Exercise-induced respiratory symptoms are not always asthma

Eighty-eight patients with a history of exercise-induced respiratory sympto ms performed a maximal exercise test in order to study the reasons for stop ping the test. There was a wide range of percentage maximal fall in peak ex piratory flow (PEF), from minus 3% to 63%, mean 11%, recorded 0-30 min, mea n 12 min after the break. In the controls the maximal decrease was 0-16%, m ean 6%. Diagnostic criteria for asthma were fulfilled by 48 patients (55%). Of these patients 42% had a fall in PEF greater than or equal to 15% (exer cise-induced asthma). Of the non-asthma patients 10% had a fall greater tha n or equal to 15%. The most common reason for stopping the exercise in the asthma group was breathing troubles (46%), the most common reason in the no n-asthma group was chest pain/discomfort (35%). In about 20% of the patient s dizziness and/or pricking sensations in arms or legs indicated hyperventi lation as an additional reason for stopping the exercise. It is concluded t hat other kinds of reaction, than bronchial obstruction such as breathing t roubles not directly related to bronchial obstruction and chest pain, may b e important factors that can restrict physical capacity in patients with ex ercise-induced respiratory symptoms. (C) 1999 HARCOURT PUDLISHERS LTD.