Plasma Glucose Following Prolonged Heat Exposure
Conditions
Keywords
heat, plasma glucose, worker, glycemia, OGTT
Brief 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.
Interventions
OTHERHot environment
Participants exercising in a 36 degrees celsius environment
OTHERTemperate condition
Participants exercising in a 18 degrees celsius environment
Sponsors
Loughborough University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Outcomes Assessor)
Intervention model description
Randomised, crossover design
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
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
* 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Plasma glucose | 8hours | Measured using colorimetric assay from venous blood samples |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Urine specific gravity/osmolality | 8hours | Determined from urine samples collected before and after exercise |
| Rate of perceived exertion | 8hours | using Borg scales (from 6 \[no effort\] to 20 \[maximal effort\]) |
| Rate of thermal sensation | 8hours | using -10 \[cold\] to +10 \[hot\] scale. |
| Feelings of thirst, urge to urinate, GI comfort, and stomach bloatedness | 8hours | using scales (0 = no feeling, 10 = extreme feeling) |
| Plasma insulin | 8hours | Measured using ELISA from venous blood samples |
| Plasma osmolality | 8hours | Measured using freezing point depression from venous blood samples |
| Plasma volume change | 8hours | Determined from haemoglobin and haematocrit measures in blood samples |
| Urine volume | 8hours | Determined from urine samples collected before and after exercise |
| Body mass | 8hours | Determined from weighing participants before and after exercise |
| Rectal temperature | 8hours | Measured via rectal probe |
| Blood pressure | 8hours | Measured via and automated sphygmomanometer |
| Respiratory gas exchanges | 8hours | Measured via Douglas bag, gas content and volume |
Other
| Measure | Time frame | Description |
|---|---|---|
| Stroop test | 8hours | 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. |
| Go/no-go task for response inhibition (cognitive function) | 8hours | 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. |
| N-back task for working memory (cognitive function) | 8hours | 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. |
Contacts
Primary ContactStephen A Mears, PhD
Outcome results
None listed