Inverse association between obesity and aortic pressure augmentation is attenuated in women: the Wakuya study

OBJECTIVE: Pressure wave reflection predicts cardiovascular events in the general population. Obesity is negatively associated with pressure wave reflection. Muscular arterial diameter (responsible for pressure wave reflection) increases with obesity, and obesity-dependent dilation of muscular arteries is attenuated in women compared with men. We investigated the sex differences in the cross-sectional relationship between obesity and pressure wave reflection in a general population cohort. METHODS: Tonometric pressure waveforms were recorded in 928 adults (mean age, 56 ± 10 years) to estimate the aortic augmentation index. The BMI was calculated using height and body weight, and waist circumference was recorded at the umbilical level. RESULTS: Aortic augmentation index was significantly higher in women than in men. Indices of obesity (BMI and waist circumference) were negatively correlated with the aortic augmentation index in both men and women, even after adjusting for mean arterial pressure (both P < 0.001). Sex and BMI had no synergistic effect on the aortic augmentation index. However, when waist circumference was substituted for BMI, sex and waist circumference had a reciprocal influence on decreasing the aortic augmentation index independent of age, mean arterial pressure, diabetes, and hyperlipidemia (interaction, P = 0.045). CONCLUSION: The negative correlation between overweight/obesity and aortic pressure augmentation from peripheral wave reflection is inhibited in women more than in men. Sex differences in aortic pressure augmentation are greater in individuals with central (abdominal) obesity than in those with general obesity.