Association of leisure time physical activity and NMR-detected circulating amino acids in peripubertal girls: A 7.5-year longitudinal study

Exploring the association of physical activity with the plasma and urine metabolome in adolescents and young adults

BACKGROUND

Regular physical activity elicits many health benefits. However, the underlying molecular mechanisms through which physical activity influences overall health are less understood. Untargeted metabolomics enables system-wide mapping of molecular perturbations which may lend insights into physiological responses to regular physical activity. In this study, we investigated the associations of habitual physical activity with plasma and urine metabolome in adolescents and young adults.

METHODS

This cross-sectional study included participants from the DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) study with plasma samples n = 365 (median age: 18.4 (18.1, 25.0) years, 58% females) and 24 h urine samples n = 215 (median age: 18.1 (17.1, 18.2) years, 51% females). Habitual physical activity was assessed using a validated Adolescent Physical Activity Recall Questionnaire. Plasma and urine metabolite concentrations were determined using ultra-high-performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) methods. In a sex-stratified analysis, we conducted principal component analysis (PCA) to reduce the dimensionality of metabolite data and to create metabolite patterns. Multivariable linear regression models were then applied to assess the associations between self-reported physical activity (metabolic equivalent of task (MET)-hours per week) with single metabolites and metabolite patterns, adjusted for potential confounders and controlling the false discovery rate (FDR) at 5% for each set of regressions.

RESULTS

Habitual physical activity was positively associated with the "lipid, amino acids and xenometabolite" pattern in the plasma samples of male participants only (β = 1.02; 95% CI: 1.01, 1.04, p = 0.001, adjusted p = 0.042). In both sexes, no association of physical activity with single metabolites in plasma and urine and metabolite patterns in urine was found (all adjusted p > 0.05).

CONCLUSIONS

Our explorative study suggests that habitual physical activity is associated with alterations of a group of metabolites reflected in the plasma metabolite pattern in males. These perturbations may lend insights into some of underlying mechanisms that modulate effects of physical activity.

Branched-Chain and Aromatic Amino Acids Are Associated With Insulin Resistance During Pubertal Development in Girls

PURPOSE

Cross-sectional studies in children show branched-chain and aromatic amino acids are associated with insulin resistance, but whether these associations persist from childhood to adulthood is not known. This study aimed to assess whether circulating amino acids associate with insulin resistance during pubertal development.

METHODS

This was a 7.5-year longitudinal study from childhood to early adulthood. A total of 396 nondiabetic Finnish girls aged 11.2 ± .8 years at baseline participated in the study which was conducted at the Health Science Laboratory, University of Jyväskylä. Serum concentrations of glucose and insulin were determined by enzymatic photometric methods and amino acids by nuclear magnetic resonance spectroscopy. Insulin resistance was determined by the homeostatic model assessment of insulin resistance (HOMA-IR).

RESULTS

All amino acids were positively associated with HOMA-IR both before and after menarche (p < .05 for all), except for histidine. Branched-chain amino acids and aromatic amino acids showed the strongest associations, the magnitude of correlation coefficients being similar before and after menarche (R² = .064-.171). After adjusting for body mass index z-score and height, the associations between branched-chain amino acids and aromatic amino acids and HOMA-IR remained significant both before and after menarche.

CONCLUSIONS

Branched-chain amino acids and aromatic amino acids associate with insulin resistance during pubertal development, independent of adiposity. Further studies are needed to determine whether changes in amino acid metabolism link pubertal hyperinsulinemia to accelerated physiological growth and/or heightened cardiometabolic risk later in life.