Serum 25-hydroxyvitamin D in Relation to Five Different Measures of Cognitive Functioning: Results of the Longitudinal Aging Study Amsterdam

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 257-280-Disorders of Vitamin D Metabolism & Action
Basic/Translational
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-258
Natasja M van Schoor*1, HC Comijs2 and Paul Lips3
1VU University Medical Center, EMGO Institute for Health and Care Research, Amsterdam, Netherlands, 2VU University Medical Center, Amsterdam, Netherlands, 3VU University Medical Centre, Amsterdam, Netherlands
Introduction: The vitamin D receptor is expressed in many different tissues suggesting a more widespread function than calcium homeostasis alone. The objective of this study is to examine both the cross-sectional and longitudinal association between serum 25(OH)D and five different measures of cognitive functioning in older persons.

Methods: The study was conducted among 1253 men and women aged 65 years and older of the Longitudinal Aging Study Amsterdam, an ongoing population-based cohort study. Serum 25(OH)D was determined using a competitive protein binding assay in 1995/6. Cognitive functioning was assessed in 1995/6 and 1998/9 using different tests: the Mini-Mental State Examination (MMSE, a measure for general cognitive functioning), Raven’s Coloured Progressive Matrices (RCPM, ability of nonverbal and abstract reasoning), the Coding Task (CT, information processing speed) and the 15 Words Test (15WT, immediate memory and delayed recall). The data were analyzed using linear regression analyses. For the MMSE, the following transformation was used to normalize the data: ln(31-MMSE).

Results: In total, 612 men and 641 women were included with a mean age of 75.4 (SD 6.5) years and a mean serum 25(OH)D level of 53.8 (SD 24.2) nmol/l. After adjustment for age, sex, season of blood collection, education, depression, chronic diseases and lifestyle variables, subjects with serum 25(OH)D levels below 25 nmol/l had significantly lower MMSE scores as compared with subjects having serum 25(OH)D levels >= 75 nmol/l in the cross-sectional analyses (beta of ln(31-MMSE)=0.161; p=0.018). In addition, subjects with serum 25(OH)D levels up to 50 nmol/l had significantly lower CT scores (beta=-2.764, p<0.001 for serum 25(OH)D<25 nmol/l; beta=-1.045, p=0.046 for serum 25(OH)D 25-50 nmol/l). For the other cognitive functions, no statistically significant associations were observed in the cross-sectional analyses. In the longitudinal analyses, no statistically significant associations were observed after adjustment for baseline cognitive functioning.

Conclusion: Although the MMSE and Coding Task were cross-sectionally associated with serum 25(OH)D, no longitudinal associations were observed. This does not support causality.

Nothing to Disclose: NMV, HC, PL

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm