Table 2.

The chemical shift and variation of each metabolite level among the three groups.

Chemical Shift (ppm)	Metabolites	CHD vs. HC			PAH-CHD vs. CHD			PAH-CHD vs. HC
		VIP	Vary	p	VIP	Vary	p	VIP	Vary	p
0.93	Leucine		↑↑	0.000		↓↓	0.000		—	ns
0.98	Isoleucine		↑↑	0.000		—	ns		↑	0.019
1.02	Valine		↑↑	0.000		↓↓	0.006		↑↑	0.008
1.04	Isobutyrate		↑↑	0.000		—	ns		↑↑	0.000
1.45	Alanine		—	ns	1.10	↓↓	0.000		—	ns
1.90	Acetate		↑↑	0.000		↑↑	0.001		↑↑	0.000
2.32	Glutamate		↑↑	0.000		—	ns		↑↑	0.000
2.35	Pyruvate		↑↑	0.009		—	ns		—	ns
2.43	Glutamine	1.94	↑↑	0.000		↓↓	0.003	1.56	↑↑	0.000
2.50	Citrate		↑↑	0.000		↑↑	0.007	1.04	↑↑	0.000
2.61	Methionine		↑↑	0.000		—	ns		↑↑	0.000
2.90	Trimethylamine		↑↑	0.000		↑	0.037		↑↑	0.000
2.98	Lysine	1.77	↑↑	0.000		—	ns	1.74	↑↑	0.000
3.25	GPC		↑↑	0.005		↓	0.024		—	ns
3.26	Carnitine		↑↑	0.000		—	ns		↑↑	0.000
3.36	Methanol	2.04	↑↑	0.000		↓↓	0.004	1.79	↑↑	0.000
3.39	Glucose	2.80	↑	0.018	3.35	↓↓	0.000	1.49	—	ns
3.42	Acetoacetate		↑↑	0.000		↑	0.022		↑↑	0.000
3.53	Glycine		↑	0.011	1.15	↓↓	0.002		—	ns
3.56	Threonine		↑↑	0.002	2.19	↑↑	0.000	2.09	↑↑	0.000
3.91	Creatine		↑↑	0.000		—	ns		↑↑	0.000
3.95	Serine		↑↑	0.000		↑↑	0.003	1.47	↑↑	0.000
4.05	Choline		↑↑	0.001		↓↓	0.001		—	ns
4.09	Lactate	1.08	—	ns	2.02	↑↑	0.000	2.22	↑↑	0.000
6.87	Tyrosine		↑↑	0.000		—	ns		↑↑	0.000
7.30	Phenylalanine		↑↑	0.000		—	ns		↑↑	0.000
7.73	Histidine		↑↑	0.000		↓	0.019		—	ns
8.43	Formate		↑↑	0.000		↑↑	0.000		↑↑	0.000

Notes: the variation in metabolite level: ↑ and ↓ denotes p < 0.05, ↑↑ and ↓↓ denotes p < 0.01, ns means “not significant”; only listing the values of VIP > 1. Abbreviations: PAH-CHD, pulmonary arterial hypertension associated with congenital heart disease; CHD, congenital heart disease; HC, healthy control; GPC, Glycerylphosphorylcholine; VIP, variable importance in projection.