[Causes and consequences of cognitive decline in the very elderly; the 'Leiden 85-plus Study'].

In view of the absolute and relative increase in the number of oldest old, it is important to identify the causes and consequences of disease in this group. One of the areas of focus in the 'Leiden 85-plus Study', a population-based prospective study amongst 85-year-olds in the Dutch town of Leiden, is therefore to study the causes and consequences of cognitive decline in the very elderly. Cognitive impairment is the main threat to independence in the oldest old; 85-year-old people with impaired cognitive function (prevalence: 35%) have a ten times greater risk of being limited in their activities of daily life. If this cognitive impairment could be prevented, a large proportion of the independence limitations in the general population could be prevented (population attributable risk: 70%). Limitations in cognitive functioning are strongly associated with the incidence of cardiovascular disease, as well as with a lower average HDL-cholesterol concentration and signs of inflammation. Vascular factors appear to be closely related to development of cognitive impairment in very elderly. Therefore, future therapeutic research will have to demonstrate to what extent influencing the cardiovascular risk factors can lead to the prevention of cognitive decline in the very elderly.