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Feeding-induced changes in energy expenditure in children with cystic fibrosis
C A Horswill1, L Kien, W B Zipf
1Department of Pediatrics, Ohio State University College of Medicine, Columbus, USA.
Insights
Measuring carbon dioxide production using isotopic dilution accurately reflects changes in energy expenditure in children with cystic fibrosis. Feeding significantly increases both carbon dioxide production and energy expenditure in these patients.
Area of Science:
- Pediatric Nutrition
- Metabolic Research
- Respiratory Medicine
Background:
- Cystic fibrosis (CF) affects energy metabolism and nutritional status in children.
- Accurate assessment of energy expenditure is crucial for managing CF patients.
- Previous methods for measuring energy expenditure may have limitations in pediatric populations.
Purpose of the Study:
- To evaluate the utility of carbon dioxide production (CO2) measurement via isotopic dilution for assessing energy expenditure in children with CF.
- To investigate the impact of feeding on CO2 production and energy expenditure in this cohort.
Main Methods:
- Seven children (aged 7-12 years) with cystic fibrosis were studied.
- A primed, constant intravenous infusion of sodium bicarbonate (NaH13CO3) was used to estimate the rate of CO2 appearance (RaCO2).
- Net CO2 excretion (VCO2) and energy expenditure (calculated via food quotient) were measured in both fasted and fed states.
Main Results:
- RaCO2 was higher than VCO2 in both fasted (117%) and fed (105%) states.
- Feeding increased RaCO2 by 23% and VCO2 by 37%.
- Energy expenditure increased by 19% in the fasted state and 33% in the fed state (p < .05) following feeding.
Conclusions:
- CO2 production measurement by isotopic dilution is a valuable tool for tracking group changes in energy expenditure in children with CF.
- Feeding significantly elevates CO2 production and energy expenditure in children with cystic fibrosis.
- This method offers a reliable index for metabolic assessments in pediatric CF research.
Abstract:
Seven children with cystic fibrosis (aged 7 to 12 years) were studied in the fasted and fed states. Using a primed, constant, intravenous infusion of NaH13CO3, the rate of appearance of CO2 (RaCO2) was estimated. Net CO2 excretion (VCO2) was also measured. Energy expenditure was calculated using the food quotient. RaCO2 (mean +/- SD) (mumol.kg-1.min-1) in the fasted and fed states (297 +/- 59 and 359 +/- 67) was 117% and 105% of VCO2 (259 +/- 48 and 352 +/- 72). Feeding induced a 23% and a 37% increase in RaCO2 and VCO2, respectively, and respective 19% and 33% increases in energy expenditure (p < .05). Measurement of CO2 production by isotopic dilution is a useful index of group changes in energy expenditure, including those induced by feeding.