Cardiorespiratory screening in elite endurance sports athletes: the Quebec study

Background: Cardiorespiratory disorders are common in athletes. However, these conditions are often underdiagnosed, which potentially results in impaired performance and increased health risks. The aim of this study was to evaluate, in a research setting, the prevalence of cardiorespiratory disorders in athletes in order to determine the potential value of a screening program.Methods: One hundred thirty-three athletes were studied. Each subject underwent a physical examination. A eucapnic voluntary hyperventilation (EVH) test and a methacholine inhalation test were performed to confirm the diagnosis of asthma. A cardiovascular evaluation was also performed, including maximal exercise test with electrocardiogram, 24-hour ambulatory blood pressure monitoring, 24-hour Holter monitoring, and blood sampling.Results: Seventy-four (56%) athletes had airway hyperresponsiveness to EVH or the methacholine inhalation test. Among those with airway hyperresponsiveness, 45 (61%) athletes were only hyperresponsive to EVH, and 10 (14%) were only hyperresponsive to the methacholine inhalation test (using the criteria of a PC20 ≤ 4 mg/mL). Thirty-two (24%) athletes had a known diagnosis of asthma, while 34 (26%) athletes received a new asthma diagnosis. Ninety-seven (73%) athletes were sensitized to common airborne allergens. Forty-seven (35%) athletes completed the cardiovascular evaluation. Three (6%) and 7 (15%) athletes had a previous or new diagnosis of cardiovascular disease, respectively. Resting systemic hypertension was documented in 2 (4%) athletes and exaggerated blood pressure response to exercise was found in 12 (26%) athletes.Conclusion: This cardiorespiratory screening data set in athletes showed a high prevalence of exercise-induced asthma and exercise hypertension, which in many cases were not previously diagnosed.