CYP3A5 genotype is associated with blood pressure and have an interaction with calculated 24h urinary sodium excretion level in Japanese male

Background: Cytochrome P-450 3A5 (CYP3A5) gene has been proposed to contribute to salt sensitivity hypertension in humans. CYP3A5*1/*3 variant which determine most expression of CYP3A enzyme is largely determined by A6986G polymorphism (dBSNP: rs776746) in intron 3. Our objective is to determine whether the polymorphism is associated with blood pressure in Japanese, and the interactions between this polymorphism and calculated 24hUNaV were also detected.
Methods: A cross-sectional study was conducted among 238 unrelated Japanese male workers (20-64 year). CYP3A5*1/*3 polymorphism was determined for each individual by genotyping A6986G polymorphism. 24-h urinary sodium (24HUNaV) excretion was estimated by a verified method using spot urine specimens.
Results: Our data showed that there is a significant association between CYP3A5*1/*3 polymorphism and DBP in Japanese healthy male. Subjects with *1/*1 genotype have a higher DBP than *3/*3 carriers. The association remained significant when age, BMI and 24hUNaV were taken into account. There were significant interactive effects between CYP3A5*1/*3 polymorphism and calculated 24HUNaV on SBP (p=0.046) and DBP (p=0.003) adjusted age and BMI.
Conclusions: Our data indicate that CYP3A5*1/*3 polymorphism affects DBP and may contribute to salt-sensitivity hypertension in Japanese. (185 words)