Body mass index and waist circumference are associated with blood pressure in preschool-aged children

Purpose
Population-derived data on the association between body mass index (BMI) and blood pressure (BP) during early childhood are lacking. We investigated the association between BMI, waist circumference, and BP among preschool-aged children.

Methods
A total of 1294 children ages 3 to 6 years were examined in the Sydney Paediatric Eye Disease Study during 2007 to 2009. Height, weight, and waist circumference were collected and BMI calculated. The weight status of each child was classified on the basis of age- and sex-specific BMI percentiles. BP was measured by the use of a standard protocol.

Results
A prevalence of 11.0% and 15.1% of children were obese or overweight, respectively. The prevalence of elevated BP was 21.3% among obese children compared with 12.4% of nonoverweight/obese children (p = .03). An increase of 1 BMI unit was independently associated with, on average, a 0.57 and 0.56 mm Hg increase in systolic and diastolic BP, respectively. Each unit increase in waist circumference was associated with a 0.14 and 0.23 mm Hg increase in systolic and diastolic BP, respectively.

Conclusions
A strong and independent association between adiposity and BP was present during early childhood. These data have important public health implications because elevated BP at a young age may be associated with increased cardiovascular risk in later life.