Association of Low BMI with Aortic Stiffness in Young Healthy Individuals

Background: Increased arterial stiffness is an independent predictor of cardiovascular morbidity and mortality. It is unknown whether low BMI has any detrimental effect on the arterial wall during young age. Objectives: The present study was aimed to determine if low BMI can increase arterial stiffness in young, healthy individuals. Methods: A cross-sectional study was conducted on young, healthy subjects (n=100) with low BMI <18.5 (n=50) and normal BMI: 18.5-24.9 (n=50) with ages ranging between 15-23 years. BMI, heart rate, blood pressure, and arterial stiffness indices such as regional pulse wave velocity (PWV) between brachial-ankle (baPWV), carotid-femoral (cfPWV), heart-ankle (haPWV), heart brachial (hbPWV) were measured. Results: A significantly increased pulse pressure (p=0.014), baPWV (1059.2 +/- 140.26 cm/s vs 994.66 +/- 129.23 cm/s; p=0.019) and cfPWV (641.03 +/- 113.83 cm/s vs 583.96 +/- 120.48 cm/s; p=0.017) was found in individuals with low BMI than normal BMI group. There was a significant negative correlation between BMI and central arterial PWV. Further multiple regression analysis showed that BMI was robustly associated with cf-PWV (p=0.004) and baPWV (p=0.016) even after multiple adjustments with potential confounders using several models. Conclusions: These findings show a significant increased aortic stiffness and pulse pressure in low BMI subjects compared to those with normal BMI. Low BMI was inversely and independently associated with central arterial or aortic stiffness. These findings suggest that low BMI may be a risk factor for aortic stiffness in young, healthy individuals.