Gender-specific non-linear relationship between BMI and estimated pulse wave velocity in Brazilian adults: a secondary analysis of cross-sectional data

Objective Arterial stiffness, commonly assessed through pulse wave velocity (PWV), is an important predictor of cardiovascular events. While body mass index (BMI) has been associated with arterial stiffness, the shape of this relationship and potential gender differences remain unclear, especially across populations. Methods We performed a secondary cross-sectional analysis of 1537 participants from the Marco Av Silva study.Multivariate linear regression and restricted cubic spline analyses evaluated linear and non-linear associations between BMI and e1-PWV24hBP., with comprehensive adjustment for confounders. Results After full adjustment, we observed significant non-linear relationships between BMI and e1-PWV24hBP in both genders. Females exhibited a U-shaped relationship with an inflection point at BMI = 34.29 kg/m², with significant negative association before ( β = -0.03, 95% CI : -0.05 to -0.00, P = 0.0216) and positive association after this point ( β = 0.06, 95% CI : 0.01 to 0.10, P = 0.0125). Males demonstrated an inverted J-shaped pattern with an inflection point at BMI = 34.94 kg/m², showing negative association afterward ( β = -0.11, 95% CI : -0.16 to -0.05, P = 0.0003) and a non-significant trend before ( β = -0.01,95% CI : -0.04 to 0.01, P = 0.3305). Conclusions These findings suggest that BMI’s impact on arterial stiffness differs markedly between genders in Brazilian adults, highlighting the importance of gender-specific approaches in cardiovascular risk assessment and the potential existence of an “obesity paradox” in arterial stiffness, particularly among men.