Self-reported physician-diagnosed asthma among Swedish adolescent, adult and former elite endurance athletes.
OBJECTIVE
Asthma is common among elite endurance athletes. Since the first published Swedish studies in 1993, awareness of "skiers' asthma" has increased. The current prevalence of asthma among Swedish skiers is unknown. This paper aims to present the design of a 5-year prospective annual questionnaire study on asthma among Swedish current and former elite endurance athletes, the first cross-sectional results on prevalence, age of onset, and predictors of self-reported physician-diagnosed asthma in the study population.


METHODS
An annual postal questionnaire is sent to Swedish elite skiers and orienteers during 2011-2015. In 2013, former Swedish Olympic skiers were similarly invited. We present cross-sectional data obtained in 2011 from the adolescents and adults and in 2013 from former skiers. A total of 491 athletes were invited. The results are presented by age, sex and sport. Chi-square test was used for group comparisons. Predictors of asthma were identified using logistic regression.


RESULTS
Response rate was 82%. Among athletes aged 15-19, 29% of the skiers (38% of the female skiers), and 17% of the orienteers reported asthma (p = 0.071). Among the athletes aged 20-34, 35% of the skiers and 16% of the orienteers reported asthma (p = 0.029). Among the former skiers aged 40-94, 22% reported asthma. Among the active athletes, the onset of asthma was in early adolescence. Logistic regression found increasing age, female sex, allergy, family history of allergy/asthma and being skier predictors of self-reported physician-diagnosed asthma.


CONCLUSIONS
The prevalence of physician-diagnosed asthma is high among Swedish endurance athletes, especially female adolescent skiers.
a Faculty of Medicine , Umeå University , Umeå , Sweden .
Johan
J
Norqvist
a Faculty of Medicine , Umeå University , Umeå , Sweden .
Linda
L
Eriksson
b Unit of Research , Education and Development - Östersund, Umeå University , Umeå , Sweden , and.
Lars
L
Söderström
c Unit of Medicine, Department of Public Health and Internal Medicine, Faculty of Medicine , Umeå University , Umeå , Sweden.
Anne
A
Lindberg
c Unit of Medicine, Department of Public Health and Internal Medicine, Faculty of Medicine , Umeå University , Umeå , Sweden.
Nikolai
N
Stenfors
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology*; D001250:Asthma, Exercise-Induced / Q000175:diagnosis / Q000453:epidemiology; D056352:Athletes / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D057566:Self Report; D012737:Sex Factors; D012865:Skiing / Q000706:statistics & numerical data*; D013177:Sports / Q000706:statistics & numerical data; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
Airway symptoms; epidemiology; medication; orienteers; risk factors; skiers