Use of Breath Acetone aa a Marker of Energy Balance (ACEX)

University of Lausanne (UNIL)

Status: Completed

Conditions: Fed; Fasting

Treatments: Other: Fasting condition; Other: Fat condition; Other: Sugar condition

Study type: Interventional

Funder types: Other

Identifiers

NCT03390881

2016-01740

Details and patient eligibility

About

This study aims at assessing whether breath acetone concentration is a good bio-marker of instantaneous energy balance in healthy subjects.

Full description

Each participant will be studied on three occasions, separated by 1-4 weeks. Each evaluation will consist in the same set of metabolic measurements, but will be performed fasting or during administration of a 70% fat or 70% carbohydrate liquid diet, according to a randomized order.

On each occasion, subjects will consume a standardized dinner the day before the experiment. They will remain fasted since 10 pm until the test day.

On the day of the experiments, one venous cannula will be inserted into a forearm vein for the collection of blood samples. An indirect calorimetry (measurement of respiratory gas exchanges using a ventilated canopy at rest, or a face mask during exercise) will be performed throughout the 6-hour test to measure energy expenditure and net substrate oxidation rate. Blood samples will be obtained every 60 min for the measurement of plasma glucose, insulin, free fatty acids, and beta-hydroxybutyrate concentrations. Breath samples will be also collected every 60 min (in 500 ml sampling bag) for the measurement of breath acetone concentration using a novel gas analyzer based on infrared laser spectroscopy.

Measurements will be done during 3 consecutive periods:

• 0-120 min: Fast + Rest: subjects will remain lying in bed in fasting conditions (negative energy balance).
• 120-360 min: Fed + Rest: subjects will remain in bed in a fasting state (C) or will receive every hour a liquid meal containing either 70% fat, 15% carbohydrate and 15% protein (Fat), or 70% carbohydrate, 15% fat and 15% protein (Sugar), corresponding to 1.5 X hourly resting energy requirement (positive energy balance).
• 360-480 min: Fed + Exercise: subjects will be transferred to an ergometric bicycle and will be asked to bike at a power output of 25 W [i.e. increasing total energy expenditure to ca. 2 time resting energy expenditure (negative energy balance)].

Enrollment: 8 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• BMI 19.5-29.9 kg/m2,
• Healthy

Exclusion criteria

• any known disease (with the exception of allergies);
• consumption of alcohol > 40 g/day;
• any current drug treatment (with the exception of contraceptive agents, antihistaminergic drugs for allergies, or multivitamin supplementations),
• history of lactose intolerance,
• history of exercise intolerance.

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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8 participants in 3 patient groups

Fasting condition

Experimental group

Description:

Effects of cumulated negative energy balance (fasting over 480 min) on breath acetone changes

Treatment:

Other: Fasting condition

Sugar condition

Active Comparator group

Description:

Effects of sugar consumption on breath acetone changes

Treatment:

Other: Sugar condition

Fat condition

Active Comparator group

Description:

Effects of fat consumption on breath acetone changes

Treatment:

Other: Fat condition