Epsilon 4 allele of apolipoprotein E gene associates with lower blood pressure in young Japanese subjects: the Suita Study.

OBJECTIVES

The apolipoprotein epsilon 4 allele (APOE/epsilon 4) increases plasma cholesterol level and the risk for the late onset type of Alzheimer's disease. However, the correlation between hypertension and APOE/epsilon 4 has not yet been clarified. To examine the APOE/epsilon 4 effect in the general population of Japan, we performed a large genetic epidemiological survey (the Suita Study).

DESIGN AND METHODS

The Suita Study was a cohort study based on a random sample of 14,200 Japanese residents of Suita city. Subjects who gave informed consent for genetic analysis were recruited in the current study ( = 3997). APOE polymorphism was clearly determined by the TaqMan polymerase chain reaction method.

RESULTS

Subjects with APOE/epsilon 4 were significantly ( P < 0.03) more frequent (19.7%) in normotensives than in hypertensives (16.9%), the estimated odds ratio for hypertension (with APOE/epsilon 4 versus without APOE/epsilon 4) being 0.83 [95% confidence interval (CI), 0.70-0.98]. The significance of the association (OR = 0.64; 95% CI, 0.48-0.86) was increased in young subjects ( < or = 60 years old) but disappeared in old subjects. APOE/epsilon 4 also significantly contributed to a 2.9% increase of total cholesterol, 11.8% increase of triglyceride and 3.2% of decrease of high-density lipoprotein-cholesterol.

CONCLUSIONS

We concluded that APOE/epsilon 4 was associated with an increase of plasma lipid levels and with a decrease of systolic blood pressure. The final conclusion on whether APOE/epsilon 4 contributes to the risk for cardiovascular disease will be clarified by analysis of the cumulative incidence, which will be obtained in the future Suita Study.