Resting Energy Expenditure by Gastrointestinal Functional Status

Official title

Comparison of Resting Energy Expenditure According to Gastrointestinal Functional Status

Overview

This prospective, comparative interventional study will evaluate resting energy expenditure in adults with different gastrointestinal functional status. A total of 92 participants aged 18 to 65 years will be included: 30 healthy adults with normal gastrointestinal function and 62 patients with clinically confirmed intestinal failure. The intestinal failure group will include patients with short bowel syndrome and patients with other causes of intestinal failure. Participants will be assigned to one of two protocol-defined groups according to their gastrointestinal functional status. Each participant will attend one study visit lasting approximately 90 to 120 minutes. The research procedures will include measurement of resting energy expenditure by indirect calorimetry after an overnight fast, assessment of body composition by dual-energy X-ray absorptiometry and bioelectrical impedance analysis, and blood sampling for inflammatory markers. The primary objective is to compare resting energy expenditure between healthy participants and patients with intestinal failure and to determine whether resting energy expenditure differs according to the underlying cause of intestinal failure. Secondary objectives are to evaluate the associations between resting energy expenditure, lean body mass, fat mass, phase angle, and inflammatory markers. The results may contribute to more individualized nutritional management of patients with intestinal failure.

Detailed description

Intestinal failure is a condition in which the gastrointestinal tract is unable to provide adequate digestion and absorption of nutrients, electrolytes, and fluids. Patients may therefore require partial or complete parenteral nutrition. Their resting energy expenditure may be affected by the underlying cause of intestinal failure, changes in body composition, nutritional and metabolic status, and systemic inflammation. Accurate assessment of energy requirements is important for planning individualized nutritional support.

This is a prospective, comparative interventional study with two non-randomized, protocol-defined groups. Group A will include 30 healthy adults with normal gastrointestinal function. Group B will include 62 clinically stable patients with confirmed intestinal failure. Within Group B, approximately 38 participants will have short bowel syndrome and 24 will have other causes of type II or type III intestinal failure, including chronic intestinal dysmotility or extensive disease of the small intestinal mucosa.

The study intervention consists of metabolic, body-composition, and laboratory assessments performed according to a standardized research protocol. Each participant will complete the study during one visit at the Institute of Oncology Ljubljana. The visit will last approximately 90 to 120 minutes. Resting energy expenditure will be measured in the morning, after fasting, in a thermoneutral environment using indirect calorimetry. The indirect calorimetry measurement will last approximately 30 minutes and will determine oxygen consumption and carbon dioxide production.

Body composition will be assessed using dual-energy X-ray absorptiometry to measure lean body mass, fat mass, and bone mineral density. Bioelectrical impedance analysis will also be performed to determine phase angle as an indicator of cellular integrity and function. A blood sample will be collected to assess inflammatory markers, including C-reactive protein and calculated neutrophil-to-lymphocyte, platelet-to-lymphocyte, and lymphocyte-to-monocyte ratios.

Resting energy expenditure will be evaluated as an absolute value in kilocalories per day and in standardized forms, including adjustment for lean body mass, age, and sex. The primary analyses will compare resting energy expenditure between healthy participants and patients with intestinal failure and between patients with short bowel syndrome and patients with other causes of intestinal failure.

Secondary analyses will examine the associations between resting energy expenditure and body-composition parameters, phase angle, and inflammatory markers. The study is intended to improve understanding of metabolic requirements in intestinal failure and to support the development of more individualized nutritional recommendations for these patients.

Interventions

• Diagnostic test Protocol-Defined Metabolic and Body Composition Assessment
  Participants undergo a standardized research assessment during one study visit. Resting energy expenditure is measured by indirect calorimetry after fasting. Body composition is assessed by dual-energy X-ray absorptiometry and bioelectrical impedance analysis. Blood samples are collected for the assessment of inflammatory markers. These assessments are performed outside routine clinical care according to the study protocol.

Primary outcome measures

• Resting Energy Expenditure Measured by Indirect Calorimetry [Time frame: During the single study visit; REE is assessed over approximately 30 minutes]

Secondary outcome measures (7)

• Lean Body Mass Assessed by Dual-Energy X-Ray Absorptiometry [Time frame: During the single study visit, lasting approximately 90 to 120 minutes]
• Fat Mass Assessed by Dual-Energy X-Ray Absorptiometry [Time frame: During the single study visit, lasting approximately 90 to 120 minutes]
• Phase Angle Assessed by Bioelectrical Impedance Analysis [Time frame: During the single study visit, lasting approximately 90 to 120 minutes]
• C-Reactive Protein [Time frame: During the single study visit, lasting approximately 90 to 120 minutes]
• Neutrophil-to-Lymphocyte Ratio [Time frame: During the single study visit, lasting approximately 90 to 120 minutes]
• Platelet-to-Lymphocyte Ratio [Time frame: During the single study visit, lasting approximately 90 to 120 minutes]
• Lymphocyte-to-Monocyte Ratio [Time frame: During the single study visit, lasting approximately 90 to 120 minutes]

Eligibility criteria

Inclusion criteria

Group A - Healthy Controls:

• Age 18 to 65 years
• No diagnosed chronic diseases
• No hospitalization within the previous 30 days
• No acute illness within the previous 14 days

Group B - Participants With Intestinal Failure:

• Age 18 to 65 years
• Diagnostically confirmed intestinal failure
• Stable clinical condition

Exclusion criteria

• Uncontrolled hyperthyroidism or hypothyroidism
• Diabetes mellitus with poor glycemic control
• Adrenal gland disease
• Active inflammatory bowel disease, including Crohn's disease or ulcerative colitis
• Celiac disease
• Chronic pancreatitis
• Active gastric or esophageal disease
• Irritable bowel syndrome with significant symptoms
• History of major abdominal surgery that permanently affects gastrointestinal function, except in participants with intestinal failure when this forms part of the condition under study
• Heart failure
• Active ischemic heart disease or recent myocardial infarction
• Chronic obstructive pulmonary disease
• Respiratory failure or need for long-term oxygen therapy
• Progressive neurodegenerative disease
• Dementia impairing the ability to participate
• Severe stroke with significant functional impairment
• Active tuberculosis
• HIV/AIDS with clinically significant immunosuppression
• Active systemic autoimmune disease
• Active malignant disease
• Advanced liver cirrhosis
• Chronic kidney disease
• Treatment with hemodialysis or peritoneal dialysis
• Pregnancy or breastfeeding

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Basic science

Study locations

Slovenia · 1 center

• Institute of Oncology Ljubljana — Ljubljana

Identifiers

NCT: NCT07714499 · ORI2025-12

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗