Renal Function Dependent Association of AGTR1 Polymorphism (A1166C) and Electrocardiographic Left-Ventricular Hypertrophy

BACKGROUND: The association of renin-angiotensin system (RAS) polymorphisms and left-ventricular hypertrophy (LVH) may depend on the presence of risk factors for LVH, such as renal dysfunction. We studied whether renal function modulates the association between RAS polymorphisms and LVH in a cross-sectional study of 8592 inhabitants of Groningen. METHODS: Left-ventricular hypertrophy was determined with electrocardiograms, using the Cornell voltage-duration product. The following RAS polymorphisms were determined: angiotensin II type-1 receptor (AGTR1 A1166C), angiotensin-converting enzyme (ACE) insertion/deletion (I/D), and angiotensinogen (AGT G-6A). The AGTR1 A1166C and ACE I/D polymorphisms were in Hardy-Weinberg equilibrium. RESULTS: Electrocardiographic LVH was present in 417 (5.0%) subjects. Subjects with LVH were older (53 v 49 years) and overall had more cardiovascular risk factors. Using logistic regression, creatinine clearance interacted with the relationship between the AGTR1 A1166C polymorphism and LVH (beta, -0.19; P = .033). In subjects with the CC genotype, in contrast to carriers of an A allele, the prevalence of LVH increased with more pronounced renal dysfunction. Creatinine clearance also interacted with the relationship between the ACE I/D polymorphism and LVH (beta, 0.12; P = .037), although less strongly, and the other way around. Creatinine clearance did not influence the association between the AGT G-6A polymorphism and LVH (beta, -0.006; P = .491). CONCLUSIONS: In this population-based study, the AGTR1 A1166C polymorphism was associated with LVH, dependent on concomitant renal dysfunction. A weaker renal function dependent association between the ACE I/D polymorphism and LVH was also observed. Renal function should be taken into account as a relevant environmental factor for the pathogenetic effects of RAS polymorphisms.