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Renal Considerations in the Heat Stress Recommendations (Aim1)

Primary Purpose

Hot Weather; Adverse Effect, Kidney Dysfunction, Kidney Injury

Status
Recruiting
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
23.0°C WBGT - Fixed Work Rate
25.5°C WBGT - Fixed Work Rate
27.5°C WBGT - Fixed Work Rate
28.5°C WBGT - Fixed Work Rate
35.5°C WBGT - Fixed Work Rate
26.0°C WBGT - Fixed work-to-rest ratio
30.5°C WBGT - Fixed work-to-rest ratio
30.5°C WBGT - Fixed work-to-rest ratio (high intensity)
Sponsored by
Indiana University
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Hot Weather; Adverse Effect

Eligibility Criteria

18 Years - 44 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

  • Men and women
  • 18-44 y old
  • Body mass index ≤35.0 kg/m2
  • Self-reported to be healthy.

Exclusion Criteria:

  • Not within defined age range
  • Estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2
  • Deemed highly active according to the physical activity questionnaire (i.e., >3500 MET*min/wk)
  • Body mass index >35.0 kg/m2
  • Current or history of any renal disease, heart disease, stroke, immune or autoimmune disease, and/or gastrointestinal disease/surgery
  • Hypertension during screening (systolic blood pressure >139 or diastolic blood pressure >89)
  • Using medications that blunt the physiological response to exercise (e.g., beta blockers)
  • Prescription medication with a known side effect of impaired temperature regulation or fluid balance (e.g., diuretics)
  • Positive pregnancy test at any time during the study or breast feeding
  • Current tobacco or electronic cigarette use or consistent use within the last 2 years
  • Inability to safely complete the peak oxygen uptake test

Sites / Locations

  • School of Public HealthRecruiting

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Experimental

Arm Label

Fixed Work Rate

Fixed work-to-rest ratio

Arm Description

Participants will walk on a treadmill at 3 mph and the grade will be adjusted to elicit 430 W of metabolic heat production (the most common work intensity). This study will systematically examine the NIOSH recommendations for prescribing work-to-rest ratios with increasing environmental heat stress (defined as Wet Bulb Globe Temperature, WBGT) at this fixed rate of metabolic heat production on kidney function.

This study will systematically examine the NIOSH recommendations on changes in kidney function when the work-to-rest ratio is fixed at 30 min per hour (the most commonly prescribed work-to-rest ratio), but the rate of metabolic heat production and environmental heat stress differs (Figure 2). As described in Study 1, the appropriate rate of metabolic heat production will be elicited by having participants walk on a treadmill at 3 mph and the grade will be adjusted accordingly.

Outcomes

Primary Outcome Measures

Peak urinary [IGFBP7•TIMP-2]
Kidney injury marker

Secondary Outcome Measures

Urinary NGAL
Kidney injury marker
Plasma NGAL
Kidney injury marker
Urinary IGFBP7
Kidney injury marker
Urinary TIMP-2
Kidney injury marker
Urinary IL-18
Kidney injury marker
Urinary L-FABP
Kidney injury marker
Renal artery blood velocity
Index of kidney blood flow
Segmental artery blood velocity
Index of kidney blood flow

Full Information

First Posted
February 17, 2021
Last Updated
February 27, 2023
Sponsor
Indiana University
Collaborators
State University of New York at Buffalo
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1. Study Identification

Unique Protocol Identification Number
NCT04767347
Brief Title
Renal Considerations in the Heat Stress Recommendations
Acronym
Aim1
Official Title
Renal Considerations in the Heat Stress Recommendations
Study Type
Interventional

2. Study Status

Record Verification Date
February 2023
Overall Recruitment Status
Recruiting
Study Start Date
March 1, 2021 (Actual)
Primary Completion Date
December 31, 2023 (Anticipated)
Study Completion Date
December 31, 2023 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Indiana University
Collaborators
State University of New York at Buffalo

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No

5. Study Description

Brief Summary
An epidemic of chronic kidney disease is occurring in laborers who undertake physical work outdoors in hot conditions. The reason for this is unknown, but may be related to kidney dysfunction caused by increases in body temperature and dehydration. The current heat stress recommendations for workers were not developed with regards for kidney health. The purpose of this study is to determine if the current recommendations protect against kidney dysfunction.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Hot Weather; Adverse Effect, Kidney Dysfunction, Kidney Injury, Hyperthermia, Dehydration

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Model Description
This study will systematically examine the NIOSH recommendations for prescribing work-to-rest ratios during occupational heat stress on kidney function.
Masking
ParticipantOutcomes Assessor
Masking Description
The participant will not be directly informed of the experimental conditions and will be blinded to the hypotheses. The outcomes assessor will be blinded to the experimental conditions when analyzing the data.
Allocation
Randomized
Enrollment
40 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Fixed Work Rate
Arm Type
Experimental
Arm Description
Participants will walk on a treadmill at 3 mph and the grade will be adjusted to elicit 430 W of metabolic heat production (the most common work intensity). This study will systematically examine the NIOSH recommendations for prescribing work-to-rest ratios with increasing environmental heat stress (defined as Wet Bulb Globe Temperature, WBGT) at this fixed rate of metabolic heat production on kidney function.
Arm Title
Fixed work-to-rest ratio
Arm Type
Experimental
Arm Description
This study will systematically examine the NIOSH recommendations on changes in kidney function when the work-to-rest ratio is fixed at 30 min per hour (the most commonly prescribed work-to-rest ratio), but the rate of metabolic heat production and environmental heat stress differs (Figure 2). As described in Study 1, the appropriate rate of metabolic heat production will be elicited by having participants walk on a treadmill at 3 mph and the grade will be adjusted accordingly.
Intervention Type
Other
Intervention Name(s)
23.0°C WBGT - Fixed Work Rate
Intervention Description
For four hours, participants will walk on a treadmill to elicit 430 W of metabolic heat production in the following conditions: 23.0°C WBGT (29°C, 46% relative humidity) @ 60 min exercise per hour
Intervention Type
Other
Intervention Name(s)
25.5°C WBGT - Fixed Work Rate
Intervention Description
For four hours, participants will walk on a treadmill to elicit 430 W of metabolic heat production in the following conditions: 25.5°C WBGT (31°C, 52% relative humidity) @ 45 min exercise per hour
Intervention Type
Other
Intervention Name(s)
27.5°C WBGT - Fixed Work Rate
Intervention Description
For four hours, participants will walk on a treadmill to elicit 430 W of metabolic heat production in the following conditions: 27.5°C WBGT (33°C, 53% relative humidity) @ 30 min exercise per hour
Intervention Type
Other
Intervention Name(s)
28.5°C WBGT - Fixed Work Rate
Intervention Description
For four hours, participants will walk on a treadmill to elicit 430 W of metabolic heat production in the following conditions: 28.5°C WBGT (34°C, 54% relative humidity) @ 15 min exercise per hour
Intervention Type
Other
Intervention Name(s)
35.5°C WBGT - Fixed Work Rate
Intervention Description
For four hours, participants will walk on a treadmill to elicit 430 W of metabolic heat production in the following conditions: 35.5°C WBGT (40°C, 65% relative humidity) @ 15 min exercise per hour
Intervention Type
Other
Intervention Name(s)
26.0°C WBGT - Fixed work-to-rest ratio
Intervention Description
For four hours, participants will walk on a treadmill at differing levels of metabolic heat production and environmental conditions (noted below), but at a fixed work-rest ratio of 30 minutes per hour. 26.0°C WBGT (31°C, 55% relative humidity) @ 530 W metabolic heat production
Intervention Type
Other
Intervention Name(s)
30.5°C WBGT - Fixed work-to-rest ratio
Intervention Description
For four hours, participants will walk on a treadmill at differing levels of metabolic heat production and environmental conditions (noted below), but at a fixed work-rest ratio of 30 minutes per hour. 30.5°C WBGT (36°C, 55% relative humidity) @ 230 W metabolic heat production
Intervention Type
Other
Intervention Name(s)
30.5°C WBGT - Fixed work-to-rest ratio (high intensity)
Intervention Description
For four hours, participants will walk on a treadmill at differing levels of metabolic heat production and environmental conditions (noted below), but at a fixed work-rest ratio of 30 minutes per hour. 30.5°C WBGT (36°C, 55% relative humidity) @ 530 W metabolic heat production
Primary Outcome Measure Information:
Title
Peak urinary [IGFBP7•TIMP-2]
Description
Kidney injury marker
Time Frame
through study completion, up to 20 weeks
Secondary Outcome Measure Information:
Title
Urinary NGAL
Description
Kidney injury marker
Time Frame
through study completion, up to 20 weeks
Title
Plasma NGAL
Description
Kidney injury marker
Time Frame
through study completion, up to 20 weeks
Title
Urinary IGFBP7
Description
Kidney injury marker
Time Frame
through study completion, up to 20 weeks
Title
Urinary TIMP-2
Description
Kidney injury marker
Time Frame
through study completion, up to 20 weeks
Title
Urinary IL-18
Description
Kidney injury marker
Time Frame
through study completion, up to 20 weeks
Title
Urinary L-FABP
Description
Kidney injury marker
Time Frame
through study completion, up to 20 weeks
Title
Renal artery blood velocity
Description
Index of kidney blood flow
Time Frame
through study completion, up to 20 weeks
Title
Segmental artery blood velocity
Description
Index of kidney blood flow
Time Frame
through study completion, up to 20 weeks
Other Pre-specified Outcome Measures:
Title
Core body temperature
Description
Heat strain variable
Time Frame
through study completion, up to 20 weeks
Title
Mean skin temperature
Description
Heat strain variable
Time Frame
through study completion, up to 20 weeks
Title
Oxygen uptake
Description
Heat strain variable
Time Frame
through study completion, up to 20 weeks
Title
Heart rate
Description
Heat strain variable
Time Frame
through study completion, up to 20 weeks
Title
Blood pressure
Description
Heat strain variable
Time Frame
through study completion, up to 20 weeks
Title
Whole-body sweat rate
Description
Hydration and heat strain variable
Time Frame
through study completion, up to 20 weeks
Title
Percentage change in body weight
Description
Hydration status variable
Time Frame
through study completion, up to 20 weeks
Title
Plasma osmolality
Description
Hydration status variable
Time Frame
through study completion, up to 20 weeks
Title
Urine osmolality
Description
Hydration status variable
Time Frame
through study completion, up to 20 weeks
Title
Blood and plasma volume
Description
Hydration status variable
Time Frame
through study completion, up to 20 weeks
Title
Urine specific gravity
Description
Hydration status variable
Time Frame
through study completion, up to 20 weeks
Title
Plasma copeptin
Description
Hydration status variable
Time Frame
through study completion, up to 20 weeks
Title
Creatinine clearance
Description
Kidney function variable
Time Frame
through study completion, up to 20 weeks
Title
Fractional excretion of electrolytes
Description
Kidney function variable
Time Frame
through study completion, up to 20 weeks
Title
Free water clearance
Description
Kidney function variable
Time Frame
through study completion, up to 20 weeks
Title
Serum uric acid
Description
Kidney function variable
Time Frame
through study completion, up to 20 weeks
Title
Urinary uric acid
Description
Kidney function variable
Time Frame
through study completion, up to 20 weeks

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
44 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: Men and women 18-44 y old Body mass index ≤35.0 kg/m2 Self-reported to be healthy. Exclusion Criteria: Not within defined age range Estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2 Deemed highly active according to the physical activity questionnaire (i.e., >3500 MET*min/wk) Body mass index >35.0 kg/m2 Current or history of any renal disease, heart disease, stroke, immune or autoimmune disease, and/or gastrointestinal disease/surgery Hypertension during screening (systolic blood pressure >139 or diastolic blood pressure >89) Using medications that blunt the physiological response to exercise (e.g., beta blockers) Prescription medication with a known side effect of impaired temperature regulation or fluid balance (e.g., diuretics) Positive pregnancy test at any time during the study or breast feeding Current tobacco or electronic cigarette use or consistent use within the last 2 years Inability to safely complete the peak oxygen uptake test
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Zachary J Schlader, PhD
Phone
8128556953
Email
zschlade@indiana.edu
Facility Information:
Facility Name
School of Public Health
City
Bloomington
State/Province
Indiana
ZIP/Postal Code
47405-7109
Country
United States
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Zachary Schlader
Phone
812-855-6953
Email
zschlade@indiana.edu

12. IPD Sharing Statement

Citations:
PubMed Identifier
36211944
Citation
Hess HW, Tarr ML, Baker TB, Hostler D, Schlader ZJ. Ad libitum drinking prevents dehydration during physical work in the heat when adhering to occupational heat stress recommendations. Temperature (Austin). 2022 Jul 20;9(3):292-302. doi: 10.1080/23328940.2022.2094160. eCollection 2022.
Results Reference
derived

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Renal Considerations in the Heat Stress Recommendations

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