Angiotensin converting enzyme genetic polymorphism is not associated with hypertension in a cross-sectional sample of a Japanese population: The Shibata Study

Background The studies on the association of deletion/insertion (D/I) polym orphism of angiotensin converting enzyme (ACE) gene with blood pressure and hypertension reported contradictory results. Because there was no populati on-based study in Japan, we examine the hypothesized association in a cross -sectional sample of a Japanese cohort. Methods and results The blood pressure of 464 men and 876 women aged 40-80 years was measured, and their DNA was analyzed for ACE D/I genotypes. The p revalence of the D allele was 38.7 and 39.2% in men and women, respectively (overall 39%). There was a tendency for higher covariate (age, body mass i ndex, albuminuria, hematocrit, alcohol consumption, smoking, diabetes melli tus, ischemic heart disease and antihypertensive medication) adjusted mean levels of diastolic blood pressure for the DD genotype in men but not in wo men. However, this tendency disappeared after dichotomization of blood pres sure into diagnostic categories (normotension and hypertension). Results di d not differ when the subjects were divided into two age groups (less than or equal to 59 and greater than or equal to 60 years). Covariate-adjusted o dds ratios for hypertension for presence of the D allele were close to the null value of one. ACE genetic variation accounted for only 0.1 and 0.7% of the inter-individual variation in systolic and diastolic blood pressure in men. These estimates were 0.2 and 0.1%, respectively, in women. Conclusion Although there is a tendency of higher diastolic blood pressure in men with DD genotypes, there is no convincing evidence that ACE genotype s are associated with hypertension in this Japanese population.