Changes in Cardiorespiratory Fitness in Children and Adolescents Predicts Adulthood Body Composition Phenotypes

Abstract

PURPOSE: Childhood and adolescence are critical periods for the decrease or increase of cardiorespiratory fitness (CRF), which may influence the development of selected obesity phenotypes in adulthood. We investigated the independent associations between CRF changes from childhood and adolescence to adulthood, with body composition phenotypes in adulthood, including total body fat (TBF), android fat (AF) and trunk fat (TF). METHODS: Baseline assessments, from the Portuguese European Youth Heart Study arm, were conducted in 1999/2000 in 26 girls and 43 boys aged 9-15 years old, which were later followed into young adulthood (24-31 years old). CRF, as estimated by a maximal cycle ergometer test was taken at baseline and follow-up. CRF was dichotomized using established criteria and grouped as follow (initial|follow up): FIT|FIT; FIT|UNFIT; UNFIT|FIT; UNFIT|UNFIT. TBF, AF, and TF were measured in adulthood using dual energy x-ray absorptiometry and dichotomized according to the highest risk quartile. AF was evaluated using the default region of interest provided by the software, set between the top of the iliac crest and bellow the last rib. Linear and binary logistic regression analysis were performed. RESULTS: Changes in CRF were negatively associated with TBF (R=-0.249, p=0.044), AF (R=-0.289, p<0.018) and TF (R=-0.282, p=0.022) in adulthood. Logistic regression analysis demonstrated that children and adolescents that remained unfit through adulthood were at increased risk for high TBF, AF and TF. After adjusting for possible confounders (age, gender, follow-up period and initial BMI), only TBF (OR=6.59, CI: 1.27-34.32) and TF (OR=8.22, CI: 1.37-46.09) associations remained significant. CONCLUSIONS: Low CRF values during childhood and young adulthood are associated with unfavorable body composition phenotypes. These results highlight that CRF should be considered as an important attribute in childhood and adolescence to prevent long-term total and central obesity phenotypes.