Cardiopulmonary Fitness in Children With Asthma Versus Healthy Children

This retrospective study was carried out from November 2010 to September 2015 for control children (already published PMID: 29170358) : and January 2015 to December 2019 for asthmatic children. CPET were realised in 2 paediatric CPET laboratories (centre 1: Montpellier University Hospital, France; centre 2: Paediatric Cardiology and Rehabilitation Centre, Institut-Saint-Pierre, Palavas-Les-Flots, France). Children aged 5 to 18 years old were recruited in one of the 2 CPET laboratories. Two groups were identified: children with asthma and the control children. 1. The asthma group consisted of children followed for asthma by any pediatrician or pulmonologist and referred to one of the 2 CPET laboratories. The following clinical data were collected : gender, weight, height, treatments to deduce treatment level (GINA step), associated pathologies, activity level, symptoms during exercice 2. The control group consisted of children referred for a non-severe functional symptom linked to exercise (murmur, palpitation, or dyspnoea) or for a medical sports certificate. These children were classified in the control group only after a completely normal check-up, including physical examination, electrocardiogram, echocardiography, and spirometry. Children with any chronic disease, medical condition (cardiac, neurologic, respiratory, muscular, or renal), or medical treatment and those requiring any further specialized medical consultation were not eligible. The clinical data collected concerned gender, weight, height. CPET procedures in both centres were harmonized before the study started. Spirometry was systematically performed before the exercise test with a flow volume curve and measurement of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and the FEV1/FVC ratio (FEV1/FVC), with normalization to GLI 2012 Z scores. The same investigator coordinator manually calculated the VO2max and the ventilatory anaerobic threshold (VAT) using Beaver's method. VO2max and VAT values were normalized in a percentage of the predicted VO2max using normal values from Wasserman and Cooper. The investigators considered VO2max below 80% of predicted value as pathologic value and a VAT value below 55 % of predicted VO2max was in favor of muscular deconditioning. All informations from CPET were recorded : heart rate (HR), blood pressure (BP), estimated VO2/HR, VAT, breathing reserves (BR), respiratory rate (RR), VE/VCO2 slope, Tidal Volume (VT)