Impact of vitamin D, muscle mass and strength on bone health parameters of adolescents engaged in different sports: ABCD - Growth Study

• Grant number: 23/07700-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): September 01, 2024
• Effective date (End): August 31, 2028
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Rômulo Araújo Fernandes
• Grantee: Eduardo Duarte de Lima Mesquita
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Introduction: Vitamin D has fundamental functions in human organism, with the processes of bone mineralization and homeostasis of calcium and phosphorus having the most prominent ones. However, recent studies have been addressing its relationship with muscle tissue and strength, which together, may affect bone tissue. In this sense, the literature still discusses the effects of muscle mass and strength on bone variables in adolescents. Objective: Analyze the impact of lower limb muscle mass and strength on bone health in adolescents, and to identify the mediating role of serum vitamin D concentrations in this process. Methods: Longitudinal study (12-month duration in two waves of assessment [baseline and 12 months on collection 1 and baseline and 12 months on collection 2]) will be conducted in the city of Presidente Prudente - SP. The sample will be composed of 78 individuals classified as: control (school children not engaged in regular practice of sports), high/medium impact (judo, basketball, gymnastics and soccer) and non-repetitive impact (swimming). Bone mineral density, bone mineral content, bone geometry, muscle mass will be estimated from a bone densitometry equipment. Lower limb muscle strength will be measured by jumping platform. Vitamin D, osteocalcin, P1NP and CTX will be measured by blood analysis. Mediation variables will be serum vitamin D concentration and muscle strength. Adjustment variables will be sex, age, biological maturation and allocation group. All analyses will be performed in Stata software (version 15.0) and statistical significance (p-value) will be pre-set to less than 5%. Expected Results: It is expected to finally understand the role of muscle mass and strength on bone health parameters in pediatric population, as well as whether vitamin D could mediate this process.