Systolic blood pressure is strongly related to indices of obesity in children

Abstract

OBJECTIVE: Obesity is a well-known cause of hypertension in adults. We hypothesized that it is strongly related to blood pressure in children. METHODS: Blood pressure data on 1981 participants aged 8–19 yrs (1007 boys, 974 girls, mean age 13.0±3.5 yrs) in the United States National Health and Nutrition Examination Survey (NHANES) 2011–2 were analysed. The National Center for Health Statistics Research Ethics Review Board approved the protocol. Certified personnel measured blood pressure. Lifestyle information was obtained using questionnaires. RESULTS: Systolic and diastolic blood pressure (SBP, DBP) correlated with waist circumference (WC) (r=0.41 and 0.21 respectively, p<0.001), and to a lesser extent, BMI (r=0.40 and 0.19 respectively, p<0.001). SBP correlated with WC more strongly in boys than girls (r=0.47 and 0.36 respectively, p<0.001). The slope of the regression of SBP on WC was the same, 0.2 mmHg/cm (p<0.001), for age groups 8–11, 12–15 and 16–19 yrs. There was no significant association between SBP or DBP with amount of sleep, amount or rigour of physical exercise, hours of television viewing or hours at the computer. In a general linear model, WC, age and gender explained 28% (32% in boys and 16% in girls) of the variance in SBP. CONCLUSIONS: The size of the effect of abdominal obesity on blood pressure in children is large and is found in children as young as 8 years old. Addressing obesity in childhood may help to prevent the development of hypertension later in life.