Table 1

Subjects’ characteristics and asthma-related results in cross-country skiers and controls

	Cross-country skiers		Controls		P value
	Median/n	Q₁–Q₃/%	Median/n	Q₁–Q₃/%	P value
Age, years.	16.5	14.3–21.5	17.0	15–22.5	0.033
Body mass index, kg/m^2–	21.0	3.6	21.8	5.4	<0.001
Female subjects	204	58.1	235	69.5	0.002
Engaged in competitive sports other than cross-country skiing	223	63.5	88	26.0	<0.001
Team sports	36	16.1	54	61.3	<0.001
High ventilation sports (cycling, running, triathlon, orienteering, aerobic gymnastics)	195	87.6	7	7.9	<0.001
Moderate ventilation sports (combat sports, gymnastics, dancing)	0	0	19	21.6	<0.001
Low ventilation sports (shooting, horseback riding, weightlifting)	34	15.2	5	5.7	0.022
Smoking	0	0	20	5.9	<0.001
Physician-diagnosed allergy to pollens or animals	113	32.2	82	24.5	0.025
Self-reported allergic rhinitis	160	45.7	122	36.9	0.019
Asthma in parents or siblings	137	39.0	100	29.6	0.007
Training or heavy exercise/week, hours	10.0	8.0–10	2.4	1.0–4.5	<0.001
Use of any asthma medication	123	35.0	39	11.5	<0.001
Has been diagnosed with, or been investigated for, asthma	189	53.8	69	20.4	<0.001
Current asthma	91	25.9	31	9.2	<0.001
Allergic asthma (% of current asthma)	36	39.6	19	61.3	0.036
Non-allergic asthma (% of current asthma)	55	60.4	12	38.7	0.036
Age at first asthma-related symptoms in subjects with asthma, years*	13.0	8.25–16.0	8.0	2.25–11.75	<0.001
Age at diagnosis of asthma, years*	15.0	12.0–17.8	10.0	3.0–12.0	<0.001
Time from onset of asthma-related symptoms to diagnosis of asthma, years*	1.0	1.0–3.0	1.0	0–4.0	0.789
Asthma Control Test score*	22.0	21–24	22.0	19–24	0.611

*In subjects with current asthma.