Body mass index is not independently associated with increased aortic stiffness in a Brazilian population.

BACKGROUND: Obesity has been described as a predictor of cardiovascular mortality, and some studies have reported an association with obesity and increased aortic stiffness. Other studies have not identified obesity to be an independent risk factor. Therefore, the purpose of our study was to determine the association between aortic stiffness and obesity in the Brazilian population.
METHODS: A cross-sectional study recruited 1,662 individuals aged 25-64 years from the population of Vitória, Brazil following the guidelines of the MONICA-WHO Project. Anthropometric, clinical, and hemodynamic measurements and analyses of aortic stiffness (using carotid-femoral pulse wave velocity <PWV) were obtained in 1,608 subjects.
RESULTS: PWV correlated positively with age, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure, heart rate (HR), body mass index (BMI), waist circumference (WC), cholesterol levels, triglyceride levels, and blood glucose levels. A multivariate regression analysis demonstrated that the mean BP (β = 0.405, P < 0.01), age (β = 0.314, P < 0.01), HR (β = 0.107, P < 0.01), BMI (β = -103, P < 0.01), and blood glucose levels (β = 0.093, P < 0.01) explained nearly 37% of the PWV variability. A multivariate regression analysis using the WC instead of the BMI failed to reveal any significant effect of this parameter on the PWV.
CONCLUSIONS: In conclusion, our study failed to provide evidence of a positive, blood pressure (BP)-independent association between obesity on aortic stiffness. Our data suggests that the previously reported finding of an association between obesity and aortic stiffness was probably confounded by the progressive increase in BP observed in obesity.