- Anders Husøy is a research fellow at the Department of Sports Medicine.
- On October 9th, he will defend his thesis “Physical activity, cardiorespiratory fitness and cardiometabolic risk factors from childhood to young adulthood”.
About the study
In the UngKan follow-up study we sought to examine the trends, levels, and associations of physical activity, cardiorespiratory fitness, and cardiometabolic risk factors from childhood (age 9 years) to adolescence (15 years) and further into young adulthood (age 24 years).
In the first study, we found that sedentary time increases from childhood to adolescence. A decrease from childhood to adolescence was seen for time spent in light, moderate, and vigorous physical activity.
Contrary to our expectations, little change in these variables was observed between adolescence and young adulthood. Furthermore, variables collected at both age 9 and 15 years were poor predictors of total physical activity at age 24 years - which may indicate that the transitional phase between adolescence and young adulthood could be formative of physical activity behaviour in young adulthood.
However, the least active 9-years-olds were at higher odds for ending up as the least active adults and may be targeted for early intervention.
In the second study, we found that higher levels of sedentary time in adolescence was associated with lower levels of maximal oxygen uptake in young adulthood - an important independent predictor of cardiovascular diseases.
Higher levels of time spent in both moderate-to-vigorous physical activity and vigorous physical activity were associated with higher levels of maximal oxygen uptake in young adulthood. Additionally, time spent in vigorous physical activity was associated with beneficial changes in visceral fat mass, insulin levels, and a clustered cardiometabolic risk score.
These findings underline the importance of the current recommendation of an average of 60 minutes/day of moderate-to-vigorous physical activity for adolescents while reducing time spent sedentary, and further emphasise the importance of spending time in physical activity of vigorous intensity for maximum cardiometabolic health benfit.
We also found the greatest health benefit of physical activity among those in the highest BMI tertile at age 9 years, as compared to those belonging to the lower tertiles. This corroborates our finding from a systematic review included in the dissertation, where the cardiometabolic health benefits of physical activity was most pronounced among youth with low levels of cardiorespiratory fitness.
These findings may indicate greatest health benefit from physical activity among “at risk”-youth, e.g., obese and low-fit children.
Finally, we found that several cardiometabolic risk factors demonstrated moderate to strong tracking, or stability, from childhood to young adulthood, i.e., children with an unfavourable cardiometabolic risk profile were more likely to still have an unfavourable risk profile in young adulthood. The variables demonstrating the most pronounced stability included BMI, waist circumference, LDL-cholesterol, maximal oxygen uptake, and a clustered cardiometabolic risk score.
This may indicate that early intervention is necessary to prevent further development of cardiometabolic risk factors. However, sedentary time demonstrated low tracking over this time span, and may be a more modifiable risk factor than those showing greater stability over time.
Results
- Sedentary time increased from childhood to adolescence but remained stable thereafter.
- Physical activity decreased from childhood to adolescence and showed little change afterward.
- Variables measured in childhood and adolescence were poor predictors of adult activity, suggesting a formative period between adolescence and young adulthood.
- Higher sedentary time in adolescence was associated with unfavourable changes in maximal oxygen uptake in young adulthood.
- Higher moderate-to-vigorous physical activity in adolescence was beneficially associated with maximal oxygen uptake in young adulthood.
- Higher vigorous physical activity in adolescence was associated with beneficial changes in maximal oxygen uptake, visceral fat mass, insulin levels, and clustered cardiometabolic risk in young adulthood.
- The greatest health benefits of physical activity were seen in youth with the highest BMI and the lowest cardiorespiratory fitness, which may indicate that physical activity has the greatest benefit among youth who need it the most.
- Several traditional cardiometabolic risk factors demonstrated moderate to strong tracking from childhood to young adulthood, with BMI, waist circumference, LDL-cholesterol, maximal oxygen uptake, and clustered cardiometabolic risk showing the most pronounced tracking.
- Early intervention may be necessary to prevent further development of cardiometabolic risk factors
- Sedentary time demonstrated low tracking and may be a more modifiable risk factor.
Committee
First opponent: Principal Researcher, Dr. Tuija Tammelin, JAMK University of Applied Sciences, Jyväskylä, Finland
Second opponent: Professor, Dr. Jos Twisk, Amsterdam University Medical Centers, Netherlands
Committee chair: Associate Professor, Julie Sørbø Stang, Department of Sports Medicine, NIH
Supervisors
Main supervisor: Sigmund Alfred Anderssen, professor Department of Sports Medicine, NIH
Co-supervisor: Ulf Ekelund, professor Department of Sports Medicine, NIH
Program
- 10.15-11.00: Trial lecture: How to decrease sedentary behavior among older adults?
- 13.00-16.00: Public defence of the thesis: “Physical activity, cardiorespiratory fitness and cardiometabolic risk factors from childhood to young adulthood”
Practical info
The public defence is open to the public and will be streamed on the NIH's YouTube channel.