Lung function and exercise performance in XXXX before and after treatment.

@entity1 @entity1223 @entity26 @entity1378 @entity2710
In order to investigate the mechanism of dyspnoea in @entity1378 measurements of spirometry, lung volume, transfer factor for @entity1223 and its subdivisions, maximal respiratory pressures, @entity2710 challenge, arterial blood gases were made and exercise studies performed on 16 @entity1 before treatment for @entity1378 . @entity2710 challenge showed that only three of 14 @entity1 increased airway reactivity, which was mild. Maximal pressures which could be generated by the respiratory muscles were reduced in some @entity1 , as was functional residual capacity. Exercise ventilation and breathing frequency were increased and the respiratory exchange ratio was abnormally high. Anaerobic threshold was measured in nine of 15 subjects and was below normal in each case. All but two subjects stopped exercise because of dyspnoea, and the maximum @entity26 uptake achieved by the group was 53 per cent (n = 15, range 26-66 per cent) of predicted maximum @entity26 consumption. The maximum ventilation averaged only 43 per cent (n = 15, range 16-96 per cent) of the maximal breathing capacity predicted from spirometric tests. Nine @entity1 were studied shortly after being rendered euthyroid by treatment. At rest, only maximal respiratory pressures increased significantly. On exercise, the maximal workload attained and the ventilation achieved increased significantly. Breathing patterns, maximal @entity26 consumption, ventilation, anaerobic threshold and cardiac frequency remained unchanged. We conclude that: @entity1 with @entity1378 do not generally have increased airway reactivity; when @entity1378 , respiratory muscles are weak, and improve following treatment; exercise capacity is impaired in @entity1378 @entity1 probably because of a combination of an inefficiently rapid and shallow breathing pattern, an increase of anaerobic metabolism and discomfort associated with the act of breathing. Although exercise capacity increases and the sensation of dyspnoea may decrease after treatment the pattern of breathing does not immediately return to normal.
