Cognitive Dysfunction and Physical Disability Are Associated with Mortality in Extremely Elderly Patients

Abstract

A few reports have demonstrated that cognitive or physical dysfunction is associated with increased mortality in very elderly patients, those over 80 years of age. Using simple clinical tests, we evaluated the impact of cognitive or physical dysfunction on future total and cardiovascular deaths. We conducted a multicenter prospective study of 523 extremely elderly outpatients, aged > or = 80 years (mean +/- SD age: 84 +/- 5.3 years). These patients had normal activities of daily living at baseline. They were followed for an average of 34 months (range: 3-70 months), after which the total and cardiovascular deaths were evaluated. Cognitive and physical functions were evaluated by a short-term memory test using visual working memory and the get-up-and-go test, respectively. Seventy-five deaths, including 36 cardiovascular deaths, occurred during the follow-up period. In a Cox regression analysis model controlling for age, sex, body mass index (BMI), diastolic blood pressure (BP), cholesterol level, and history of cardiovascular diseases, cognitive dysfunction was found to be an independent risk factor for total death (p < 0.001), and cognitive dysfunction (p < 0.001) and physical dysfunction (p = 0.05) were independent risk factors for cardiovascular death. The determinants of cognitive dysfunction were associated with a lower diastolic BP (p = 0.04) adjusted for age, BMI, and a history of cardiovascular disease. Cognitive function, which was associated with lower BP levels, and physical function were the independent predictors of total and cardiovascular mortality among all cardiovascular risk factors in the very elderly, those at least 80 years of age.