Effect of Passive Heat Therapy on Metabolism

Lithuanian Sports University25 enrolled

Overview

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?"

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

Allocation

Purpose

PREVENTION

Masking

NONE

Enrollment

Conditions

Healthy

Interventions

Heat therapyPROCEDURE

14 heat sessions, during each session subjects were fully immersed in a 45°C water bath for 5 minutes.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 35 YearsHealthy volunteers:

Medical Language ↔ Plain English

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.

Locations (1)

Institute of Sport Science and Innovations

Kaunas, Lithuania

Outcomes

Primary Outcomes

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

Time frame: 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

Time frame: 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.

Time frame: 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).

Time frame: 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.

Time frame: 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.

Data from ClinicalTrials.gov

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Secondary Outcomes

Change in body mass (kg)

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

Time frame: 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.

Time frame: 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

Time frame: 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

Time frame: 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

Time frame: 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

Time frame: 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.

Time frame: Pre-condition, post-condition (after 14 days), and after 1 month recovery