Cardiovascular risk factors and dementia mortality: 40 years of follow-up in the Seven Countries Study

Abstract

Previous research shows that cardiovascular risk factors in mid-adulthood could increase the risk of dementia later in life, but studies with very long follow-up are still scarce. We assessed whether cardiovascular risk factors measured in midlife were associated with dementia mortality during a 40-year follow-up. 10,211 men, aged 40-59 at baseline, from 13 cohorts of the Seven Countries Study were followed for 40 years. Information on cardiovascular risk factors was obtained at baseline from questionnaires and a physical examination. Dementia death was assigned if there was any mention of dementia on the death certificate. Associations between cardiovascular risk factors and death from dementia were estimated through Cox proportional hazards models. We identified 160 dementia deaths during the follow-up. Smoking, hypercholesterolemia, high blood pressure, low forced vital capacity and previous history of cardiovascular disease at baseline were associated with a higher risk of death from dementia in the follow-up. The hazard ratio (HR) of dementia death among heavy smokers was 1.58 (95% confidence interval (CI) 1.03, 2.43) compared to non-smokers. Similarly, the HR (95% CI) among those with systolic BP>or=160 or diastolic BP>or=95 mm Hg compared to normotensives (<140/90) was 1.55 (1.02, 2.35). Individuals with the largest forced vital capacity had a lower risk of dying of dementia (HR 0.54, 95% CI 0.30, 0.98). Finally, total serum cholesterol was directly associated with higher risk of dementia mortality (p for trend=0.03). In men, cardiovascular risk factors in midlife are associated with increased risk of dementia death later in life.