The present study provides a cross-sectional investigation of 763 Japanese men and women (18 − 70 years old) to clarify the effects of cardiorespiratory fitness on the relationship between arterial stiffness and 5,10-methylene tetrahydrofolate reductase (MTHFR) C677T and ghrelin (GHRL) C214A gene polymorphism. Arterial stiffness was assessed by carotid β-stiffness with urtrasonography and tonometry. The study subjects were divided into High-Fit and Low-Fit groups based on the median value of peak oxygen uptake in each gender and decade. The plasma homocysteine level was higher in the TT genotype of MTHFR C677T polymorphism compared with CC and CT genotype individuals. There was no effect of MTHFR C677T polymorphism on carotid β-stiffness, but was significant interaction effect fitness and MTHFR C677T polymorphism on carotid β-stiffness (P = 0.0017). In the Low-Fit subjects, carotid β-stiffness was significantly higher in TT genotype individuals than that in CC and CT genotypes. However, there were no such differences in High-Fit subjects. In addition, total cholesterol, LDL cholesterol and triglyceride level was lower in the AA genotype of GHRL C214A polymorphism compared with CC and CA genotype individuals. There was no effect of GHRL C214A polymorphism on carotid β-stiffness in either fitness level. These results suggest that the higher cardiorespiratory fitness may attenuate the central artery stiffening associated with MTHFR C677T polymorphism.

DESCENTE SPORTS SCIENCE Vol.32/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE