[Basal energy expenditure in smokers and non-smokers with Crohn's disease]

Crohn's disease (CD) is associated with smoking and ulcerative colitis with non-smokers. The aim of study was to compare resting energy status of smokers is worse when compared with non-smokers. The aim of the study was to compare resting energy expenditure (REE) in smokers and non-smokers with CD.

REE was measured in the morning in 18 fasting patients with CD (11 non-smokers, 7 smokers) using a metabolic cart (Deltatrac Datex) in a canopy system. In smokers REE was measured before and 30 minutes after having smoked one cigarette, in non-smokers before and 30 minutes after light physical activity. The results were expressed in per cent of the expected values calculated from Harris-Benedict formula (%HB). In CD REE was significantly higher in smokers when compared with non-smokers (mean +/- S.E.M.: 113.3 +/- 12.7 vs 103.1 +/- 10.2; p < 0.03; t-test). The increase of the second measurement was not significant both in smokers (115.4 +/- 9.4) and non-smokers (105.4 +/- 10.3). In 15 CD patients substrate utilization was also estimated from indirect calorimetry and urea production. There was a higher rate of glycides (mean +/- S.E.M.: 185.9 +/- 81.9 gm/min) and a lower rate of protein oxidation (22.7 +/- 15.5) in smokers when compared with non-smokers (glycides: 141.6 +/- 78.0, NS; proteins: 41.8 +/- 36.7, NS). There was no significant difference between smokers and non-smokers with CD in lipids oxidation (33.7 +/- 19.5 vs 32.9 +/- 22.3).

A significantly higher REE was found in smokers with CD when compared with non-smokers with CD. Differences in substrate utilization were not significant. Our results support a recommendation for CD patients to be non-smokers.