Significant Increases in Peripheral and Central Blood Pressure in Children at Much Lower Body Mass Index Than Expected

Objective: Cardiovascular (CV) complications are the most common causes of death worldwide. Increased body weight and higher blood pressure (BP) are known risk factors for CV disease with a known association of higher body mass index (BMI) with higher BP. Our study intended to describe at which BMI-level significant increases in either central (cBP) or peripheral BP (pBP) can be detected in young children. Design and method: We measured cBP and pBP in 1,183 schoolchildren (first/second graders; mean age 7.9±0.6 years; 51% male). pBP measurements were performed with a validated oscillometric device (Dinamap-VC150-GE). cBP was measured noninvasively with the Mobil-O-Graph (IEM). Multivariable linear regression models (corrected for age, sex, height) were used to compare pBP/cBP values of children with a BMI=50th-=65th-=75th-=85th-=95thpct). Results: BMI was 17±3 kg/m 2 (M±SD), 275 children (22.8%) were overweight (BMI>=85th pct), 126 (10.5%) obese (BMI>=95thpct). Peripheral systolic blood pressure (pSBP) was 104±8mmHg (M±SD), peripheral diastolic blood pressure (pDBP) 61±6mmHg (M±SD); 5% of the cohort displayed hypertensive pBP values >=95thpct. In the unadjusted analysis, we saw an increase in pSBP (Fig.1A) and cSBP (Fig.1B) already at a BMI around 60thpct. Further analysis comparing the corrected means revealed that pSBP showed already a significant increase for children with a BMI>=75thpct (ß=1.8, p=0.026) when compared to children with a BMI=65thpct. (ß=1.7, p=0.031), while cDBP increased significantly in children with a BMI >=75thpct (ß=1.5; p=0.012) when compared to children with a BMI<50thpct. Conclusions: Our findings suggest that increases in body weight affect pBP and particularly cBP at much lower BMI pct level than expected. These results are alarming as pediatricians usually get concerned at BMI levels above the 85thpct (defined as cut-off for overweight in children based on WHO growth reference values). Given the important interaction between both risk factors and their track from childhood to adulthood, effective overweight prevention must take place in early childhood.