Resting heart rate in children and adolescents: association with blood pressure, exercise and obesity.

Objective: Resting heart rate (RHR) is increasingly recognised as a prognostic marker for long term cardiovascular outcomes in adults. This study assessed associations of RHR with blood pressure (BP), anthropometry and exercise in a large representative sample of Hong Kong children.
Study Design, Setting and Subjects: A territory-wide growth survey carried out in 2005-2006 included students sampled from each of Hong Kong's 18 districts. RHR and BP were measured by validated oscillometric BP devices and anthropometric data and exercise frequency were recorded. Multiple linear regressions were used to test associations among RHR and BP, anthropometry and exercise frequency.
Results: Data on 14 842 children aged 6-18 years were available. Multiple linear regression analyses showed that RHR was positively associated with BP, and negatively associated with age and exercise frequency (p<0.001). RHR was more positively linked to waist circumference among the anthropometric measurements, and positive independent association was only identified in boys (p<0.001).
Conclusions: Elevated RHR is independently associated with elevated BP in children, whereas increased structured exercise is related to lower RHR.