Table 2.

Specific metabolites identified to be related to insulin resistance and future metabolic risk based on 10 included studies.

Affected metabolic pathways		Metabolites related to IR	Reference
Amino acids metabolism	Branched-chain amino acids	Valine, leucine, and isoleucine	[21–24, 26]
		Isovalerylcarnitine and isobutyrylcarnitine	[21, 23]
	Aromatic amino acids	Tyrosine and phenylalanine	[20–23, 26]
	Sulfur amino acids	Cysteine and homocysteine	[29]
	Other	Asparagine, glycine, serine, proline, citrulline, glutamate, and methionine	[20, 21, 24, 26]
Lipid metabolism	Acylcarnitines	C2, C3, C5, C2/(C3 + C5), C5/C6-oxo, C4/C5-oxo, C6-oxo/xLeu, and long-chain dicarboxylic acylcarnitines	[20, 22–24]
	Fatty acids	NEFA and FAO by-products	[21, 24]
	Steroid	Androgen hormones	[21, 23]