Relationship between physical activity level and markers of non-alcoholic fatty liver disease among adolescents: ABCD Growth Study

• Grant number: 18/11839-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2019
• End date: June 30, 2020
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Rômulo Araújo Fernandes
• Grantee: Lucas Gabriel de Moraes Chagas
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Physical activity has been studied in the academic community, due to its great impact on the health of the human body. On the other hand, the insufficient practice of physical activities and the sedentary lifestyle have been linked to the aggregation of cardiovascular risk factors since the first decades of life. In view of the fact that the liver plays a fundamental role in the functioning of the body, and in turn can be affected by the excessive accumulation of body fat, it is not yet clear in the scientific literature the possible mediating role of trunk fat in the relation between different intensities of physical activities and liver markers among adolescents. Objective: To analyze the possible mediating role of body adiposity on the relationship between different physical exercise intensities and hepatic markers among adolescents, through the measurement of serum glutamic-oxalacetic transaminase (TGO) and serum glutamic pyruvic transaminase (TGP) in adolescents active and insufficiently active. Methods: Cross-sectional study, data from the longitudinal study "Analysis of Behaviors of Children During Growth" (ABCD Growth Study), developed in the city of Presidente Prudente, SP. The sample will be composed of athletes and students from schools in the city, being divided into active and insufficiently active, in accordance with the following inclusion criteria: i) age between 11 and 17 years; ii) do not present any clinical or metabolic disorder (previously diagnosed); (iii) not to make occasional or regular consumption of any medicine which may interfere with hepatic metabolism; (iv) Term of consent and assent both signed. The usual physical activity will be measured by accelerometer and face-to-face questionnaire. Serum levels of TGO and TGP will be analyzed through blood collection. Total body and trunk fat will be estimated by means of bone densitometry. Body weight and stature will be measured in order to estimate the peak growth velocity (PVC). Chronological age, sex, PVC, and z-score of dyslipidemia (total cholesterol (TC) and fractions [HDL-c, LDL-c, VLDL-c and triacylglycerol (TG)]) will be treated as confounding factors. Student t test for independent samples will be applied in order to compare numerical variables dichotomized by physical activity. Pearson's correlation will be applied in order to verify the relationship of physical activity and serum levels of TGO and TGP. The structural equation model will be applied to test the possible mediator role developed by body fat on the relationship between physical activity and hepatic markers, adjusted by sex, chronological age, peak growth velocity and dyslipidemia. In all the statistical procedures used, the statistical significance adopted will be p-value <0.05, and all analyzes were performed in the BioEstat and Stata software (version 5.0, Tefé, Amazonas, version 15.0, respectively). Expected results: It is expected to verify if body adiposity, specifically trunk fat plays a mediating role on the relationship between different intensities of physical activity practice and liver markers among adolescents. (AU)