Resting energy expenditure in cryptogenic fibrosing alveolitis

A proportion of patients with chronic airflow limitation appear to have a raised resting energy expenditure (REE). This has been suggested as the reason for weight loss which may occur in these patients. A previous study found an increased REE in patients with interstitial lung disease of mixed aetiology. We were interested in studying REE in a more homogeneous group, with cryptogenic fibrosing alveolitis (CFA). Twenty patients with CFA were studied. They were compared with 18 controls matched for age, sex, weight and height. REE was measured by indirect calorimetry. Fat-free mass (FFM), was estimated by anthropometry. Patients had respiratory function tests performed, disability related to breathlessness was assessed by the activity section of the St George's Respiratory Questionnaire. Mean REE in the CFA group was not different from the control group: 5.20 (0.56) versus 5.12 (0.51) kj x h(-1) x kgFFM(-1). REE was elevated to greater than 110% of the value predicted by the Harris-Benedict equation in one CFA patient and in no control subjects. There was no correlation of REE with weight, pulmonary function tests, arterial oxygen saturation or activity score. The prevalence of a raised resting energy expenditure in cryptogenic fibrosing alveolitis patients with low transfer factor and relatively preserved vital capacity is low, and is less than that reported previously in a group of patients with interstitial lung disease of mixed aetiology.