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Not yet recruitingNCT06982612Updated May 21, 2025

Glycemic Control Following Occupational Work in a Hot Environment

An interventional study of Hot environment and Temperate condition in Plasma Glucose Following Prolonged Heat Exposure, sponsored by Loughborough University. Not yet recruiting. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-05-21.

Sponsored by Loughborough University · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
20
Allocation
Randomized
Ages
18 Years to 45 Years
Sex
All
01

Study summary

Occupational workers regularly perform physically demanding tasks in hot environments, exposing them to heat stress and potential dehydration. While the physiological impacts of heat exposure are well-documented, its effects on glycemic control remain less understood. Given the rising global temperatures due to climate change and the increasing prevalence of metabolic disorders such as obesity and type 2 diabetes, it is essential to investigate how heat exposure during work influences glycemic regulation. Understanding these interactions will help inform future occupational health guidelines and metabolic health recommendations in physically demanding industries.

02

Conditions studied

  • Plasma Glucose Following Prolonged Heat Exposure

Keywords

  • heat
  • plasma glucose
  • worker
  • glycemia
  • OGTT
03

Who can participate

Ages eligible
18 Years to 45 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Male or female
  • Generally fit and healthy
  • Participate in endurance or intermittent exercise at least 3 times a week or minimum of 150 minutes moderate intensity activity per week

Exclusion criteria

Exclusion Criteria:

  • Under 18 or 45 and over,
  • any morbidity or medication that might influence carbohydrate/fat metabolism (i.e., liver/renal/cardiovascular disease) or cycling ability (musculoskeletal injury etc),
  • coagulation or bleeding disorders,
  • blood-borne illness,
  • heart conditions,
  • congenital heart disease,
  • uncontrolled exercise-induced asthma,
  • smoking (including vaping),
  • allergies to the products used in the study,
  • dieting or restrained eating behaviours.
  • Females with amenorrhea would be an exclusion criteria.
04

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Single (Outcomes assessor)
Enrollment
20 participants (estimated)

Study arms

  • Experimental
    Hot condition

    Light exercise in a hot environment with ad libitum water intake

    Other: Hot environment

  • Experimental
    Temperate condition

    Light exercise in a temperate environment with ad libitum water intake

    Other: Temperate condition

Interventions

  • OtherHot environment

    Participants exercising in a 36 degrees celsius environment

  • OtherTemperate condition

    Participants exercising in a 18 degrees celsius environment

05

What researchers measure

Primary outcomes

  1. Plasma glucose

    Measured using colorimetric assay from venous blood samples

    Time frame: 8hours

Secondary outcomes

  1. Plasma insulin

    Measured using ELISA from venous blood samples

    Time frame: 8hours

  2. Plasma osmolality

    Measured using freezing point depression from venous blood samples

    Time frame: 8hours

  3. Plasma volume change

    Determined from haemoglobin and haematocrit measures in blood samples

    Time frame: 8hours

  4. Urine volume

    Determined from urine samples collected before and after exercise

    Time frame: 8hours

  5. Body mass

    Determined from weighing participants before and after exercise

    Time frame: 8hours

  6. Urine specific gravity/osmolality

    Determined from urine samples collected before and after exercise

    Time frame: 8hours

  7. Rectal temperature

    Measured via rectal probe

    Time frame: 8hours

  8. Blood pressure

    Measured via and automated sphygmomanometer

    Time frame: 8hours

  9. Respiratory gas exchanges

    Measured via Douglas bag, gas content and volume

    Time frame: 8hours

  10. Rate of perceived exertion

    using Borg scales (from 6 \[no effort\] to 20 \[maximal effort\])

    Time frame: 8hours

  11. Rate of thermal sensation

    using -10 \[cold\] to +10 \[hot\] scale.

    Time frame: 8hours

  12. Feelings of thirst, urge to urinate, GI comfort, and stomach bloatedness

    using scales (0 = no feeling, 10 = extreme feeling)

    Time frame: 8hours

Other outcomes

  1. N-back task for working memory (cognitive function)

    The task will comprise three progressively harder memory loads (1-Back, 2-Back, 3-Back). Each stimulus type will be used in all memory loads. Participants will have to respond using the space bar when they see a stimulus that is presented one, two, or three steps previously, dependent on the load condition.

    Time frame: 8hours

  2. Go/no-go task for response inhibition (cognitive function)

    Participants will be instructed to press the space bar when a green image appears onscreen ("go" stimulus) and to inhibit responding when a red image is presented (the "no-go" stimulus). Increased commission error responses (i.e. responding incorrectly on a no-go trial) will indicate reduced response inhibition. Commission errors and correct responses will be measured as indices of performance.

    Time frame: 8hours

  3. Stroop test

    The Stroop Test is a psychological assessment that measures a person's ability to inhibit cognitive interference and control attention. Typically, it involves naming the color of the ink in which a word is printed, even when the word itself names a different color (e.g., the word "red" printed in blue ink). The delay in response time when the word and ink color do not match-known as the Stroop effect-reflects the difficulty of suppressing automatic cognitive processes.

    Time frame: 8hours

06

Study locations

No study locations are listed for this record.

07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT06982612
Lead sponsor
Loughborough University
Responsible party
Stephen Mears (Dr - Senior lecturer, Loughborough University) — Principal investigator
First posted
May 21, 2025
Start date
May 2025 (estimated)
Primary completion
May 1, 2026 (estimated)
Completion
Oct 1, 2026 (estimated)
Last update
May 21, 2025

Study contacts

Stephen A Mears, PhD
Contact
s.a.mears@lboro.ac.uk
+44 1509 226391

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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