BACKGROUND: Coronary artery calcification (CAC) is an important indicator of future coronary artery disease events. Since elevated blood pressure (BP) is an important predictor of CAC, genetic polymorphisms in the renin-angiotensin system and their interaction may play a role in explaining CAC quantity variation. MATERIAL/ METHODS: As part of the Epidemiology of Coronary Artery Calcification Study, 166 asymptomatic women and 166 asymptomatic men were genotyped for the insertion/deletion polymorphism in the angiotensin-converting enzyme (ACE) gene and the -6 promoter polymorphism of the angiotensinogen (AGT) gene. We used a novel method to detect gene-gene interaction and compared it to the standard two-way analysis of variance (ANOVA) method. RESULTS: Based on a two-way ANOVA model, there was no evidence for epistasis for either systolic BP or CAC in either men or women. However, using a novel method, we found evidence of significant gene-gene interaction in systolic BP in men and gene-gene interaction in both systolic BP levels and CAC quantity in women. CONCLUSIONS: Our study demonstrates that new methods of assessing epistasis maybe important in understanding the complex genetics of systolic blood pressure as well as subclinical coronary atherosclerosis.
BACKGROUND:Coronary artery calcification (CAC) is an important indicator of future coronary artery disease events. Since elevated blood pressure (BP) is an important predictor of CAC, genetic polymorphisms in the renin-angiotensin system and their interaction may play a role in explaining CAC quantity variation. MATERIAL/ METHODS: As part of the Epidemiology of Coronary Artery Calcification Study, 166 asymptomatic women and 166 asymptomatic men were genotyped for the insertion/deletion polymorphism in the angiotensin-converting enzyme (ACE) gene and the -6 promoter polymorphism of the angiotensinogen (AGT) gene. We used a novel method to detect gene-gene interaction and compared it to the standard two-way analysis of variance (ANOVA) method. RESULTS: Based on a two-way ANOVA model, there was no evidence for epistasis for either systolic BP or CAC in either men or women. However, using a novel method, we found evidence of significant gene-gene interaction in systolic BP in men and gene-gene interaction in both systolic BP levels and CAC quantity in women. CONCLUSIONS: Our study demonstrates that new methods of assessing epistasis maybe important in understanding the complex genetics of systolic blood pressure as well as subclinical coronary atherosclerosis.
Authors: Sharon L R Kardia; Yan V Sun; Sara C Hamon; Ruth Ann Barkley; Eric Boerwinkle; Stephen T Turner Journal: BMC Med Genet Date: 2007-09-13 Impact factor: 2.103