Combined effects of APOE genotype, blood pressure, and antihypertensive drug use on incident AD.
OBJECTIVE
To study the hypotheses that APOE-epsilon4 allele may interact with blood pressure to affect Alzheimer's disease (AD) occurrence and that antihypertensive therapy could modify such an effect.


METHODS
A dementia-free cohort of 966 community-dwelling persons aged 75 years and older in Stockholm, Sweden was followed to detect patients with AD using the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition (DSM-III-R) diagnostic criteria. Data were analyzed using Cox proportional hazards models with adjustment for several potential confounders.


RESULTS
During a 6-year follow-up period, AD was diagnosed in 204 persons. APOE-epsilon4 allele, high systolic pressure (> or = 140 mm Hg), and low diastolic pressure (<70 mm Hg) were associated with an increased risk of AD. APOE-epsilon4 allele combined with low diastolic pressure greatly increased the risk of AD independent of antihypertensive drug use. Antihypertensive therapy significantly reduced the risk of AD regardless of APOE-epsilon4 status and counteracted the combined risk effect of the epsilon4 allele with high systolic pressure on the disease.


CONCLUSIONS
Elderly people with genetic susceptibility for Alzheimer's disease may experience a further increased disease risk if they have either high systolic pressure or low diastolic pressure. Antihypertensive therapy decreases the risk of Alzheimer's disease exerted by the APOE-epsilon4 allele.
Qiu
Chengxuan
C
Aging Research Center, Division of Geriatric Epidemiology and Medicine, Department of Neurotec, Karolinska Institutet and the Stockholm Gerontology Research Center, Stockholm, Sweden. chengxuan.qiu@neurotec.ki.se
Winblad
Bengt
B
Fastbom
Johan
J
Fratiglioni
Laura
L
D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000235:genetics / Q000517:prevention & control; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics*; D001794:Blood Pressure; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D015994:Incidence; D008297:Male; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology
D000959:Antihypertensive Agents; D053327:Apolipoprotein E4; D001057:Apolipoproteins E