Device-measured physical activity, sedentary time, and cardiometabolic risk in youth: harmonized meta-analysis of prospective studies

Background: Few studies have examined prospective associations between physical activity/sedentary time and cardiometabolic risk markers in youth.

Purpose: To do a harmonized meta-analysis of prospective studies with device-measured physical activity and sedentary time in relation to cardiometabolic risk markers in children and adolescents.

Methods: We used data from the International Children’s Accelerometry Database supplemented with data from three additional cohorts. All studies measured physical activity/sedentary time by accelerometry at baseline and traditional cardiometabolic risk markers at baseline and subsequently at follow-up. Exposure data were processed using a harmonized approach. Linear regression models (with 95%CI) were used to determine associations with a composite cardiometabolic risk score at follow-up, created by combining standard deviation scores of insulin, glucose, BMI, LDL-cholesterol, triglycerides, and systolic blood pressure. Statistical models were multivariable-adjusted including baseline outcome and repeated with and without adjustment for baseline BMI. Multiple imputation was used to handle missing data.

Results: We included a total of 7512 children and adolescents (51% girls) with a mean baseline age of 11.6 (SD: 3.0) years and 2.6 (SD: 0.4) years of follow-up. Moderate-to-vigorous physical activity and vigorous physical activity were not associated with follow-up composite risk score with or without adjustment for baseline BMI (standardized betas with 95% CI, 0.00 [-0.02, 0.03] and 0.01 [-0.01, 0.03]. Insulin and triglycerides were inversely associated with moderate-to-vigorous and vigorous physical activity but substantially attenuated following adjustment for BMI. Higher sedentary time was associated with lower composite risk (-0.04 [-0.07, -0.01] which was not affected by adjustment for baseline BMI.

Conclusions: Physical activity and sedentary time may not be major determinants of later cardiometabolic risk markers in population-based children and adolescents.

Practical implications: Promotion of physical activity and reductions in sedentary time in young people may primarily be targeted on other outcomes rather than on cardiometabolic risk markers.

Funding: None