Table 2. Breath VOCs in IBD: adjusted for age and gender.
| Factor | CD (N=24) | UC (N=11) | IPAA (N=30) | OGD (N=6) | HC (N=53) | P value |
|---|---|---|---|---|---|---|
| 2-Propanol | 83.3 (61.0, 113.8)a,b | 86.3 (54.3, 136.9)b | 322.1 (243.7, 425.9)a,c,d,e | 41.2 (21.6, 78.6)b | 44.5 (35.8, 55.3)b,e | <0.001 |
| Acetaldehyde | 38.8 (30.9, 48.6)b | 40.8 (29.2, 57.0)b | 170.7 (139.5, 208.9)a,c,d,e | 35.4 (22.2, 56.5)b | 26.8 (22.9, 31.4)b | <0.001 |
| Acetone | 220.9 (156.6, 311.6)b | 197.2 (118.4, 328.3)b | 853.3 (627.1, 1161.0)a,c,d,e | 247.6 (121.4, 504.6)b | 157.0 (123.4, 199.6)b | <0.001 |
| Acetonitrilef | 15.0 (11.8, 19.0) | 12.4 (8.7, 17.6) | 21.3 (17.3, 26.3) | 14.5 (8.9, 23.7) | 14.1 (10.7, 18.5) | 0.038 |
| Acrylonitrile | 1.08 (0.91, 1.3)a | 1.2 (0.89, 1.5)a | 1.08 (0.92, 1.3)a | 1.3 (0.89, 1.9) | 0.76 (0.67, 0.86)b,d,e | <0.001 |
| Benzene | 4.2 (3.1, 5.6)b | 3.6 (2.3, 5.6)b | 13.3 (10.3, 17.4)a,c,d,e | 3.9 (2.1, 7.1)b | 3.3 (2.7, 4.1)b | <0.001 |
| Carbon disulfide | 4.3 (3.4, 5.4)a,b | 4.3 (3.1, 5.9)a,b | 11.6 (9.5, 14.2)a,c,d,e | 4.2 (2.6, 6.6)b | 2.4 (2.1, 2.8)b,d,e | <0.001 |
| Dimethyl sulfide | 2.9 (2.2, 3.7)a,b | 3.0 (2.1, 4.3)b | 27.6 (22.1, 34.6)a,c,d,e | 3.4 (2.0, 5.7)b | 1.8 (1.5, 2.2)b,e | <0.001 |
| Ethanol | 111.5 (83.0, 149.6)a,b | 113.4 (73.3, 175.5)b | 256.5 (197.1, 333.9)a,c,d,e | 63.0 (34.2, 115.9)b | 57.3 (46.6, 70.4)b,e | <0.001 |
| Isoprene | 30.3 (23.3, 39.4)a,b | 22.6 (15.3, 33.3)b | 150.3 (118.8, 190.2)a,c,d,e | 24.5 (14.2, 42.2)b | 16.8 (14.0, 20.2)b,e | <0.001 |
| Pentane | 20.2 (16.2, 25.0)b | 18.5 (13.4, 25.5)b | 87.0 (71.7, 105.6)a,c,d,e | 18.9 (12.1, 29.6)b | 14.1 (12.1, 16.4)b | <0.001 |
| 1-Decene | 5.4 (3.7, 7.8)b | 5.3 (3.0, 9.1)b | 0.86 (0.62, 1.2)a,c,d,e | 9.8 (4.5, 21.1)b | 6.7 (5.1, 8.6)b | <0.001 |
| 1-Heptene | 12.2 (7.9, 19.0)b | 9.4 (4.9, 18.0)b | 2.2 (1.5, 3.3)a,c,d,e | 16.7 (6.7, 41.4)b | 11.0 (8.1, 14.9)b | <0.001 |
| 1-Nonene | 4.3 (3.0, 6.0)b | 4.2 (2.5, 7.0)b | 0.97 (0.72, 1.3)a,c,d,e | 11.4 (5.6, 23.1)b | 4.9 (3.9, 6.2)b | <0.001 |
| 1-Octene | 20.5 (14.3, 29.3)b | 20.8 (12.3, 35.3)b | 3.1 (2.2, 4.2)a,c,d,e | 21.9 (10.5, 45.8)b | 19.3 (15.1, 24.8)b | <0.001 |
| 3-Methylhexane | 32.6 (26.0, 41.0)b | 31.0 (22.1, 43.4)b | 67.3 (55.0, 82.5)a,c,d,e | 19.6 (12.3, 31.4)b | 25.3 (21.6, 29.7)b | <0.001 |
| (E)-2-nonene | 2.7 (1.9, 3.9)b | 2.3 (1.3, 3.9)b | 0.84 (0.61, 1.2)a,c,d,e | 3.2 (1.5, 6.7)b | 2.3 (1.8, 3.0)b | <0.001 |
| Ammonia | 76.5 (60.0, 97.6)c | 70.1 (48.9, 100.5) | 60.2 (48.4, 74.8) | 33.9 (20.5, 56.0)e | 62.0 (52.3, 73.4) | 0.065 |
| Ethane | 94.1 (82.3, 107.6)b | 92.0 (75.4, 112.2)b | 167.0 (148.1, 188.3)a,c,d,e | 69.4 (52.5, 91.6)b | 76.9 (70.0, 84.4)b | <0.001 |
| Hydrogen sulfide | 0.46 (0.35, 0.60) | 0.51 (0.34, 0.75) | 0.32 (0.25, 0.40)c | 1.01 (0.58, 1.8)a,b | 0.41 (0.34, 0.50)c | 0.003 |
| Triethyl amine | 1.3 (1.05, 1.6)a,b | 1.2 (0.86, 1.6) | 0.75 (0.62, 0.91)c,e | 2.2 (1.4, 3.4)a,b | 0.89 (0.77, 1.03)c,e | <0.001 |
| Trimethyl amine | 11.0 (8.2, 14.7)b | 8.8 (5.7, 13.5)b | 25.4 (19.6, 32.9)a,c,d,e | 9.8 (5.4, 17.7)b | 7.5 (6.1, 9.2)b | <0.001 |
Abbreviations: ANCOVA, analysis of covariance; CD, Crohn's disease; CI, confidence interval; HC, non-inflammatory controls; IBD, inflammatory bowel disease; IC, inflammatory control; IPAA, ileal pouch anal anastomosis; OGD, inflammatory controls; UC, ulcerative colitis; VOC, volatile organic compound.
Values presented as mean (95% CI) and were obtained using ANCOVA analysis. The logarithm of each VOC was modeled as the outcome variable with group, age, and gender as the independent variables. VOC values are presented as parts per billion.
Bonferroni correction was used for all post hoc comparisons.
Significantly different from healthy controls.
Significantly different from pouch.
Significantly different from ICs.
Significantly different from UC.
Significantly different from CD.
Acetonitrile measured in only 19 healthy controls. Bold and italic values are significant.