O3‐02‐07: Blood pressure, apoe genotype, and dementia: The swedish brain power project

Population-based cross-sectional studies have shown an inverse association between blood pressure and risk of dementia. We sought to explore whether the inverse cross-sectional association varies by APOE genotype and antihypertensive therapy. We pooled data from the three community-based cross-sectional surveys, i.e., the Kungsholmen Project in Stockholm, the H-70 Study in Göteborg, and the Finnish CAIDE Study in Kuopio and Joensuu, in which dementia was diagnosed following the standard procedure and criteria (DSM-III-R or DSM-IV). Logistic regression analysis was performed to estimate the OR and 95% CI of dementia in association with blood pressure taking into account potential confounders. The analysis included a total number of 3976 subjects (mean age, 76.3 years; 70.8% women); of them, 331 (8.3%) were diagnosed with dementia. Multi-adjusted OR (95% CI) of dementia was 0.71 (0.55-0.92) for antihypertensive therapy, and 2.49 (1.86-3.33) for carrying the APOE ϵ4 allele. Overall, compared to the first quartile of systolic pressure, the multi-adjusted OR (95% CI) of dementia related to the second, third, and fourth quartile was 0.46 (0.33-0.65), 0.48 (0.33-0.69), and 0.34 (0.23-0.50), respectively (p for trend < 0.001); such an inverse association did not significantly vary by APOE ϵ4 status and use of antihypertensive drugs. By contrast, overall the quartile of diastolic pressure was not significantly associated with dementia. However, there was statistical interaction between the fourth quartile of diastolic pressure and use of antihypertensive drugs (p = 0.02), such that persons with higher diastolic pressure had a higher OR of dementia among non-users of antihypertensive drugs. Furthermore, there was a statistical interaction between the third quartile of diastolic pressure and the OR of dementia (p = 0.02), such that high diastolic pressure was related to an increased OR of dementia among ϵ4 allele carriers. There is an inversely cross-sectional association between systolic pressure and risk of dementia in the elderly; such an association does not vary by APOE genotype and antihypertensive treatment. However, elevated diastolic pressure is associated with an increased odds ratio of dementia among older adults who do not use antihypertensive drugs or who carry the APOE ϵ4 allele.