1
|
Chapman CL, Johnson BD, Hostler DP, Schlader ZJ. Diagnostic accuracy of thermal, hydration, and heart rate assessments in discriminating positive acute kidney injury risk following physical work in the heat. J Occup Environ Hyg 2024; 21:326-341. [PMID: 38512776 DOI: 10.1080/15459624.2024.2315161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Occupational heat stress increases the risk of acute kidney injury (AKI). This study presents a secondary analysis to generate novel hypotheses for future studies by investigating the diagnostic accuracy of thermal, hydration, and heart rate assessments in discriminating positive AKI risk following physical work in the heat in unacclimatized individuals. Unacclimatized participants (n = 13, 3 women, age: ∼23 years) completed four trials involving 2 h of exercise in a 39.7 ± 0.6 °C, 32 ± 3% relative humidity environment that differed by experimental manipulation of hyperthermia (i.e., cooling intervention) and dehydration (i.e., water drinking). Diagnostic accuracy was assessed via receiver operating characteristic curve analysis. Positive AKI risk was identified when the product of concentrations insulin-like growth factor binding protein 7 and tissue inhibitor of metalloproteinase-2 [IGFBP7∙TIMP-2] exceeded 0.3 (ng∙mL-1)2∙1000-1. Peak absolute core temperature had the acceptable discriminatory ability (AUC = 0.71, p = 0.009), but a relatively large variance (AUC 95% CI: 0.57-0.86). Mean body temperature, urine specific gravity, urine osmolality, peak heart rate, and the peak percent of both maximum heart rate and heart rate reserve had poor discrimination (AUC = 0.66-0.69, p ≤ 0.051). Mean skin temperature, percent change in body mass and plasma volume, and serum sodium and osmolality had no discrimination (p ≥ 0.072). A peak increase in mean skin temperature of >4.7 °C had a positive likelihood ratio of 11.0 which suggests clinical significance. These data suggest that the absolute value of peak core temperature and the increase in mean skin temperature may be valuable to pursue in future studies as a biomarker for AKI risk in unacclimatized workers.
Collapse
Affiliation(s)
- Christopher L Chapman
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
| | - Blair D Johnson
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana
| | - David P Hostler
- Department of Exercise & Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Zachary J Schlader
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana
| |
Collapse
|
2
|
Freemas JA, Worley ML, Gabler MC, Hess HW, Goss CS, Baker TB, Johnson BD, Chapman CL, Schlader ZJ. Renal vascular control during normothermia and passive heat stress does not differ between healthy younger men and women. Am J Physiol Renal Physiol 2024; 326:F802-F813. [PMID: 38545652 DOI: 10.1152/ajprenal.00034.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 05/04/2024] Open
Abstract
Men are likely at greater risk for heat-induced acute kidney injury compared with women, possibly due to differences in vascular control. We tested the hypothesis that the renal vasoconstrictor and vasodilator responses will be greater in younger women compared with men during passive heat stress. Twenty-five healthy adults [12 women (early follicular phase) and 13 men] completed two experimental visits, heat stress or normothermic time-control, assigned in a block-randomized crossover design. During heat stress, participants wore a water-perfused suit perfused with 50°C water. Core temperature was increased by ∼0.8°C in the first hour before commencing a 2-min cold pressor test (CPT). Core temperature remained clamped and at 1-h post-CPT, subjects ingested a whey protein shake (1.2 g of protein/kg body wt), and measurements were taken pre-, 75 min, and 150 min post-protein. Beat-to-beat blood pressure (Penaz method) was measured and segmental artery vascular resistance (VR, Doppler ultrasound) was calculated as segmental artery blood velocity ÷ mean arterial pressure. CPT-induced increases in segmental artery VR did not differ between trials (trial effect: P = 0.142) nor between men (heat stress: 1.5 ± 1.0 mmHg/cm/s, normothermia: 1.4 ± 1.0 mmHg/cm/s) and women (heat stress: 1.4 ± 1.2 mmHg/cm/s, normothermia: 2.1 ± 1.1 mmHg/cm/s) (group effect: P = 0.429). Reductions in segmental artery VR following oral protein loading did not differ between trials (trial effect: P = 0.080) nor between men (heat stress: -0.6 ± 0.8 mmHg/cm/s, normothermia: -0.6 ± 0.6 mmHg/cm/s) and women (heat stress: -0.5 ± 0.5 mmHg/cm/s, normothermia: -1.1 ± 0.6 mmHg/cm/s) (group effect: P = 0.204). Renal vasoconstrictor responses to the cold pressor test and vasodilator responses following an oral protein load during heat stress or normothermia do not differ between younger men and younger women in the early follicular phase of the menstrual cycle.NEW & NOTEWORTHY The mechanisms underlying greater heat-induced acute kidney injury risk in men versus women remain unknown. This study examined renal vascular control, including both vasodilatory (oral protein load) and vasoconstrictor (cold presser test) responses, during normothermia and heat stress and compared these responses between men and women. The results indicated that in both conditions neither renal vasodilatory nor vasoconstrictor responses differ between younger men and younger women.
Collapse
Affiliation(s)
- Jessica A Freemas
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, Indiana University School of Public Health, Bloomington, Indiana, United States
| | - Morgan L Worley
- Department of Exercise and Nutrition Sciences, Center for Research and Education in Special Environments, University at Buffalo, Buffalo, New York, United States
| | - Mikaela C Gabler
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, Indiana University School of Public Health, Bloomington, Indiana, United States
| | - Hayden W Hess
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, Indiana University School of Public Health, Bloomington, Indiana, United States
- Department of Exercise and Nutrition Sciences, Center for Research and Education in Special Environments, University at Buffalo, Buffalo, New York, United States
| | - Curtis S Goss
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, Indiana University School of Public Health, Bloomington, Indiana, United States
| | - Tyler B Baker
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, Indiana University School of Public Health, Bloomington, Indiana, United States
| | - Blair D Johnson
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, Indiana University School of Public Health, Bloomington, Indiana, United States
| | - Christopher L Chapman
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
- Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, United States
| | - Zachary J Schlader
- Department of Kinesiology, H.H. Morris Human Performance Laboratories, Indiana University School of Public Health, Bloomington, Indiana, United States
| |
Collapse
|
3
|
Atkins WC, McKenna ZJ, McDermott BP. Sports drinks do not increase acute kidney injury risk in males during industrial work in the heat when euhydration is maintained, a randomized crossover trial. Appl Physiol Nutr Metab 2024. [PMID: 38452351 DOI: 10.1139/apnm-2023-0393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Industrial workers regularly perform physical labor under high heat stress, which may place them at risk for dehydration and acute kidney injury. Current guidelines recommend that workers should consume sports drinks to maintain euhydration during work shifts. However, the impact of fructose sweetened sports drinks on acute kidney injury risk is unknown. The purpose of this study was to investigate the effects of sports drink consumption on markers of acute kidney injury following simulated industrial work in the heat. Twenty males completed two matched 2 h simulated industrial work trial visits in a warm and humid environment (30 °C and 55% relative humidity). During and following the bout of simulated work, participants consumed either a commercially available sports drink or a noncaloric placebo. Urine and blood samples, collected pre-, post-, and 16 h post-work were assayed for markers of hydration (plasma/urine osmolality, and urine specific gravity) and acute kidney injury (KIM-1 and NGAL). There were no differences in physiological or perceptual responses to the bout of work (interaction p > 0.05 for all indices), and markers of hydration were similar between trials (interaction p > 0.05 for all indices). KIM-1 (Placebo: Δ Ln 1.18 ± 1.64; Sports drink: Δ Ln 1.49 ± 1.10 pg/mL; groupwide d = 0.89, p < 0.001) and NGAL (Placebo: Δ Ln 0.44 ± 1.11; Sports drink: Δ Ln 0.67 ± 1.22 pg/mL; groupwide d = 0.39, p = 0.03) were elevated pre- to post-work, but there were no differences between trials (interaction p > 0.05). These data provide no evidence that consumption of fructose sweetened sports drinks increases the risk of acute kidney injury during physical work in the heat.
Collapse
Affiliation(s)
- Whitley C Atkins
- Exercise Science Research Center, University of Arkansas, Fayetteville, AR, USA
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Zachary J McKenna
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Brendon P McDermott
- Exercise Science Research Center, University of Arkansas, Fayetteville, AR, USA
| |
Collapse
|
4
|
Deshayes TA, Sodabi DGA, Dubord M, Gagnon D. Shifting focus: Time to look beyond the classic physiological adaptations associated with human heat acclimation. Exp Physiol 2024; 109:335-349. [PMID: 37885125 PMCID: PMC10988689 DOI: 10.1113/ep091207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023]
Abstract
Planet Earth is warming at an unprecedented rate and our future is now assured to be shaped by the consequences of more frequent hot days and extreme heat. Humans will need to adapt both behaviorally and physiologically to thrive in a hotter climate. From a physiological perspective, countless studies have shown that human heat acclimation increases thermoeffector output (i.e., sweating and skin blood flow) and lowers cardiovascular strain (i.e., heart rate) during heat stress. However, the mechanisms mediating these adaptations remain understudied. Furthermore, several possible benefits of heat acclimation for other systems and functions involved in maintaining health and performance during heat stress remain to be elucidated. This review summarizes recent advances in human heat acclimation, with emphasis on recent studies that (1) advanced our understanding of the mechanisms mediating improved thermoeffector output and (2) investigated adaptations that go beyond those classically associated with heat acclimation. We highlight that these studies have contributed to a better understanding of the integrated physiological responses underlying human heat acclimation while leaving key unanswered questions that will need to be addressed in the future.
Collapse
Affiliation(s)
- Thomas A. Deshayes
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| | - Dèwanou Gilles Arnaud Sodabi
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| | - Marianne Dubord
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| | - Daniel Gagnon
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| |
Collapse
|
5
|
Hess HW, Baker TB, Tarr ML, Zoh RS, Johnson BD, Hostler D, Schlader ZJ. Occupational Heat Stress Recommendation Compliance Attenuates AKI Risk Compared with a Work-Rest Ratio-Matched, Positive Control Scenario. Kidney360 2023; 4:1752-1756. [PMID: 37907448 PMCID: PMC10758508 DOI: 10.34067/kid.0000000000000288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 10/19/2023] [Indexed: 11/02/2023]
Abstract
Occupational heat stress recommendations attenuate AKI risk compared with a work–rest ratio–matched positive control scenario. Heat-induced AKI risk is strongly related to peak core temperature. The peak change in serum creatinine largely paralleled peak changes in urinary [insulin-like growth factor-binding protein 7·tissue inhibitor metalloproteinase 2].
Collapse
Affiliation(s)
- Hayden W. Hess
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana
| | - Tyler B. Baker
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana
| | - Macie L. Tarr
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana
| | - Roger S. Zoh
- Department of Epidemiology and Biostatistics, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana
| | - Blair D. Johnson
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana
| | - David Hostler
- Department of Exercise and Nutrition Sciences, Center for Research and Education in Special Environments, University at Buffalo, Buffalo, New York
| | - Zachary J. Schlader
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana
| |
Collapse
|