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Effect of Passive Heat Therapy on Metabolism

Not Applicable
Completed
Conditions
Healthy
Interventions
Procedure: Heat therapy
Registration Number
NCT06147557
Lead Sponsor
Lithuanian Sports University
Brief Summary

The goal of this prospective interventional study is to examine if repeated brief hot stimuli affects glucose metabolism and substrate oxidation in young non-obese adults. Young adult participants were asked to participate in fourteen 5-min procedures involving whole body passive heating at 45°C water.

The main question it aims to answer is: "Does repeated brief noxious heat stimuli is sufficient to improve glucose tolerance, insulin sensitivity, and fat oxidation in young non-obese adults?"

Detailed Description

No studies yet addressed whether brief heat stimuli could be viable time-efficient alternative approach in order to improve glucose metabolism and fat oxidation. Consequently, we aimed to examine the ability of brief noxious heat stimuli to improve glucose tolerance, insulin sensitivity, and fat oxidation in young adults. Non-obese males and females completed fourteen 5-min sessions involving whole body passive heating at 45°C water. Changes in catecholamines, cytokines, substrate oxidation, resting energy expenditure, glucose tolerance and insulin response were assessed.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
25
Inclusion Criteria
  • healthy non-obese (BMI between 18.5 and 29.9 kg/m2) males and females;
  • no diseases, or conditions that could be worsened by exposure to acute hot water and affect experimental variables;
  • no participation in any excessive formal physical exercise or sports program, temperature manipulation program or exposure to extreme temperatures.
Exclusion Criteria
  • smokers;
  • obesity (BMI greater than 30 kg/m2);
  • needle phobia;
  • taking medication and/or dietary supplements that may affect experimental variables.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Heat therapyHeat therapy14 heat sessions of whole-body immersed in a 45°C water bath for 5 minutes.
Primary Outcome Measures
NameTimeMethod
Change in fat oxidation (g/minPre-condition, post-condition (after 14 days), and after 1 month recovery

Oxygen consumption (VO2) and carbon dioxide (VCO2) output on a breath-by breath basis using a stationary MetaLyzer® 3B spiroergometry system (Cortex Biophysik GmbH) was measured at rest, and the fat oxidation (FATox; g/min) was calculated by using the equation: FATox = 1.67 × VO2 - 1.67 × VCO2,

Changes in cytokines concentration (pg/mL)Pre-condition, post-condition (after 14 days), and after 1 month recovery

The venous serum interleukin-6 and tumor necrosis factor alpha concentrations (in pg/mL) were measured using enzyme-linked immunosorbent assay kits and a Spark multimode microplate reader

Change in resting energy expenditure (kcal/day)Pre-condition, post-condition (after 14 days), and after 1 month recovery

Oxygen consumption (VO2) and carbon dioxide (VCO2) output on a breath-by breath basis using a stationary MetaLyzer® 3B spiroergometry system (Cortex Biophysik GmbH) was measured at rest, and the resting energy expenditure (REE; kcal/day) was calculated by using the Weir equation: REE = (3.941(VO2) + 1.106(VCO2)) × 1440.

Change in glucose concentration (mmol/L)Pre-condition, post-condition (after 14 days), and after 1 month recovery

The venous glucose concentration (in mmol/L) was measured using a Glucocard X-mini plus meter.

Changes in catecholamines concentration (ng/mL)Pre-condition, post-condition (after 14 days), and after 1 month recovery

The venous plasma adrenaline and noradrenaline concentrations (in ng/mL) were measured using enzyme-linked immunosorbent assay kits and a Spark multimode microplate reader

Change in insulin sensitivityPre-condition, post-condition (after 14 days), and after 1 month recovery

Indices for insulin sensitivity/resistance assessment were computed using the homeostatic model assessment for insulin resistance, quantitative insulin-sensitivity check index (QUICKI), and the Matsuda insulin sensitivity index were calculated.

Change in fat oxidation (g/min)Pre-condition, post-condition (after 14 days), and after 1 month recovery

Oxygen consumption (VO2) and carbon dioxide (VCO2) output on a breath-by breath basis using a stationary MetaLyzer® 3B spiroergometry system (Cortex Biophysik GmbH) was measured at rest, and the carbohydrate oxidation (CARBox; g/min) was calculated by using the equation: CARBox = 4.55 × VCO2 - 3.21 × VO2

Change in insulin concentration (μIU/mL)Pre-condition, post-condition (after 14 days), and after 1 month recovery

The venous serum insulin concentrations (in μIU/mL) were measured using enzyme-linked immunosorbent assay kits (Cat. No. E-EL-H2237, Elabscience, China) and a Spark multimode microplate reader (Tecan, Austria).

Change in substrate oxidationPre-condition, post-condition (after 14 days), and after 1 month recovery

Oxygen consumption (VO2) and carbon dioxide (VCO2) output on a breath-by breath basis using a stationary MetaLyzer® 3B spiroergometry system (Cortex Biophysik GmbH) was measured at rest, and the respiratory quotient (RQ=VCO2/VO2) was computed to determine substrate utilisation.

Secondary Outcome Measures
NameTimeMethod
Change in fat mass (kg)Pre-condition, post-condition (after 14 days), and after 1 month recovery

Fat mass (in kg) was evaluated using Tanita Body Composition Analyzer.

Change in body mass (kg)Pre-condition, post-condition (after 14 days), and after 1 month recovery

Body mass (in kg) was evaluated using Tanita Body Composition Analyzer.

Change in fat free mass (kg)Pre-condition, post-condition (after 14 days), and after 1 month recovery

Fat free mass (in kg) was evaluated using Tanita Body Composition Analyzer

Change in body mass index (kg/m2)Pre-condition, post-condition (after 14 days), and after 1 month recovery

Body mass index (in kg/m2) was evaluated using Tanita Body Composition Analyzer

Change in oxygen consumption and carbon dioxide output (mL/min)Pre-condition, post-condition (after 14 days), and after 1 month recovery

Oxygen consumption and carbon dioxide output (in mL/min) on a breath-by breath basis using a stationary MetaLyzer® 3B spiroergometry system (Cortex Biophysik GmbH) was measured at rest.

Change in fat mass (%)Pre-condition, post-condition (after 14 days), and after 1 month recovery

Fat mass (in %) was evaluated using Tanita Body Composition Analyzer

Change in fat free mass (%)Pre-condition, post-condition (after 14 days), and after 1 month recovery

Fat free mass (in %) was evaluated using Tanita Body Composition Analyzer

Trial Locations

Locations (1)

Institute of Sport Science and Innovations

🇱🇹

Kaunas, Lithuania

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