APOLIPOPROTEIN-E PHENOTYPES, DEMENTIA AND MORTALITY IN A PROSPECTIVE POPULATION-SAMPLE

OBJECTIVE: To study the relationships between apoE phenotypes, dementi a, and mortality. SETTING: A population-based study in Helsinki, Finla nd (the Helsinki Ageing Study). DESIGN: A prospective birth cohort stu dy with 5-year follow-up. PARTICIPANTS: A total of 550 subjects of thr ee birth cohorts of 75 (n = 182), 80 (n = 185), and 85 (n = 183) years of age. MEASUREMENTS: ApoE phenotype was determined from baseline blo od samples. The cognitive function of the subjects was tested at basel ine and at a 5-year follow-up using the Mini-Mental State Examination (MMSE) and the Clinical Dementia Rating (CDR). Diagnosis and type of d ementia were determined by a neurologist. The cohorts were followed fo r 5 years, and causes of death were determined. Cox proportional hazar ds model was used for survival analyses. Analyses were performed compa ring the apoE e4 allele and others. RESULTS: At baseline, the apoE e4 allele was found in 148 of 550 subjects (27%), in 24% of nondemented p ersons, in 51% of patients with probable or uncertain Alzheimer's dise ase (AD), and in 34% patients with vascular dementia. The CDR score wa s worse among subjects with an e4 allele compared with others at basel ine (P < .001) and after a 5-year follow-up (P = .007). The crude mort ality rates of subjects with and without an e4 allele were 48% (n = 71 ) and 37% (n = 148), respectively. After controlling for age and gende r, the hazard ratio of an e4 allele was 1.61 (95% CI, 1.21-2.14) for a ll-cause mortality, deaths caused by dementia 2.20 (95% CI, 1.03-4.72) , and presence of AD 3.24 (95% CI, 1.67-6.25). CONCLUSIONS: In a popul ation aged 75 to 85 years, the presence of an apoE e4 allele is associ ated with impaired cognitive function, clinical dementia, AD, and exce ss 5-year mortality resulting from dementia and all causes.