Clinical science
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Clinical Trial Controlled Clinical Trial
Energy expenditure and substrate metabolism measured by 24 h whole-body calorimetry in patients receiving cyclic and continuous total parenteral nutrition.
1. Twenty-four hour energy expenditure and its components, i.e. 'basal metabolic rate', activity energy expenditure and diet-induced thermogenesis were measured, using continuous whole-body indirect calorimetry, in patients receiving total parenteral nutrition while in remission from Crohn's disease (weight 51.9 +/- 9.9 kg, body mass index 19.2 +/- 2.0 kg/m2). 2. Total parenteral nutrition was infused continuously over 24 h in four subjects and cyclically, between 22.00 and 10.00 hours, in eight subjects. ⋯ The non-protein non-glycerol respiratory quotient exceeded 1.0 for varying periods of time (0.5-17 h) in 11 subjects, indicating net lipogenesis from carbohydrate. 6. The results demonstrate favourable rates of deposition, during intravenous feeding, of both energy and nitrogen over a 24 h period in patients recovering from an episode of Crohn's disease. The efficacy of these commonly used total parenteral nutrition regimens in these patients is related to three features that are absent in normal healthy individuals, namely a low basal metabolic rate, a low activity-related energy expenditure and prolonged periods of lipogenesis from carbohydrate.