Different Associations of Systolic Blood Pressure and Body Mass Index With Cardiac Structure and Function in Young Children.

Abstract

Both elevated systolic blood pressure (SBP) and excess weight can lead to early cardiovascular organ damage in children. In this study, we investigated whether there is a difference in the associations of SBP and body mass index (BMI) with cardiovascular structure and function in 4-year-old children. In 1474 children (52.3% males) from the Shanghai Birth Cohort, physical examination and echocardiography were performed. Standardized linear regression models were used to evaluate the associations of BMI Z score and SBP Z score with cardiovascular parameters and to compare the strengths of these associations. The incidence of SBP elevation significantly increased in overweight children. SBP was positively related to heart rate, left ventricular (LV) ejection fraction and fraction shortening (β=1.824 [95% CI, 1.014-2.634], 0.579 [0.294-0.864], and 0.480 [0.257-0.704], respectively). BMI Z score was positively associated with LV mass index (β=1.225 [0.863-1.587]) and the risk of LV hypertrophy (odds ratio=1.428 [1.157-1.761]) but negatively related to measures of systolic function, including LV ejection fraction, LV fraction short, and global longitudinal strain (β=-0.417 [-0.735 to -0.099], -0.302 [-0.551 to -0.053], and -0.392 [-0.621 to -0.163], respectively). No noteworthy additive or multiplicative interactions between BMI and SBP were detected. Elevations in both BMI and SBP were related to cardiac structure and function in children as young as 4 years old. Elevated SBP was associated with increased heart rate and LV ejection at the early stage of BP elevation. BMI showed a closer relationship with left heart diameters and geometry than SBP.