Do Physical Activity, Body Mass Index, and Sleep Duration Predict Clustered Cardiovascular Disease Risk in Children?- A Part of the OPUS Study

Objective To investigate the single and combined associations of physical activity (PA), body mass index (BMI), and sleep duration with clustering of cardiovascular disease risk markers in healthy children.

Methods We did a cross-sectional pilot-study of 74 Danish school children aged 8-11 years. Risk factors included in a continuous metabolic syndrome score (cMETscore) were mean z-scores of high-density lipoprotein, triglyceride, insulin resistance, and mean arterial blood pressure. Physical activity (counts/min) and sleep duration were assessed for 7 days using an accelerometer.

Results Mean BMI was 17.1 (range 13.4-25.4) kg/m², with 10.8% classified as overweight using isoBMI. Controlled for age and sex, P A was negatively associated with cMET-score (Standardised beta coefficients (sBeta)=-0.32); n=74; P=0.016) and BMI was positively associated with cMETscore (sBeta=0.49; n=74; P

Discussion The association between PA and the cMET-score was halved after adjusting for BMI. Accordingly, BMI was almost three times stronger associated with the cMET -score than PA. The lack of association between PA and cMET -score after adjusting for BMI, is most likely a combination of BMI explaining some of the association and due to low statistical power. Sleep duration does not seem to be associated with cMET-score. The present study indicates that intervention towards lowering of BMI and increasing PA should start already in childhood in order to decrease risk markers of cardiovascular disease.