Influence of CYP11B2 gene polymorphism on the prevalence of hypertension and the blood pressure in Japanese men: interaction with dietary salt intake.

AIMS

CYP11B2 gene encodes a key enzyme for the production of aldosterone. Our aim is to investigate the association of -344T/C polymorphism with hypertension in Japanese men. The interaction between genotypes and dietary salt intake was also considered.

METHODS

Three hundred and ten Japanese male workers participated in this study. Daily salt intake was calculated from a food frequency questionnaire. Melting curve analysis was used to determine CYP11B2 genotypes.

RESULTS

There was a significant association between the CT + TT genotype and higher prevalence of hypertension (odds ratio: 3.03; p = 0.014). The association presented in a recessive manner and was strongest in the high-salt intake group (odds ratio: 9.44; p = 0.049). Only in the high-intake group, systolic blood pressure (SBP) was significantly higher in the CT + TT group than in the CC group (p = 0.038). The SBP had a positive correlation with salt intake in the CT + TT group (p for linear trend = 0.021), but not in the CC group (p for interaction = 0.011).

CONCLUSIONS

CYP11B2 gene -344C/T polymorphism affects the risk of hypertension in Japanese men and high-salt intake levels strengthen this association. This gene-diet interaction warrants further study to elucidate the efficacy of salt restriction as an antihypertensive therapy in different genotypes.