1
|
Costin A, Fisher D, Harper B, Nahhas RW, Sullenbarger J. Climate Change and Mental Health: An Interactive Educational Session. MEDEDPORTAL : THE JOURNAL OF TEACHING AND LEARNING RESOURCES 2024; 20:11418. [PMID: 38645713 PMCID: PMC11026302 DOI: 10.15766/mep_2374-8265.11418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 03/14/2024] [Indexed: 04/23/2024]
Abstract
Introduction Climate change is the single biggest health threat facing humanity, with direct and indirect impacts on mental health, yet health impacts of climate change remain notably absent from most medical school curricula. We describe a timely interactive educational session on climate change and mental health that was implemented and studied on a medical student clinical psychiatry rotation. Methods We developed a 1-hour introductory session on the mental health impacts of climate change and potential solutions. The session was delivered to third-year medical students on their 4-week clinical psychiatry rotation and included pre- and postsession survey questions assessing their knowledge, comfort, and readiness regarding the topic. Results Seventy students participated in the session, with 49 students completing the pre- and postsession surveys, giving a response rate of 70%. The average score for the four Likert-scale questions on the survey increased from 2.7 presession to 3.9 postsession on a 5-point scale (1 = strongly disagree, 5 = strongly agree). All questions displayed statistically significant improvement. Qualitative analysis identified knowledge gained about the mental health impacts of climate change as the most important aspect of the session to students. Discussion The introductory session effectively filled an urgent need in medical education curricula regarding climate change's effects on human health. Overall, distribution of and improvement upon this timely teaching content can serve a valuable role in medical student education as the effects of climate change, particularly on mental health, continue to progress throughout the century.
Collapse
Affiliation(s)
- Andrea Costin
- Fourth-Year Medical Student, Wright State University Boonshoft School of Medicine
| | - Daniel Fisher
- Third-Year Resident, Department of Psychiatry, Wright State University
| | - Bethany Harper
- Director of Medical Student Education in Psychiatry and Associate Professor, Department of Psychiatry, Wright State University
| | - Ramzi W. Nahhas
- Professor, Department of Population and Public Health Sciences and Department of Psychiatry, Wright State University
| | - John Sullenbarger
- Assistant Residency Training Program Director and Assistant Professor, Department of Psychiatry, Wright State University
| |
Collapse
|
2
|
Klous L, Reinten J, Mol D, Roijendijk L, van Beurden M, Kingma B. No large effects on cognitive performance in high versus low solar green-flag WBGT conditions. ERGONOMICS 2024; 67:194-206. [PMID: 37278045 DOI: 10.1080/00140139.2023.2218625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 05/23/2023] [Indexed: 06/07/2023]
Abstract
Excessive solar radiation negatively affects cognitive performance. Occupational guidelines typically combine environmental components into one value, such as wet-bulb globe temperature (WBGT). Here, we evaluated cognitive performance in two similar 28.6 °C WBGT-effective (WBGTeff) that were designed differently; using high or low levels of solar radiation. Eight soldiers were exposed to a virtual-reality environment in a climate chamber set to high (900 Wm-2) or low solar radiation conditions (300 Wm-2). Soldiers walked 3 x 30 min at 5 kmh-1. Cognitive performance was evaluated using a virtual-reality scenario and a computerised test battery. There was no statistically significant effect of condition on the cognitive tasks (p > 0.05). Associations were found between mean body temperature (Tb) and visual detection (P ≤ 0.01). Differences in solar radiation with similar WBGTeff (28.6 °C) do not cause large systematic differences in cognitive performance. Certain aspects of cognitive performance (i.e. response inhibition) seem to be partly associated with Tb rather than solar radiation.Practitioner summary: Cognitive performance was evaluated in two similar WBGT conditions that were designed differently; using high or low levels of solar radiation. Differences in solar radiation with similar WBGT do not cause systematic differences in cognitive performance. Certain aspects of cognition were partly associated with mean body temperature rather than solar radiation.
Collapse
Affiliation(s)
- Lisa Klous
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Jikke Reinten
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Douwe Mol
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Linsey Roijendijk
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Maurice van Beurden
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| | - Boris Kingma
- Department of Human Performance, Unit Defence, Safety and Security, Netherlands Organization for Applied Scientific Research (TNO), Soesterberg, The Netherlands
| |
Collapse
|
3
|
McGarr GW, Meade RD, Notley SR, Akerman AP, Richards BJ, McCourt ER, King KE, McCormick JJ, Boulay P, Sigal RJ, Kenny GP. Physiological responses to 9 hours of heat exposure in young and older adults. Part III: Association with self-reported symptoms and mood state. J Appl Physiol (1985) 2024; 136:408-420. [PMID: 38153847 DOI: 10.1152/japplphysiol.00740.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/13/2023] [Accepted: 12/20/2023] [Indexed: 12/30/2023] Open
Abstract
Older adults are at greater risk of heat-related morbidity and mortality during heat waves, which is commonly linked to impaired thermoregulation. However, little is known about the influence of increasing age on the relation between thermal strain and perceptual responses during daylong heat exposure. We evaluated thermal and perceptual responses in 20 young (19-31 yr) and 39 older adults (20 with hypertension and/or type 2 diabetes; 61-78 yr) resting in the heat for 9 h (heat index: 37°C). Body core and mean skin temperature areas under the curve (AUC, hours 0-9) were assessed as indicators of cumulative thermal strain. Self-reported symptoms (68-item environmental symptoms questionnaire) and mood disturbance (40-item profile of mood states questionnaire) were assessed at end-heating (adjusted for prescores). Body core temperature AUC was 2.4°C·h [1.0, 3.7] higher in older relative to young adults (P < 0.001), whereas mean skin temperature AUC was not different (-0.5°C·h [-4.1, 3.2] P = 0.799). At end-heating, self-reported symptoms were not different between age groups (0.99-fold [0.80, 1.23], P = 0.923), with or without adjustment for body core or mean skin temperature AUC (both P ≥ 0.824). Mood disturbance was 0.93-fold [0.88, 0.99] lower in older, relative to young adults (P = 0.031). Older adults with and without chronic health conditions experienced similar thermal strain, yet those with these conditions reported lower symptom scores and mood disturbance compared with young adults and their age-matched counterparts (all P ≤ 0.026). Although older adults experienced heightened thermal strain during the 9-h heat exposure, they did not experience greater self-reported symptoms or mood disturbance relative to young adults.NEW & NOTEWORTHY Despite experiencing greater cumulative thermal strain during 9 h of passive heat exposure, older adults reported similar heat-related symptoms and lower mood disturbance than young adults. Furthermore, self-reported symptoms and mood disturbance were lower in older adults with common age-associated health conditions than young adults and healthy age-matched counterparts. Perceptual responses to heat in older adults can underestimate their level of thermal strain compared with young adults, which may contribute to their increased heat vulnerability.
Collapse
Affiliation(s)
- Gregory W McGarr
- Consumer and Clinical Radiation Protection Bureau, Health Canada, Ottawa, Ontario, Canada
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Robert D Meade
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Sean R Notley
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Ashley P Akerman
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Brodie J Richards
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Emma R McCourt
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Kelli E King
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - James J McCormick
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Pierre Boulay
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Ronald J Sigal
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
- Department of Medicine, Faculties of Medicine and Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Department of Cardiac Sciences, Faculties of Medicine and Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Department of Community Health Sciences, Faculties of Medicine and Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| |
Collapse
|
4
|
Bach AJE, Cunningham SJK, Morris NR, Xu Z, Rutherford S, Binnewies S, Meade RD. Experimental research in environmentally induced hyperthermic older persons: A systematic quantitative literature review mapping the available evidence. Temperature (Austin) 2024; 11:4-26. [PMID: 38567267 PMCID: PMC7615797 DOI: 10.1080/23328940.2023.2242062] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/21/2023] [Indexed: 04/04/2024] Open
Abstract
The heat-related health burden is expected to persist and worsen in the coming years due to an aging global population and climate change. Defining the breadth and depth of our understanding of age-related changes in thermoregulation can identify underlying causes and strategies to protect vulnerable individuals from heat. We conducted the first systematic quantitative literature review to provide context to the historical experimental research of healthy older adults - compared to younger adults or unhealthy age matched cases - during exogenous heat strain, focusing on factors that influence thermoregulatory function (e.g. co-morbidities). We identified 4,455 articles, with 147 meeting eligibility criteria. Most studies were conducted in the US (39%), Canada (29%), or Japan (12%), with 71% of the 3,411 participants being male. About 71% of the studies compared younger and older adults, while 34% compared two groups of older adults with and without factors influencing thermoregulation. Key factors included age combined with another factor (23%), underlying biological mechanisms (18%), age independently (15%), influencing health conditions (15%), adaptation potential (12%), environmental conditions (9%), and therapeutic/pharmacological interventions (7%). Our results suggest that controlled experimental research should focus on the age-related changes in thermoregulation in the very old, females, those with overlooked chronic heat-sensitive health conditions (e.g. pulmonary, renal, mental disorders), the impact of multimorbidity, prolonged and cumulative effects of extreme heat, evidence-based policy of control measures (e.g. personal cooling strategies), pharmaceutical interactions, and interventions stimulating protective physiological adaptation. These controlled studies will inform the directions and use of limited resources in ecologically valid fieldwork studies.
Collapse
Affiliation(s)
- Aaron J. E. Bach
- School of Medicine and Dentistry, Griffith University, Gold Coast, QLD, Australia
- Cities Research Institute, Griffith University, Gold Coast, QLD, Australia
| | - Sarah J. K. Cunningham
- School of Medicine and Dentistry, Griffith University, Gold Coast, QLD, Australia
- Cities Research Institute, Griffith University, Gold Coast, QLD, Australia
| | - Norman R. Morris
- School of Health Sciences and Social Work, Griffith University, Gold Coast, QLD, Australia
- Metro North Hospital and Health Service, The Prince Charles Hospital. Allied Health Research Collaborative, Brisbane, QLD, Australia
- Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD, Australia
| | - Zhiwei Xu
- School of Medicine and Dentistry, Griffith University, Gold Coast, QLD, Australia
- Cities Research Institute, Griffith University, Gold Coast, QLD, Australia
| | - Shannon Rutherford
- School of Medicine and Dentistry, Griffith University, Gold Coast, QLD, Australia
- Cities Research Institute, Griffith University, Gold Coast, QLD, Australia
| | - Sebastian Binnewies
- School of Information and Communication Technology, Griffith University, Gold Coast, QLD, Australia
| | - Robert D. Meade
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada
- Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
| |
Collapse
|
5
|
Henderson MJ, Grandou C, Chrismas BCR, Coutts AJ, Impellizzeri FM, Taylor L. Core Body Temperatures in Intermittent Sports: A Systematic Review. Sports Med 2023; 53:2147-2170. [PMID: 37526813 PMCID: PMC10587327 DOI: 10.1007/s40279-023-01892-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2023] [Indexed: 08/02/2023]
Abstract
BACKGROUND Hyperthermia (and associated health and performance implications) can be a significant problem for athletes and teams involved in intermittent sports. Quantifying the highest thermal strain (i.e. peak core body temperature [peak Tc]) from a range of intermittent sports would enhance our understanding of the thermal requirements of sport and assist in making informed decisions about training or match-day interventions to reduce thermally induced harm and/or performance decline. OBJECTIVE The objective of this systematic review was to synthesise and characterise the available thermal strain data collected in competition from intermittent sport athletes. METHODS A systematic literature search was performed on Web of Science, MEDLINE, and SPORTDiscus to identify studies up to 17 April 2023. Electronic databases were searched using a text mining method to provide a partially automated and systematic search strategy retrieving terms related to core body temperature measurement and intermittent sport. Records were eligible if they included core body temperature measurement during competition, without experimental intervention that may influence thermal strain (e.g. cooling), in healthy, adult, intermittent sport athletes at any level. Due to the lack of an available tool that specifically includes potential sources of bias for physiological responses in descriptive studies, a methodological evaluation checklist was developed and used to document important methodological considerations. Data were not meta-analysed given the methodological heterogeneity between studies and therefore were presented descriptively in tabular and graphical format. RESULTS A total of 34 studies were selected for review; 27 were observational, 5 were experimental (2 parallel group and 3 repeated measures randomised controlled trials), and 2 were quasi-experimental (1 parallel group and 1 repeated measures non-randomised controlled trial). Across all included studies, 386 participants (plus participant numbers not reported in two studies) were recruited after accounting for shared data between studies. A total of 4 studies (~ 12%) found no evidence of hyperthermia, 24 (~ 71%) found evidence of 'modest' hyperthermia (peak Tc between 38.5 and 39.5 °C), and 6 (~ 18%) found evidence of 'marked' hyperthermia (peak Tc of 39.5 °C or greater) during intermittent sports competition. CONCLUSIONS Practitioners and coaches supporting intermittent sport athletes are justified to seek interventions aimed at mitigating the high heat strain observed in competition. More research is required to determine the most effective interventions for this population that are practically viable in intermittent sports settings (often constrained by many competing demands). Greater statistical power and homogeneity among studies are required to quantify the independent effects of wet bulb globe temperature, competition duration, sport and level of competition on peak Tc, all of which are likely to be key modulators of the thermal strain experienced by competing athletes. REGISTRATION This systematic review was registered on the Open Science Framework ( https://osf.io/vfb4s ; https://doi.org/10.17605/OSF.IO/EZYFA , 4 January 2021).
Collapse
Affiliation(s)
- Mitchell J Henderson
- School of Sport, Exercise and Rehabilitation, Faculty of Health, University of Technology Sydney (UTS), Sydney, Australia.
- Human Performance Research Centre, University of Technology Sydney (UTS), Sydney, Australia.
| | - Clementine Grandou
- School of Sport, Exercise and Rehabilitation, Faculty of Health, University of Technology Sydney (UTS), Sydney, Australia
- Human Performance Research Centre, University of Technology Sydney (UTS), Sydney, Australia
| | - Bryna C R Chrismas
- Department of Physical Education, College of Education, Qatar University, Doha, Qatar
| | - Aaron J Coutts
- School of Sport, Exercise and Rehabilitation, Faculty of Health, University of Technology Sydney (UTS), Sydney, Australia
- Human Performance Research Centre, University of Technology Sydney (UTS), Sydney, Australia
| | - Franco M Impellizzeri
- School of Sport, Exercise and Rehabilitation, Faculty of Health, University of Technology Sydney (UTS), Sydney, Australia
- Human Performance Research Centre, University of Technology Sydney (UTS), Sydney, Australia
| | - Lee Taylor
- School of Sport, Exercise and Rehabilitation, Faculty of Health, University of Technology Sydney (UTS), Sydney, Australia
- Human Performance Research Centre, University of Technology Sydney (UTS), Sydney, Australia
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| |
Collapse
|
6
|
McGarr GW, Meade RD, Kenny GP. Indoor overheating influences self-reported symptoms and mood-state in older adults during a simulated heatwave: Effects of mid-day cooling centre use. Physiol Behav 2023; 271:114335. [PMID: 37607601 DOI: 10.1016/j.physbeh.2023.114335] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 08/24/2023]
Abstract
Public health agencies recommend that older adults without home air-conditioning visit cooling centres to mitigate physiological strain from high ambient temperatures during heat waves. However, there is little evidence regarding their influence on self-reported environmental symptoms and mood-state after returning to the heat. METHODS Forty adults (64-79 years) underwent a daylong laboratory-based indoor overheating simulation (9-hours, heat index: 37 °C) with (cooling, n = 20) or without (control, n = 20) a 2-hour air-conditioning intervention (hours 5-6). Mean skin and core temperature areas under the curve (AUC, hours 0-9) were used to assess cumulative thermal strain. Group differences in total symptom scores and subjective heat illness (68-item environmental symptoms questionnaire) as well as total mood disturbance and energy index (40-item profile of mood states questionnaire) were evaluated at end-heating (adjusted for pre-exposure scores). RESULTS Cooling reduced mean skin and core temperature AUCs by 4.0 [0.1, 0.8] and 1.6 [0.4, 2.8] °C·hour compared to control (both p < 0.048). However, at end-heating neither mean skin nor core temperatures differed between groups (both p > 0.999). Total symptom scores and subjective heat illness were 0.58-fold [0.44, 0.77] and 0.56-fold [0.40, 0.78] lower in the cooling compared to control group (both p < 0.001). Mood disturbance was 0.91-fold [0.83, 0.99] lower for cooling than control (p = 0.036), although energy index was not different between groups (p = 0.141). CONCLUSION Cooling centres can have sustained positive effects on perceived thermal strain and mood-state in older adults after returning to the heat. However, continued vigilance and use of appropriate countermeasures to mitigate physiological strain from indoor overheating should be encouraged as body temperatures can rapidly return to pre-cooling levels.
Collapse
Affiliation(s)
- Gregory W McGarr
- Consumer and Clinical Radiation Protection Bureau, Health Canada, Ottawa, Ontario, Canada; Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Robert D Meade
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada; Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
| |
Collapse
|
7
|
Choi EY, Lee H, Chang VW. Cumulative exposure to extreme heat and trajectories of cognitive decline among older adults in the USA. J Epidemiol Community Health 2023; 77:728-735. [PMID: 37541774 DOI: 10.1136/jech-2023-220675] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/24/2023] [Indexed: 08/06/2023]
Abstract
BACKGROUND The projected increase in extreme heat days is a growing public health concern. While exposure to extreme heat has been shown to negatively affect mortality and physical health, very little is known about its long-term consequences for late-life cognitive function. We examined whether extreme heat exposure is associated with cognitive decline among older adults and whether this association differs by race/ethnicity and neighbourhood socioeconomic status. METHODS Data were drawn from seven waves of the Health and Retirement Study (2006-2018) merged with historical temperature data. We used growth curve models to assess the role of extreme heat exposure on trajectories of cognitive function among US adults aged 52 years and older. RESULTS We found that high exposure to extreme heat was associated with faster cognitive decline for blacks and residents of poor neighbourhoods, but not for whites, Hispanics or residents of wealthier neighbourhoods. CONCLUSION Extreme heat exposure can disproportionately undermine cognitive health in later life for socially vulnerable populations. Our findings underscore the need for policy actions to identify and support high-risk communities for increasingly warming temperatures.
Collapse
Affiliation(s)
- Eun Young Choi
- Department of Social and Behavioral Sciences, School of Global Public Health, New York University, New York, NY, USA
| | - Haena Lee
- Department of Sociology, Sungkyunkwan University, Seoul, Korea (the Republic of)
| | - Virginia W Chang
- Department of Social and Behavioral Sciences, School of Global Public Health, New York University, New York, NY, USA
- Department of Population Health, Grossman School of Medicine, New York University, New York, New York, USA
| |
Collapse
|
8
|
Deming N, Steer S, Hernandez J, Dinenno F, Richards J. Carbohydrate ingestion attenuates the reduction in complex cognitive function and cerebral blood flow during prolonged passive heat stress in humans. J Therm Biol 2023; 117:103698. [PMID: 37734348 DOI: 10.1016/j.jtherbio.2023.103698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 08/07/2023] [Accepted: 08/23/2023] [Indexed: 09/23/2023]
Abstract
PURPOSE To determine whether carbohydrate ingestion would reduce cognitive dysfunction in humans following long duration passive heat stress (PHS) versus consuming electrolytes alone. METHODS Fifteen young (27 ± 4 y) healthy adults were exposed to 120 min of PHS through the use of a liquid perfused suit (50 °C) on two randomized visits. Subjects consumed fluids supplemented with electrolytes (E) or electrolytes + carbohydrates (E + C). Pre- and post-heat stress, body mass (BM) and plasma osmolality (pOsm) were measured. Heart rate (HR), blood pressure (BP), Physiological Strain Index (PSI), core temperature (Tc), plasma glucose, respiration rate (RR), end-tidal CO2 (PetCO2) and internal carotid artery (ICA) blood flow were recorded at baseline and every 15 min of heat stress. Cognitive function was assessed via the Automated Neuropsychological Assessment Metric at baseline and at 30- and 120 min during heat stress. RESULTS There were no significant differences between fluid conditions for BM, pOsm, PSI, Tc, RR or PetCO2. Plasma glucose was ∼75% greater in the E + C condition compared to the E condition after 90 min of PHS (P < 0.05). Cognitive function (120 min) was impaired following PHS only in E condition (P < 0.05) and performance on complex cognitive tasks were better by ∼22-340% in the E + C vs. E (P < 0.05). Compared to the E condition, HR and BP were lower and ICA blood flow, vascular conductance, and glucose delivery was ∼90% greater in the E + C after 90 min of PHS (P < 0.05). CONCLUSIONS These data are the first to demonstrate that carbohydrate ingestion may have a protective effect on cognitive function during long duration PHS. Furthermore, this protection was associated with preserved ICA blood flow and glucose delivery to the brain.
Collapse
Affiliation(s)
- Nathan Deming
- Human Performance Laboratory, Directorate of Athletics, USAF Academy, CO, 80840, USA; Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA
| | - Sarah Steer
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA
| | - Jesse Hernandez
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA
| | - Frank Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA
| | - Jennifer Richards
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80521, USA.
| |
Collapse
|
9
|
Wang J, Solianik R, Eimantas N, Baranauskiene N, Brazaitis M. Age-Related Difference in Cognitive Performance under Severe Whole-Body Hyperthermia Parallels Cortisol and Physical Strain Responses. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1665. [PMID: 37763784 PMCID: PMC10535853 DOI: 10.3390/medicina59091665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/21/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023]
Abstract
Background and Objectives: To date, understanding age-related changes in cognitive processes during heat exposure still needs to be better-understood. Thus, the main aim of the current study was to evaluate the effects of whole-body hyperthermia (WBH), i.e., a ≈ 2.5 °C increase in rectal temperature (Tre) from overnight-fast baseline value, on cognitive functioning in old and young men and to explore factors, such as stress and thermophysiological strain, that could influence such changes. Materials and Methods: Ten young (19-21 years of age) and nine old (61-80 years of age) healthy men underwent an experimental trial with passive lower-body heating in hot water immersion (HWI) at 43 °C (HWI-43 °C) until Tre reached 39 °C in old adults and 39.5 °C in young adults. Cognitive performance and cortisol concentration were assessed before and after HWI, and the physiological strain index (PSI) was assessed during HWI-43 °C. Results: PSI was lower and cortisol concentration was greater after HWI-43 °C in the old group compared with the young group (p < 0.05). Surprisingly, hyperthermia improved cognitive flexibility only in old adults, whereas short-term and visual recognition memories were maintained in both age groups. Conclusions: A ≈ 2.5 °C increase in rectal temperature can improve executive function in old adults, and this increase parallels the increased cortisol concentration and the lower thermophysiological strain under severe WBH conditions.
Collapse
Affiliation(s)
| | | | | | | | - Marius Brazaitis
- Institute of Sport Science and Innovations, Lithuanian Sports University, LT-44221 Kaunas, Lithuania; (J.W.); (R.S.); (N.E.); (N.B.)
| |
Collapse
|
10
|
Chaudhari N, Strutton PH, Wickham AJ, McGregor AH, Mullington CJ. Heat stress associated with aerosol PPE and its impact. Occup Med (Lond) 2023; 73:120-127. [PMID: 36282602 PMCID: PMC10132207 DOI: 10.1093/occmed/kqac114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Aerosol personal protective equipment (PPE) is subjectively reported to negatively impact healthcare workers' performance and well-being, but this has not been assessed objectively. AIMS This randomized controlled crossover study aimed to quantify the heat stress associated with aerosol PPE and to investigate its impact upon mood, cognitive and motor function, and task performance. METHODS Sixteen healthy, young, lean participants (eight males) undertook an exercise protocol, which simulated the metabolic expenditure of hospital work: once wearing aerosol PPE (PPE visit) and once wearing standard surgical attire (control visit). Participants walked on a treadmill for 2 h followed by 30-min rest. Core temperature, heart rate, urine specific gravity, weight, grip strength, mood (Bond-Lader scale) and task performance (Intubation of a Manikin) were recorded. Values are between-visit mean (standard deviation) differences. RESULTS On the PPE visit core temperature (+0.2 (0.3)°C; P < 0.01), heart rate (+12 (13) bpm; P < 0.001), urine specific gravity (+0.003 (0.005); P < 0.05) and intubation task time (+50 (81) s; P < 0.01) were greater than on the control visit; and alertness (-14 (21) mm; P < 0.001), contentment (-14 (15) mm; P < 0.001) and grip strength (-4 (4) N; P < 0.01) were less. CONCLUSIONS This study demonstrates that wearing aerosol PPE in a simulated hospital environment results in heat exhaustion and has a negative impact upon mood, motor function, and task performance. Whilst wearing PPE is important to prevent disease transmission, strategies should be developed to limit its impact upon healthcare workers' performance and well-being.
Collapse
Affiliation(s)
- N Chaudhari
- MSk Lab, Imperial College London, London W12 0BZ, UK
| | - P H Strutton
- MSk Lab, Imperial College London, London W12 0BZ, UK
| | - A J Wickham
- Theatres and Anaesthesia, Imperial College Healthcare NHS Trust, London W2 1NY, UK
| | - A H McGregor
- MSk Lab, Imperial College London, London W12 0BZ, UK
| | - C J Mullington
- MSk Lab, Imperial College London, London W12 0BZ, UK
- Theatres and Anaesthesia, Imperial College Healthcare NHS Trust, London W2 1NY, UK
| |
Collapse
|
11
|
Ingestion of carbonated water increases middle cerebral artery blood velocity and improves mood states in resting humans exposed to ambient heat stress. Physiol Behav 2022; 255:113942. [PMID: 35964802 DOI: 10.1016/j.physbeh.2022.113942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/02/2022] [Accepted: 08/10/2022] [Indexed: 11/21/2022]
Abstract
Sugar-free carbonated water is consumed worldwide. The consumption of carbonated water is high in summer, when the heat loss responses of sweating and skin vasodilation are activated, and thermal perceptions (thermal sensation and comfort) and mood states are negatively modulated. However, whether ingesting carbonated water under ambient heat exposure modulates cerebral blood flow index, heat loss responses, thermal perceptions, and mood states remains to be determined. In this study, 17 healthy, habitually active, young adults (eight women) ingested 4 °C noncarbonated or carbonated water under 37 °C ambient heat-stressed resting conditions. Both drinks increased the middle cerebral artery mean blood velocity, an index of cerebral blood flow, and mean arterial pressure, with carbonated water exhibiting higher elevations than noncarbonated water (P < 0.05). However, the heart rate, sweat rate, and skin blood flow during and after drinking remained unchanged between the two conditions (P > 0.05). The thermal sensation and comfort after drinking remained unchanged between the two conditions (P > 0.05); but, a drink-induced reduction in sleepiness was higher, and drink-induced elevations in motivation and exhilaration were higher after ingesting carbonated water than those after ingesting noncarbonated water (P < 0.05). The analyses suggest that in humans under ambient heat-stressed resting conditions, ingestion of cold carbonated water increases the cerebral blood flow index, blood pressure, motivation, and exhilaration, whereas it decreases sleepiness relative to ingestion of noncarbonated cold water. However, ingestion of cold carbonated water fails to modulate thermoregulatory responses and thermal perception as opposed to noncarbonated cold water.
Collapse
|
12
|
Aoki M, Yamazaki Y, Otsuka J, Okamoto Y, Takada S, Shirai N, Fujimoto T, Ochi G, Yamashiro K, Sato D, Amano T. Influence of Heat Exposure on Motor Control Performance and Learning as Well as Physiological Responses to Visuomotor Accuracy Tracking Task. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:12328. [PMID: 36231630 PMCID: PMC9566463 DOI: 10.3390/ijerph191912328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/21/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
This study aimed to determine whether heat exposure attenuates motor control performance and learning, and blunts cardiovascular and thermoregulatory responses to visuomotor accuracy tracking (VAT) tasks. Twenty-nine healthy young adults (22 males) were divided into two groups performing VAT tasks (5 trials × 10 blocks) in thermoneutral (NEUT: 25 °C, 45% RH, n = 14) and hot (HOT: 35 °C, 45% RH, n = 15) environments (acquisition phase). One block of the VAT task was repeated at 1, 2, and 4 h after the acquisition phase (retention phase). Heat exposure elevated skin temperature to ~3 °C with a marginally increased core body temperature. VAT performance (error distance of curve tracking) was more attenuated overall in HOT than in NEUT in the acquisition phase without improvement in magnitude alteration. Heat exposure did not affect VAT performance in the retention phase. The mean arterial blood pressure and heart rate, but not for sweating and cutaneous vascular responses to VAT acquisition trials, were more attenuated in HOT than in NEUT without any retention phase alternations. We conclude that skin temperature elevation exacerbates motor control performance and blunts cardiovascular response during the motor skill acquisition period. However, these alternations are not sustainable thereafter.
Collapse
Affiliation(s)
- Mao Aoki
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata 950-2181, Japan
| | - Yudai Yamazaki
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City 305-8574, Japan
- Japan Society for the Promotion of Science, Tokyo 102-0083, Japan
| | - Junto Otsuka
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata 950-2181, Japan
| | - Yumi Okamoto
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata 950-2181, Japan
| | - Shota Takada
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata 950-2181, Japan
| | - Nobu Shirai
- Department of Psychology, College of Contemporary Psychology, Rikkyo University, Saitama 352-8558, Japan
| | - Tomomi Fujimoto
- Institute for Human Movement and Medical Sciences, Department of Health and Sports, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Genta Ochi
- Institute for Human Movement and Medical Sciences, Department of Health and Sports, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Koya Yamashiro
- Institute for Human Movement and Medical Sciences, Department of Health and Sports, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Daisuke Sato
- Institute for Human Movement and Medical Sciences, Department of Health and Sports, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Tatsuro Amano
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata 950-2181, Japan
| |
Collapse
|
13
|
Yeoman K, Weakley A, DuBose W, Honn K, McMurry T, Eiter B, Baker B, Poplin G. Effects of heat strain on cognitive function among a sample of miners. APPLIED ERGONOMICS 2022; 102:103743. [PMID: 35313260 PMCID: PMC9170134 DOI: 10.1016/j.apergo.2022.103743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 02/24/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Heat stress is associated with workplace injuries, likely through a combination of fatigue, reduced cognitive function, and thermal discomfort. The purpose of this study was to evaluate four cognitive tasks for sensitivity to heat stress. Eight participants performed treadmill exercise followed by assessments of serial reaction time (RT), Stroop effect, verbal delayed memory, and continuous performance working memory in an environmental chamber. A control (21.1 °C) trial, and "Hot 1" and "Hot 2" (both 37.8 °C) trials were run sequentially on two separate days to evaluate the four cognitive tasks. Heat strain (comparing Hot 1 and Hot 2 with the control trial) resulted in impairments in the serial RT test response and Stroop accuracy. Delayed memory was impacted only in the Hot 2 trial compared with the control trial. Given the demonstrated impact of heat on cognitive processes relevant to workers' real-world functioning in the workplace, understanding how to assess and monitor vigilant attention in the workplace is essential.
Collapse
Affiliation(s)
- Kristin Yeoman
- National Institute for Occupational Safety and Health, 315 E. Montgomery Ave, Spokane, WA, 99207, USA.
| | - Alyssa Weakley
- University of California Davis School of Medicine, Department of Neurology, 4860 Y St #3900, Sacramento, CA, 95817, USA
| | - Weston DuBose
- National Institute for Occupational Safety and Health, 315 E. Montgomery Ave, Spokane, WA, 99207, USA
| | - Kimberly Honn
- Washington State University Sleep and Performance Research Center & Elson S. Floyd College of Medicine Washington State University, 412 E. Spokane Falls Blvd., Spokane, WA, USA
| | - Timothy McMurry
- University of Virginia Department of Public Health Sciences, PO Box 800717, Charlottesville, VA, 22908, USA
| | - Brianna Eiter
- National Institute for Occupational Safety and Health, 315 E. Montgomery Ave, Spokane, WA, 99207, USA
| | - Brent Baker
- National Institute for Occupational Safety and Health, 1095 Willowdale Road, MS 4020, Morgantown, WV, 26505-2888, USA
| | - Gerald Poplin
- National Institute for Occupational Safety and Health, 315 E. Montgomery Ave, Spokane, WA, 99207, USA
| |
Collapse
|
14
|
The influence of rest break frequency and duration on physical performance and psychophysiological responses: a mining simulation study. Eur J Appl Physiol 2022; 122:2087-2097. [PMID: 35727402 PMCID: PMC9381606 DOI: 10.1007/s00421-022-04979-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/31/2022] [Indexed: 11/17/2022]
Abstract
Purpose To investigate the influence of shorter, more frequent rest breaks during simulated work (outdoor mining) in the heat on physical performance and psychophysiological responses. Methods On separate days, thirteen males undertook two 225 min simulation trials in the afternoon (12.00–3.45 pm) including 180 min of treadmill walking at a constant rate of perceived exertion of 11 (or ‘light’) on the 6–20 Borg scale in a heat chamber (37 °C, 40% RH), interspersed with 45 min of rest breaks in an air-conditioned room (22 °C, 35% RH). Rest breaks in the current practice (CP) trial occurred at 1.00 and 2.30 pm (30 min and 15 min, respectively), while in the experimental (EXP) trial were at 1.00 (15 min), 1.45, 2.25 and 3.05 pm (10 min each). Results Total distance covered was not different (p = 0.086) between CP (12,858 ± 2207 m) and EXP (12,094 ± 2174 m). Heart rate, thermal sensation and thermal comfort were significantly higher at 120–180 min (all p < 0.05) in CP compared to EXP. Moderate- to large-effect sizes (Hedge’s g) between trials were also found at 120–180 min for core temperature (g = 0.50 and 0.99, respectively). No differences were found between trials for cognitive performance, perceived fatigue, urine specific gravity, or total water intake (p > 0.05). Conclusion Shorter, more frequent rest breaks have little impact on physical performance, thermal strain and exercise-related sensations. Current practices should remain in place until further studies can be conducted on an actual mine site during summer where outdoor workers perform their work duties.
Collapse
|
15
|
Zhang L, Luo Y, Zhang Y, Pan X, Zhao D, Wang Q. Green Space, Air Pollution, Weather, and Cognitive Function in Middle and Old Age in China. Front Public Health 2022; 10:871104. [PMID: 35586008 PMCID: PMC9108722 DOI: 10.3389/fpubh.2022.871104] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/09/2022] [Indexed: 11/13/2022] Open
Abstract
Prior research has shown that environmental hazards, such as limited green space, air pollution, and harmful weather, have the strong adverse impact on older adults' cognitive function; however, most of the studies were conducted in developed countries and limited to cross-sectional analyses. China has the largest aging population in the world so the research evidence from it can offer an insight to the study in other developing countries facing similar issues and inform future public health policy and disease control. This study examined the long-term impact of environmental factors, namely, green space coverage, air pollution, and weather conditions on cognitive function using a nationally representative sample consisting of adults aged 45 years and older selected from the China Health and Retirement Longitudinal Study (CHARLS 2011–2018), the China City Statistical Yearbook, and other sources. Multilevel growth curve models were utilized for analysis and the mediator effects of physical activity and social engagement on the relationship between environmental factors and cognitive function were examined. Findings of this study showed that after controlling for sociodemographic characteristics, annual precipitation of 80 cm or more, living in areas with July temperature of 28°C or higher, urban community, and green space coverage were positively associated with cognition score at the baseline and lower precipitation, urban community, and greater green space coverage were associated with slower cognitive decline over a 7-year period. The impact of gross domestic product (GDP) seemed to take into effect more and more over time. These effects did not substantially change after weekly total hours of physical activities and levels of social engagement were added. More research on the mechanisms of the effect of environmental factors on cognition is needed such as the subgroup analyses and/or with more aspects of environmental measures.
Collapse
Affiliation(s)
- Lingling Zhang
- Department of Nursing, University of Massachusetts Boston, Boston, MA, United States
| | - Ye Luo
- Department of Sociology, Anthropology and Criminal Justice, Clemson University, Clemson, SC, United States
- *Correspondence: Ye Luo
| | - Yao Zhang
- Department of Nursing, University of Massachusetts Boston, Boston, MA, United States
| | - Xi Pan
- Department of Sociology, Texas State University, San Marcos, TX, United States
| | - Dandan Zhao
- Department of Sociology, Anthropology and Criminal Justice, Clemson University, Clemson, SC, United States
| | - Qing Wang
- Department of Biostatistics, Shandong University, Jinan, China
| |
Collapse
|
16
|
Qiu Y, Deng Z, Jiang C, Wei K, Zhu L, Zhang J, Jiao C. The Associations of Meteorological and Environmental Factors with Memory Function of the Older Age in Urban Areas. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19095484. [PMID: 35564874 PMCID: PMC9105547 DOI: 10.3390/ijerph19095484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 02/04/2023]
Abstract
Individual, meteorological, and environmental factors are associated with cognitive function in older age. However, little is known about how meteorological and environmental factors interact with individual factors in affecting cognitive function in older adults. In the current study, we used mixed effects models to assess the association of individual, meteorological, and environmental factors with cognitive function among older adults in urban areas. Data from 2623 adults aged 60 to 91 years from 25 provinces (or autonomous regions/municipalities) from the China Family Panel Studies (CFPS) were used. We used the memory test in CFPS to measure memory function, while meteorological data from the daily climate data set of China’s surface international exchange stations, and the traffic and greening data compiled by the National Bureau of Statistics (NBS) of China, were used to assess meteorological and environmental factors. The ICC of the empty model indicated that 7.7% of the variation in memory test scores for the older adults was caused by provincial characteristics. Results showed that the temperature and relative humidity of provinces moderated the effect of gender on the memory function for the older urban adults. Specifically, in the high temperature areas, memory scores for females were higher than those of males, and in the middle humidity areas, memory scores were also higher for the females than those of males. This study explained how meteorological and environmental factors played roles in influencing demographic factors on memory function among older adults. Further research is needed to better define the role and potential mechanism of this moderation.
Collapse
Affiliation(s)
- Yuehong Qiu
- School of Psychology, Shenzhen University, Shenzhen 518060, China; (Y.Q.); (Z.D.); (K.W.); (L.Z.)
- Center for Mental Health, Shenzhen University, Shenzhen 518060, China
| | - Zeming Deng
- School of Psychology, Shenzhen University, Shenzhen 518060, China; (Y.Q.); (Z.D.); (K.W.); (L.Z.)
- Center for Mental Health, Shenzhen University, Shenzhen 518060, China
| | - Chujuan Jiang
- School of Music and Dance, Division of Arts, Shenzhen University, Shenzhen 518060, China;
| | - Kaigong Wei
- School of Psychology, Shenzhen University, Shenzhen 518060, China; (Y.Q.); (Z.D.); (K.W.); (L.Z.)
- Center for Mental Health, Shenzhen University, Shenzhen 518060, China
| | - Lijun Zhu
- School of Psychology, Shenzhen University, Shenzhen 518060, China; (Y.Q.); (Z.D.); (K.W.); (L.Z.)
- Center for Mental Health, Shenzhen University, Shenzhen 518060, China
| | - Jieting Zhang
- School of Psychology, Shenzhen University, Shenzhen 518060, China; (Y.Q.); (Z.D.); (K.W.); (L.Z.)
- Center for Mental Health, Shenzhen University, Shenzhen 518060, China
- Correspondence: (J.Z.); (C.J.)
| | - Can Jiao
- School of Psychology, Shenzhen University, Shenzhen 518060, China; (Y.Q.); (Z.D.); (K.W.); (L.Z.)
- Center for Mental Health, Shenzhen University, Shenzhen 518060, China
- Correspondence: (J.Z.); (C.J.)
| |
Collapse
|
17
|
Doohan MA, Stewart IB, Coulter TJ, Drovandi C, Weier S, Borg DN. Modified Stroop Task Performance When Wearing Protective Clothing in the Heat: An Evaluation of the Maximum Adaptability Model. Physiol Behav 2021; 246:113690. [PMID: 34958826 DOI: 10.1016/j.physbeh.2021.113690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 01/30/2023]
Abstract
INTRODUCTION This exploratory study investigated whether performance in a behavioural inhibition task followed the shape proposed by the Maximum Adaptability Model during progressive exertional heat stress-that is, an initial improvement in cognitive performance is followed by a plateau, and subsequent decline once body temperature continues to rise unabated. METHODS Seventeen adult males walked on a treadmill at 4 km•h-1 (1% grade) for up to 120 min, in three protective clothing ensembles, across three simulated environments. The simulated environments were equivalent to wet bulb globe temperatures 21, 30 and 37°C. Cognitive function was assessed using a modified colour-word Stroop Task, with performance expressed as inverse efficiency scores in the simple (congruent) and more complex (incongruent) task conditions. The Stroop Task was completed before a trial, at termination, and every 30 min during walking, and core body temperature was continuously measured. Data were modelled using Bayesian penalised regression, with core body temperature included as a non-linear term (i.e., second degree polynomial). RESULTS We did not find any evidence that core body temperature had an effect on congruent or incongruent inverse efficiency scores, and no evidence that the relationship between these variables followed the shaped described by the Maximum Adaptability Model. There was, however, evidence that higher pre-exercise serum osmolality values were associated with slower congruent (β = 9.19) and incongruent (β = 8.67) inverse efficiency scores. The posterior probability that these effects were greater than zero was 0.971 and 0.952, respectively. CONCLUSIONS In young, fit men, performance in the behavioural inhibition task was unaffected by increases in body temperature up to 39°C and did not follow the shape proposed by the Maximum Adaptability Model. A secondary finding of the study was that pre-exercise hydration status affected performance in the inhibition task. Future studies are needed to confirm this result.
Collapse
Affiliation(s)
- Meg A Doohan
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia
| | - Ian B Stewart
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Tristan J Coulter
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia
| | - Christopher Drovandi
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia; Australian Research Council Centre of Excellence for Mathematical and Statistical Frontiers, Queensland University of Technology, Brisbane, Queensland, Australia; Centre for Data Science, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Steven Weier
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - David N Borg
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia; The Hopkins Centre, Menzies Health Institute Queensland, Griffith University, Brisbane, Australia.
| |
Collapse
|
18
|
Girard O, Gaoua N, Grantham J, Knez W, Walsh A, Racinais S. Effects of living and working in a hot environment on cognitive function in a quiet and temperature-controlled room: An oil and gas industry study. Temperature (Austin) 2021; 8:372-380. [PMID: 34901319 DOI: 10.1080/23328940.2021.1959289] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
We investigate the effects of seasonal heat stress on cognitive function in outdoor workers. Thirty-nine workers from an oil and gas industry in the Middle-East volunteered for cognitive testing before (5.30 to 7.00 am) and after (3.30 to 5.00 pm) their daily work-shift in hot (August - average daily temperature: ~41°C) and temperate (January - average daily temperature: ~22°C) seasons. While physical activity was reduced in hot compared to temperate season (average normalized acceleration: 96 ± 33 vs. 112 ± 31 × 10-3 g; -12.5 ± 4.7%; P = 0.010), the average core temperature during the work-shift was higher in the hot season (37.4 ± 0.2 vs. 37.2 ± 0.2°C; P = 0.002). Peak core temperature was 38.0 ± 0.1°C and 37.8 ± 0.1°C in hot and temperate seasons, respectively. Cognitive performance did not differ between seasons for tests of recognition memory (P = 0.169), working memory (P = 0.797) and executive function (P = 0.145), independent of testing time. Whereas there was no significant main effect of testing time for tests of recognition memory (P = 0.503) and working memory (P = 0.849), the number of problems solved on the first choice for the executive function test was lower in the afternoon than the morning (-9.2 ± 5.3%; P = 0.039). There was no season × testing time interaction for any cognitive tests (P ≥ 0.145). In the absence of hyperthermia, living and working in a hot environment does not alter cognitive function in oil and gas industry workers tested in a quiet and temperature-controlled room, with reduced clothing encumbrance (relative to work). Conclusions should not be extrapolated to more stressful situations (i.e., thermal stressor present, pronounced dehydration, noise).
Collapse
Affiliation(s)
- Olivier Girard
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Western Australia, Australia.,Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar
| | - Nadia Gaoua
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar.,Sport and Exercise Science Research Centre (SESRC), London South Bank University, London, UK
| | - Justin Grantham
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar.,RelatePerform, Relate Perform Ltd, Hong Kong
| | - Wade Knez
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar
| | - Andrew Walsh
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar.,Brisbane Lions Football Club, Brisbane, Queensland, Australia
| | - Sebastien Racinais
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar
| |
Collapse
|
19
|
Schlader ZJ, Schwob J, Hostler D, Cavuoto L. Simultaneous assessment of motor and cognitive tasks reveals reductions in working memory performance following exercise in the heat. Temperature (Austin) 2021; 9:344-356. [PMID: 36339090 PMCID: PMC9629122 DOI: 10.1080/23328940.2021.1992239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This study tested the hypothesis that, following exercise in the heat, motor task performance will be impaired when assessed simultaneously with a cognitive task. In a randomized, crossover and counterbalanced design, twelve healthy adults (23 ± 2 years, 5 women) completed four 10-minute exercise circuits involving upper and lower body exercise in a moderate (18.1 ± 1.7°C, 38 ± 10% relative humidity) and a hot (40.3 ± 1.1°C, 26 ± 5% relative humidity) environment. Experimental testing was completed in a temperate thermal environment before exercise (~25°C) and in either the moderate or hot environment following exercise. The 3 Back test (a test of working memory) was used as the cognitive task and postural sway was used as the motor task. Cognitive and motor task performance assessments were conducted both individually (solo) and simultaneously (dual). At the end of exercise, core temperature (by 0.4 ± 0.3°C, P < 0.001), heart rate (by 12 ± 18 bpm, P = 0.025), and mean skin temperature (by 7.6 ± 0.8°C, P < 0.001) were higher in the Hot trial compared to Moderate. During solo testing, postural sway increased from pre- to post-exercise in the Hot (P ≤ 0.028), but not the Moderate (P ≥ 0.261) trial. During dual testing, postural sway did not differ between trials (P ≥ 0.065) or over time (P ≥ 0.094). During solo testing, 3 Back performance did not differ between trials (P = 0.810) or over time (P = 0.707), but during dual testing 3 Back performance following exercise was reduced in the Hot compared to the Moderate trial (P = 0.028). Simultaneous assessment of motor and cognitive tasks reveals that motor performance is reduced following exercise in the heat. .
Collapse
Affiliation(s)
- Zachary J. Schlader
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, USA,Department of Kinesiology, School of Public Health, Indiana University, Bloomington, USA
| | - Jacqueline Schwob
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, USA
| | - David Hostler
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, USA,Department of Emergency Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, USA
| | - Lora Cavuoto
- Department of Industrial and Systems Engineering, School of Engineering and Applied Sciences, University at Buffalo, Buffalo, USA,CONTACT Lora Cavuoto
| |
Collapse
|
20
|
Lo YTC, Su WP, Mei SH, Jou YY, Huang HB. Association between ambient temperature and cognitive function in a community-dwelling elderly population: a repeated measurement study. BMJ Open 2021; 11:e049160. [PMID: 34876421 PMCID: PMC8655549 DOI: 10.1136/bmjopen-2021-049160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES Evidence on the associations between short-term and long-term air temperature exposure and cognitive function in older adults, particularly those in Asia, is limited. We explored the relationships of short-term and long-term air temperature exposure with cognitive function in Taiwanese older adults through a repeated measures survey. DESIGN AND SETTING We used data the ongoing Taiwan Longitudinal Study on Aging, a multiple-wave nationwide survey. PARTICIPANTS We identified 1956, 1700, 1248 and 876 older adults in 1996, 1999, 2003 and 2007, respectively. PRIMARY AND SECONDARY OUTCOME MEASURES Participants' cognitive function assessment was based on the Short Portable Mental Status Questionnaire. We calculated the temperature moving average (TMA) for temperature exposure windows between 1993 and 2007 using data from air quality monitoring stations, depending on the administrative zone of each participant's residence. Generalised linear mixed models were used to examine the effects of short-term and long-term temperature changes on cognitive function. RESULTS Short-term and long-term temperature exposure was significantly and positively associated with moderate-to-severe cognitive impairment, with the greatest increase in ORs found for 3-year TMAs (OR 1.247; 95% CI 1.107 to 1.404). The higher the quintiles of temperature exposure were, the higher were the ORs. The strongest association found was in long-term TMA exposure (OR 3.674; 95% CI 2.103 to 6.417) after covariates were controlled for. CONCLUSIONS The risk of mild cognitive impairment increased with ambient temperature in community-dwelling older adults in Taiwan.
Collapse
Affiliation(s)
- Yuan-Ting C Lo
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
| | - Wei-Peng Su
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
| | - Shu-Hsuan Mei
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
| | - Yann-Yuh Jou
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
- Health Promotion Administration, Ministry of Health and Welfare, Taipei, Taiwan
| | - Han-Bin Huang
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
| |
Collapse
|
21
|
Barry H, Gendron P, Gagnon C, Bherer L, Gagnon D. Passive heat acclimation does not modulate processing speed and executive functions during cognitive tasks performed at fixed levels of thermal strain. Appl Physiol Nutr Metab 2021; 47:261-268. [PMID: 34710341 DOI: 10.1139/apnm-2021-0243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE This study evaluated if passive controlled hyperthermia heat acclimation (HA) modulates cognitive performance during passive heat stress. METHODS Eight healthy adults (25 ± 4 years) underwent 7 consecutive days of hot water immersion (core temperature ≥38.6°C) and a 7-day time-control period. On days 1 and 7 of HA, participants performed a digital Stroop test at baseline, when core temperature reached 38.6°C, and after 60 minutes at a core temperature ≥38.6°C to evaluate reaction time during tasks targeting processing speed (reading and counting) and executive functions (inhibition and switching). On days 1 and 7 of the time-control intervention, participants performed the Stroop test with equivalent amounts of time separating each task as for HA. RESULTS During day 1 of HA, reaction time was quicker during the reading (-44 ms [-71, -17], P<0.01) and counting (-39 ms [-76, -2], P=0.04) tasks when rectal temperature reached 38.6°C, but after a further 60 minutes of heat exposure, reaction time only remained quicker during the reading task (-56 ms [-83, -29], P<0.01). Changes in reaction time during heat exposure were unaffected by subsequent HA (interaction, all P≥0.09). CONCLUSION Seven days of HA does not modulate processing speed and executive functions during passive heat exposure. Novelty: - Whether heat acclimation (HA) to improve cognitive performance during heat exposure remains understudied. - We tested the hypothesis that HA modulates reaction time during cognitive tasks performed at matched levels of thermal strain. - Despite classical signs of HA, reaction time during heat exposure was unaffected by HA.
Collapse
Affiliation(s)
- Hadiatou Barry
- Montreal Heart Institute, 25465, Montreal, Quebec, Canada.,Universite de Montreal, 5622, Montreal, Quebec, Canada;
| | - Philippe Gendron
- Universite du Quebec a Trois-Rivieres, 14847, DSAP, Trois-Rivieres, Quebec, Canada;
| | | | - Louis Bherer
- Montreal Heart Institute, 25465, Montreal, Quebec, Canada.,Universite de Montreal, 5622, Montreal, Quebec, Canada;
| | - Daniel Gagnon
- Montreal Heart Institute, 25465, Montreal, Canada.,Université de Montréal, 5622, Montreal, Canada;
| |
Collapse
|
22
|
Piil JF, Kingma B, Morris NB, Christiansen L, Ioannou LG, Flouris AD, Nybo L. Proposed framework for forecasting heat-effects on motor-cognitive performance in the Summer Olympics. Temperature (Austin) 2021; 8:262-283. [PMID: 34485620 PMCID: PMC8409751 DOI: 10.1080/23328940.2021.1957367] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Heat strain impairs performance across a broad spectrum of sport disciplines. The impeding effects of hyperthermia and dehydration are often ascribed to compromised cardiovascular and muscular functioning, but expert performance also depends on appropriately tuned sensory, motor and cognitive processes. Considering that hyperthermia has implications for central nervous system (CNS) function and fatigue, it is highly relevant to analyze how heat stress forecasted for the upcoming Olympics may influence athletes. This paper proposes and demonstrates the use of a framework combining expected weather conditions with a heat strain and motor-cognitive model to analyze the impact of heat and associated factors on discipline- and scenario-specific performances during the Tokyo 2021 games. We pinpoint that hyperthermia-induced central fatigue may affect prolonged performances and analyze how hyperthermia may impair complex motor-cognitive performance, especially when accompanied by either moderate dehydration or exposure to severe solar radiation. Interestingly, several short explosive performances may benefit from faster cross-bridge contraction velocities at higher muscle temperatures in sport disciplines with little or no negative heat-effect on CNS fatigue or motor-cognitive performance. In the analyses of scenarios and Olympic sport disciplines, we consider thermal impacts on “motor-cognitive factors” such as decision-making, maximal and fine motor-activation as well as the influence on central fatigue and pacing. From this platform, we also provide perspectives on how athletes and coaches can identify risks for their event and potentially mitigate negative motor-cognitive effects for and optimize performance in the environmental settings projected.
Collapse
Affiliation(s)
- Jacob Feder Piil
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark
| | - Boris Kingma
- Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.,TNO, the Netherlands Organization for Applied Scientific Research, Unit Defense, Safety & Security, Soesterberg, The Netherlands
| | - Nathan B Morris
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark
| | - Lasse Christiansen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark
| | - Leonidas G Ioannou
- FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Andreas D Flouris
- FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark
| |
Collapse
|
23
|
The Association of Meteorological Factors with Cognitive Function in Older Adults. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18115981. [PMID: 34199578 PMCID: PMC8199712 DOI: 10.3390/ijerph18115981] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 11/17/2022]
Abstract
Individual and meteorological factors are associated with cognitive function in older adults. However, how these two factors interact with each other to affect cognitive function in older adults is still unclear. We used mixed effects models to assess the association of individual and meteorological factors with cognitive function among older adults. Individual data in this study were from the database of China Family Panel Studies. A total of 3448 older adults from 25 provinces were included in our analysis. Cognitive functions were measured using a memory test and a logical sequence test. We used the meteorological data in the daily climate dataset of China’s surface international exchange stations, and two meteorological factors (i.e., average temperature and relative humidity) were assessed. The empty model showed significant differences in the cognitive scores of the older adults across different provinces. The results showed a main impact of residence (i.e., urban or rural) and a significant humidity–residence interaction on memory performance in older adults. Specifically, the negative association between humidity and memory performance was more pronounced in urban areas. This study suggested that meteorological factors may, in concert with individual factors, be associated with differences in memory function in older adults.
Collapse
|
24
|
Cheng JL, Williams JS, Hoekstra SP, MacDonald MJ. Improvements in vascular function in response to acute lower limb heating in young healthy males and females. J Appl Physiol (1985) 2021; 131:277-289. [PMID: 34013754 DOI: 10.1152/japplphysiol.00630.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Regular exposure to passive heat stress improves vascular function, but the optimal heating prescription remains undefined. Local limb heating is more feasible than whole body heating, but the evidence demonstrating its efficacy is lacking. The purpose of this study was to determine whether acute improvements in vascular function can be achieved with lower limb heating in 16 young healthy individuals (8 female, 8 male). In separate visits, participants underwent 45 min of ankle- and knee-level hot water immersion (45°C). A subset of seven participants also participated in a time-control visit. Endothelial function was assessed through simultaneous brachial and superficial femoral artery flow-mediated dilation (FMD) tests. Macrovascular function was quantified by %FMD, whereas microvascular function was quantified by vascular conductance during reactive hyperemia. Arterial stiffness was assessed through carotid-femoral and femoral-foot pulse wave velocity (PWV). Plasma concentrations of interleukin-6 and extracellular heat shock protein-72 (eHSP72) were used as indicators of inflammation. Our findings showed that 45 min of lower limb heating-regardless of condition-acutely improved upper limb macrovascular endothelial function (i.e., brachial %FMD; Pre: 4.6 ± 1.7 vs. Post: 5.4 ± 2.0%; P = 0.004) and lower limb arterial stiffness (i.e., femoral-foot PWV; Pre: 8.4 ± 1.2 vs. Post: 7.7 ± 1.1 m/s; P = 0.011). However, only knee-level heating increased upper limb microvascular function (i.e., brachial peak vascular conductance; Pre: 6.3 ± 2.7 vs. Post: 7.8 ± 3.5 mL/min ⋅ mmHg; P ≤ 0.050) and plasma eHSP72 concentration (Pre: 12.4 ± 9.4 vs. Post: 14.8 ± 9.8 ng/mL; P ≤ 0.050). These findings show that local lower limb heating acutely improves vascular function in younger individuals, with knee-level heating improving more outcome measures.NEW & NOTEWORTHY This study demonstrates that lower limb hot water immersion is an effective strategy for acutely improving vascular function in young, healthy males and females, thereby encouraging the development of accessible modes of heat therapy for vascular health.
Collapse
Affiliation(s)
- Jem L Cheng
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | | | - Sven P Hoekstra
- The Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, United Kingdom
| | | |
Collapse
|
25
|
Maldonado T, Orr JM, Goen JRM, Bernard JA. Age Differences in the Subcomponents of Executive Functioning. J Gerontol B Psychol Sci Soc Sci 2021; 75:e31-e55. [PMID: 31943092 DOI: 10.1093/geronb/gbaa005] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVES Across the life span, deficits in executive functioning (EF) are associated with poor behavioral control and failure to achieve goals. Though EF is often discussed as one broad construct, a prominent model of EF suggests that it is composed of three subdomains: inhibition, set shifting, and updating. These subdomains are seen in both younger (YA) and older adults (OA), with performance deficits across subdomains in OA. Therefore, our goal was to investigate whether subdomains of EF might be differentially affected by age, and how these differences may relate to broader global age differences in EF. METHODS To assess these age differences, we conducted a meta-analysis at multiple levels, including task level, subdomain level, and of global EF. Based on previous work, we hypothesized that there would be overall differences in EF in OA. RESULTS Using 1,268 effect sizes from 401 articles, we found overall differences in EF with age. Results suggested that differences in performance are not uniform, such that variability in age effects emerged at the task level, and updating was not as affected by age as other subdomains. DISCUSSION These findings advance our understanding of age differences in EF, and stand to inform early detection of EF decline.
Collapse
Affiliation(s)
- Ted Maldonado
- Department of Psychological and Brain Sciences, Texas A&M University, College Station
| | - Joseph M Orr
- Department of Psychological and Brain Sciences, Texas A&M University, College Station.,Texas A&M Institute for Neuroscience, Texas A&M University, College Station
| | - James R M Goen
- Department of Psychological and Brain Sciences, Texas A&M University, College Station
| | - Jessica A Bernard
- Department of Psychological and Brain Sciences, Texas A&M University, College Station.,Texas A&M Institute for Neuroscience, Texas A&M University, College Station
| |
Collapse
|
26
|
Perry BG, Mündel T. Lower body positive pressure affects systemic but not cerebral haemodynamics during incremental hyperthermia. Clin Physiol Funct Imaging 2020; 41:226-233. [PMID: 33238075 DOI: 10.1111/cpf.12682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/17/2020] [Accepted: 11/18/2020] [Indexed: 11/28/2022]
Abstract
Hyperthermia produces profound redistribution of blood and circulatory reflex function. We investigated the potential for lower body positive pressure (LBPP) to maintain or restore haemodynamics during graded hyperthermia. Eight healthy adults rested supine in a custom-made LBPP box, sealed distal to the iliac crest. Following 5 min of normothermic rest, 20 mmHg of LBPP was applied and repeated when core temperature (Tcore ) had increased passively by +0.5 and +1°C. Primary dependent variables included mean middle cerebral artery blood velocity (MCAvmean , transcranial Doppler), mean arterial blood pressure (MAP, finger photoplethysmography), heart rate (HR) and partial pressure of end-tidal carbon dioxide (PET CO2 ). The absolute increase in MAP during LBPP was lower at Tcore +1°C (2 ± 3 mmHg), compared with normothermia (7 ± 3 p = .01). The modest increase in MCAvmean was unchanged by Tcore (normothermia, 2 ± 3 cm/s; +0.5°C, 3 ± 3 cm/s and +1°C, 3 ± 4 cm/s, p = .74). By design, PET CO2 was unchanged in all conditions from normothermic baseline (42 ± 1, p = .81). LBPP-induced changes in HR were greater at +0.5°C (-13 ± 4 b/min) and +1°C (-12 ± 6 b/min) compared with normothermia (-3 ± 3 b/min, p = .01 and p = .01, respectively). These data indicate that despite a significant attenuation in MAP to LBPP with moderate hyperthermia, MCAvmean dynamics were unchanged among the thermal manipulations.
Collapse
Affiliation(s)
- Blake G Perry
- School of Health Sciences, Massey University, Wellington, New Zealand.,School of Sport, Exercise and Nutrition, Massey University, Palmerston North, New Zealand
| | - Toby Mündel
- School of Sport, Exercise and Nutrition, Massey University, Palmerston North, New Zealand
| |
Collapse
|
27
|
Finlay J, Khan A, Gronlund C, Sol K, Jang J, Melendez R, Judd S, Clarke P. Weather Woes? Exploring Potential Links between Precipitation and Age-Related Cognitive Decline. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17239011. [PMID: 33287278 PMCID: PMC7730226 DOI: 10.3390/ijerph17239011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/25/2020] [Accepted: 11/30/2020] [Indexed: 02/06/2023]
Abstract
Rain, snow, or ice may discourage older adults from leaving their homes with potential consequences for social isolation, decreased physical activity, and cognitive decline. This study is the first to examine potential links between annual precipitation exposure and cognitive function in a large population-based cohort of older Americans. We examined the association between precipitation (percent of days with snow or rain in the past year) and cognitive function in 25,320 individuals aged 45+ from the Reasons for Geographic and Racial Differences in Stroke Study. Linear mixed models assessed the relationship between precipitation and cognitive function, as well as rates of change in cognitive function with age. We found a non-linear relationship between precipitation and cognitive function. Compared to those exposed to infrequent precipitation (less than 20% of days with rain/snow in the past year), cognitive function was higher among older adults experiencing moderately frequent precipitation (20–40% of annual days with precipitation). However, beyond more than about 45% of days with precipitation in the past year, there was a negative association between precipitation and cognitive function, with faster rates of cognitive decline with age. These exploratory findings motivate further research to better understand the complex role of precipitation for late-life cognitive function.
Collapse
Affiliation(s)
- Jessica Finlay
- Social Environment and Health Program, Survey Research Center, Institute for Social Research, University of Michigan, 426 Thompson Street, Ann Arbor, MI 48104, USA; (A.K.); (C.G.); (J.J.); (R.M.); (P.C.)
- Correspondence: ; Tel.: +1-734-647-0858
| | - Anam Khan
- Social Environment and Health Program, Survey Research Center, Institute for Social Research, University of Michigan, 426 Thompson Street, Ann Arbor, MI 48104, USA; (A.K.); (C.G.); (J.J.); (R.M.); (P.C.)
- School of Public Health, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109, USA
| | - Carina Gronlund
- Social Environment and Health Program, Survey Research Center, Institute for Social Research, University of Michigan, 426 Thompson Street, Ann Arbor, MI 48104, USA; (A.K.); (C.G.); (J.J.); (R.M.); (P.C.)
| | - Ketlyne Sol
- Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI 48109, USA;
| | - Joy Jang
- Social Environment and Health Program, Survey Research Center, Institute for Social Research, University of Michigan, 426 Thompson Street, Ann Arbor, MI 48104, USA; (A.K.); (C.G.); (J.J.); (R.M.); (P.C.)
| | - Robert Melendez
- Social Environment and Health Program, Survey Research Center, Institute for Social Research, University of Michigan, 426 Thompson Street, Ann Arbor, MI 48104, USA; (A.K.); (C.G.); (J.J.); (R.M.); (P.C.)
| | - Suzanne Judd
- School of Public Health, University of Alabama at Birmingham, 1665 University Blvd, Birmingham, AL 35233, USA;
| | - Philippa Clarke
- Social Environment and Health Program, Survey Research Center, Institute for Social Research, University of Michigan, 426 Thompson Street, Ann Arbor, MI 48104, USA; (A.K.); (C.G.); (J.J.); (R.M.); (P.C.)
- School of Public Health, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109, USA
| |
Collapse
|
28
|
Piil JF, Christiansen L, Morris NB, Mikkelsen CJ, Ioannou LG, Flouris AD, Lundbye-Jensen J, Nybo L. Direct exposure of the head to solar heat radiation impairs motor-cognitive performance. Sci Rep 2020; 10:7812. [PMID: 32385322 PMCID: PMC7210303 DOI: 10.1038/s41598-020-64768-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 04/22/2020] [Indexed: 02/02/2023] Open
Abstract
Health and performance impairments provoked by thermal stress are societal challenges geographically spreading and intensifying with global warming. Yet, science may be underestimating the true impact, since no study has evaluated effects of sunlight exposure on human brain temperature and function. Accordingly, performance in cognitively dominated and combined motor-cognitive tasks and markers of rising brainstem temperature were evaluated during exposure to simulated sunlight (equal to ~1000 watt/m2). Acute exposure did not affect any performance measures, whereas prolonged exposure of the head and neck provoked an elevation of the core temperature by 1 °C and significant impairments of cognitively dominated and motor task performances. Importantly, impairments emerged at considerably lower hyperthermia levels compared to previous experiments and to the trials in the presents study without radiant heating of the head. These findings highlight the importance of including the effect of sunlight radiative heating of the head and neck in future scientific evaluations of environmental heat stress impacts and specific protection of the head to minimize detrimental effects.
Collapse
Affiliation(s)
- Jacob F Piil
- Department of Nutrition, Exercise and Sports, Section for integrative physiology, University of Copenhagen, 2200, Copenhagen N, Denmark.
| | - Lasse Christiansen
- Department of Nutrition, Exercise and Sports, Section for integrative physiology, University of Copenhagen, 2200, Copenhagen N, Denmark.,Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650, Hvidovre, Denmark
| | - Nathan B Morris
- Department of Nutrition, Exercise and Sports, Section for integrative physiology, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - C Jacob Mikkelsen
- Department of Nutrition, Exercise and Sports, Section for integrative physiology, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Leonidas G Ioannou
- Department of Nutrition, Exercise and Sports, Section for integrative physiology, University of Copenhagen, 2200, Copenhagen N, Denmark.,FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Andreas D Flouris
- FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Jesper Lundbye-Jensen
- Department of Nutrition, Exercise and Sports, Section for integrative physiology, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, Section for integrative physiology, University of Copenhagen, 2200, Copenhagen N, Denmark
| |
Collapse
|
29
|
Bensalem J, Dudonné S, Etchamendy N, Pellay H, Amadieu C, Gaudout D, Dubreuil S, Paradis ME, Pomerleau S, Capuron L, Hudon C, Layé S, Desjardins Y, Pallet V. Polyphenols From Grape and Blueberry Improve Episodic Memory in Healthy Elderly with Lower Level of Memory Performance: A Bicentric Double-Blind, Randomized, Placebo-Controlled Clinical Study. J Gerontol A Biol Sci Med Sci 2020; 74:996-1007. [PMID: 30032176 DOI: 10.1093/gerona/gly166] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Indexed: 01/01/2023] Open
Abstract
Polyphenols are promising nutritional bioactives exhibiting beneficial effect on age-related cognitive decline. This study evaluated the effect of a polyphenol-rich extract from grape and blueberry (PEGB) on memory of healthy elderly subjects (60-70 years-old). A bicentric, randomized, double-blind, placebo-controlled trial was conducted with 215 volunteers receiving 600 mg/day of PEGB (containing 258 mg flavonoids) or a placebo for 6 months. The primary outcome was the CANTAB Paired Associate Learning (PAL), a visuospatial learning and episodic memory test. Secondary outcomes included verbal episodic and recognition memory (VRM) and working memory (SSP). There was no significant effect of PEGB on the PAL on the whole cohort. Yet, PEGB supplementation improved VRM-free recall. Stratifying the cohort in quartiles based on PAL at baseline revealed a subgroup with advanced cognitive decline (decliners) who responded positively to the PEGB. In this group, PEGB consumption was also associated with a better VRM-delayed recognition. In addition to a lower polyphenol consumption, the urine metabolomic profile of decliners revealed that they excreted more metabolites. Urinary concentrations of specific flavan-3-ols metabolites were associated, at the end of the intervention, with the memory improvements. Our study demonstrates that PEGB improves age-related episodic memory decline in individuals with the highest cognitive impairments.
Collapse
Affiliation(s)
- Julien Bensalem
- Univ. de Bordeaux, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,INRA, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,Activ'Inside, Beychac et Caillau, France
| | - Stéphanie Dudonné
- Institute of Nutrition and Functional Foods (INAF), Laval University, Québec, Québec Canada.,OptiNutriBrain International Associated Laboratory (NutriNeuro France-INAF Canada), Bordeaux, France
| | - Nicole Etchamendy
- Univ. de Bordeaux, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,INRA, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France
| | - Hermine Pellay
- Univ. de Bordeaux, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,INRA, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,Activ'Inside, Beychac et Caillau, France
| | - Camille Amadieu
- Univ. de Bordeaux, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,INRA, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France
| | | | | | - Marie-Eve Paradis
- Institute of Nutrition and Functional Foods (INAF), Laval University, Québec, Québec Canada.,OptiNutriBrain International Associated Laboratory (NutriNeuro France-INAF Canada), Bordeaux, France
| | - Sonia Pomerleau
- Institute of Nutrition and Functional Foods (INAF), Laval University, Québec, Québec Canada
| | - Lucile Capuron
- Univ. de Bordeaux, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,INRA, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,OptiNutriBrain International Associated Laboratory (NutriNeuro France-INAF Canada), Bordeaux, France
| | - Carol Hudon
- Institute of Nutrition and Functional Foods (INAF), Laval University, Québec, Québec Canada.,Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec, Canada
| | - Sophie Layé
- Univ. de Bordeaux, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,INRA, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,OptiNutriBrain International Associated Laboratory (NutriNeuro France-INAF Canada), Bordeaux, France
| | - Yves Desjardins
- Institute of Nutrition and Functional Foods (INAF), Laval University, Québec, Québec Canada.,OptiNutriBrain International Associated Laboratory (NutriNeuro France-INAF Canada), Bordeaux, France
| | - Véronique Pallet
- Univ. de Bordeaux, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,INRA, Nutrition et Neurobiologie Intégrée, UMR, Bordeaux, France.,OptiNutriBrain International Associated Laboratory (NutriNeuro France-INAF Canada), Bordeaux, France.,Bordeaux INP, Nutrition et neurobiologie intégrée, UMR, Bordeaux, France
| |
Collapse
|
30
|
Martin K, McLeod E, Périard J, Rattray B, Keegan R, Pyne DB. The Impact of Environmental Stress on Cognitive Performance: A Systematic Review. HUMAN FACTORS 2019; 61:1205-1246. [PMID: 31002273 DOI: 10.1177/0018720819839817] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
OBJECTIVE In this review, we detail the impact of environmental stress on cognitive and military task performance and highlight any individual characteristics or interventions which may mitigate any negative effect. BACKGROUND Military personnel are often deployed in regions markedly different from their own, experiencing hot days, cold nights, and trips both above and below sea level. In spite of these stressors, high-level cognitive and operational performance must be maintained. METHOD A systematic review of the electronic databases Medline (PubMed), EMBASE (Scopus), PsycINFO, and Web of Science was conducted from inception up to September 2018. Eligibility criteria included a healthy human cohort, an outcome of cognition or military task performance and assessment of an environmental condition. RESULTS The search returned 113,850 records, of which 124 were included in the systematic review. Thirty-one studies examined the impact of heat stress on cognition; 20 of cold stress; 59 of altitude exposure; and 18 of being below sea level. CONCLUSION The severity and duration of exposure to the environmental stressor affects the degree to which cognitive performance can be impaired, as does the complexity of the cognitive task and the skill or familiarity of the individual performing the task. APPLICATION Strategies to improve cognitive performance in extreme environmental conditions should focus on reducing the magnitude of the physiological and perceptual disturbance caused by the stressor. Strategies may include acclimatization and habituation, being well skilled on the task, and reducing sensations of thermal stress with approaches such as head and neck cooling.
Collapse
Affiliation(s)
- Kristy Martin
- University of Canberra, Australian Capital Territory, Australia
| | - Emily McLeod
- University of Canberra, Australian Capital Territory, Australia
| | - Julien Périard
- University of Canberra, Australian Capital Territory, Australia
| | - Ben Rattray
- University of Canberra, Australian Capital Territory, Australia
| | - Richard Keegan
- University of Canberra, Australian Capital Territory, Australia
| | - David B Pyne
- University of Canberra, Australian Capital Territory, Australia
| |
Collapse
|
31
|
Brazaitis M, Paulauskas H, Eimantas N, Daniuseviciute L, Volungevicius G, Skurvydas A. Motor performance is preserved in healthy aged adults following severe whole-body hyperthermia. Int J Hyperthermia 2018; 36:65-74. [PMID: 30484343 DOI: 10.1080/02656736.2018.1533650] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Healthy aging is associated with a progressive decline in motor performance and thermoregulatory efficiency. Functional consequences of severe whole-body hyperthermia on neurophysiological functions in healthy aged men have not been investigated. To determine whether severe whole-body hyperthermia (increase in rectal temperature of about 2.5 °C) induced by lower-body heating in older men (64-80 years, n = 9) would suppress excitability of reflexes, voluntarily and electrically induced ankle plantar flexor contractile properties were compared with those in young men (19-21 years, n = 11). Though no aging effect on hyperthermia-induced reflex amplitudes was observed, a decrease in maximal H-reflex and V-wave latencies was found to be greater in older than in young men. In older men, lower-body heating was accompanied by a significant increase in twitch and tetani test torque in parallel with a greater decrease in muscle contraction time. There was no temperature-depended aging effect on the voluntary activation and maximal voluntary torque production. Despite delayed and weakened thermoregulation and age-related decline in neuromuscular function, motor performance in whole-body severe hyperthermia is apparently preserved in healthy aging.
Collapse
Affiliation(s)
- Marius Brazaitis
- a Institute of Sport Science and Innovations , Lithuanian Sports University , Kaunas , LT , Lithuania
| | - Henrikas Paulauskas
- a Institute of Sport Science and Innovations , Lithuanian Sports University , Kaunas , LT , Lithuania
| | - Nerijus Eimantas
- a Institute of Sport Science and Innovations , Lithuanian Sports University , Kaunas , LT , Lithuania
| | - Laura Daniuseviciute
- b Department of Educational Studies , Kaunas University of Technology , Kaunas , LT , Lithuania
| | - Gintautas Volungevicius
- a Institute of Sport Science and Innovations , Lithuanian Sports University , Kaunas , LT , Lithuania
| | - Albertas Skurvydas
- a Institute of Sport Science and Innovations , Lithuanian Sports University , Kaunas , LT , Lithuania
| |
Collapse
|
32
|
Opatz O, Nordine M, Habazettl H, Ganse B, Petricek J, Dosel P, Stahn A, Steinach M, Gunga HC, Maggioni MA. Limb Skin Temperature as a Tool to Predict Orthostatic Instability. Front Physiol 2018; 9:1241. [PMID: 30233412 PMCID: PMC6134950 DOI: 10.3389/fphys.2018.01241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 08/16/2018] [Indexed: 11/20/2022] Open
Abstract
Orthostatic instability is one of the main consequences of weightlessness or gravity challenge and plays as well a crucial role in public health, being one of the most frequent disease of aging. Therefore, the assessment of effective countermeasures, or even the possibility to predict, and thus prevent orthostatic instability is of great importance. Heat stress affects orthostatic stability and may lead to impaired consciousness and decrease in cerebral perfusion, specifically during the exposure to G-forces. Conversely, peripheral cooling can prevent orthostatic intolerance – even in normothermic healthy subjects. Indicators of peripheral vasodilation, as elevated skin surface temperatures, may mirror blood decentralization and an increased risk of orthostatic instability. Therefore, the aim of this study was to quantify orthostatic instability risk, by assessing in 20 fighter jet pilot candidates’ cutaneous limb temperatures, with respect to the occurrence of G-force-induced almost loss of consciousness (ALOC), before and during exposure to a push-pull maneuver, i.e., head-down tilt, combined with lower body negative pressure. Peripheral skin temperatures from the upper and lower (both proximal and distal) extremities and core body temperature via heat-flux approach (i.e., the Double Sensor), were continuously measured before and during the maneuver. The 55% of subjects that suffered an ALOC during the procedure had higher upper arm and thigh temperatures at baseline compared to the 45% that remained stable. No difference in baseline core body temperature and distal limbs (both upper and lower) skin temperatures were found between the two groups. Therefore, peripheral skin temperature data could be considered a predicting factor for ALOC, prior to rapid onset acceleration. Moreover, these findings could also find applications in patient care settings such as in intensive care units.
Collapse
Affiliation(s)
- Oliver Opatz
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany
| | - Michael Nordine
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany
| | - Helmut Habazettl
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany
| | - Bergita Ganse
- German Aerospace Center (DLR- Deutsches Zentrum für Luft- und Raumfahrt), Institute of Aerospace Medicine (Institut für Luft- und Raumfahrtmedizin), Cologne, Germany
| | - Jan Petricek
- Institute of Aviation Medicine, Military University Hospital Prague, Prague, Czechia
| | - Petr Dosel
- Institute of Aviation Medicine, Military University Hospital Prague, Prague, Czechia
| | - Alexander Stahn
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany.,Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States
| | - Mathias Steinach
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany
| | - Hanns-Christian Gunga
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany
| | - Martina A Maggioni
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany.,Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy
| |
Collapse
|
33
|
Caldwell AR, Burchfield J, Moyen NE, Tucker MA, Butts CL, Elbin RJ, Ganio MS. Obesity, but not hypohydration, mediates changes in mental task load during passive heating in females. PeerJ 2018; 6:e5394. [PMID: 30128190 PMCID: PMC6098944 DOI: 10.7717/peerj.5394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/16/2018] [Indexed: 12/18/2022] Open
Abstract
Background The independent effects of hypohydration and hyperthermia on cognition and mood is unclear since the two stresses often confound each other. Further, it is unknown if obese individuals have the same impairments during hyperthermia and hypohydration that is often observed in non-obese individuals. Methods The current study was designed to assess the independent and combined effects of mild hypohydration and hyperthermia on cognition, mood, and mental task load in obese and non-obese females. Twenty-one healthy females participated in two passive heating trials, wherein they were either euhydrated or hypohydrated prior to and throughout passive heating. Cognition (ImPACT), mental task load (NASA-TLX), and mood (Brunel Mood Scale; BRUMS) were measured before and after a 1.0 °C increase in core temperature (TC). Results After a 1.0 °C TC elevation, hypohydration resulted in greater (p < 0.05) body mass loss (-1.14 ± 0.48 vs -0.58 ± 0.48 kg; hypohydrated and euhydrated, respectively) and elevation in serum osmolality (292 ± 4 vs 282 ± 3 mOsm; p < 0.05) versus euhydration. Hypohydration, independent of hyperthermia, did not affect mental task load or mood (p > 0.05). Hyperthermia, regardless of hydration status, impaired (∼5 A.U) measures of memory-based cognition (verbal and visual memory), and increased mental task load, while worsening mood (p < 0.05). Interestingly, obese individuals had increased mental task load while hyperthermic compared to the non-obese individuals (p < 0.05) even while euhydrated. Hypohydration did not exacerbate any heat-related effects on cognition between obese and non-obese females (p > 0.05). Conclusion These data indicate that hyperthermia independently impairs memory-based aspects of cognitive performance, mental task load, and leads to a negative mood state. Mild hypohydration did not exacerbate the effects of hyperthermia. However, obese individuals had increased mental task load during hyperthermia.
Collapse
Affiliation(s)
- Aaron R Caldwell
- Exercise Science Research Center, University of Arkansas at Fayetteville, Fayetteville, AR, United States of America
| | - Jenna Burchfield
- Exercise Science Research Center, University of Arkansas at Fayetteville, Fayetteville, AR, United States of America
| | - Nicole E Moyen
- Exercise Science Research Center, University of Arkansas at Fayetteville, Fayetteville, AR, United States of America
| | - Matthew A Tucker
- Exercise Science Research Center, University of Arkansas at Fayetteville, Fayetteville, AR, United States of America.,Georgia Prevention Institute, Augusta University, Augusta, GA, United States of America
| | - Cory L Butts
- Exercise Science Research Center, University of Arkansas at Fayetteville, Fayetteville, AR, United States of America
| | - R J Elbin
- Exercise Science Research Center, University of Arkansas at Fayetteville, Fayetteville, AR, United States of America
| | - Matthew S Ganio
- Exercise Science Research Center, University of Arkansas at Fayetteville, Fayetteville, AR, United States of America
| |
Collapse
|
34
|
Malcolm RA, Cooper S, Folland JP, Tyler CJ, Sunderland C. Passive Heat Exposure Alters Perception and Executive Function. Front Physiol 2018; 9:585. [PMID: 29887804 PMCID: PMC5981197 DOI: 10.3389/fphys.2018.00585] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/02/2018] [Indexed: 11/13/2022] Open
Abstract
Findings regarding the influence of passive heat exposure on cognitive function remain equivocal due to a number of methodological issues including variation in the domains of cognition examined. In a randomized crossover design, forty-one male participants completed a battery of cognitive function tests [Visual Search, Stroop, Corsi Blocks and Rapid Visual Information Processing (RVIP) tests] prior to and following 1 h of passive rest in either hot (39.6 ± 0.4°C, 50.8 ± 2.3% Rh) or moderate (21.2 ± 1.8°C, 41.9 ± 11.4% Rh) conditions. Subjective feelings of heat exposure, arousal and feeling were assessed alongside physiological measures including core temperature, skin temperature and heart rate, at baseline and throughout the protocol. Response times were slower in the hot trial on the simple (main effect of trial, P < 0.001) and complex (main effect of trial, P < 0.001) levels of the Stroop test (Hot: 872 ± 198 ms; Moderate: 834 ± 177 ms) and the simple level of the visual search test (Hot: 354 ± 54 ms; Moderate: 331 ± 47 ms) (main effect of trial, P < 0.001). Participants demonstrated superior accuracy on the simple level of the Visual Search test in the hot trial (Hot: 98.5 ± 3.1%; Moderate: 97.4 ± 3.6%) (main effect of trial, P = 0.035). Participants also demonstrated an improvement in accuracy on the complex level of the visual search test following 1 h passive heat exposure (Pre: 96.8 ± 5.9%; Post: 98.1 ± 3.1%), whilst a decrement was seen across the trial in the moderate condition (Pre: 97.7 ± 3.5; Post: 97.0 ± 5.1%) (time*trial interaction, P = 0.029). No differences in performance were observed on the RVIP or Corsi Blocks tests (all P > 0.05). Subjective feelings of thermal sensation and felt arousal were higher, feeling was lower in the hot trial, whilst skin temperature, core temperature and heart rate were higher (main effects of trial, all P < 0.001). The findings of the present study suggest that response times for perception and executive function tasks are worse in the heat. An improvement in accuracy on perceptual tasks may suggest a compensatory speed-accuracy trade-off effect occurring within this domain, further highlighting the task dependant nature of heat exposure on cognition.
Collapse
Affiliation(s)
- Rachel A Malcolm
- Department of Sport Sciences, Sport, Health and Performance Enhancement Research Centre, Nottingham Trent University, Nottingham, United Kingdom
| | - Simon Cooper
- Department of Sport Sciences, Sport, Health and Performance Enhancement Research Centre, Nottingham Trent University, Nottingham, United Kingdom
| | - Jonathan P Folland
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Christopher J Tyler
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| | - Caroline Sunderland
- Department of Sport Sciences, Sport, Health and Performance Enhancement Research Centre, Nottingham Trent University, Nottingham, United Kingdom
| |
Collapse
|
35
|
Brazaitis M, Paulauskas H, Eimantas N, Obelieniene D, Baranauskiene N, Skurvydas A. Heat transfer and loss by whole-body hyperthermia during severe lower-body heating are impaired in healthy older men. Exp Gerontol 2017; 96:12-18. [DOI: 10.1016/j.exger.2017.05.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/04/2017] [Accepted: 05/19/2017] [Indexed: 11/25/2022]
|
36
|
Cognitive Functioning and Heat Strain: Performance Responses and Protective Strategies. Sports Med 2016; 47:1289-1302. [DOI: 10.1007/s40279-016-0657-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
37
|
Schlader ZJ, Temple JL, Hostler D. Exercise in personal protective equipment in a hot, humid environment does not affect risk propensity. Temperature (Austin) 2016; 3:262-270. [PMID: 27857956 PMCID: PMC4964995 DOI: 10.1080/23328940.2016.1148526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/25/2016] [Accepted: 01/25/2016] [Indexed: 10/26/2022] Open
Abstract
We tested the hypothesis that heat stress created by light exertion in encapsulating personal protective equipment (PPE) in a hot, humid environment increases risk propensity. Ten healthy subjects (29 ± 7 y) completed 2 trials presented in a counter-balanced manner. Subjects donned encapsulating PPE, and in one trial they wore a tube-lined shirt underneath that was perfused with 5°C water. Subjects completed 2 15 min bouts of walking exercise on a treadmill at ˜50% maximal heart rate in a 32°C, 81% RH environment. Subjects completed the Balloon Analog Risk Task (BART), an objective measure of risk-taking, before, between the 2 exercise bouts, and following the final exercise bout. Personal cooling lowered (P < 0.01) mean skin temperature by 8.0 ± 1.6°C. Intestinal temperature rose (P < 0.01) in both trials, but was lower (P < 0.01) at the end of exercise in the cooling trial (38.0 ± 0.3°C vs. 37.6 ± 0.3°C). BART derived indices of risk propensity were not affected by trial or time (trial × time interaction: P ≥ 0.33). These data indicate that 60 min of exposure to mild heat stress created by light exertion in encapsulating PPE does not affect risk-taking behavior.
Collapse
Affiliation(s)
- Zachary J Schlader
- Emergency Responder Human Performance Lab, Department of Exercise and Nutrition Sciences, University at Buffalo , Buffalo, NY, USA
| | - Jennifer L Temple
- Emergency Responder Human Performance Lab, Department of Exercise and Nutrition Sciences, University at Buffalo , Buffalo, NY, USA
| | - David Hostler
- Emergency Responder Human Performance Lab, Department of Exercise and Nutrition Sciences, University at Buffalo , Buffalo, NY, USA
| |
Collapse
|
38
|
Stanhewicz AE, Greaney JL, Alexander LM, Kenney WL. Blunted increases in skin sympathetic nerve activity are related to attenuated reflex vasodilation in aged human skin. J Appl Physiol (1985) 2016; 121:1354-1362. [PMID: 27789772 DOI: 10.1152/japplphysiol.00730.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 10/06/2016] [Accepted: 10/21/2016] [Indexed: 11/22/2022] Open
Abstract
Reflex cutaneous vasodilation in response to passive heating is attenuated in human aging. This diminished response is mediated, in part, by age-associated reductions in endothelial function; however, the contribution of altered skin sympathetic nervous system activity (SSNA) is unknown. We hypothesized that 1) healthy older adults would demonstrate blunted SSNA responses to increased core temperature compared with young adults and 2) the decreased SSNA response would be associated with attenuated cutaneous vasodilation. Reflex vasodilation was elicited in 13 young [23 ± 1 (SE) yr] and 13 older (67 ± 2 yr) adults using a water-perfused suit to elevate esophageal temperature by 1.0°C. SSNA (peroneal microneurography) and red cell flux (laser Doppler flowmetry) in the innervated dermatome (the dorsum of foot) were continuously measured. SSNA was normalized to, and expressed as, a percentage of baseline. Cutaneous vascular conductance (CVC) was calculated as flux/mean arterial pressure and expressed as a percentage of maximal CVC (local heating, 43°C). Reflex vasodilation was attenuated in older adults (P < 0.001). During heating, SSNA increased in both groups (P < 0.05); however, the response was significantly blunted in older adults (P = 0.01). The increase in SSNA during heating was linearly related to cutaneous vasodilation in both young (R2 = 0.87 ± 0.02, P < 0.01) and older (R2 = 0.76 ± 0.05, P < 0.01) adults; however, slope of the linear regression between ΔSSNA and ΔCVC was reduced in older compared with young (older: 0.05 ± 0.01 vs. young: 0.08 ± 0.01; P < 0.05). These data demonstrate that age-related impairments in reflex cutaneous vasodilation are mediated, in part, by blunted efferent SSNA during hyperthermia.
Collapse
Affiliation(s)
- Anna E Stanhewicz
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
| | - Jody L Greaney
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
| | - Lacy M Alexander
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
| | - W Larry Kenney
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
| |
Collapse
|
39
|
Dai L, Kloog I, Coull BA, Sparrow D, Spiro A, Vokonas PS, Schwartz JD. Cognitive function and short-term exposure to residential air temperature: A repeated measures study based on spatiotemporal estimates of temperature. ENVIRONMENTAL RESEARCH 2016; 150:446-451. [PMID: 27391696 PMCID: PMC5003630 DOI: 10.1016/j.envres.2016.06.036] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 05/23/2016] [Accepted: 06/22/2016] [Indexed: 05/21/2023]
Abstract
Few studies have examined the association between ambient temperature and cognitive function, or used exposure to temperature at a given address instead of a single stationary monitor. The existing literature on the temperature-cognition relationship has mostly consisted of experimental studies that involve a small sample size and a few specific temperature values. In the current study, we examined the association between residential air temperature and Mini-Mental State Examination (MMSE) scores, a quantitative measurement of cognitive function, in a longitudinal cohort of elderly men. Residential air temperature was estimated by a novel spatiotemporal approach that incorporates satellite remote sensing, land use regression, meteorological variables and spatial smoothing in the Northeastern USA. We then applied logistic regression generalized estimating equations to examine the relationship between residential temperature (range: -5.8-25.7°C), and the risk of low MMSE scores (MMSE scores ≤25) among 594 elderly men (1085 visits in total) from the Veterans Affairs Normative Aging Study, 2000-2008. Sensitivity analysis on visits wherein subjects lived within 30km of the clinic center in Massachusetts or aged ≥70 years was also evaluated. A statistically significant, U-shaped association between residential air temperature and low MMSE score (p-value=0.036) was observed. Sensitivity analysis suggested that the estimated effect remains among individuals aged ≥70 years. In conclusion, the data suggest that risk of low MMSE scores is highest when temperature is either high or low, and lowest when ambient temperature is approximately within 10-15°C in a cohort of elderly men. Further research is needed to confirm our findings and assess generalizability to other populations.
Collapse
Affiliation(s)
- Lingzhen Dai
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Itai Kloog
- The Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Brent A Coull
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - David Sparrow
- Veterans Affairs Normative Aging Study, Veterans Affairs Boston Healthcare System, Boston, MA, USA; Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Avron Spiro
- Veterans Affairs Normative Aging Study, Veterans Affairs Boston Healthcare System, Boston, MA, USA; Department of Epidemiology, Department of Psychiatry, Boston University School of Public Health, Boston, MA, USA
| | - Pantel S Vokonas
- Veterans Affairs Normative Aging Study, Veterans Affairs Boston Healthcare System, Boston, MA, USA; Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Joel D Schwartz
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| |
Collapse
|
40
|
Abstract
An elevated temperature has many aetiologies, both infective and non-infective, and while the fever of sepsis probably confers benefit, there is increasing evidence that the central nervous system is particularly vulnerable to damage from hyperthermia. A single episode of hyperthermia may cause short-term neurological and cognitive dysfunction, which may be prolonged or become permanent. The cerebellum is particularly intolerant to the effects of heat. Hyperthermia in the presence of acute brain injury worsens outcome. The thermotoxicity involved occurs via cellular, local, and systemic mechanisms. This article reviews both the cognitive and neurological consequences and examines the mechanisms of cerebral damage caused by high temperature.
Collapse
Affiliation(s)
- Edward James Walter
- Department of Intensive Care Medicine, Royal Surrey County Hospital, Egerton Road, Guildford, Surrey, GU2 7XX, UK.
| | - Mike Carraretto
- Department of Intensive Care Medicine, Royal Surrey County Hospital, Egerton Road, Guildford, Surrey, GU2 7XX, UK
| |
Collapse
|
41
|
Abstract
BACKGROUND Hajj pilgrimage, in Saudi Arabia, is one of the world's largest religious mass gatherings. We have similar mass gathering scenarios in India such as the Amarnath Yatra and Kumbh. A unique combination of physical, physiological, and psychological factors makes this pilgrimage a very stressful milieu. We studied the emergence of psychopathology and its determinants, in this adverse environment in mass gathering situation, in Indian pilgrims on Hajj 2016. MATERIALS AND METHODS This is a descriptive study analyzing the mental morbidity in 1.36 lakh Indian pilgrims during Hajj 2016, using SPSS software version 19. RESULTS Totally 182 patients reported psychological problems. Twenty-two patients (12%) required admission. Twelve (6.8%) pilgrims reported a past history of a mental illness. One hundred and sixty-five (93.2%) patients never had any mental symptoms earlier in life. The most common illnesses seen were stress related (45.7%) followed by psychosis (9.8%), insomnia (7.3%), and mood disorders (5.6%). The most common symptoms recorded were apprehension (45%), sleep (55%), anxiety (41%), and fear of being lost (27%). Psychotropics were prescribed for 46% of pilgrims. All patients completed their Hajj successfully and returned to India. CONCLUSIONS Cumulative stress causes full spectrum of mental decompensation, and prompt healing is aided by simple nonpharmacological measures including social support and counseling in compatible sociolinguistic milieu.
Collapse
Affiliation(s)
- Shahbaz Ali Khan
- Department of Psychiatry, Base Hospital Delhi Cantt, New Delhi, India
| | - V. S. Chauhan
- Department of Psychiatry, Base Hospital Delhi Cantt, New Delhi, India
| | - A. Timothy
- Department of Psychiatry, Base Hospital Delhi Cantt, New Delhi, India
| | - S. Kalpana
- Department of Psychiatry, Armed Forces Medical College, Pune, Maharashtra, India
| | - Shagufta Khanam
- Department of Psychiatry, VKS University, Patna, Bihar, India
| |
Collapse
|
42
|
Takeda R, Imai D, Suzuki A, Ota A, Naghavi N, Yamashina Y, Hirasawa Y, Yokoyama H, Miyagawa T, Okazaki K. Lower thermal sensation in normothermic and mildly hyperthermic older adults. Eur J Appl Physiol 2016; 116:975-84. [PMID: 27015984 DOI: 10.1007/s00421-016-3364-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 03/15/2016] [Indexed: 11/24/2022]
Abstract
PURPOSE It is important to know how thermal sensation is affected by normal aging under conditions that elevate core body temperature for the prevention of heat-related illness in older people. We assessed whether thermal sensation under conditions of normothermia (NT) and mild hyperthermia (HT) is lowered in older adults. METHODS Seventeen younger (23 ± 3 years) and 12 older (71 ± 3 years) healthy men underwent measurements of the cold and warmth detection thresholds ( ± 0.1 °C/s) of their chest and forearm skin, and whole body warmth perception under NT (esophageal temperature, T es, ~36.5 °C) and HT (T es, ~37.3 °C; lower legs immersed in 42 °C water) conditions. RESULTS Warmth detection threshold at the forearm was increased in older compared with younger participants under both NT (P = 0.006) and HT (P = 0.004) conditions. In contrast, cold detection threshold at the forearm was decreased in older compared with younger participants under NT (P = 0.001) but not HT (P = 0.16). Mild hyperthermia decreased cold detection threshold at forearm in younger participants (P = 0.001) only. There were no effects of age and condition on warmth and cold detection thresholds at chest. Whole body warmth perception increased during HT compared with NT in both groups (both, P < 0.001), and older participants had lower values than the younger group under NT (P = 0.001) and HT (P = 0.051). CONCLUSIONS Skin warmth detection thresholds at forearm and whole body warmth perception under NT and HT and skin cold detection thresholds at forearm under NT deteriorated with aging.
Collapse
Affiliation(s)
- Ryosuke Takeda
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan
| | - Daiki Imai
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan.,Research Center for Urban Health and Sports, Osaka City University, Osaka, Japan
| | - Akina Suzuki
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan
| | - Akemi Ota
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan
| | - Nooshin Naghavi
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan
| | - Yoshihiro Yamashina
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan
| | - Yoshikazu Hirasawa
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan
| | - Hisayo Yokoyama
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan.,Research Center for Urban Health and Sports, Osaka City University, Osaka, Japan
| | - Toshiaki Miyagawa
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan.,Research Center for Urban Health and Sports, Osaka City University, Osaka, Japan
| | - Kazunobu Okazaki
- Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan. .,Research Center for Urban Health and Sports, Osaka City University, Osaka, Japan.
| |
Collapse
|