Kivipelto M et al. (2005) Obesity and vascular risk factors at midlife and the risk of dementia and Alzheimer disease. Arch Neurol 62: 1556–1560

Rovio S et al. (2005) Leisure-time physical activity at midlife and the risk of dementia and Alzheimer's disease. Lancet Neurol 4: 705–711

Two recent studies indicate that the development of dementia and Alzheimer's disease (AD) is affected by cardiovascular risk factors in mid life.

Researchers from Scandinavia re-examined 1,449 individuals aged 65–79 years from the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) study group, who had previously been recruited at mid life.

In the first study, the relationship between mid-life BMI and development of dementia or AD was investigated, as the association between clustering of vascular risk factors and disease development. Mid-life obesity was associated with an increased risk of dementia and AD. High total cholesterol, high systolic blood pressure and mid-life obesity were all significant risk factors for dementia, increasing the risk of its development approximately twofold. Combination of these risk factors had an additive effect, such that the odds ratio for individuals with all three risk factors was 6.21 (95% CI 1.94–19.92).

In a separate study, researchers looked at the association between leisure-time physical activity in mid life, and development of dementia or AD. Mid-life leisure-time physical activiy at least twice a week was associated with approximately 50% lower odds of developing dementia, and 60% lower odds of AD development, compared with a sedentary lifestyle in mid life.

These studies indicate that mid-life cardiovascular risk factors influence the risk of developing dementia and AD in later life, which might have important implications for preventive healthcare.