Katerina Kondakis1, Marios Kondakis2, Odysseas Androutsos3, Stefaan De Henauw4, Marcela González-Gross5, Luis A Moreno6, Anthony Kafatos7, Yannis Manios3. 1. Department of Public Health, University of Ghent, Ghent, Belgium - kondakikaterina@live.com. 2. Department of Statistics, Athens University of Economics and Business, Athens, Greece. 3. Department of Nutrition and Dietetics, Harokopio University, Athens, Greece. 4. Department of Public Health, University of Ghent, Ghent, Belgium. 5. Department of Health and Human Performance, Faculty of Physical Activity and Sport Sciences, Polytechnic of Madrid, Madrid, Spain. 6. University School of Health Sciences, University of Zaragoza, Zaragoza, Spain. 7. Unit of Preventive Medicine and Nutrition, UoC School of Medicine, University of Crete, Heraklion, Greece.
Abstract
BACKGROUND: The present study aimed to examine the independent association between cardiorespiratory fitness, sedentary time and insulin resistance in European adolescents. METHODS: A subset (N.=1097) of a large multicenter European study (HELENA-CSS study) was used in the present study. Serum concentrations of glucose (G<inf>F</inf>) and insulin (I<inf>F</inf>) were measured after overnight fast and homeostasis model assessment (HOMA-IR) was calculated. Sedentary time and time spent on moderate-to-vigorous physical activity (MVPA) was objectively measured by accelerometers. Moreover, sedentary activities were self-reported via questionnaires. RESULTS: Multilevel linear regression analysis revealed that adolescents watching TV≥2 h/day had higher HOMA-IR (P=0.007). Further adjustment for MVPA, showed that watching TV≥2 h/day remained significantly associated with IR (P=0.002). In this model, MVPA was inversely associated with HOMA-IR (P=0.001). Further controlling for waist circumference showed that adolescents watching TV≥2 h/day continued to have higher HOMA-IR levels (P=0.002). Stratified analysis by weight status, revealed that watching TV≥2 h/day was independently associated with HOMA-IR only in normal weight adolescents, while MVPA was inversely associated with HOMA-IR in both overweight/obese and normal weight adolescents. Only the volume of maximum oxygen consumption (VO<inf>2</inf>max) over body fat mass ratio was inversely associated with HOMA-IR after controlling for several confounders. CONCLUSIONS: The present study showed that watching TV≥2 h/day and MVPA were associated with HOMA-IR. However, after controlling for several confounders, only VO<inf>2</inf>max/body fat mass ratio remained negatively associated with HOMA-IR. Future interventions should aim both to promote physical activity and reduce sedentary time in adolescents to improve their cardiorespiratory fitness and postpone the onset of diabetes in adulthood.
BACKGROUND: The present study aimed to examine the independent association between cardiorespiratory fitness, sedentary time and insulin resistance in European adolescents. METHODS: A subset (N.=1097) of a large multicenter European study (HELENA-CSS study) was used in the present study. Serum concentrations of glucose (G<inf>F</inf>) and insulin (I<inf>F</inf>) were measured after overnight fast and homeostasis model assessment (HOMA-IR) was calculated. Sedentary time and time spent on moderate-to-vigorous physical activity (MVPA) was objectively measured by accelerometers. Moreover, sedentary activities were self-reported via questionnaires. RESULTS: Multilevel linear regression analysis revealed that adolescents watching TV≥2 h/day had higher HOMA-IR (P=0.007). Further adjustment for MVPA, showed that watching TV≥2 h/day remained significantly associated with IR (P=0.002). In this model, MVPA was inversely associated with HOMA-IR (P=0.001). Further controlling for waist circumference showed that adolescents watching TV≥2 h/day continued to have higher HOMA-IR levels (P=0.002). Stratified analysis by weight status, revealed that watching TV≥2 h/day was independently associated with HOMA-IR only in normal weight adolescents, while MVPA was inversely associated with HOMA-IR in both overweight/obese and normal weight adolescents. Only the volume of maximum oxygen consumption (VO<inf>2</inf>max) over body fat mass ratio was inversely associated with HOMA-IR after controlling for several confounders. CONCLUSIONS: The present study showed that watching TV≥2 h/day and MVPA were associated with HOMA-IR. However, after controlling for several confounders, only VO<inf>2</inf>max/body fat mass ratio remained negatively associated with HOMA-IR. Future interventions should aim both to promote physical activity and reduce sedentary time in adolescents to improve their cardiorespiratory fitness and postpone the onset of diabetes in adulthood.