[Association of blood pressure and left ventricular mass in children from the PROC cohort study]

Objective: To explore the association between blood pressure (BP) and the left ventricular mass (LVM) in children aged 6-8 years. Methods: The participants were from the community-based census-like design child cohort on sensitization, puberty, obesity and cardiovascular risk (PROC) conducted in six public non-boarding primary schools in Shunyi District, Beijing. Repeated three measurements on anthropometrical, M-mode and 2-dimensional (2D) echocardiographic imaging (2D/M ECHO) and blood biochemical assay, and BP measurements were carried out at baseline and follow-up from October 2018 to June 2019. A total of 1 659 children who had repeated BP measurements and cardiac structure information were included in this study. The average value of last two measurements of BP was determined as BP value for analysis. Formula recommended by Devereux was used to calculate the mass of left ventricle. Robust linear regression models were used to explore the association between BP and LVM in different groups. Results: The average age of all patients was (7.10±0.29) years old, including 832 boys (50.15%). Of all, 83.54% (1 386/1 659) were grouped as normal BP with average LVM (58.54±13.33) g, and 16.46% (273/1 659) as elevated BP group with LVM (63.84±15.78) g (P<0.001). The LVM of the normal BP group was lower than elevated BP group in overall participants, boys and girls (P<0.005). Univariate analysis showed that systolic BP was associated with LVM in overall, boys and girls (P<0.001) respectively. While diastolic BP was associated with LVM in overall and girls (P<0.03). Multivariable analysis indicated that the associations between systolic BP and LVM were observed in overall, boys and girls (P<0.05) with the β (95%CI)=0.14 (0.08, 0.21), 0.18 (0.08, 0.27) and 0.12 (0.03, 0.22), respectively. However, the associations of diastolic BP and LVM were not significant. Conclusion: Systolic BP is highly associated with LVM and elevated BP could increase the LVM in children. Boys with elevated BP present a larger LVM and might indicate higher risk of left ventricular hypertrophy in adulthood.