PROSPECTIVE ASSOCIATIONS OF PHYSICAL ACTIVITY AND SEDENTARY TIME IN ADOLESCENCE WITH CARDIOMETABOLIC RISK IN YOUNG ADULTHOOD.

Abstract: Purpose: The relationship between sedentary time, physical activity, and cardiometabolic risk factors during the transition from adolescence to adulthood remain uncertain. We examined the prospective associations of sedentary time and physical activity at age 15 with cardiometabolic risk markers at age 24.Methods: We used data from the Physical Activity among Norwegian Children Studies (PANCS). Sedentary time, moderate-to-vigorous physical activity (MVPA), and vigorous physical activity (VPA) were measured by accelerometry. Outcomes included body mass index (BMI), waist circumference, visceral fat, maximal oxygen uptake (VO2max), systolic blood pressure, LDL-cholesterol, insulin, high-sensitivity CRP, and a clustered risk Z-score. The prospective associations were modelled through regression.Results: A total of 731 boys and girls participated at age 9 (2005-2006) and 15 (2011-2012), and 258 of these participated again at age 24 (2019-2021). Multiple imputation was performed for all eligible individuals (n = 708). Each standard deviation increase (min/day) in sedentary time at age 15 was associated with lower VO2max at age 24 (β: -1.6 ml/kg/min; 95%CI: -2.8, -0.5). Each standard deviation increase (min/d) in MVPA (β: 1.6 ml/kg/min; 95%CI: 0.8, 2.4) and VPA (β: 1.6 ml/kg/min; 95%CI: 0.8, 2.4) at age 15 were associated with higher VO2max at age 24. VPA in adolescence was further inversely associated with visceral fat mass (β: -41 g; 95%CI: -78, -3), insulin level (β: -4.3 pmol/L; 95%CI: -8.2, -0.4), and the clustered risk Z-score (β: -0.09; 95%CI: -0.18, -0.01) in young adulthood. Childhood BMI modified the association of both MVPA and VPA with clustered risk, with the greatest magnitude of association observed in the highest BMI tertile.Conclusions: Physical activity, especially of vigorous intensity, during adolescence appear to beneficially affect cardiometabolic health in young adulthood. These health benefits may be most pronounced among overweight/obese youth.