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- Lee, David M., et al.
(författare)
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Association between 25-hydroxyvitamin D levels and cognitive performance in middle-aged and older European men
- 2009
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Ingår i: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ. - 1468-330X .- 0022-3050. ; 80:7, s. 722-729
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although there is evidence that vitamin D inadequacy may be linked to adverse cognitive outcomes, results from studies on this topic have been inconsistent. The aim of this trial was to examine the association between 25-hydroxyvitamin D (25(OH) D) levels and cognitive performance in middle-aged and older European men. Methods: This population-based cross-sectional study included 3,369 men aged 40-79 years from eight centres enrolled in the European Male Ageing Study. Cognitive function was assessed using the Rey-Osterrieth Complex Figure (ROCF) test, the Camden Topographical Recognition Memory (CTRM) test and the Digit Symbol Substitution Test (DSST). Serum 25(OH) D levels were measured by radioimmunoassay. Additional assessments included measurement of physical activity, functional performance and mood/depression. Associations between cognitive function and 25(OH) D levels were explored using locally weighted and linear regression models. Results: In total, 3,133 men (mean (+/- SD) age 60 +/- 11 years) were included in the analysis. The mean (+/- SD) 25(OH) D concentration was 63 +/- 31 nmol/l. In age-adjusted linear regressions, high levels of 25(OH) D were associated with high scores on the copy component of the ROCF test (beta per 10 nmol/l = 0.096; 95% CI 0.049 to 0.144), the CTRM test (beta per 10 nmol/l= 0.075; 95% CI 0.026 to 0.124) and the DSST (beta per 10 nmol/l = 0.318; 95% CI 0.235 to 0.401). After adjusting for additional confounders, 25(OH) D levels were associated with only score on the DSST (beta per 10 nmol/l = 0.152; 95% CI 0.051 to 0.253). Locally weighted and spline regressions suggested the relationship between 25(OH) D concentration and cognitive function was most pronounced at 25(OH) D concentrations below 35 nmol/l. Conclusion: In this study, lower 25(OH) D levels were associated with poorer performance on the DSST. Further research is warranted to determine whether vitamin D sufficiency might have a role in preserving cognitive function in older adults.
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| 2. |
- Lee, David M., et al.
(författare)
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The association between different cognitive domains and age in a multi-centre study of middle-aged and older European men
- 2009
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Ingår i: International Journal of Geriatric Psychiatry. - : Wiley. - 1099-1166 .- 0885-6230. ; 24:11, s. 1257-1266
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Tidskriftsartikel (refereegranskat)abstract
- Objectives We determined levels of cognitive functioning in community dwelling men aged 40-79 (n = 3265) from eight European centres and investigated to what extent cognitive performance varied between centres, the association between different cognitive domains and age, educational level, co-morbidity and lifestyle factors and the respective contributions of centre and individual factors to cognitive performance. Methods Cognitive domains assessed were visuo-constructional ability and Visual memory (Rey-Osterrieth Complex Figure test, ROCF), topographical memory (Camden Topographical Recognition Memory test, CTRM) and processing speed (Digit-Symbol Substitution test, DSST). Results There were significant between-centre differences in all four cognitive test scores. Using multilevel linear regression analysis (MLRA), age, education, depression, physical performance and smoking were independent predictors of cognitive function and these variables explained 10-13% of the variation in cognitive scores between centres and 17-36% of the variation in scores between individuals within centres. Conclusion Our data suggest that although a proportion of the variance in cognitive function among European men is explained by individual level differences, a significant proportion is due to contextual phenomenon. Such contextual factors need to be considered when analysing multi-centre data and European men should not be treated as homogeneous when assessing cognitive performance using existing instruments. Copyright (C) 2009 John Wiley & Sons, Ltd.
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| 3. |
- Lee, David M., et al.
(författare)
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Vitamin D, parathyroid hormone and the metabolic syndrome in middle-aged and older European men
- 2009
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Ingår i: European Journal of Endocrinology. - 1479-683X. ; 161:6, s. 947-954
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Low serum 25-hydroxyviatmin D (25(OH)D) and elevated parathyroid hormone (PTH) levels have been linked to insulin resistance, the metabolic syndrome (MetS) and its components. Data in healthy, community-dwelling Europeans are lacking, and previous studies have not excluded subjects receiving drug treatments that may distort the relationship between 25(OH)D/PTH and MetS. The aim of our analysis was to examine the association of 25(OH)D and PTH with Adult Treatment Panel III-defined MetS in middle-aged and older European men Design: This was a population-based, cross-sectional study of 3369 men aged 40-79 years enrolled in the European Male Ageing Study. Results After exclusion of subjects with missing data. 3069 men with a mean (+/- S.D.) age of 60 +/- 11 years were included in the analysis. Age-adjusted 25(OH)D levels were inversely associated with waist circumference, systolic blood pressure (BP), triglycerides, and glucose (all P < 0.01) Age-adjusted PTH levels were only associated with waist and diastolic BP (both P < 0.05). After adjusting for age, centre, season and lifestyle factors the odds for MetS decreased across increasing 25(OH)D quintiles (odds ratios 0.48 (95% confidence intervals 0.36-0.64) highest versus lowest quintile. P-trend < 0.001). This relationship was unchanged after adjustment for PTH, but was attenuated after additional adjustment for homeostasis model assessment of insulin resistance (0.60 (0.47-0.78) P-trend < 0.001) There was no association between PTH and MetS. Conclusions: Our results demonstrate an inverse relationship between 25(OH)D levels and MetS, which is independent of several confounders and PTH. The relationship is partly explained by insulin resistance. The clinical significance of these observations warrants further study
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