Diabetes Mellitus, Type 2NCT03798717
To Bathe or Not to Bathe
A study testing Heating in people with Diabetes Mellitus, Type 2, run by University of Portsmouth at 1 site in United Kingdom.
Trial summary
Type 2 diabetes mellitus (T2DM) is characterised by chronic high blood sugar concentration (hyperglycaemia) and insulin resistance leading to a reduction in insulin sensitivity. These hyperglycaemic excursions can seriously impact metabolic, micro and macrovascular health. Read more about this study
- Who is it for?
- Ages 35 years and older
- Conditions the study is for
- Diabetes Mellitus, Type 2
- What is being tested?
- Heating
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 20 Feb 2019to 9 Mar 2020
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 35 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
None listed.
Who cannot join
- The participant may not enter / be withdrawn from the study if any of the following apply:
- Severe peripheral neuropathy (to the point to which they cannot sense temperature)
- Uncontrolled hypertension (≥180 systolic / 100 diastolic mmHg)
- Taking any medication which may interfere with data interpretation or safety
- Who have had a myocardial infarction or cerebro-vascular event
- Any cardiac abnormalities which restrict hard exercise
Show all 10Show fewer
- Current smokers or who have stopped within 3 months
- Participant is unable to understand and/or fully cooperate with the study protocol
- Any other serious medical condition which would interfere with data interpretation or safety will be excluded from participation.
- Any skin conditions including ulcerations
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Department of Sport and Exercise Science
Portsmouth, Hampshire, PO1 2ER
About this study
Official title: The Effect of Acute, Passive Heating on Glucose Tolerance in Individuals With Type 2 Diabetes Mellitus: a Randomised, Balanced Crossover, Control Trial
Type 2 diabetes mellitus (T2DM) is characterised by chronic high blood sugar concentration (hyperglycaemia) and insulin resistance leading to a reduction in insulin sensitivity. These hyperglycaemic excursions can seriously impact metabolic, micro and macrovascular health. The total cost of the direct and indirect care of individuals with diabetes (~90% T2DM) in the UK (United Kingdom) is £23.7 billion, equating to ~20% of the annual national health service (NHS) budget, with this projected to become unsustainable. Low-cost interventions to improve glycaemic control in these individuals are therefore warranted. Current interventions include pharmaceuticals, exercise and calorie restrictive diets. Pharmaceutical interventions carry a high financial cost, while exercise and diet programmes have a low adherence rate in individuals with T2DM.
Heat therapy offers one potential low cost therapy. Immersion in a hot tub for 30 mins.day-1 for 10 days has been shown to reduce fasting plasma [glucose] and HbA1c in individuals with T2DM, which may be explained by acute (e.g. muscle) and chronic (e.g. reduced inflammatory status and increased heat shock proteins (HSP)) adaptations, although experimental evidence for these hypothesis are sparse. Other potential benefits include improved glycaemic control, insulin sensitivity, elevated resting metabolic rate and improved micro- and macrovascular function.
The aim of the present study is to determine whether acute hot water immersion can improve glucose tolerance in individuals with T2DM and whether it is more beneficial to undertake this before or after a OGTT (oral glucose tolerance test).
Read the detailed description
Visit 1 (consent, screening and familiarisation) During visit 1, participants will give their informed consent, followed by a health screening questionnaire. In addition to the health screening questionnaire, medical history and a blood sample will be collected and analysed for a full blood count, glycated haemoglobin (HbA1c), liver and kidney function. Finally, a resting electrocardiogram (ECG) will also be recorded and then examined for irregularities, where a clinical decision will be made on further participation to the study by consultants at QA (Queen Alexandra) hospital. Participants will then be shown the rest of the equipment and taken through the procedure for the next 3 visits and, if the participant is happy to continue the study, the next visit will be organised.
Visit 2, 3 and 4 Participants will arrive at the laboratory at ~9 am for conditions 1 and 2 and 8 am for condition 3. Prior to a 15 min resting period (supine) before any measures are taken participants will be asked to insert a rectal thermistor (participants will be given clear instructions using the investigator's SoPs (standard operating procedure)). Condition 1, 2 and 3 will be balanced and participants randomly allocated to begin the study in either visit 2, 3 or 4 using a blinded member of the team.
For all visits (see figure 2), participants will lie in a semi recumbent position in minimal clothing (bathing shorts and a t-shirt) for the entirety of the visit. Initially, participants will be cannulated (Versatus winged and ported IV cannula, Terumo, Japan) and blood samples drawn for analysis of osmolality (Lithium Heparin (LH) tubes BD (Becton, Dickinson and Company), USA) plasma [glucose] (Fluoride/Oxalate tubes, BD, USA), [insulin] (Ethylenediaminetetraacetic acid (EDTA) K2, BD, USA), and [eHSP70 (extracellular heat shock protein 70)] (EDTA K2, BD, USA) at baseline and every 30 min of each experimental visit. Following cannulation an 180 min OGTT (75g) (Rapilose OGTT solution, Penlan healthcare, Japan) will commence in a thermoneutral room (~ 23oC). A maximum of 18 mL of blood being drawn at each time point (max 126 mL per visit). To maintain the patency of the cannula and to reduce the risk of infection, after every sample is taken, 5 mL of saline will be flushed through the cannula. Then before every sample is taken, 2.5 mL of blood will be drawn out of the cannula to ensure any remaining saline will not interfere with the samples and data interpretation (additional 17.5mL per visit). During the OGTT, HR (heart rate) (via electrocardiogram) will be measured continuously, whilst blood pressure (M5-1, Omron, Japan), deep body temperature (rectal probe) and resting metabolic rate (indirect calorimetry) (Quark CPET (cardiopulmonary exercise test), Cosmed, Italy) will be assessed every 30 min.
Condition 2 will employ identical procedures to condition 1, except thirty minutes into the OGTT, the participant will be immersed into an immersion tank (~39oC) for 60 min. Water temperature will be manipulated as required to achieve and maintain a target Trec at 38.5 oC using water between 37.5 and 39oC, and then participants will be removed horizontally back into the thermoneutral room for the reminder of the OGTT. Participants will be towel dried and given a towelled robe to wear. Condition 3 will employ identical procedures to condition 2, with the exception that the heating via immersion will start as soon as the participant is instrumented (and following a 15 min rest period) and the OGTT will commence 30 min after the 60 min immersion time for a further 180 min (see figure 2 for a schematic).
- Conditions
- Diabetes Mellitus, Type 2
- Being tested
- Heating
- Medical subject headings
- Diabetes Mellitus, Type 2
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
HeatingDiagnostic test
Also called Bath
Warm water immersion
| Study group | Role | What they receive |
|---|---|---|
| Control | No intervention | Participants will lie in a semi recumbent position in minimal clothing for the entirety of the visit. Initially, participants will be cannulated and blood samples drawn.every 30 min of each experimental visit. Following cannulation an 180 min OGTT (75g) will commence in a thermoneutral room (~ 23C). During the OGTT, HR will be measured continuously, whilst blood pressure, deep body temperature (rectal probe) and resting metabolic rate will be assessed every 30 min. |
| Pre OGTT | Experimental | Condition 2 will employ identical procedures to condition 1, except thirty minutes into the OGTT, the participant will be immersed into an immersion tank (~39oC) for 60 min. Water temperature will be manipulated as required to achieve and maintain a target Trec at 38.5 oC using water between 37.5 and 39oC, and then participants will be removed horizontally back into the thermoneutral room for the reminder of the OGTT. Participants will be towel dried and given a towelled robe to wear. Receives: Diagnostic Test: Heating |
| Post OGTT | Experimental | Condition 3 will employ identical procedures to condition 2, with the exception that the heating via immersion will start as soon as the participant is instrumented (and following a 15 min rest period) and the OGTT will commence 30 min after the 60 min immersion time for a further 180 min. Receives: Diagnostic Test: Heating |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean AUC (Area Under the Curve) Plasma [Glucose]
Does an acute bout of passive, warm water therapy reduce plasma [glucose]? Units for AUC are AU (arbitrary units) which have been derived from the trapezoidal method and have been published as such. Trapezoidal method: AUC = Δx ((y0/2)+y1+y2+y3+...+(yn/2)).
Measured: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Secondary outcomes (6)
Change in Plasma [Insulin]
Does plasma [insulin] reduce more if the passive, warm water therapy is conducted before or after the OGTT?
Measured: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Mean Insulin Sensitivity
Does insulin sensitivity increase following an acute bout of warm water therapy? Calculation of insulin sensitivity is measured in AU which have been derived from the Gutt method and have been published as such. Gutt insulin sensitivity = [75,000 + (G0-G120) × 0.19 × BW]/(120 × log [(I0 + I120)/2] × [(G0 + G120)/2]). Where G = plasma [glucose], I = plasma [insulin] and BW = body weight.
Measured: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Change in Fuel Utilisation
Does carbohydrate and fat (RER) utilisation alter during and following an acute bout of warm water therapy?
Measured: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Change in Cardiovascular Status
Does heart rate (variability) change during or after an acute bout of warm water therapy?
Measured: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Change in eHSP70 (Extracellular Heat Shock Protein 70)
Does eHSP increases during and following an acute bout of warm water therapy?
Measured: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Change in Inflammatory Status
Does inflammatory status (IL-6 \& IL-10) change during or after an acute bout of warm water therapy?
Measured: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jan 2019
- Study start20 Feb 2019
- Primary completion9 Mar 2020
- Study completion9 Mar 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Diabetes Mellitus, Type 2Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Portsmouth
- Sponsor type
- University, hospital or other
- Collaborators
- Portsmouth Hospitals NHS Trust
- Responsible party
- Principal investigator, Ant Shepherd, University of Portsmouth
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03798717
- Sponsor's protocol ID
- 003AS
- Status last verified
- Jul 2021
- First submitted
- 20 Dec 2018
- Last updated
- 21 Jul 2021
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: There is no plan to release IPD (individual patient data), until all avenues of further funding have been exhausted.
Study at a glance
From the registry record, last updated by the sponsor on 21 Jul 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Acute, Passive Heating on Glucose Tolerance in Individuals With Type 2 Diabetes Mellitus: a Randomised, Balanced Crossover, Control Trial
- ClinicalTrials.gov ID
- NCT03798717
- Acronym / sponsor ID
- 003AS
- Conditions
- Diabetes Mellitus, Type 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- University of PortsmouthUniversity, hospital or other
- Collaborators
- Portsmouth Hospitals NHS Trust
- Study start
- 20 Feb 2019 (actual)
- Primary completion
- 9 Mar 2020 (actual)
- Study completion
- 9 Mar 2020 (actual)
- First posted
- 10 Jan 2019 (actual)
- Results
- Posted 19 Jul 2021
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Type 2 diabetes mellitus (T2DM) is characterised by chronic high blood sugar concentration (hyperglycaemia) and insulin resistance leading to a reduction in insulin sensitivity. These hyperglycaemic excursions can seriously impact metabolic, micro and macrovascular health. The total cost of the direct and indirect care of individuals with diabetes (~90% T2DM) in the UK (United Kingdom) is £23.7 billion, equating to ~20% of the annual national health service (NHS) budget, with this projected to become unsustainable. Low-cost interventions to improve glycaemic control in these individuals are therefore warranted. Current interventions include pharmaceuticals, exercise and calorie restrictive diets. Pharmaceutical interventions carry a high financial cost, while exercise and diet programmes have a low adherence rate in individuals with T2DM.
Heat therapy offers one potential low cost therapy. Immersion in a hot tub for 30 mins.day-1 for 10 days has been shown to reduce fasting plasma [glucose] and HbA1c in individuals with T2DM, which may be explained by acute (e.g. muscle) and chronic (e.g. reduced inflammatory status and increased heat shock proteins (HSP)) adaptations, although experimental evidence for these hypothesis are sparse. Other potential benefits include improved glycaemic control, insulin sensitivity, elevated resting metabolic rate and improved micro- and macrovascular function.
The aim of the present study is to determine whether acute hot water immersion can improve glucose tolerance in individuals with T2DM and whether it is more beneficial to undertake this before or after a OGTT (oral glucose tolerance test).
Detailed description
Visit 1 (consent, screening and familiarisation) During visit 1, participants will give their informed consent, followed by a health screening questionnaire. In addition to the health screening questionnaire, medical history and a blood sample will be collected and analysed for a full blood count, glycated haemoglobin (HbA1c), liver and kidney function. Finally, a resting electrocardiogram (ECG) will also be recorded and then examined for irregularities, where a clinical decision will be made on further participation to the study by consultants at QA (Queen Alexandra) hospital. Participants will then be shown the rest of the equipment and taken through the procedure for the next 3 visits and, if the participant is happy to continue the study, the next visit will be organised.
Visit 2, 3 and 4 Participants will arrive at the laboratory at ~9 am for conditions 1 and 2 and 8 am for condition 3. Prior to a 15 min resting period (supine) before any measures are taken participants will be asked to insert a rectal thermistor (participants will be given clear instructions using the investigator's SoPs (standard operating procedure)). Condition 1, 2 and 3 will be balanced and participants randomly allocated to begin the study in either visit 2, 3 or 4 using a blinded member of the team.
For all visits (see figure 2), participants will lie in a semi recumbent position in minimal clothing (bathing shorts and a t-shirt) for the entirety of the visit. Initially, participants will be cannulated (Versatus winged and ported IV cannula, Terumo, Japan) and blood samples drawn for analysis of osmolality (Lithium Heparin (LH) tubes BD (Becton, Dickinson and Company), USA) plasma [glucose] (Fluoride/Oxalate tubes, BD, USA), [insulin] (Ethylenediaminetetraacetic acid (EDTA) K2, BD, USA), and [eHSP70 (extracellular heat shock protein 70)] (EDTA K2, BD, USA) at baseline and every 30 min of each experimental visit. Following cannulation an 180 min OGTT (75g) (Rapilose OGTT solution, Penlan healthcare, Japan) will commence in a thermoneutral room (~ 23oC). A maximum of 18 mL of blood being drawn at each time point (max 126 mL per visit). To maintain the patency of the cannula and to reduce the risk of infection, after every sample is taken, 5 mL of saline will be flushed through the cannula. Then before every sample is taken, 2.5 mL of blood will be drawn out of the cannula to ensure any remaining saline will not interfere with the samples and data interpretation (additional 17.5mL per visit). During the OGTT, HR (heart rate) (via electrocardiogram) will be measured continuously, whilst blood pressure (M5-1, Omron, Japan), deep body temperature (rectal probe) and resting metabolic rate (indirect calorimetry) (Quark CPET (cardiopulmonary exercise test), Cosmed, Italy) will be assessed every 30 min.
Condition 2 will employ identical procedures to condition 1, except thirty minutes into the OGTT, the participant will be immersed into an immersion tank (~39oC) for 60 min. Water temperature will be manipulated as required to achieve and maintain a target Trec at 38.5 oC using water between 37.5 and 39oC, and then participants will be removed horizontally back into the thermoneutral room for the reminder of the OGTT. Participants will be towel dried and given a towelled robe to wear. Condition 3 will employ identical procedures to condition 2, with the exception that the heating via immersion will start as soon as the participant is instrumented (and following a 15 min rest period) and the OGTT will commence 30 min after the 60 min immersion time for a further 180 min (see figure 2 for a schematic).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Control | No intervention | –Participants will lie in a semi recumbent position in minimal clothing for the entirety of the visit. Initially, participants will be cannulated and blood samples drawn.every 30 min of each experimental visit. Following cannulation an 180 min OGTT (75g) will commence in a thermoneutral room (~ 23C). During the OGTT, HR will be measured continuously, whilst blood pressure, deep body temperature (rectal probe) and resting metabolic rate will be assessed every 30 min. |
| Pre OGTT | Experimental | Diagnostic Test: HeatingCondition 2 will employ identical procedures to condition 1, except thirty minutes into the OGTT, the participant will be immersed into an immersion tank (~39oC) for 60 min. Water temperature will be manipulated as required to achieve and maintain a target Trec at 38.5 oC using water between 37.5 and 39oC, and then participants will be removed horizontally back into the thermoneutral room for the reminder of the OGTT. Participants will be towel dried and given a towelled robe to wear. |
| Post OGTT | Experimental | Diagnostic Test: HeatingCondition 3 will employ identical procedures to condition 2, with the exception that the heating via immersion will start as soon as the participant is instrumented (and following a 15 min rest period) and the OGTT will commence 30 min after the 60 min immersion time for a further 180 min. |
Who may qualify
- Ages
- 35 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (0 listed)
Key exclusion criteria (10 listed)
- The participant may not enter / be withdrawn from the study if any of the following apply:
- Severe peripheral neuropathy (to the point to which they cannot sense temperature)
- Uncontrolled hypertension (≥180 systolic / 100 diastolic mmHg)
- Taking any medication which may interfere with data interpretation or safety
- Who have had a myocardial infarction or cerebro-vascular event
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| HeatingAlso: BathWarm water immersion | Diagnostic test | Post OGTT, Pre OGTT |
Primary outcome
Mean AUC (Area Under the Curve) Plasma [Glucose]
Time frame: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Does an acute bout of passive, warm water therapy reduce plasma [glucose]? Units for AUC are AU (arbitrary units) which have been derived from the trapezoidal method and have been published as such. Trapezoidal method: AUC = Δx ((y0/2)+y1+y2+y3+...+(yn/2)).
6 secondary outcomes
Change in Plasma [Insulin]
Time frame: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Mean Insulin Sensitivity
Time frame: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Change in Fuel Utilisation
Time frame: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Change in Cardiovascular Status
Time frame: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Change in eHSP70 (Extracellular Heat Shock Protein 70)
Time frame: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Change in Inflammatory Status
Time frame: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Jul 2021.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No. There is no plan to release IPD (individual patient data), until all avenues of further funding have been exhausted.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Heating in people with Diabetes Mellitus, Type 2, run by University of Portsmouth at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 0 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 21 Jul 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 19 Jul 2021). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean AUC (Area Under the Curve) Plasma [Glucose] (time frame: Visit 2, 3 and 4. 3 times in total, until study completion, approximately 8 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Jul 2021.