Table 3. The significance of the associations between metabolites and sarcopenia traits in the joint and individual trait analyses.

Metabolite	Class	HMDB ID	Discovery cohort				Validation cohort
			Joint analysis	ALM/BMI	HGS		Joint analysis	Interaction with race	Interaction with sex	ALM/BMI	HGS
Aspartic acid	Amino acid	HMDB0000191	0.009*	0.023	0.010		0.917	0.539	0.588	0.880	0.704
Glutamic acid	Amino acid	HMDB0000148	0.025*	0.011	0.132		0.001*	0.428	0.259	0.024	0.001
Glutamine	Amino acid	HMDB0000641	0.466	0.585	0.409		0.623	0.080	0.335	0.347	0.876
N-Acetyl-L-aspartic acid	Amino acid	HMDB0000812	0.006*	0.178	0.002		0.682	0.102	0.046	0.548	0.471
Serine	Amino acid	HMDB0000187	0.964	0.920	0.842		0.214	0.668	0.500	0.288	0.294
4-Hydroxyproline	Amino acid	HMDB0000725	0.762	0.475	0.803		0.929	0.703	0.292	0.714	0.868
Arginine	Amino acid	HMDB0000517	0.679	0.582	0.677		0.957	0.293	0.995	0.959	0.796
Ornithine	L-alpha-amino acid	HMDB0000214	0.393	0.199	0.874		0.934	0.624	0.708	0.726	0.861
Proline	Amino acid	HMDB0000162	0.357	0.870	0.176		0.492	0.462	0.319	0.329	0.416
Carnosine	Hybrid peptide	HMDB0000033	0.485	0.292	0.924		0.043	0.060	0.022	0.411	0.038
Histidine	Amino acid	HMDB0000177	0.391	0.186	0.567		0.164	0.471	0.657	0.589	0.117
Urocanic acid	Imidazole	HMDB0000301	0.667	0.952	0.406		0.958	0.443	0.526	0.942	0.828

*FDR q-value < 0.05. Raw P values < 0.05 are bold.

ALM/BMI, body mass index adjusted appendicular lean mass; HGS, hand grip strength; HMDB, the Human Metabolome Database.