Evaluation of bioavailability and absorption kinetics of different forms of B-hydroxy-B-methylbutyrate (HMB)

• Grant number: 19/24434-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2020
• End date: August 31, 2021
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Guilherme Giannini Artioli
• Grantee: Heitor Rodrigues Ribeiro
• Host Institution: Escola de Educação Física e Esporte (EEFE). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Based on the potential of HMB supplementation to optimize strength and muscle mass gains from strength training, which may have important applications in the context of sport and health, and based on uncertainties regarding the pharmacological form with better bioavailability, This research project aims to analyze the bioavailability, absorption kinetics and clearance of blood HMB, as well as the body retention rate of HMB in its two forms (AL-HMB and CaHMB).2-Methods and Data AnalysisThis proposal is part of a previous project, partially executed by our research team. In general, the samples have already been collected and will be analyzed in this project. HMB concentration will be determined in urine and plasma samples by tandem electrospray ionization mass spectrometry coupled with high performance liquid chromatography in triple-quadrupole equipment (TSQ-Altis TM, Thermo Scientific). Pure urine samples will be diluted in water (1: 100 v / v) for analysis without extraction, given the low complexity of the matrix. The standards and plasma and urine samples will be unicata quantified and analyzed by HPLC-ESI + -MS / MS online using beta-hydroxyvaleric acid-d8 (HMB-d8) as the internal standard. The analyzes will be performed using selected reaction monitoring (SRM), in a method already optimized for HMB separation and quantification at FoRC-USP.Plasma HMB concentration data will be plotted individually as a function of time. Initially, we will use the best-fit strategy to test different adjustments to the obtained curve and verify which type of equation best describes the data obtained (eg zero-order linear vs. first-order exponential). Plasma HMB concentration data and calculated pharmacokinetic parameters will be compared between conditions by linear or quadratic mixed models (proc mixed, SAS v.9.3), depending on the type of curve obtained. Subjects will be the random factor, and treatment and time will be fixed factors. Different covariance matrix structures will be tested, and the Akaike criterion will be used to determine the one that best fits each data set. Urine HMB data will be used to calculate HMB body retention rate, which will be compared between treatments by one-way repeated measures ANOVA.