Lack of association between a polymorphism of the aldosterone synthase gene and left ventricular structure

Background-Cardiac growth and function may be modulated in part by trophic effects of neurohormones, Specifically, aldosterone has been shown to stimu late the growth of cardiac myocytes and the accumulation of cardiac extrace llular matrix proteins. Moreover, a variant of the aldosterone synthase gen e (a cytosine/thymidine exchange at position -344 in the transcriptional re gulatory region) has been associated with enlargement and disturbed filling of the left ventricle (LV) in a small sample of young white adults. The ai m of the present study was to reinvestigate the implications of aldosterone synthase -344C/T allele status for serum aldosterone levels, blood pressur e, and LV structure and function in large population-based samples. Methods and Results-Individuals who participated in the echocardiographic s ubstudy of the third MONICA (MONitoring trends and determinants in CArdiova scular disease) survey (n=1445) or in the second follow-up of the first MON ICA survey (n=562) were studied by standardized anthropometric, echocardiog raphic, and biochemical measurements as well as genotyping for aldosterone synthase -344C/T allele status. In both surveys, the distribution of sex, a ge, arterial blood pressure, and body mass index was homogeneous in the ald osterone synthase genotype groups. Echocardiographic LV wall thicknesses, d imensions, and mass indexes were not significantly associated with a specif ic aldosterone synthase genotype, Likewise, no association was detectable w ith echocardiographic measures of LV systolic or diastolic function. Data w ere consistent in both samples and not materially different in subgroups de fined by age, sex, or intake of antihypertensive medication. Finally, no si gnificant association was observed for aldosterone synthase allele status a nd serum aldosterone levels in the group of 562 individuals. Conclusions-The data are not in favor of a significant contribution of the C/T exchange at position -344 in the aldosterone synthase transcriptional r egulatory region to the variability of serum aldosterone levels, blood pres sure, or cardiac size or function as found in 2 white population-based samp les.