Physical activity trajectories from childhood to late adolescence and their implications for health in young adulthood.

Physical activity has been associated with physical and mental health across the life course, yet few studies have used group-based trajectory modeling to examine the effect of longitudinal patterns of physical activity during childhood and adolescence on adult health outcomes. The Raine Study data from Gen2 follow-ups at 8, 10, 14, 17, 20, and 22 years collected between 1998 and 2014 were used. Latent class analysis identified trajectories using parent-reported physical activity for ages 8 to 17. Associations between trajectories and physical and mental health outcomes at ages 20 and 22 were explored, adjusting for current physical activity and considering sex interactions. Analysis in 2019 identified three trajectories: low (13%), mid (65%) and high (22%) physical activity (n = 1628). Compared to the low-activity trajectory, those in the high-activity trajectory had lower adiposity, insulin, HOMA-IR and fewer diagnosed disorders, higher HDL-cholesterol, and faster cognitive processing. For example, those in the high-activity trajectory had lower percent body fat at age 20 compared to those in the mid-activity (-4.2%, 95%CI: -5.8, -2.7) and low-activity (-9.5%, 95%CI: -11.7, -7.2) trajectories. Physical activity trajectories showed different associations between sexes for self-reported physical and mental health, BMI, systolic blood pressure, and depression symptoms. Being in the high- or mid-activity trajectory was associated with a more favorable cardiometabolic and mental health profile in young adulthood. Strategies are needed to help less active children to increase physical activity throughout childhood and adolescence to improve young adult health outcomes.

Mucociliary clearance and its relation with the level of physical activity in daily life in healthy smokers and nonsmokers.

OBJECTIVES: To investigate the relationship between mucociliary transport and physical activity in daily life (PADL) in smokers and nonsmokers. METHODS: Fifty-two current smokers were submitted to assessment of mucociliary transport (Sacharin Transit Time, STT), carbon monoxide levels in the exhaled air, lung function and smoking history. In addition, subjects kept a pedometer worn at the waist for six days in order to determine their level of PADL (steps/day). The tests were also performed on 30 matched healthy nonsmokers who served as control group. RESULTS: Light smokers (≤15 cigarettes/day) had a STT of 9 (7-11) min (median [confidence interval]), which was similar to nonsmokers (8 [8-11]min; p=0.8). Both moderate (16-25 cigarettes/day) and heavy (>25 cigarettes/day) smokers had significantly higher STT (13 [11-17] min and 13 [10-21] min, respectively) than nonsmokers and light smokers (p<0.05 for all). There was no difference in the number of steps/day between any of the groups (p>0.05 for all). In the general group of smokers, STT was not significantly correlated with PADL, pack/years index, years of smoking or age (r<-0.23; p>0.09 for all). There was significant negative correlation between STT and PADL only in light smokers (r=-0.55; p=0.02) and nonsmokers (r=-0.42; p=0.02), but not in moderate and heavy smokers. CONCLUSION: In light smokers and non-smokers, better mucociliary function is associated to higher daily physical activity level, as opposed to the decreased mucociliary function observed in smokers, i.e., those with moderate and heavy cigarette consumption.