Reduced metabolic efficiency in patients with Crohn's disease

Area of Science:

• Gastroenterology
• Nutritional Science
• Metabolic Research

Background:

• Malnutrition is common in inflammatory bowel disease (IBD), necessitating nutritional support.
• Patients with Crohn's disease (CD) often exhibit poor weight gain despite nutritional interventions, indicating impaired energy retention.

Purpose of the Study:

• To investigate substrate utilization and body composition changes in Crohn's disease patients during enteral nutrition.
• To determine optimal nutrient supply for positive energy and nitrogen balance in CD patients.

Main Methods:

• Ten Crohn's disease patients in remission received continuous enteral nutrition over eight days.
• Two protocols were used: constant (1.5x basal energy expenditure) and increasing (0.5-2.0x basal energy expenditure) nutrient supply.
• Measurements included substrate utilization, nutrient balances, and body composition changes.

Main Results:

• Overfeeding led to positive energy, substrate, and nitrogen balances.
• Carbohydrates and proteins were stored, while fat was predominantly oxidized at lower infusion rates.
• Positive energy balance required >31 kcal/kg/day, with specific substrate supplies.
• Body weight increased due to extracellular and body cell mass gains, with a decrease in fat mass.
• Hormonal changes (increased T3 and insulin, decreased sympathetic activity) were observed.

Conclusions:

• Crohn's disease patients exhibit altered substrate metabolism during overfeeding, prioritizing carbohydrate and protein storage over fat accumulation.
• Achieving positive energy balance requires specific nutrient intake levels.
• Body composition changes indicate a shift towards lean mass gain and fat loss, contrary to healthy individuals.