Aldosterone Synthase Gene T-344C Polymorphism, Sodium and Blood Pressure in a Free-Living Population: A Community-Based Study

Abstract

There have been few epidemiological studies on the gene-environmental interaction between the aldosterone synthase gene (CYP11B2) T-344C polymorphism and sodium in relation to blood pressure in a free-living general population. We hypothesized a priori that persons with the T allele of CYP11B2 would have elevated blood pressure levels in response to a higher sodium intake, and thus the association between the T-344C polymorphism and blood pressure would be more evident among persons with a high sodium intake than among those with a low sodium intake. Study subjects were 2,823 men and women aged 30-74 in a Japanese community. We examined the associations between the T-344C polymorphism and blood pressure levels, stratified by sodium variables estimated by 24-h urinary sodium excretion and a dietary questionnaire. There was no significant difference in blood pressure levels among the CC, TC and TT groups for either or both sexes. However, among persons with higher sodium excretion, mean systolic blood pressure levels tended to be higher in those with the TC (+3.0 mmHg, p=0.06) and TT (+2.9 mmHg, p=0.07) genotypes than in those with the CC genotype, but this tendency was not seen among those with lower sodium excretion (-4.0 mmHg, p=0.03 for TC vs. CC; -3.0 mmHg, p=0.11 for TT vs. CC; p for interaction =0.006). In conclusion, we found no association between CYP11B2 and blood pressure for total subjects or for persons with a higher sodium intake. However, a possible gene-blood pressure association among persons with higher sodium intake needs to be explored further.

Aldosterone synthase (CYP11B2) C-344T polymorphism affects the association of age-related changes of the serum C-reactive protein

“…In keeping with the results of earlier studies, the associations of the CYP11B2 C-344T polymorphism with BP remain inconclusive. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] In addition, our results were not consistent with previous reports indicating that BP elevation was sensitive in elderly subjects with the TT genotype. 20,21 Furthermore, we suggested that the association of the CC genotype with CRP was consistent with previous reports describing the association of the genotype with cardiac structures and atherosclerosis as discussed above, 17,34 whereas some apparent contradictory associations between the genotype and atherosclerosis, including cardiac structure and coronary artery diseases, have been shown in previous studies.…”

“…3 An overview of published studies suggests a higher frequency of hypertension or increase in blood pressure (BP) in subjects with the T allele or TT genotype as compared with that in subjects with the C allele or CC genotype, [4][5][6][7][8][9][10] although several studies have reported the opposite association 11,12 or the absence of any association. [13][14][15][16][17][18][19] Thus, the associations remain controversial. Recently, two interesting studies have suggested a key indicator that may resolve the association.…”

Polymorphisms in CYP11B2 and CYP11B1 genes associated with primary hyperaldosteronism

“…In some previous hypertension studies, the rs1799998 polymorphism is not associated with increased aldosterone and increased blood pressure. [23][24][25] Maybe, the different groups with different ethnic backgrounds could account for the differences, but further research is needed to verify this.…”

Associations of the –344T>C polymorphism of CYP11B2 gene with 24-hour blood pressure profiles in middle-aged women with essential hypertension

“…Similarly, Casiglia et al found in unselected elderly population that systolic blood pressure was significantly lower in subjects with the CC genotype, higher in the TT and intermediate in the CT [18]. On the other hand, other studies failed to demonstrate the differences in blood pressure between TT, CC and CT carriers [19]. Moreover, to our best knowledge, there have been no previous reports assessing the association of CYP11B2 polymorphisms with circadian variations in blood pressure.…”