Plasma Amino Acids and Acylcarnitines Are Associated with the Female but Not Male Adolescent Swimmer's Performance: An Integration between Mass Spectrometry and Complex Network Approaches

Abstract

The main aim of this study was to compare the performance over different distances, the critical velocity (CV), and plasma acylcarnitines/amino acids of male and female adolescent swimmers. Moreover, we applied the complex network approach to identify which molecules are associated with athletes' performances. On the first day under a controlled environment, blood samples were collected after 12 h of overnight fasting. Performance trials (100, 200, 400, and 800-m) were randomly performed in the subsequent four days in a swimming pool, and CV was determined by linear distance versus time mathematical function. Metabolomic analyses were carried out on a triple quadrupole mass spectrometer performing electrospray ionization in the positive ionization mode. No difference was observed between the performance of male and female swimmers. Except for 200-m distance (p = 0.08), plasma tyrosine was positively and significantly associated with the female times during the trials (100-m, p = 0.04; 400-m, p = 0.04; 800-m, p = 0.02), and inversely associated with the CV (p = 0.02). The complex network approach showed that glycine (0.406), glutamine (0.400), arginine (0.335), free carnitine (0.355), tryptophan (0.289), and histidine (0.271) were the most influential nodes to reach tyrosine. These results revealed a thread that must be explored in further randomized/controlled designs, improving the knowledge surrounding nutrition and the performance of adolescent swimmers.

Keywords: athletic performance; critical velocity; metabolism; metabolomics; swimming.

Figure 1

Experimental design of the study; MS—Mass Spectrometry.

Figure 2

Comparison of performances over distinct distances and the critical velocity (CV) between male and female adolescent swimmers; (A) Comparison of performances on the 100-m; (B) Comparison of performances on the 200-m; (C) Comparison of performances on the 400-m; (D) Comparison of performances on the 800-m; (E) Comparison of CV; p ≤ 0.05.

Figure 3

Univariate and multivariate analyses on the plasma amino acid of adolescent swimmers. (A) Independent t-test and False Discovery Rate (FDR) of plasma amino acids between male and female adolescent swimmers; (B) discriminatory approach by the Principal Component Analysis (PCA) and the Partial Least Squares-Discriminant Analysis (PLS-DA); (C) Random Forest classification; * Significant difference; p ≤ 0.05.

Figure 4

Univariate and multivariate analyses on the acylcarnitines of adolescent swimmers. (A) Independent t-test and False Discovery Rate (FDR) of plasma acylcarnitines between male and female adolescent swimmers; (B) discriminatory approach by the Principal Component Analysis (PCA) and the Partial Least Squares-Discriminant Analysis (PLS-DA); (C) Random Forest classification.

Figure 5

Upper panel presents the correlations between the performance trials for 100, 200, 400, and 800 m in addition to the critical velocity (CV) and plasma tyrosine of female adolescent swimmers. The lower panel presents the complex network based on the amino acids and acylcarnitines considering tyrosine as the target node.