Nitric Oxide (NO) values of schoolchildren with and without reported symptoms of asthma, allergy or colds (indicated as healthy and diseased, respectively), with and without noseclip or breathholding, measured when ambient NO was <10 ppb
| Status | Subjects | NC− | NC+ | NC+ | NC− |
| n | BH− | BH− | BH+ | BH+ | |
| Healthy | 72 | 5.1±0.2 (2.1–10.9) | 4.5±0.2** (1.1–9.5) | 6.2±0.4** (2.2–20.5) | 6.4±0.4*** (2.7–21.6) |
| Diseased | 49 | 6.8±0.3* (2.4–15.3) | 5.9±0.4* (1.8–14.3) | 8.9±1.1* (2.0–46.2) | 8.3±0.9* (2.3–32.1) |
Data are presented as mean±sd (range)
NC: nose clip
BH: breathholding
+: worm/performed
−: not worm/performed
*: p<0.001 compared to healthy children, same measurement conditions
**: p<0.001 compared to healthy children without noseclip and breathhold
***: p<0.0001 compared to healthy children without noseclip and breathhold