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Table 1 Clinical and biochemical data

From: Serum concentrations of kynurenines in adult patients with attention-deficit hyperactivity disorder (ADHD): a case–control study

 

ADHD

N

Control

N

p value

133

131

Female, N (%)

71 (53.4)

133

75 (57.3)

131

0.52a

Age (range 18–40), median (SD)

28.0 (6.5)

133

22.5 (2.8)

131

<0.001***b

Alcohol problems, N (%)

24 (19.2)

125

1 (0.8)

131

<0.001***a

Problems with illicit drugs, N (%)

34 (27.0)

126

0 (0.0)

131

<0.001***a

Serious anxiety and/or depression, N (%)

82 (65.1)

126

5 (3.8)

126

<0.001***a

Bipolar disorder, N (%)

12 (9.9)

121

0 (0.0)

131

<0.001***a

Moderate smokersd, N (%)

51 (38.3)

133

12 (9.2)

131

<0.001***a

Heavy smokersd, N (%)

27 (27.8)

133

4 (3.1)

131

<0.001***a

Total WURS (range 0–100), median (SD)

60.0 (16.9)

118

12.0 (10.4)

129

<0.001***b

Total ASRS (range 0–72), median (SD)

47.0 (11.6)

123

22.0 (7.7)

128

<0.001***b

Combined typee, N (%)

65 (52.8)

123

3 (2.3)

128

<0.001***a

Hyperactive typee, N (%)

3 (2.4)

123

1 (0.8)

128

0.32a

Inattentive typee, N (%)

31 (25.2)

123

4 (3.1)

128

<0.001***a

Tryptophanf, i

77.3 (68.1–92.3)

133

83.6 (76.6–94.0)

130

0.004**c

Kynureninef, i

1.51 (1.29–1.78)

133

1.57 (1.40–1.76)

130

0.15c

Kynurenine/tryptophan ratio (KTR)g, i

19.0 (16.5–21.6)

133

18.4 (16.7–20.8)

130

0.46c

3-hydroxykynurenine (HK)h, i

31.8 (22.2–39.4)

131

30.6 (26.1–28.1)

130

0.43c

Kynurenic acid (KA)h, i

38.9 (30.9–52.2)

131

46.7 (34.0–57.5)

130

0.03*c

Xanthurenic acid (XA)h, i

14.2 (11.0–22.4)

131

18.9 (13.7–24.7)

130

0.004**c

Anthranilic acid (AA)h, i

19.4 (13.2–24.3)

131

17.6 (14.9–22.8)

130

0.52c

3-hydroxyanthranilic acid (HAA)h, i

29.8 (20.0–40.1)

131

35.4 (29.2–46.5)

130

<0.001***c

Quinolinic acid (QA)h, i

303 (258–387)

131

306 (274–364) 

130

0.76c

Riboflavin (Vit. B2)h, i

18.1 (12.7–25.9)

131

19.9 (16.1–28.3)

130

0.02*c

Total vitamin B6h, i

58.5 (41.8–83.9)

131

67.1 (49.0–88.4)

130

0.05*c

Cotinineh, i

678 (2.48–1088)

131

1.2 (0.55–6.06)

130

<0.001***c

  1. Significance <0.001: ‘***’, <0.01: ‘**’, <0.05: ‘*’
  2. aχ2 test
  3. bStudent’s T test
  4. cMann–Whitney U test
  5. dCalculated based on serum cotinine levels: 80–1000 nmol/l: moderate smoker, >1000 nmol/l: heavy smoker
  6. eCalculated based on ASRS scores: A score of 21 or higher on the nine questions on inattentiveness is indicative of inattentive type, while a score of 21 or higher on the hyperactivity/impulsive questions is indicative for hyperactive/impulsive type. Combined type requires a score of 21 or higher on both subscales
  7. fμmol/L
  8. gμmol/μmol
  9. h nmol/L
  10. iMedian (25–75 percentile)