Metabolic and inflammatory responses to pulmonary exacerbation in adults with cystic fibrosis

Background We hypothesized that increased resting energy expenditure in adu lts with cystic fibrosis was related to chronic inflammation secondary to p ulmonary infection and could be modified by treatment of the underlying inf ection. Method To determine the relationship between resting energy expenditure and the inflammatory and metabolic responses, we studied 22 adults with cystic fibrosis and chronic Pseudomonas aeruginosa infection before and after tre atment of a respiratory exacerbation. Resting energy expenditure was measur ed by indirect calorimetry. Spirometry and circulating concentrations of C- reactive protein, neutrophil elastase alpha(1)-antiproteinase complex, cate cholamines, non-esterified fatty acids and glycerol were determined. Results The mean (95% confidence interval)% predicted FEV1 was 28.5% (20.6, 36.4) and mean body weight 50.7 kg (47.4, 54.1). Following treatment, 1-s forced expiratory volume (FEV1) and weight increased, while C-reactive prot ein (P < 0.0001) and neutrophil elastase alpha(1)-antiproteinase complex co ncentrations (P < 0.0001) were reduced. Resting energy expenditure decrease d from 6.8 (6.3, 7.2) to 6.25 (5.9, 6.6) MJ day(-1) by day 15 (P < 0.001). Changes in resting energy expenditure and C-reactive protein were related ( r = 0.66, P < 0.0001). Weight gain was inversely related to resting energy expenditure (r = 0.43, P = 0.02) and unrelated to energy intake (r = 0.02, P = 0.47). Post-treatment reduction in norepinephrine was related to change s in heart rate (r = 0.57, P < 0.01), resting energy expenditure (r = 0.51, P = 0.001) and non-esterified fatty acids (r = 0.42, P < 0.05). Conclusions A parallel reduction in the host inflammatory and catabolic res ponses followed treatment of a respiratory exacerbation and may have contri buted to weight gain.