Inter- and intra-individual variations of urinary endogenous metabolites in healthy male college students using (1)H NMR spectroscopy.
BACKGROUND
Most human metabolomics studies have shown that spectral outputs of (1)H nuclear magnetic resonance fingerprinting are strongly influenced by inter- and intra-individual variations; however, few studies have been performed to evaluate the inter- and intra-individual variations in urinary endogenous metabolites.


METHODS
We recruited 30 male college students to evaluate the factors affecting intra- and inter-individual variations in urinary endogenous metabolites. Statistical analysis for variations in urinary metabolites was performed after eliminating outliers found in principal component analysis (PCA) plots.


RESULTS
Inter-individual variations were relatively low for 2-oxoglutarate, succinate, citrate, dimethylglycine, and taurine, but high for trimethylaminoxide (TMAO), hippurate, and lactate. Intra-individual variations for 2-oxoglutarate, citrate, dimethylglycine, and taurine were relatively low, but high for TMAO and hippurate. The factors affecting inter-individual variation of lactate were age, body mass index, beverages, and alcohol, whereas the factors affecting intra-individual variation of lactate were age and fish. Kim Chi intake affected the inter-individual variation of succinate, citrate, TMAO, and hippurate; however, it did not affect the intra-individual variation of endogenous metabolites.


CONCLUSIONS
Our results showed that inter- and intra-individual variations in urinary endogenous metabolites were very large, and significant factors affecting inter- and intra-individual variation were diverse, even after eliminating outliers in PCA analysis.
Mi Park
Eun
E
Department of Public Health, Graduate School of Medicine, Korea University, Seoul, Korea.
Lee
Eunil
E
Jin Joo
Hyun
H
Oh
Eunha
E
Lee
Joohyun
J
Lee
Ji-Sung
JS
D000328:Adult; D000704:Analysis of Variance; D002264:Carboxylic Acids / Q000652:urine*; D006262:Health; D006801:Humans; D007656:Ketoglutaric Acids / Q000652:urine*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008744:Methylamines / Q000652:urine*; D025341:Principal Component Analysis; D011522:Protons; D015203:Reproducibility of Results; D012521:Sarcosine / Q000031:analogs & derivatives* / Q000652:urine; D012680:Sensitivity and Specificity; D013654:Taurine / Q000652:urine*
D002264:Carboxylic Acids; D007656:Ketoglutaric Acids; D008744:Methylamines; D011522:Protons; D013654:Taurine; C025138:dimethylglycine; D012521:Sarcosine