Association between exercise-induced asthma and parental socio-economic status among school-aged adolescents in a semiurban community in Nigeria

Exercise Induced Bronchospasm and associated factors in primary school children: a cross-sectional study

BACKGROUND

Exercise Induced Bronchospasm(EIB) is not equivalent to asthma. As many as 20%of school aged children are estimated to have EIB. In Nigeria, there is still a dearth of information on EIB as a clinical entity. This study determined the presence of EIB(using pre and post-exercise percentage difference in peak expiratory flow rate(PEFR) and associated factors such as age, gender, social class and nutritional status in primary school children in Nnewi, Anambra state, South-East Nigeria. The study also grouped those with EIB into those with asthma(EIBA) and those without asthma(EIBWA).

METHODS

This was a community based cross-sectional study involving 6-12 year olds. The PEFR was taken at rest and after a 6 min free running test on the school play-ground using a Peak Flow Meter. A diagnosis of EIB was made if there was a decline of ≥ 10%. Those who had EIB were grouped further based on the degree of decline in post-exercise PEFR (a decline ≥ 10% < 25% → Mild EIB, ≥ 25% < 50% → Moderate EIB and ≥ 50% → Severe EIB) and then categorized as those with EIBWA/EIBA.

RESULTS

EIB in the various minutes post-exercise was as follows: 19.2%(1stmin), 20.9%(5thmin), 18.7%(10thmin), 10%(20thmin), 0.7%(30thmin). Mild EIB accounted for the greater proportion in all minutes post-exercise and none of the pupils had severe EIB. Using values obtained in the 5thmin post-exercise for further analysis, EIBWA/EIBA = 84.1%/15.9% respectively. Mean difference in the post-exercise PEFR of EIB/no EIB and EIBWA/EIBA was -48.45(t = -7.69, p =  < 0.001) and 44.46(t = 3.77, p = 0.01) respectively. Age and gender had a significant association to the presence of EIB and 58% of the pupils with EIB were of high social class. The BMI for age and gender z-scores of all study subjects as well as those with EIB was -0.34 ± 1.21, -0.09 ± 1.09 respectively. Other features of allergy(history of allergic rhinitis: OR-5.832, p = 0.001; physical findings suggestive of allergic dermatitis: OR-2.740, p = 0.003)were present in pupils diagnosed with EIB.

CONCLUSION

EIB has a high prevalence in primary school children in Nnewi and the greater proportion of those with EIB had EIBWA. EIB therefore needs to be recognized as a clinical entity and stratified properly based on the presence or absence of asthma. This will help the proper management and prognostication.

Exercise-induced bronchoconstriction: prevalence, pathophysiology, patient impact, diagnosis and management

Exercise-induced bronchoconstriction (EIB) can occur in individuals with and without asthma, and is prevalent among athletes of all levels. In patients with asthma, symptoms of EIB significantly increase the proportion reporting feelings of fearfulness, frustration, isolation, depression and embarrassment compared with those without symptoms. EIB can also prevent patients with asthma from participating in exercise and negatively impact their quality of life. Diagnosis of EIB is based on symptoms and spirometry or bronchial provocation tests; owing to low awareness of EIB and lack of simple, standardised diagnostic methods, under-diagnosis and mis-diagnosis of EIB are common. To improve the rates of diagnosis of EIB in primary care, validated and widely accepted symptom-based questionnaires are needed that can accurately replicate the current diagnostic standards (forced expiratory volume in 1 s reductions observed following exercise or bronchoprovocation challenge) in patients with and without asthma. In patients without asthma, EIB can be managed by various non-pharmacological methods and the use of pre-exercise short-acting β2-agonists (SABAs). In patients with asthma, EIB is often associated with poor asthma control but can also occur in individuals who have good control when not exercising. Inhaled corticosteroids are recommended when asthma control is suboptimal; however, pre-exercise SABAs are also widely used and are recommended as the first-line therapy. This review describes the burden, key features, diagnosis and current treatment approaches for EIB in patients with and without asthma and serves as a call to action for family physicians to be aware of EIB and consider it as a potential diagnosis.