Mediation role of cardiorespiratory fitness on the association between fatness and cardiometabolic risk in European adolescents:The HELENA study

We thank the adolescents who participated in the study and their parents and teachers for their collaboration. We also acknowledge the HELENA study members involved in fieldwork for their efforts. The HELENA project was supported by the European Community 6th Framework Programme for Research and Technological Development (contract FOODCT-2005-007034). The data for this study were gathered under the aegis of the HELENA project, and further analysis was additionally supported by the Spanish Ministry of Economy and Competitiveness (Grants RYC-2010-05957 and RYC-2011-09011), the Spanish Ministry of Health: Maternal, Child Health and Development Network (Grants RD08/0072 and RD16/0022), the Fondo Europeo de Desarrollo Regional (MICINN-FEDER), and the University of Granada, Plan Propio de Investigaci~on 2016, Excellence Actions: Units of Excellence; Unit of Excellence on Exercise and Health (UCEES). The content of this article reflects the authors' views alone, and the European Community is not liable for any use that may be made of the information contained herein.
Purpose: This study was aimed to analyze the mediation role of cardiorespiratory fitness (CRF) on the association between fatness and cardiometa-bolic risk scores (CMRs) in European adolescents. Methods: A cross-sectional study was conducted in adolescents (n = 525; 46% boys; 14.1 +/- 1.1 years old, mean +/- SD) from 10 European cities involved in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. CRF was measured by means of the shuttle run test, while fatness measures included body mass index (BMI), waist to height ratio, and fat mass index estimated from skinfold thicknesses. A clustered CMRs was computed by summing the standardized values of homeostasis model assessment, systolic blood pressure, triglycerides, total cholesterol/high-density lipoprotein cholesterol ratio, and leptin. Results: Linear regression models indicated that CRF acted as an important and partial mediator in the association between fatness and CMRs in 12-17-year-old adolescents (for BMI: coefficients of the indirect role beta = 0.058 (95% confidence interval (95%CI): 0.023-0.101), Sobel test z = 3.11 (10.0% mediation); for waist to height ratio: beta = 4.279 (95%CI: 2.242-7.059), z = 3.86 (11.5% mediation); and for fat mass index: beta = 0.060 (95%CI: 0.020-0.106), z = 2.85 (9.4% mediation); all p < 0.01). Conclusion: In adolescents, the association between fatness and CMRs could be partially decreased with improvements to fitness levels; therefore, CRF contribution both in the clinical field and public health could be important to consider and promote in adolescents independently of their fatness levels.
European Community 6th Framework Programme for Research and Technological Development FOODCT-2005-007034
Spanish Ministry of Economy and Competitiveness RYC-2010-05957 RYC-2011-09011
Spanish Government RD08/0072 RD16/0022
Fondo Europeo de Desarrollo Regional (MICINN-FEDER)
University of Granada, Plan Propio de Investigacion 2016, Excellence Actions: Units of Excellence
Unit of Excellence on Exercise and Health (UCEES)