Impaired Cardiovascular Response to Exercise in Patients with Severe Asthma: A Case-Control Study.

Background: Although asthmatics may present reduced exercise capacity, data on their cardiovascular responses during exercise testing have been scarcely investigated. The aim of this pilot case-control study is to test: a) whether double product (DP), an index of cardiovascular reserve, differs among patients with severe and mild-moderate asthma, and b) whether DP is associated with asthma control level, physical activity (PA) and exercise capacity, in asthmatics population. Materials and Methods: A group of patients with severe asthma (group S) and a matched group of patients with mild-moderate asthma (group M) was studied. All participants completed asthma control and physical activity (IPAC) questionnaires, lung function measurements and six-minute walk test. The exercise capacity (as 6-minute walk distance (6MWD) and corresponding work), the Borg Dyspnea, the rating of perceived excursion and the average PA METS were recorded. Results: A total of 18 patients were studied. DP at exercise end was significantly lower in group S, compared to group M (16412.2±4732.1 Conclusion: Patients with severe asthma may have impaired cardiovascular reserve as established by DP, even when exercise capacity is indifferent from patients with milder disease. As an easy-to-assess parameter, DP may offer further information in the functional evaluation of these patients.