Obesity & Overweight
Conditions
Keywords
sauna, heat-therapy, obesity, overweight, continuous glucose monitoring
Brief summary
The goal of this clinical trial is to examine the effect of a single 40-minute sauna session on glucose control in individuals at risk for metabolic impairments. Research Questions: * Can a single sauna session completed before a meal reduce the post-meal blood glucose response? * Can a single sauna session improve 24-hour glucose control? Study Design: Participants will complete two lab visits: one involving a sauna session and one placebo visit (resting condition). Researchers will compare the effects on glucose control using a continuous glucose monitor (CGM). What Participants Will Do: Attend a sauna familiarization session Have a CGM sensor placed on the upper arm Visit the lab twice (once for sauna, once for placebo) Consume three standardized meals at home after each session
Detailed description
At least 72 hours prior to the first trial, participants will complete a familiarization session consisting of two 20-minute infrared sauna exposures. The study employs a randomized crossover design, with each participant completing both experimental conditions-infrared sauna (two 20-minute sessions at 175°F / 79°C, separated by a 5-minute break) and seated rest (two 20-minute periods of quiet sitting, separated by a 5-minute break)-separated by at least 72 hours. On each trial day, participants will arrive at the laboratory at 7:50 a.m. after an overnight fast from 8:00 p.m., with water permitted throughout. Participants will wear a continuous glucose monitor (CGM) during both trial days. Baseline measurements of blood pressure, heart rate, and oral body temperature will be recorded, and food logs reviewed. Following the condition session, a sedentary recovery period will occur until 9:45 a.m., with repeated physiological measurements. Final measurements of blood pressure, heart rate, and oral body temperature will be collected prior to a standardized breakfast provided from 9:45 to 10:10 a.m. Participants will depart thereafter by car or public transportation and remain sedentary for the remainder of the day. Meals for the rest of the day, i.e., breakfast, lunch, dinner, and a bedtime snack, will be provided and identical across trial days. Participants will fast again from 9:00 p.m. until 9:00 a.m. the following morning.
Interventions
OTHERInfrared sauna session
Infrared sauna session (approximately 165°F; two 20-minute sessions separated by a 5-minute rest outside the sauna)
OTHERResting condition
Seated resting session (45 minutes outside the sauna)
Sponsors
University of Prince Edward Island
DexCom, Inc.
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Randomized controlled trial (pilot study)
Eligibility
Sex/Gender
ALL
Age
30 Years to 55 Years
Healthy volunteers
No
Inclusion criteria
Are 30-55 years old Have a body mass index of ≥ 27 kg/m2 Have a waist size \>102 cm (men) or \>88 cm (women) Have access to transportation for the 2 experimental visits (e.g., car, public transit, or drop-off). Are cleared for participation based on the Physical Activity Readiness Questionnaire (PAR-Q+).
Exclusion criteria
Take medications that affect blood sugar Exercise intensely 2+ times/week Have diabetes, heart issues, low blood sugar or pressure Are pregnant Regularly use saunas or other heat therapy 1+ times/week
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incremental 2-hour postprandial glucose area under the curve (Breakfast) | 2 hours | 2-hour postprandial incremental AUC of CGM glucose above baseline, measured after the standardized breakfast consumed 45 minutes following the sauna or resting (control) session. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 2-hour postprandial glucose area under the curve (Breakfast) | 2 hours | 2-hour postprandial AUC of CGM glucose above baseline, measured after the standardized breakfast consumed 45 minutes following the sauna or resting (control) session. |
| Incremental 2-hour postprandial glucose area under the curve (Lunch) | 2 hours | Incremental 2-hour postprandial AUC of CGM glucose above baseline, measured after the standardized lunch consumed 225 minutes following the sauna or resting (control) session. |
| Incremental 2-hour postprandial glucose area under the curve (Dinner) | 2 hours | Incremental 2-hour postprandial AUC of CGM glucose above baseline, measured after the standardized lunch consumed 435 minutes following the sauna or resting (control) session. |
| Incremental 2-hour postprandial glucose area under the curve (Bedtime snack) | 2 hours | Incremental 2-hour postprandial AUC of CGM glucose above baseline, measured after the standardized lunch consumed 645 minutes following the sauna or resting (control) session. |
| Average incremental 2-hour postprandial glucose area under the curve (4 meals) | 2 hours | Average incremental 2-hour postprandial CGM glucose AUC above baseline, measured after each standardized meal consumed following the sauna or resting (control) session. The incremental AUC for all four meals will be summed and divided by four to calculate the average incremental postprandial response. |
| Time below range | 24 hours | Total time (minutes) during which CGM glucose values remained below 3.9 mmol/L over the 24-hour period following the sauna or resting (control) session. |
| Time above range | 24 hours | Total time (minutes) during which CGM glucose values remained above 7.8 mmol/L over the 24-hour period following the sauna or resting (control) session. |
| Time in range | 24 hours | Total time (minutes) during which CGM glucose values remained between 3.9 and 7.8 mmol/L over the 24-hour period following the sauna or resting (control) session. |
| Session-induced delta glucose | 45 minutes | Change in CGM glucose during the 45-minute sauna or resting (control) session, calculated as the difference between post-session and pre-session values (Δ = post - pre). |
| Fasting glucose | 15 minutes | CGM glucose representing fasting levels the morning after the sauna or resting (control) session, computed as the mean glucose over the 15 minutes preceding the standardized breakfast. |
| Daily mean glucose | 24 hours | CGM glucose average over the 24h period following the sauna or resting (control session). |
Countries
Canada
Contacts
CONTACTEtienne Myette-Cote, PhD
CONTACTRomina Babazadeh, MSc
PRINCIPAL_INVESTIGATOREtienne Myette-Cote
University of Prince Edward Island
Outcome results
None listed