Effect of Passive Heat Therapy on Metabolism

Effect of Repeated Brief Passive Heat Therapy on Metabolism in Healthy Young Adults

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?"

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Procedure: Heat therapy

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.

• Study Type: Interventional
• Enrollment (Actual): 25
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Lithuania
  • Kaunas, Lithuania
    • Institute of Sport Science and Innovations

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Heat therapy; 14 heat sessions of whole-body immersed in a 45°C water bath for 5 minutes.	Procedure: Heat therapy; 14 heat sessions, during each session subjects were fully immersed in a 45°C water bath for 5 minutes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in catecholamines concentration (ng/mL)	The venous plasma adrenaline and noradrenaline concentrations (in ng/mL) were measured using enzyme-linked immunosorbent assay kits and a Spark multimode microplate reader	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Changes in cytokines concentration (pg/mL)	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	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in glucose concentration (mmol/L)	The venous glucose concentration (in mmol/L) was measured using a Glucocard X-mini plus meter.	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in insulin concentration (μIU/mL)	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).	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in insulin sensitivity	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.	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in substrate oxidation	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.	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in fat oxidation (g/min	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,	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in fat oxidation (g/min)	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	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in resting energy expenditure (kcal/day)	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.	Pre-condition, post-condition (after 14 days), and after 1 month recovery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in body mass (kg)	Body mass (in kg) was evaluated using Tanita Body Composition Analyzer.	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in fat mass (kg)	Fat mass (in kg) was evaluated using Tanita Body Composition Analyzer.	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in fat mass (%)	Fat mass (in %) was evaluated using Tanita Body Composition Analyzer	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in fat free mass (kg)	Fat free mass (in kg) was evaluated using Tanita Body Composition Analyzer	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in fat free mass (%)	Fat free mass (in %) was evaluated using Tanita Body Composition Analyzer	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in body mass index (kg/m2)	Body mass index (in kg/m2) was evaluated using Tanita Body Composition Analyzer	Pre-condition, post-condition (after 14 days), and after 1 month recovery
Change in oxygen consumption and carbon dioxide output (mL/min)	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.	Pre-condition, post-condition (after 14 days), and after 1 month recovery

Collaborators and Investigators

• Sponsor: Lithuanian Sports University
• Investigators: Principal Investigator: Marius Brazaitis, PhD, Lithuanian Sports University

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2020
• Primary Completion (Actual): May 31, 2022
• Study Completion (Actual): May 31, 2022

Study Registration Dates

• First Submitted: November 15, 2023
• First Submitted That Met QC Criteria: November 17, 2023
• First Posted (Actual): November 27, 2023

Study Record Updates

• Last Update Posted (Actual): November 27, 2023
• Last Update Submitted That Met QC Criteria: November 17, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: LithuananianSportsU-16

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No