Physical activity and dementia risk in the elderly: findings from a prospective Italian study.

OBJECTIVE: To examine the effect of physical activity on risk of developing Alzheimer disease (AD) and vascular dementia (VaD) in the elderly. METHODS: Data are from a prospective population-based cohort of 749 Italian subjects aged 65 and older who, in 1999/2000, were cognitively normal at an extensive assessment for clinically overt and preclinical dementia and, in 2003/2004, underwent follow-up for incident dementia. Baseline physical activity was measured as energy expenditure on activities of different intensity (walking, stair climbing, moderate activities, vigorous activities, and total physical activity). RESULTS: Over 3.9 +/- 0.7 years of follow-up there were 86 incident dementia cases (54 AD, 27 VaD). After adjustment for sociodemographic and genetic confounders, VaD risk was significantly lower for the upper tertiles of walking (hazard ratio [HR] 0.27, 95% CI 0.12 to 0.63), moderate (HR 0.29, 95% CI 0.12 to 0.66), and total physical activity (HR 0.24, 95% 0.11 to 0.56) compared to the corresponding lowest tertile. The association persisted after accounting for vascular risk factors and overall health status. After adjustment for sociodemographic and genetic confounders, AD risk was not associated with measures of physical activity and results did not change after further adjustment for vascular risk factors and overall health and functional status. CONCLUSIONS: In this cohort, physical activity is associated with a lower risk of vascular dementia but not of Alzheimer disease. Further research is needed about the biologic mechanisms operating between physical activity and cognition.

Atrial fibrillation and risk of dementia in non-demented elderly subjects with and without mild cognitive impairment (MCI).

MCI is regarded as a precursor of dementia, but not all patients with MCI actually develop dementia. As Alzheimer and vascular dementia (AD and VD, respectively) are thought to share many common etiopathogenetic mechanisms, we investigated whether the vascular risk factor atrial fibrillation affect the risk of conversion to dementia for different MCI subtypes diagnosed according to international criteria. One-hundred-eighty elderly outpatients with MCI and 431 elderly outpatients with a normal cognition were followed-up for a mean of 3 and 4 years, respectively. The risk of conversion to dementia associated with atrial fibrillation was studied in both samples using a Cox proportional-hazards model adjusted for sociodemographic and medical variables. Overall conversion rate to dementia was 10.5 (8.0-13.8) per 100 person-years in the MCI group and 2.2 (1.5-3.1) per 100 person-years in the normal cognition group. Atrial fibrillation was significantly associated with conversion to dementia (hazard ratio=HR=4.63, 95% confidence interval=Cl=1.72-12.46) in the MCI group, but not in the cognitively normal group (HR=1.10, 95% Cl=0.40-3.03). Current diagnostic criteria for MCI subtypes define heterogeneous populations, but atrial fibrillation can be useful in identifying people with increased risk of conversion to dementia.

Risk factors for dementia: data from the Conselice study of brain aging.

Among the age-related diseases, the development of cognitive impairments, in particular dementia, is the most devastating for the individual and has great social and healthcare costs. Accurate information is needed about the prevalence and incidence of cognitive disorders and the physiology of the aging brain. In particular, only scarce data are available about the relationship between aging, cognitive status and nutritional factors. In order to address these issues, we planned the Conselice Study, a longitudinal study of physiological and pathological brain aging. The center involved in the study was the municipality of Conselice, (Province of Ravenna), in the Northern-Italian Region Emilia-Romagna. A total of 1,016 subjects aged 65 years and over was enrolled at baseline. Information about cognitive status at 4-years of follow-up was collected from 940 of them. These data have been used to estimate prevalence and incidence of dementia in the elderly Italian population and to investigate the possible role of homocysteine as a predictor of dementia.