Table 2.

The quantified free amino acids in serum samples of two studied groups using the LC-ESI-MS/MS method. P values for the comparison of the variables between two groups were calculated according to Mann-Whitney U test, Student's t-test or Welch's F test. AUC values were obtained in univariate ROC curve analyses.

Amino acid	Concentration in serum samples [µM]						p value	AUC
	The prostate cancer group (n = 49)			The control group (n = 40)
	Average	Median	Range	Average	Median	Range
1-methylhistidine	5.1	2.0	0.3 - 44.7	6.0	4.6	0.7 - 24.8	< 0.001	0.666
3-methylhistidine	4.5	4.5	2.1 - 8.9	3.2	3.1	1.6 - 6.3	0.008	0.746
alanine	396.5	384.8	281.9 - 604.1	488.3	479.9	207.6 - 782.2	< 0.001	0.734
arginine	71.5	67.4	47.9 - 110.4	95.0	87.7	58.3 - 180.1	< 0.001	0.771
asparagine	39.0	38.7	26.5 - 55.1	44.3	43.7	27.7 - 63.4	0.001	0.700
aspartic acid	14.2	14.0	4.6 - 26.4	11.8	11.2	5.0 - 21.0	0.034	0.609
citrulline	26.1	24.6	10.4 - 54.2	26.9	27.8	7.4 - 45.2	0.271	0.569
cystine	12.9	2.6	1.0 - 56.0	4.3	2.7	1.0 - 30.5	0.488	0.542
ethanolamine	7.6	7.6	5.1 - 10.4	9.8	9.6	6.3 - 16.2	< 0.001	0.793
glutamic acid	53.7	47.5	24.6 - 142.7	65.4	59.3	24.8 - 187.3	0.021	0.643
glutamine	407.8	404.0	303.8 - 509.1	496.3	488.1	333.6 - 734.3	< 0.001	0.786
glycine	227.7	219.2	163.6 - 362.1	234.5	229.7	136.8 - 404.6	0.600	0.533
histidine	55.8	56.8	36.1 - 75.6	63.7	61.2	47.9 - 101.2	0.001	0.699
hydroxyproline	13.3	10.4	5.1 - 35.9	12.3	9.5	3.1 - 40.7	0.433	0.549
isoleucine	56.3	54.3	29.4 - 103.1	69.9	70.1	45.5 - 101.5	< 0.001	0.778
leucine	101.6	100.0	59.1 - 163.4	124.7	125.5	77.6 - 189.0	< 0.001	0.753
lysine	154.9	150.9	115.2 - 233.2	188.8	189.5	122.5 - 299.9	< 0.001	0.748
methionine	16.9	16.7	10.6 - 28.9	23.7	22.5	14.3 - 36.3	< 0.001	0.859
ornithine	79.3	81.1	32.4 - 139.5	92.9	85.4	46.7 - 158.4	0.054	0.619
phenylalanine	47.8	45.7	34.9 - 72.5	55.8	55.8	41.2 - 83.7	< 0.001	0.758
proline	202.6	191.0	101.1 - 413.9	188.8	183.5	98.9 - 311.3	0.417	0.550
sarcosine	1.7	1.4	0.6 - 5.6	1.2	1.2	0.2 - 3.0	0.006	0.675
serine	126.4	128.5	84.9 - 174.7	121.7	117.4	78.2 - 199.1	0.396	0.575
taurine	115.1	117.2	32.7 - 174.5	105.6	105.5	48.0 - 232.1	0.073	0.611
threonine	102.1	106.0	53.4 - 168.0	100.6	95.5	62.6 - 152.3	0.754	0.542
tryptophan	41.2	40.3	27.1 - 60.2	44.9	43.4	30.3 - 67.4	0.083	0.608
tyrosine	40.6	38.8	25.1 - 68.9	43.6	41.8	26.5 - 68.7	0.180	0.585
valine	222.8	220.9	139.9 - 328.6	236.8	232.6	161.9 - 307.6	0.112	0.591
α-aminoadipic acid	1.0	0.9	0.3 - 2.5	1.0	0.9	0.5 - 2.0	0.817	0.524
α-amino-n-butyric acid	20.9	18.9	6.6 - 46.1	24.1	23.6	13.1 - 42.8	0.009	0.660
β-alanine	21.5	18.7	4.4 - 54.3	15.6	14.2	5.9 - 45.1	0.013	0.654
β-aminoisobutyric acid	2.0	1.7	0.7 - 7.3	1.9	1.8	0.8 - 4.2	0.843	0.510