The findings of a report published in 2007 suggested that over 40% of older, community-living adults in the United States and Europe were vitamin D deficient. There is clinical evidence for a relationship between low serum 25-hydroxyvitamin D (25[OH] D) levels and cognitive dysfunction with aging. Although data in several small clinical studies showing such an association were equivocal, 3 of 4 large population-based cross-sectional studies reported a relationship between levels of serum 25(OH) D and cognitive dysfunction in the elderly. No prior prospective population-based studies have investigated the possible association between vitamin D status and incident dementia or cognitive decline.This prospective population-based study was designed to determine whether low serum levels of 25(OH) D were associated with an increased risk of substantial cognitive decline in an elderly population. Data were obtained from a sample of elderly individuals enrolled in the InCHIANTI study, a large, prospective cohort study conducted in Italy to identify risk factors for late-life disability. The study participants were 858 adults aged 65 years or older who had completed 1 or more follow-up cognitive assessment between 1998 and 2006, with follow-up every 3 years. Cognitive decline was assessed using 2 tests of cognitive function: the Mini-Mental State Examination (MMSE) and the Trail-Making Tests A and B; both were administered at baseline, with follow-up at 3 and 6 years. Substantial cognitive decline was defined with MMSE as a decrease in score of 3 or more points, and with Trails A and Trails B as scoring in the worst 10% of cognitive decline or having the testing discontinued.In multivariate logistic regression fully adjusted models, the relative risk (RR) of substantial cognitive decline on the MMSE among participants who were severely 25(OH) D deficient was 60% greater compared with those who were 25(OH) D sufficient (RR, 1.60; 95% confidence interval [CI], 1.19-2.00; P (value for linear trend) <0.02). In fully adjusted random-effects models, the MMSE score declined by an additional 0.3 points per year more among severely 25(OH) D deficient participants compared with those who were 25(OH) D sufficient. With the Trails B, severely vitamin D deficient participants were 31% more likely of having a substantial decline in cognitive performance scores compared to those with sufficient levels of vitamin D; the RR was 1.31, with a 95% CI of 1.03-1.51 (P (value for linear trend) < 0.04). No significant association was found between 25(OH) D levels and cognitive performance on Trails A.These findings are the first to show in a prospective study that low levels of vitamin D are associated with increased risk of substantial cognitive decline in an elderly population. The data suggest that tests of cognitive function may be useful in future prospective trials of vitamin D supplementation in the elderly.
Vitamin D and risk of cognitive decline in elderly persons
Cherubini A.
;
2011
Abstract
The findings of a report published in 2007 suggested that over 40% of older, community-living adults in the United States and Europe were vitamin D deficient. There is clinical evidence for a relationship between low serum 25-hydroxyvitamin D (25[OH] D) levels and cognitive dysfunction with aging. Although data in several small clinical studies showing such an association were equivocal, 3 of 4 large population-based cross-sectional studies reported a relationship between levels of serum 25(OH) D and cognitive dysfunction in the elderly. No prior prospective population-based studies have investigated the possible association between vitamin D status and incident dementia or cognitive decline.This prospective population-based study was designed to determine whether low serum levels of 25(OH) D were associated with an increased risk of substantial cognitive decline in an elderly population. Data were obtained from a sample of elderly individuals enrolled in the InCHIANTI study, a large, prospective cohort study conducted in Italy to identify risk factors for late-life disability. The study participants were 858 adults aged 65 years or older who had completed 1 or more follow-up cognitive assessment between 1998 and 2006, with follow-up every 3 years. Cognitive decline was assessed using 2 tests of cognitive function: the Mini-Mental State Examination (MMSE) and the Trail-Making Tests A and B; both were administered at baseline, with follow-up at 3 and 6 years. Substantial cognitive decline was defined with MMSE as a decrease in score of 3 or more points, and with Trails A and Trails B as scoring in the worst 10% of cognitive decline or having the testing discontinued.In multivariate logistic regression fully adjusted models, the relative risk (RR) of substantial cognitive decline on the MMSE among participants who were severely 25(OH) D deficient was 60% greater compared with those who were 25(OH) D sufficient (RR, 1.60; 95% confidence interval [CI], 1.19-2.00; P (value for linear trend) <0.02). In fully adjusted random-effects models, the MMSE score declined by an additional 0.3 points per year more among severely 25(OH) D deficient participants compared with those who were 25(OH) D sufficient. With the Trails B, severely vitamin D deficient participants were 31% more likely of having a substantial decline in cognitive performance scores compared to those with sufficient levels of vitamin D; the RR was 1.31, with a 95% CI of 1.03-1.51 (P (value for linear trend) < 0.04). No significant association was found between 25(OH) D levels and cognitive performance on Trails A.These findings are the first to show in a prospective study that low levels of vitamin D are associated with increased risk of substantial cognitive decline in an elderly population. The data suggest that tests of cognitive function may be useful in future prospective trials of vitamin D supplementation in the elderly.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
