Table 1 Serum levels of kynurenine metabolites, tryptophan, and 5-HIAA, in patients affected by chronic migraine (CM) and healthy controls

Gender (F, %)

69 (82.1)

86 (72.3)

2.66

0.071

Age (years; mean ± SD)

40.4 ± 9.43

44.0 ± 11.6

4446

0.180

Trp (μg/ml) (mean ± SD)

5.00 ± 1.55

5.27 ± 1.70

4198

0.052

KYN (μg/ml) (mean ± SD)

0.34 ± 0.12

0.23 ± 0.09

2286

<0.001

KYNA (ng/ml) (mean ± SD)

3.27 ± 1.85

2.46 ± 1.29

3692

0.002

ANA (ng/ml) (mean ± SD)

2.28 ± 2.14

10.0 ± 5.92

565

<0.001

3-HK (ng/ml) (mean ± SD)

2.39 ± 3.14

1.21 ± 0.69

3498

<0.001

3-HANA (ng/ml) (mean ± SD)

9.11 ± 4.33

3.42 ± 1.40

553

<0.001

QUINA (ng/ml) (mean ± SD)

18.2 ± 12.5

3.78 ± 3.34

580

<0.001

5-HIAA (ng/ml) (mean ± SD)

32.6 ± 11.4

20.8 ± 8.16

1991

<0.001

XA (ng/ml) (mean ± SD)

1.80 ± 1.01

2.30 ± 1.52

4108

0.048