (95% confidence interval), 1.60 (1.05-2.42) for women with 25(OH)D <10 ng/mL (25 nmol/L) compared with those with 25(OH)D levels ≥30 ng/mL (75 nmol/L). Compared with women with baseline 25(OH)D level ≥30 ng/mL (75 nmol/L), women with lower levels had an increased risk of global cognitive decline: odds ratio (95% confidence interval), 1.58(1.12-2.22) for women with levels <10 ng/mL (25 nmol/L), and 1.31 (1.04-1.64) for those with levels 10-19.9 ng/mL (25-49 nmol/L). Levels of 25(OH)D were not associated with executive cognitive function. Conclusions :Low 25(OH)D levels among older women were associated with a higher odds of global cognitive impairment and a higher risk of global cognitive decline.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1092-1098 |
| Number of pages | 7 |
| Journal | Journals of Gerontology - Series A Biological Sciences and Medical Sciences |
| Volume | 67 A |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 2012 |
Bibliographical note
Funding Information:Role of the sponsor: The funding agencies had no direct role in the conduct of the study; the collection, management, analyses, and interpretation of the data; or preparation or approval of the manuscript. Disclosure: Ms. Paudel, Ms. Lui, Ms. Blackwell, Dr. Taylor, Dr. Rossom, Dr. Slinin, Dr. Hochberg, and Dr. Ensrud report no disclosures. Dr. Ishani receives grant support from the National Institutes of Health (NIH) and VA RR&D. Dr. Yaffe has served on the Alzheimer ’ s Association Scientific Plenary Committee, International Conference on Alzheimer ’ s Disease, Women’s Health Initiative OSMB committee, and Texas Alzheimer ’ s Advisory committee. She received funding for travel from the NIH, Alzheimer ’ s Association, American Academy of Neurology, Canadian Colloquium on Dementia, and Alzheimer ’ s Disease Research Centers of California. Dr. Yaffe has served as an Associate Editor for the American Journal of Geriatric Psychiatry. She received honoraria and/or consulting fees from Novartis, Posit Science, Inc., American Academy of Neurology, Drexel University, and Sidley Austin. Her research support is received from the U.S. Department of Defense, National Institutes of Health, National Alliance for Research on Schizophrenia and Depression, and an anonymous foundation.
Funding Information:
The Study of Osteoporotic Fractures is supported by National Institutes of Health funding. The National Institute on Aging provides support under the following grant numbers: AG05407, AR35582 , AG05394, AR35584 , AR35583 , AG005407, AG027576, AG005394, and AG027574.
Keywords
- Cognitive decline
- Cohort studies
- Executive function
- Risk factors in epidemiology
- Vitamin D