Serum metabolomic adaptations following a 12-week high-intensity interval training combined to citrulline supplementation in obese older adults

Physical activity and nutrition play important roles in preventing adverse health outcomes that accompany aging. It has been shown that high-intensity interval training (HIIT) combined with citrulline (CIT) supplementation can improve physical and functional capacities. The aim of this study was to evaluate serum metabolites following a 12-week HIIT combined or not with CIT in obese older adults, and to correlate the metabolic changes with clinico-biological parameters changes. Eighty-six obese older adults completed a 12-week HIIT program combined with a 10 g daily supplementation of either CIT or placebo (PLA) during a double-blinded randomized interventional trial. Only participants with blood samples at T0 (before the intervention) and/or T12 (after the intervention) were included in our sub-analysis (HIIT-PLA-T0: n = 44 and HIIT-PLA-T12: n = 28; HIIT-CIT-T0: n = 39 and HIIT-CIT-T12: n = 42). Serum samples were analyzed by different liquid or gas phase chromatography methods coupled to mass spectrometry. Among the identified metabolites, 44 changed significantly following the 12-week intervention (Time effect), and 10 of them were more affected when HIIT was combined with CIT (Time x Supp effect). Arginine increased significantly due to the 12-week intervention. Correlation analyses demonstrated that decreased triglyceride (TG) (16:1/18:1/16:0) and aspartic acid significantly correlated with a reduction of adiposity-related parameters (fat mass, leg lean mass, leptin, total triglycerides and low-density lipoprotein). Arginine, TG (16:1/18:1/16:0) and aspartic acid might constitute biomarkers of cardiometabolic health and adiposity. Further studies are needed to confirm these associations and understand the underlying mechanisms.

Automated summary

Physical activity and nutrition are important for preventing adverse health outcomes in aging. This study investigated the effects of high-intensity interval training (HIIT) combined with citrulline (CIT) supplementation on serum metabolites in obese older adults. Results showed significant changes in 44 metabolites after the 12-week intervention, with 10 of them more affected by HIIT combined with CIT. Decreased triglycerides and aspartic acid were correlated with reduced adiposity-related parameters. Arginine, triglycerides, and aspartic acid may serve as biomarkers for cardiometabolic health and adiposity.