Angiotensin-converting Enzyme Deletion Polymorphism is Associated with Essential Hypertension in Men with Higher Salt Intake

Background: Hypertension is etiologically associated with lifestyles and genetic factors. A number of investigations in various populations have shown discordant evidence on the association of the insertion-deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) gene with hypertension. However, there is no population study on hypertension, ACE gene and salt. This study explored whether the ACE I/D polymorphism is associated with essential hypertension in relation to dietary salt intake. Methods: A cross-sectional study was conducted on a total of 4,588 healthy male subjects aged 20 to 79 years. ACE genotypes were determined using polymerase chain reaction. Semi-quantitative questionnaire using weekly recall method was used to assess dietary salt intake. With regard to level of salt intake, subjects were divided into tertile groups. Results: The overall OR of ACE DD genotype for hypertension showed 29% increased risk (OR=1.29, 95% CI, 1.08 - 1.56) (p=0.003), with adjustment for age, body mass index, and impaired fasting glucose. According to salt intake, only a group consuming higher salt (more than 17 gram/day) showed that DD genotype was at increased risk for hypertension, having 48% increased risk in DD genotype than ID/II genotype (OR 1.48, 95% CI 1.06-2.05). Conclusions: Among Korean men studied, ACE DD genotype was at increased risk of hypertension in men consuming higher dietary salt. Finding suggests that ACE polymorphism may be one of the factors involved in the predisposition of hypertension, in men consuming high salt.