Tumour necrosis factor-alpha, resting energy expenditure and cachexia in cystic fibrosis.

1. We investigated the relationship between circulating tumour necrosis factor-alpha concentrations, resting energy expenditure, cachexia and altered intermediary metabolism in patients with cystic fibrosis and chronic pulmonary infection. 2. Twenty adult patients with cystic fibrosis and chronic bronchial sepsis covering a spectrum of severity of lung disease (forced expiratory volume in 1 s 30-100% of predicted) were compared with 10 age matched, healthy, non-cystic fibrosis subjects. 3. Circulating tumour necrosis factor-alpha, C-reactive protein and neutrophil elastase-alpha 1-antiproteinase complex concentrations were determined simultaneously with glycerol, non-esterified fatty acids, catecholamines, anthropometric indices and resting energy expenditure (ventilated hood method). 4. Weight, body mass index and arm muscle mass were reduced in patients with cystic fibrosis compared with healthy control subjects (P < 0.01), whereas mean resting energy expenditure was increased [121 versus 101% predicted, mean difference 19.2% (95% confidence interval 11.0-27.4%), P < 0.001]. Circulating concentrations of glycerol (P < 0.01), non-esterified fatty acids (P < 0.01), adrenaline (P < 0.05), tumour necrosis factor-alpha, C-reactive protein and neutrophil elastase-alpha 1-antiproteinase complex (P < 0.01) were increased in patients compared with control subjects [tumour necrosis factor-alpha 96.9 versus 24.7 pg/ml, mean difference 72.2 pg/ml [95% confidence interval 27.7-116.7 pg/ml), P < 0.001]. Resting energy expenditure was significantly related to tumour necrosis factor-alpha levels and forced expiratory volume in 1 s. 5. In patients with cystic fibrosis and chronic pulmonary sepsis changes in resting energy expenditure, body composition and intermediary metabolism are consistent with the systemic effects of the host inflammatory response, which may be responsible for cachexia in adult patients. In particular these changes are consistent with the action of tumour necrosis factor-alpha, which was detected in the circulation during a period of apparent clinical stability.

Effects of focusing attention on breathing with and without apparatus on the face.

In an attempt to identify a cause for the alteration in breathing pattern seen when conventional respiratory apparatus is applied to the face, we have studied the effects of causing the subject to focus attention on breathing by counting breaths in threes for 5 min. We used the respiratory inductance plethysmograph in 18 naive subjects who were unaware that their breathing was being measured. In the control periods, distraction was provided by a recorded story played through head-phones. The experiment was repeated with the rim of a facemask applied to the face. Focusing attention on breathing caused a prolongation of inspiration at a constant mean inspiratory flow, and lengthening of expiration. Tidal volume but not ventilation was increased. The facemask rim caused no significant change. It is concluded that conscious awareness of breathing could account for a major part of the effect of conventional respiratory apparatus.