Publications by authors named "Andreas D Flouris"

166 Publications

Irisin regulates thermogenesis and lipolysis in 3T3-L1 adipocytes.

Biochim Biophys Acta Gen Subj 2022 Jan 10;1866(4):130085. Epub 2022 Jan 10.

Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy. Electronic address:

Background: Adipose tissue plays a pivotal role in the development and progression of the metabolic syndrome which along with its complications is an epidemic of the 21st century. Irisin is an adipo-myokine secreted mainly by skeletal muscle and targeting, among others, adipose tissue. In brown adipose tissue it upregulates uncoupling protein-1 (UCP1) which is responsible for mitochondrial non-shivering thermogenesis.

Methods: Here we analyzed the effects of irisin on the metabolic activity of 3T3-L1 derived adipocytes through a mitochondrial flux assay. We also assessed the effects of irisin on the intracellular signaling through Western Blot. Finally, the gene expression of ucp1 and lipolytic genes was examined through RT-qPCR.

Results: Irisin affects mitochondrial respiration and lipolysis in a time-dependent manner through the regulation of PI3K-AKT pathway. Irisin also induces the expression of UCP1 and the regulation of NF-κB, and CREB and ERK pathways.

Conclusion: Our data supports the role of irisin in the induction of non-shivering thermogenesis, the regulation of energy expenditure and lipolysis in adipocytes.

General Significance: Irisin may be an attractive therapeutic target in the treatment of obesity and related metabolic disorders.
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http://dx.doi.org/10.1016/j.bbagen.2022.130085DOI Listing
January 2022

Effects of In Vitro Muscle Contraction on Thermogenic Protein Levels in Co-Cultured Adipocytes.

Life (Basel) 2021 Nov 12;11(11). Epub 2021 Nov 12.

Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece.

The crosstalk between the exercising muscle and the adipose tissue, mediated by myokines and metabolites, derived from both tissues during exercise has created a controversy between animal and human studies with respect to the impact of exercise on the browning process. The aim of this study was to investigate whether co-culturing of C2C12 myotubes and 3T3-L1 adipocytes under the stimuli of electrical pulse stimulation (EPS) mimicking muscle contraction can impact the expression of UCP1, PGC-1a, and IL-6 in adipocytes, therefore providing evidence on the direct crosstalk between adipocytes and stimulated muscle cells. In the co-cultured C2C12 cells, EPS increased the expression of PGC-1a ( = 0.129; d = 0.73) and IL-6 ( = 0.09; d = 1.13) protein levels. When EPS was applied, we found that co-culturing led to increases in UCP1 ( = 0.044; d = 1.29) and IL-6 ( = 0.097; d = 1.13) protein expression in the 3T3-L1 adipocytes. The expression of PGC-1a increased by EPS but was not significantly elevated after co-culturing ( = 0.448; d = 0.08). In vitro co-culturing of C2C12 myotubes and 3T3-L1 adipocytes under the stimuli of EPS leads to increased expression of thermogenic proteins. These findings indicate changes in the expression pattern of proteins related to browning of adipose tissue, supporting the use of this in vitro model to study the crosstalk between adipocytes and contracting muscle.
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http://dx.doi.org/10.3390/life11111227DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8625343PMC
November 2021

Quantifying the impact of heat on human physical work capacity; part II: the observed interaction of air velocity with temperature, humidity, sweat rate, and clothing is not captured by most heat stress indices.

Int J Biometeorol 2021 Nov 6. Epub 2021 Nov 6.

Environmental Ergonomics Research Centre, Loughborough University, Loughborough, LE11 3TU, UK.

Increasing air movement can alleviate or exacerbate occupational heat strain, but the impact is not well defined across a wide range of hot environments, with different clothing levels. Therefore, we combined a large empirical study with a physical model of human heat transfer to determine the climates where increased air movement (with electric fans) provides effective body cooling. The model allowed us to generate practical advice using a high-resolution matrix of temperature and humidity. The empirical study involved a total of 300 1-h work trials in a variety of environments (35, 40, 45, and 50 °C, with 20 up to 80% relative humidity) with and without simulated wind (3.5 vs 0.2 m∙s), and wearing either minimal clothing or a full body work coverall. Our data provides compelling evidence that the impact of fans is strongly determined by air temperature and humidity. When air temperature is ≥ 35 °C, fans are ineffective and potentially harmful when relative humidity is below 50%. Our simulated data also show the climates where high wind/fans are beneficial or harmful, considering heat acclimation, age, and wind speed. Using unified weather indices, the impact of air movement is well captured by the universal thermal climate index, but not by wet-bulb globe temperature and aspirated wet-bulb temperature. Overall, the data from this study can inform new guidance for major public and occupational health agencies, potentially maintaining health and productivity in a warming climate.
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http://dx.doi.org/10.1007/s00484-021-02212-yDOI Listing
November 2021

Determinants of heat stress and strain in electrical utilities workers across North America as assessed by means of an exploratory questionnaire.

J Occup Environ Hyg 2021 Dec 16:1-11. Epub 2021 Dec 16.

Human and Environmental Physiology Research Unit, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada.

Previous field studies monitoring small groups of participants showed that heat stress in the electrical utilities industry may be detrimental to worker health and safety. Our aim in this study was to characterize heat stress and strain in electrical utilities workers across North America. A total of 428 workers in the power generation, transmission, and distribution industry across 16 U.S. states and 3 Canadian Provinces completed a two-part on-line questionnaire anonymously. The first part comprised 13 general questions on the employee's workplace location, role in the organization, years of experience, general duties, average work shift duration, and other job-related information. It also included two questions on self-reported heat stress. The second part consisted of the "Heat Strain Score Index" (HSSI), a validated questionnaire which evaluates heat stress at the workplace as "safe level" (score ≤13.5: worker experiences no/low heat strain), "caution level" (score 13.6 to 18.0: moderate risk for heat strain), and "danger level" (score >18.0: high risk for heat strain). In addition to the survey, we obtained meteorological data from weather stations in proximity (12.3 ± 12.2 km) to the work locations. Based on the HSSI, 32.9%, 22.3%, and 44.4% of the responders' workplaces were diagnosed as "safe level," "caution level," and "danger level," respectively. The HSSI varied significantly depending on the occupation from 4.9 ± 3.2 in contact center workforce to 19.1 ± 5.4 in mechanics ( < 0.001), and demonstrated moderate linear relationships with summertime (June, July, August) midday air temperature (r = 0.317,  < 0.001) and outdoor midday Wet-Bulb Globe Temperature (r = 0.322,  < 0.001). The highest HSSI was observed in mechanics, machine operators in line installations, line workers, electricians, and meter-readers. We conclude that electrical utilities workers experience instances of severe environmental heat stress resulting in elevated levels of heat strain, particularly when performing physically demanding tasks (e.g., manually climbing utility poles, installing lines).
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http://dx.doi.org/10.1080/15459624.2021.2001475DOI Listing
December 2021

Quantifying the impact of heat on human physical work capacity; part III: the impact of solar radiation varies with air temperature, humidity, and clothing coverage.

Int J Biometeorol 2022 Jan 28;66(1):175-188. Epub 2021 Oct 28.

Environmental Ergonomics Research Centre, Loughborough University, Loughborough, LE11 3TU, UK.

Heat stress decreases human physical work capacity (PWC), but the extent to which solar radiation (SOLAR) compounds this response is not well understood. This study empirically quantified how SOLAR impacts PWC in the heat, considering wide, but controlled, variations in air temperature, humidity, and clothing coverage. We also provide correction equations so PWC can be quantified outdoors using heat stress indices that do not ordinarily account for SOLAR (including the Heat Stress Index, Humidex, and Wet-Bulb Temperature). Fourteen young adult males (7 donning a work coverall, 7 with shorts and trainers) walked for 1 h at a fixed heart rate of 130 beats∙min1, in seven combinations of air temperature (25 to 45°C) and relative humidity (20 or 80%), with and without SOLAR (800 W/m from solar lamps). Cumulative energy expenditure in the heat, relative to the work achieved in a cool reference condition, was used to determine PWC%. Skin temperature was the primary determinant of PWC in the heat. In dry climates with exposed skin (0.3 Clo), SOLAR caused PWC to decrease exponentially with rising air temperature, whereas work coveralls (0.9 Clo) negated this effect. In humid conditions, the SOLAR-induced reduction in PWC was consistent and linear across all levels of air temperature and clothing conditions. Wet-Bulb Globe Temperature and the Universal Thermal Climate Index represented SOLAR correctly and did not require a correction factor. For the Heat Stress Index, Humidex, and Wet-Bulb Temperature, correction factors are provided enabling forecasting of heat effects on work productivity.
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http://dx.doi.org/10.1007/s00484-021-02205-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8727397PMC
January 2022

Effects of Weather Parameters on Endurance Running Performance: Discipline-specific Analysis of 1258 Races.

Med Sci Sports Exerc 2022 Jan;54(1):153-161

FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, GREECE.

Introduction: This study evaluated how single or combinations of weather parameters (temperature, humidity, wind speed, and solar load) affect peak performance during endurance running events and identified which events are most vulnerable to varying weather conditions.

Methods: Results for the marathon, 50-km racewalking, 20-km racewalking, and 10,000-, 5000-, and 3000-m steeplechase were obtained from the official Web sites of large competitions. We identified meteorological data from nearby (8.9 ± 9.3 km) weather stations for 1258 races held between 1936 and 2019 across 42 countries, enabling analysis of 7867 athletes.

Results: The wet bulb globe temperature (WBGT) across races ranged from -7°C to 33°C, with 27% of races taking place in cold/cool, 47% in neutral, 18% in moderate heat, 7% in high heat, and 1% in extreme heat conditions, according to the World Athletics classification. Machine learning decision trees (R2 = 0.21-0.58) showed that air temperature (importance score = 40%) was the most important weather parameter. However, when used alone, air temperature had lower predictive power (R2 = 0.04-0.34) than WBGT (R2 = 0.11-0.47). Conditions of 7.5°C-15°C WBGT (or 10°C-17.5°C air temperature) increased the likelihood for peak performance. For every degree WBGT outside these optimum conditions, performance declined by 0.3%-0.4%.

Conclusion: More than one-quarter of endurance running events were held in moderate, high, or extreme heat, and this number reached one-half when marathons were excluded. All four weather parameters should be evaluated when aiming to mitigate the health and performance implications of exercising at high intensities in a hot environment with athletes adopting heat mitigation strategies when possible.
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http://dx.doi.org/10.1249/MSS.0000000000002769DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8677617PMC
January 2022

Current and projected regional economic impacts of heatwaves in Europe.

Nat Commun 2021 10 4;12(1):5807. Epub 2021 Oct 4.

Department of Nutrition and Exercise Sciences, University of Copenhagen (NEXS), 2100, Copenhagen, Denmark.

Extreme heat undermines the working capacity of individuals, resulting in lower productivity, and thus economic output. Here we analyse the present and future economic damages due to reduced labour productivity caused by extreme heat in Europe. For the analysis of current impacts, we focused on heatwaves occurring in four recent anomalously hot years (2003, 2010, 2015, and 2018) and compared our findings to the historical period 1981-2010. In the selected years, the total estimated damages attributed to heatwaves amounted to 0.3-0.5% of European gross domestic product (GDP). However, the identified losses were largely heterogeneous across space, consistently showing GDP impacts beyond 1% in more vulnerable regions. Future projections indicate that by 2060 impacts might increase in Europe by a factor of almost five compared to the historical period 1981-2010 if no further mitigation or adaptation actions are taken, suggesting the presence of more pronounced effects in the regions where these damages are already acute.
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http://dx.doi.org/10.1038/s41467-021-26050-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8490455PMC
October 2021

Associations between nutrition, energy expenditure and energy availability with bone mass acquisition in dance students: a 3-year longitudinal study.

Arch Osteoporos 2021 09 24;16(1):141. Epub 2021 Sep 24.

The Faculty of Education, Health and Wellbeing, University of Wolverhampton, Gorway Rd, Walsall, Wolverhampton, WS1 3BE, UK.

Three years of study showed that female and male vocational dancers displayed lower bone mass compared to controls, at forearm, lumbar spine and femoral neck. Energy intake was found to positively predict bone mass accruals only in female dancers at femoral neck. Vocational dancers can be a risk population to develop osteoporosis.

Purpose: To determine whether risk factors normally associated with low bone mass in athletic populations (i.e. nutrition intake, energy expenditure and energy availability) are significant predictors of bone mass changes in vocational dance students.

Methods: The total of 101 vocational dancers (63 females, 12.8 ± 2.2 years; 38 males, 12.7 ± 2.2 years) and 115 age-matched controls (68 females, 13.0 ± 2.1 years; 47 males, 13.0 ± 1.8 years) were monitored for 3 consecutive years. Bone mass parameters were measured annually at impact sites (femoral neck, FN; lumber spine, LS) and non-impact site (forearm) using DXA. Nutrition (3-day record), energy expenditure (accelerometer), energy availability and IGF-1 serum concentration (immunoradiometric assays) were also assessed.

Results: Female and male vocational dancers had consistently reduced bone mass at all anatomical sites (p < 0.001) than controls. IGF-1 did not differ between male vocational dancers and controls, but female dancers showed it higher than controls. At baseline, calcium intake was significantly greater in female vocational dancers than controls (p < 0.05). Male vocational dancers' fat and carbohydrate intakes were significantly lower than matched controls (p < 0.001 and p < 0.05, respectively). Energy availability of both female and male vocational dancers was within the normal range. A significant group effect was found at the FN regarding energy intake (p < 0.05) in female dancers. No significant predictors were found to explain bone mass differences in males.

Conclusion: Our 3-year study revealed that both female and male vocational dancers displayed lower bone mass compared to controls, at both impact and non-impact sites. The aetiology of these findings may be grounded on factors different than those usually considered in athletic populations.
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http://dx.doi.org/10.1007/s11657-021-01005-5DOI Listing
September 2021

Effects of alpha-lipoic acid supplementation on human diabetic nephropathy: A systematic review and meta-analysis.

Curr Diabetes Rev 2021 Sep 13. Epub 2021 Sep 13.

FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, GR42100. Greece.

Background: Diabetic nephropathy (DN) is a kidney dysfunction, which occurs due to elevated urine albumin excretion rate and reduced glomerular filtration rate. Studies in animals have shown that alpha-lipoic acid (ALA) supplementation can reduce the development of DN.

Objectives: We performed a systematic review and meta-analysis to examine the effects of ALA supplementation on biological indices (albumin, creatinine etc.) indicative of human DN.

Methods: The searching procedure included the databases PubMed Central, Embase, Cochrane Library (trials) and Web of Science, (protocol registration: INPLASY 202060095).

Results: We found that ALA supplementation decreased urine albumin 24h excretion rate in patients with diabetes [standardized mean difference=-2.27; confidence interval (CI)=(-4.09)-(-0.45); I2=98%; Z=2.44; p=0.01]. A subgroup analysis revealed that the studies examining only ALA, did not differ from those examined ALA in combination with additional medicines (Chi-squared=0.19; p=0.66; I2=0%), while neither ALA nor ALA plus medication had an effect on urine albumin 24h excretion rate (p>0.05). Also, ALA supplementation decreased urine albumin mg/l [mean difference (MD)=-12.95; CI=(-23.88)-(-2.02); I2=44%; Z=2.32; p=0.02] and urine albumin to creatinine ratio [MD=-26.96; CI=(-35.25)-(-18.67); I2=0%; Z=6.37; p<0.01] in patients with diabetes. When the studies that examined ALA plus medication were removed, ALA supplementation had no effect on urine albumin mg/l (p>0.05), but did significantly decrease urine albumin to creatinine ratio [MD=-25.88, CI=(34.40-(-17.36), I2=0%, Z=5.95, p<0.00001].

Conclusion: The available evidence suggests that ALA supplementation does not improve biological indices that reflect DN in humans. Overall, we identified limited evidence and therefore, the outcomes should be considered with caution.
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http://dx.doi.org/10.2174/1573399817666210914103329DOI Listing
September 2021

Mortality due to circulatory causes in hot and cold environments in Greece.

Scand Cardiovasc J 2021 Dec 8;55(6):333-335. Epub 2021 Sep 8.

FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece.

Ambient temperature can affect the survival rate of humans. Studies have shown a relationship between ambient temperature and mortality rate in hot and cold environments. This effect of ambient temperature on mortality seems to be more pronounced in older people. The aim of this study is to examine the effects of thermal stress on cardiovascular mortality and the associated relative risk per degree Celsius in Greek individuals ≥70 years old. Mortality data 1999-2012 were matched with the midday temperature. The present study found a higher circulatory mortality when ambient temperature is below or above the temperature range 6 to 39 °C.
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http://dx.doi.org/10.1080/14017431.2021.1970801DOI Listing
December 2021

Health vs. wealth: Employer, employee and policy-maker perspectives on occupational heat stress across multiple European industries.

Temperature (Austin) 2021 14;8(3):284-301. Epub 2020 Dec 14.

Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.

Successful implementation of cooling strategies obviously depends on identifying effective interventions, but in industrial settings, it is equally important to consider feasibility and economic viability. Many cooling interventions are available, but the decision processes affecting adoption by end-users are not well elucidated. We therefore arranged two series of meetings with stakeholders to identify knowledge gaps, receive feedback on proposed cooling interventions, and discuss factors affecting implementation of heat-health interventions. This included four meetings attended by employers, employees, and health and safety officers (n = 41), and three meetings attended primarily by policy makers (n = 74), with feedback obtained via qualitative and quantitative questionnaires and focus group discussions. On a 10-point scale, both employers and employees valued worker safety (9.1 ± 1.8; mean±SD) and health (8.5 ± 1.9) as more important than protecting company profits (6.3 ± 2.3). Of the respondents, 41% were unaware of any cooling strategies at their company and of those who were aware, only 30% thought the interventions were effective. Following presentation of proposed interventions, the respondents rated "facilitated hydration", "optimization of clothing/protective equipment", and "rescheduling of work tasks" as the top-three preferred solutions. The main barriers for adopting cooling interventions were cost, feasibility, employer perceptions, and legislation. In conclusion, preventing negative health and safety effects was deemed to be more important than preventing productivity loss. Regardless of work sector or occupation, both health and wealth were emphasized as important parameters and considered as somewhat interrelated. However, a large fraction of the European worker force lacks information on effective measures to mitigate occupational heat stress. : OH-Stress: Occupational heat stress; WBGT: Wet Bulb Globe Temperature.
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http://dx.doi.org/10.1080/23328940.2020.1852049DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8409781PMC
December 2020

Proposed framework for forecasting heat-effects on motor-cognitive performance in the Summer Olympics.

Temperature (Austin) 2021 20;8(3):262-283. Epub 2021 Aug 20.

Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark.

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.
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http://dx.doi.org/10.1080/23328940.2021.1957367DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8409751PMC
August 2021

Heat Safety in the Workplace: Modified Delphi Consensus to Establish Strategies and Resources to Protect the US Workers.

Geohealth 2021 Aug 1;5(8):e2021GH000443. Epub 2021 Aug 1.

Department of Exercise Science Arnold School of Public Health University of South Carolina Columbia SC USA.

The purpose of this consensus document was to develop feasible, evidence-based occupational heat safety recommendations to protect the US workers that experience heat stress. Heat safety recommendations were created to protect worker health and to avoid productivity losses associated with occupational heat stress. Recommendations were tailored to be utilized by safety managers, industrial hygienists, and the employers who bear responsibility for implementing heat safety plans. An interdisciplinary roundtable comprised of 51 experts was assembled to create a narrative review summarizing current data and gaps in knowledge within eight heat safety topics: (a) heat hygiene, (b) hydration, (c) heat acclimatization, (d) environmental monitoring, (e) physiological monitoring, (f) body cooling, (g) textiles and personal protective gear, and (h) emergency action plan implementation. The consensus-based recommendations for each topic were created using the Delphi method and evaluated based on scientific evidence, feasibility, and clarity. The current document presents 40 occupational heat safety recommendations across all eight topics. Establishing these recommendations will help organizations and employers create effective heat safety plans for their workplaces, address factors that limit the implementation of heat safety best-practices and protect worker health and productivity.
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http://dx.doi.org/10.1029/2021GH000443DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8388206PMC
August 2021

An exploratory survey of heat stress management programs in the electric power industry.

J Occup Environ Hyg 2021 09 18;18(9):436-445. Epub 2021 Aug 18.

Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada.

Workers in the electric power industry commonly perform physically demanding jobs in hot environments, which combined with the protective clothing worn, places them at risk of disease and health problems related to occupational heat stress. With climate change fueling an increase in the occurrence of hot weather, a targeted approach to heat stress management within the industry is needed. To better understand current heat management practices and identify opportunities for refinement, we conducted an exploratory survey among 33 electric utility companies operating in the United States (n = 32) and Canada (n = 1). Forty-six employees responsible for health and safety of company workers completed 26 questions assessing heat stress as a workplace hazard and heat management practices within five categories: (1) use and administration of heat stress management program; (2) surveillance of heat stress and heat strain; (3) job evaluation and heat-mitigation guidance; (4) education and training programs; and (5) treatment of heat-related illness. While a majority of the respondents (87.0%) indicated heat stress is a workplace hazard and their organization has a heat stress management program (78.3%), less than half reported performing real-time monitoring of heat stress in the workplace (47.8%) or tracking worker heat strain (19.6%) (i.e., physiological response to heat stress). However, most organizations indicated they conducted pre-job evaluations for heat stress (71.7%) and implemented an employee training program on managing heat stress (73.9%). The latter included instruction on various short- and long-term heat-mitigation guidance for workers (e.g., use of work exposure limits, hydration protocols) and the prevention (52.2%) and treatment (63.1%) of heat-related illnesses. Altogether, our survey demonstrates that although many companies employ some form of a heat management program, the basic components defining the programs vary and are lacking for some companies. To maximize worker health and safety during work in hot environments, a consensus-based approach, which considers the five basic components of a heat management program, should be employed to formulate effective practices and methodologies for creating an industry-specific heat management strategy.
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http://dx.doi.org/10.1080/15459624.2021.1954187DOI Listing
September 2021

Health and social needs of migrant construction workers for big sporting events.

BMJ 2021 08 5;374:n1591. Epub 2021 Aug 5.

The Migrant Health Research Group, Institute for Infection and Immunity, St George's, University of London, UK.

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http://dx.doi.org/10.1136/bmj.n1591DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8340932PMC
August 2021

Improving the evidence on health inequities in migrant construction workers preparing for big sporting events.

BMJ 2021 08 5;374:n1615. Epub 2021 Aug 5.

Migrant Health Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK.

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http://dx.doi.org/10.1136/bmj.n1615DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8340916PMC
August 2021

The Impacts of Sun Exposure on Worker Physiology and Cognition: Multi-Country Evidence and Interventions.

Int J Environ Res Public Health 2021 07 20;18(14). Epub 2021 Jul 20.

FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece.

Background: A set of four case-control ( = 109), randomized-controlled ( = 7), cross-sectional ( = 78), and intervention ( = 47) studies was conducted across three countries to investigate the effects of sun exposure on worker physiology and cognition.

Methods: Physiological, subjective, and cognitive performance data were collected from people working in ambient conditions characterized by the same thermal stress but different solar radiation levels.

Results: People working under the sun were more likely to experience dizziness, weakness, and other symptoms of heat strain. These clinical impacts of sun exposure were not accompanied by changes in core body temperature but, instead, were linked with changes in skin temperature. Other physiological responses (heart rate, skin blood flow, and sweat rate) were also increased during sun exposure, while attention and vigilance were reduced by 45% and 67%, respectively, compared to exposure to a similar thermal stress without sunlight. Light-colored clothes reduced workers' skin temperature by 12-13% compared to darker-colored clothes.

Conclusions: Working under the sun worsens the physiological heat strain experienced and compromises cognitive function, even when the level of heat stress is thought to be the same as being in the shade. Wearing light-colored clothes can limit the physiological heat strain experienced by the body.
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http://dx.doi.org/10.3390/ijerph18147698DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8303297PMC
July 2021

Occupational Heat Stress: Multi-Country Observations and Interventions.

Int J Environ Res Public Health 2021 06 10;18(12). Epub 2021 Jun 10.

FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100 Trikala, Greece.

Background: Occupational heat exposure can provoke health problems that increase the risk of certain diseases and affect workers' ability to maintain healthy and productive lives. This study investigates the effects of occupational heat stress on workers' physiological strain and labor productivity, as well as examining multiple interventions to mitigate the problem.

Methods: We monitored 518 full work-shifts obtained from 238 experienced and acclimatized individuals who work in key industrial sectors located in Cyprus, Greece, Qatar, and Spain. Continuous core body temperature, mean skin temperature, heart rate, and labor productivity were collected from the beginning to the end of all work-shifts.

Results: In workplaces where self-pacing is not feasible or very limited, we found that occupational heat stress is associated with the heat strain experienced by workers. Strategies focusing on hydration, work-rest cycles, and ventilated clothing were able to mitigate the physiological heat strain experienced by workers. Increasing mechanization enhanced labor productivity without increasing workers' physiological strain.

Conclusions: Empowering laborers to self-pace is the basis of heat mitigation, while tailored strategies focusing on hydration, work-rest cycles, ventilated garments, and mechanization can further reduce the physiological heat strain experienced by workers under certain conditions.
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http://dx.doi.org/10.3390/ijerph18126303DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8296111PMC
June 2021

The Presence of Fungal and Parasitic Infections in Substances of Human Origin and Their Transmission via Transfusions and Transplantations: Protocol for Two Systematic Reviews.

JMIR Res Protoc 2021 Jun 10;10(6):e25674. Epub 2021 Jun 10.

FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece.

Background: The European Union Directives stipulate mandatory tests for the presence of any infections in donors and donations of substances of human origin (SoHO). In some circumstances, other pathogens, including fungi and parasites, may also pose a threat to the microbial safety of SoHO.

Objective: The aim of the two systematic reviews is to identify, collect, and evaluate scientific evidence for the presence of fungal and parasitic infections in donors and donations of SoHO, and their transmission via transfusion and transplantation.

Methods: An algorithmic search, one each for fungal and parasitic disease, was applied to 6 scientific databases (PubMed, EMBASE, Web of Science, Scopus, Cochrane Library [trials], and CINAHL). Additionally, manual and algorithmic searches were employed in 15 gray literature databases and 22 scientific organization websites. The criteria for eligibility included peer-reviewed publications and peer-reviewed abstract publications from conference proceedings examining the prevalence, incidence, odds ratios, risk ratios, and risk differences for the presence of fungi and parasites in donors and SoHO donations, and their transmission to recipients. Only studies that scrutinized the donors and donations of human blood, blood components, tissues, cells, and organs were considered eligible. Data extraction from eligible publications will be performed independently by two reviewers. Data synthesis will include a qualitative description of the studies lacking evidence suitable for a meta-analysis and a random or fixed-effect meta-analysis model for quantitative data synthesis.

Results: This is an ongoing study. The systematic reviews are funded by the European Centre for Disease Prevention and Control, and the results are expected to be presented by the end of 2021.

Conclusions: The systematic reviews will provide the basis for developing a risk assessment for fungal and parasitic disease transmission via SoHO.

Trial Registration: PROSPERO International Prospective Register of Systematic Reviews CRD42020160090; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020160090 ; PROSPERO International Prospective Register of Systematic Reviews CRD42020160110; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020160110.

International Registered Report Identifier (irrid): DERR1-10.2196/25674.
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http://dx.doi.org/10.2196/25674DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8262548PMC
June 2021

Aerobic fitness as a parameter of importance for labour loss in the heat.

J Sci Med Sport 2021 Aug 8;24(8):824-830. Epub 2021 May 8.

Environmental Ergonomics Research Centre, School of Design and Creative Arts, Loughborough University, UK. Electronic address:

Objectives: To derive an empirical model for the impact of aerobic fitness (maximal oxygen consumption; V̇O in mL∙kg∙min) on physical work capacity (PWC) in the heat.

Design: Prospective, repeated measures.

Methods: Total work completed during 1 h of treadmill walking at a fixed heart rate of 130 b∙min was assessed in 19 young adult males across a variety of warm and hot climate types, characterised by wet-bulb globe temperatures (WBGT) ranging from 12 to 40 °C. For data presentation and obtaining initial parameter estimates for modelling, participants were grouped into low (n = 6, 74 trials), moderate (n = 8, 76 trials), and high (n = 5, 29 trials) fitness, with group mean V̇O 42, 52, and 64 mL∙kg∙min respectively. For the heated conditions (WBGT 18 to 40 °C), we calculated PWC% by expressing total energy expenditure (kJ above resting) in each trial relative to that achieved in a cool reference condition (WBGT = 12 °C = 100% PWC).

Results: The relative reduction in energy expenditure (PWC%) caused by heat was significantly smaller by up to 16% for the fit participants compared to those with lower aerobic capacity. V̇O also modulated the relationship between sweat rate and body temperature changes to increasing WBGT. Including individual V̇O data in the PWC prediction model increased the predicting power by 4%.

Conclusions: Incorporating individual V̇O improved the predictive power of the heat stress index WBGT for Physical Work Capacity in the heat. The largest impact of V̇O on PWC was observed at a WBGT between 25 and 35 °C.
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http://dx.doi.org/10.1016/j.jsams.2021.05.002DOI Listing
August 2021

Environmental and Psychophysical Heat Stress in Adolescent Tennis Athletes.

Int J Sports Physiol Perform 2021 May 21:1-6. Epub 2021 May 21.

Purpose: We investigated the environmental conditions in which all outdoor International Tennis Federation (ITF) junior tournaments (athlete ages: <18 y) were held during 2010-2019. Thereafter, we performed a crossover trial (ClinicalTrials.gov: NCT04197375) assessing the efficacy of head-neck precooling for mitigating the heat-induced psychophysical and performance impacts on junior athletes during tennis match play.

Methods: ITF junior tournament information was collected. We identified meteorological data from nearby (13.6 [20.3] km) weather stations for 3056 (76%) tournaments.

Results: Overall, 30.1% of tournaments were held in hot (25°C-30°C wet-bulb globe temperature [WBGT]; 25.9%), very hot (30°C-35°C WBGT; 4.1%), or extremely hot (>35°C WBGT; 0.1%) conditions. Thereafter, 8 acclimatized male junior tennis athletes (age = 16.0 [0.9] y; height = 1.82 [0.04] m; weight = 71.3 [11.1] kg) were evaluated during 2 matches: one with head-neck precooling (27.7°C [2.2°C] WBGT) and one without (27.9°C [1.8°C] WBGT). Head-neck precooling reduced athletes' core temperature from 36.9°C (0.2°C) to 36.4°C (0.2°C) (P = .001; d = 2.4), an effect reduced by warm-up. Head-neck precooling reduced skin temperature (by 0.3°C [1.3°C]) for the majority of the match and led to improved (P < .05) perceived exertion (by 13%), thermal comfort (by 14%), and thermal sensation (by 15%). Muscle temperature, heart rate, body weight, and urine specific gravity remained unaffected (P ≥ .05; d < 0.2). Small or moderate improvements were observed in most performance parameters assessed (d = 0.20-0.79).

Conclusions: Thirty percent of the last decade's ITF junior tournaments were held in hot, very hot, or extremely hot conditions (25°C-36°C WBGT). In such conditions, head-neck precooling may somewhat lessen the physiological and perceptual heat strain and lead to small to moderate improvements in the match-play performance of adolescent athletes.
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http://dx.doi.org/10.1123/ijspp.2020-0820DOI Listing
May 2021

Prolonged facemask use in the heat worsens dyspnea without compromising motor-cognitive performance.

Temperature (Austin) 2020 Oct 9;8(2):160-165. Epub 2020 Oct 9.

Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.

Within the context of the COVID-19 pandemic, the WHO endorses facemask use to limit aerosol-spreading of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, concerns have been raised regarding facemask-associated dyspnea, thermal distress and self-reported impairment of cognition. Accordingly, we tested how facemask-use affects motor-cognitive performances of relevance for occupational safety. We hypothesized that mask use would affect cognitively dominated performances and thermal discomfort, but not alter whole-body thermal balance. Eight participants completed a facemask and a barefaced (control) trial, in a counterbalanced order, in 40°C and 20% humidity conditions. Motor-cognitive performance, physiological (rectal, mean skin and local facial temperatures) and perceptual (thermal comfort and dyspnea) measures were assessed at baseline and following 45 min of light work (100 W). Perceived dyspnea was aggravated with prolonged facemask use (p = 0.04), resulting in 36% greater breathlessness compared to control. However, no other differences were observed in motor-cognitive performance, physiological strain, or thermal discomfort. Contradicting negative self-reported impacts of facemask-use, only dyspnea was aggravated in the present study, thereby reinforcing global recommendations of mask use, even in hot environments. (Funded by: European Union's Horizon 2020 research and innovation program under the grant agreement No 668786).
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http://dx.doi.org/10.1080/23328940.2020.1826840DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8098073PMC
October 2020

Heat Tolerance and Occupational Heat Exposure Limits in Older Men with and without Type 2 Diabetes or Hypertension.

Med Sci Sports Exerc 2021 10;53(10):2196-2206

Hypertension Program, Division of Nephrology, University of Ottawa, Ottawa, CANADA.

Purpose: To mitigate rises in core temperature >1°C, the American Conference of Governmental Industrial Hygienists (ACGIH) recommends upper limits for heat stress (action limit values [ALV]), defined by wet-bulb globe temperature (WBGT) and a worker's metabolic rate. However, these limits are based on data from young men and are assumed to be suitable for all workers, irrespective of age or health status. We therefore explored the effect of aging, type 2 diabetes (T2D), and hypertension (HTN) on tolerance to prolonged, moderate-intensity work above and below these limits.

Methods: Core temperature and heart rate were assessed in healthy, heat unacclimatized young (18-30 yr, n = 13) and older (50-70 yr) men (n = 14) and heat unacclimatized older men with T2D (n = 10) or HTN (n = 13) during moderate-intensity (metabolic rate: 200 W·m-2) walking for 180 min (or until termination) in environments above (28°C and 32°C WBGT) and below (16°C and 24°C WBGT) the ALV for continuous work at this intensity (25°C WBGT).

Results: Work tolerance in the 32°C WBGT was shorter in men with T2D (median [IQR]; 109 [91-173] min; P = 0.041) and HTN (120 [65-170] min; P = 0.010) compared with healthy older men (180 [133-180] min). However, aging, T2D, and HTN did not significantly influence (i) core temperature or heart rate reserve, irrespective of WBGT; (ii) the probability that core temperature exceeded recommended limits (>1°C) under the ALV; and (iii) work duration before core temperature exceeded recommended limits (>1°C) above the ALV.

Conclusion: These findings demonstrate that T2D and HTN attenuate tolerance to uncompensable heat stress (32°C WBGT); however, these chronic diseases do not significantly impact thermal and cardiovascular strain, or the validity of ACIGH recommendations during moderate-intensity work.
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http://dx.doi.org/10.1249/MSS.0000000000002698DOI Listing
October 2021

Effect of a Simulated Heat Wave on Physiological Strain and Labour Productivity.

Int J Environ Res Public Health 2021 03 15;18(6). Epub 2021 Mar 15.

Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, 1000 Ljubljana, Slovenia.

Background: The aim of the study was to investigate the effect of a simulated heat-wave on the labour productivity and physiological strain experienced by workers.

Methods: Seven males were confined for ten days in controlled ambient conditions. A familiarisation day was followed by three (pre, during, and post-heat-wave) 3-day periods. During each day volunteers participated in a simulated work-shift incorporating two physical activity sessions each followed by a session of assembly line task. Conditions were hot (work: 35.4 °C; rest: 26.3 °C) during, and temperate (work: 25.4 °C; rest: 22.3 °C) pre and post the simulated heat-wave. Physiological, biological, behavioural, and subjective data were collected throughout the study.

Results: The simulated heat-wave undermined human capacity for work by increasing the number of mistakes committed, time spent on unplanned breaks, and the physiological strain experienced by the participants. Early adaptations were able to mitigate the observed implications on the second and third days of the heat-wave, as well as impacting positively on the post-heat-wave period.

Conclusions: Here, we show for first time that a controlled simulated heat-wave increases workers' physiological strain and reduces labour productivity on the first day, but it promotes adaptations mitigating the observed implications during the subsequent days.
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http://dx.doi.org/10.3390/ijerph18063011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7998810PMC
March 2021

The HEAT-SHIELD project - Perspectives from an inter-sectoral approach to occupational heat stress.

J Sci Med Sport 2021 Aug 8;24(8):747-755. Epub 2021 Mar 8.

Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark. Electronic address:

Objectives: To provide perspectives from the HEAT-SHIELD project (www.heat-shield.eu): a multi-national, inter-sectoral, and cross-disciplinary initiative, incorporating twenty European research institutions, as well as occupational health and industrial partners, on solutions to combat negative health and productivity effects caused by working on a warmer world.

Methods: In this invited review, we focus on the theoretical and methodological advancements developed to combat occupational heat stress during the last five years of operation.

Results: We outline how we created climate forecast models to incorporate humidity, wind and solar radiation to the traditional temperature-based climate projections, providing the basis for timely, policy-relevant, industry-specific and individualized information. Further, we summarise the industry-specific guidelines we developed regarding technical and biophysical cooling solutions considering effectiveness, cost, sustainability, and the practical implementation potential in outdoor and indoor settings, in addition to field-testing of selected solutions with time-motion analyses and biophysical evaluations. All recommendations were adjusted following feedback from workshops with employers, employees, safety officers, and adjacent stakeholders such as local or national health policy makers. The cross-scientific approach was also used for providing policy-relevant information based on socioeconomic analyses and identification of vulnerable regions considered to be more relevant for political actions than average continental recommendations and interventions.

Discussion: From the HEAT-SHIELD experiences developed within European settings, we discuss how this inter-sectoral approach may be adopted or translated into actionable knowledge across continents where workers and societies are affected by escalating environmental temperatures.
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http://dx.doi.org/10.1016/j.jsams.2021.03.001DOI Listing
August 2021

An advanced empirical model for quantifying the impact of heat and climate change on human physical work capacity.

Int J Biometeorol 2021 Jul 5;65(7):1215-1229. Epub 2021 Mar 5.

Environmental Ergonomics Research Centre, School of Design and Creative Arts Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK.

Occupational heat stress directly hampers physical work capacity (PWC), with large economic consequences for industries and regions vulnerable to global warming. Accurately quantifying PWC is essential for forecasting impacts of different climate change scenarios, but the current state of knowledge is limited, leading to potential underestimations in mild heat, and overestimations in extreme heat. We therefore developed advanced empirical equations for PWC based on 338 work sessions in climatic chambers (low air movement, no solar radiation) spanning mild to extreme heat stress. Equations for PWC are available based on air temperature and humidity, for a suite of heat stress assessment metrics, and mean skin temperature. Our models are highly sensitive to mild heat and to our knowledge are the first to include empirical data across the full range of warm and hot environments possible with future climate change across the world. Using wet bulb globe temperature (WBGT) as an example, we noted 10% reductions in PWC at mild heat stress (WBGT = 18°C) and reductions of 78% in the most extreme conditions (WBGT = 40°C). Of the different heat stress indices available, the heat index was the best predictor of group level PWC (R = 0.96) but can only be applied in shaded conditions. The skin temperature, but not internal/core temperature, was a strong predictor of PWC (R = 0.88), thermal sensation (R = 0.84), and thermal comfort (R = 0.73). The models presented apply to occupational workloads and can be used in climate projection models to predict economic and social consequences of climate change.
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http://dx.doi.org/10.1007/s00484-021-02105-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8213606PMC
July 2021

Exercise-heat tolerance in middle-aged-to-older men with type 2 diabetes.

Acta Diabetol 2021 06 25;58(6):809-812. Epub 2021 Feb 25.

Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, 125 University, Room 367, Montpetit Hall, Ottawa, ON, K1N 6N5, Canada.

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http://dx.doi.org/10.1007/s00592-021-01684-zDOI Listing
June 2021

Human white-fat thermogenesis: Experimental and meta-analytic findings.

Temperature (Austin) 2020 Jun 5;8(1):39-52. Epub 2020 Jun 5.

FAME Laboratory, Department of Exercise Science, University of Thessaly, Trikala, Greece.

White adipose tissue (WAT) thermogenic activity may play a role in whole-body energy balance and two of its main regulators are thought to be environmental temperature (T) and exercise. Low T may increase uncoupling protein one (UCP1; the main biomarker of thermogenic activity) in WAT to regulate body temperature. On the other hand, exercise may stimulate UCP1 in WAT, which is thought to alter body weight regulation. However, our understanding of the roles (if any) of T and exercise in WAT thermogenic activity remains incomplete. Our aim was to examine the impacts of low T and exercise on WAT thermogenic activity, which may alter energy homeostasis and body weight regulation. We conducted a series of four experimental studies, supported by two systematic reviews and meta-analyses. We found increased UCP1 mRNA (p = 0.03; but not protein level) in human WAT biopsy samples collected during the cold part of the year, a finding supported by a systematic review and meta-analysis (PROSPERO review protocol: CRD42019120116). Additional clinical trials (NCT04037371; NCT04037410) using Positron Emission Tomography/Computed Tomography (PET/CT) revealed no impact of low T on human WAT thermogenic activity (p > 0.05). Furthermore, we found no effects of exercise on UCP1 mRNA or protein levels (p > 0.05) in WAT biopsy samples from a human randomized controlled trial (Clinical trial: NCT04039685), a finding supported by systematic review and meta-analytic data (PROSPERO review protocol: CRD42019120213). Taken together, the present experimental and meta-analytic findings of UCP1 and SUV, demonstrate that cold and exercise may play insignificant roles in human WAT thermogenic activity. : WAT:White adipose tissue; T: Environmental temperature; UCP1: Uncoupling protein one; BAT: Brown adipose tissue; BMI:Body mass index; mRNA: Messenger ribonucleic acid; RCT: Randomized controlled trial; WHR: Waist-to-hip ratio; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-analyses; PET/CT: Positron Emission Tomography and Computed Tomography; REE: Resting energy expenditure; F-FDG: F fludeoxyglucose; VOpeak:Peak oxygen consumption; 1RM: One repetition maximum; SUV: Maximum standardized uptake value; Std: Standardized mean difference.
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http://dx.doi.org/10.1080/23328940.2020.1769530DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7849687PMC
June 2020

Separate and combined effects of cold dialysis and intradialytic exercise on the thermoregulatory responses of hemodialysis patients: a randomized-cross-over study.

BMC Nephrol 2020 12 2;21(1):524. Epub 2020 Dec 2.

School of Physical Education, Sport Science and Dietetics, University of Thessaly, Trikala, 42100, Greece.

Background: The separate and combined effects of intradialytic exercise training (IET) and cold dialysis (CD) on patient thermoregulation remain unknown. This study assessed the thermoregulatory responses of hemodialysis patients under four different hemodialysis protocols: a) one typical dialysis (TD) protocol (dialysate temperature at 37 °C), b) one cold dialysis (CD) protocol (dialysate temperature at 35 °C), c) one typical dialysis protocol which included a single exercise bout (TD + E), d) one cold dialysis protocol which included a single exercise bout (CD + E).

Methods: Ten hemodialysis patients (57.2 ± 14.9 years) participated in this randomized, cross-over study. Core and skin temperatures were measured using an ingestible telemetric pill and by four wireless iButtons attached on the skin, respectively. Body heat storage (S) calculated using the thermometric method proposed by Burton.

Results: The TD and TD + E protocols were associated with increased S leading to moderate effect size increases in core body temperature (as high as 0.4 °C). The low temperature of the dialysate during the CD and the CD + E protocols prevented the rise in S and core temperature (p > 0.05), even during the period that IET took place.

Conclusions: TD and IET are accompanied by a moderate level of hyperthermia, which can be offset by CD. We recommended that CD or with IET can prevent the excessive rise of S.

Trial Registration: Clinical Trial Registry number: NCT03905551 ( clinicaltrials.gov ), DOR: 05/04/2019.
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http://dx.doi.org/10.1186/s12882-020-02167-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7709248PMC
December 2020

Type 2 diabetes does not exacerbate body heat storage in older adults during brief, extreme passive heat exposure.

Temperature (Austin) 2020 16;7(3):263-269. Epub 2020 Mar 16.

Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Canada.

Aging exacerbates hyperthermia and cardiovascular strain during passive heat exposure, but it remains unclear whether those effects worsen in older adults with type 2 diabetes (T2D). We examined these responses in unacclimatized, physically active, older individuals with (n = 13, mean ± SD age: 60 ± 8 years, HbA1c: 7.0 ± 1.0%) and without (Control, n = 30, 62 ± 6 years) well-controlled T2D during a brief, 3-h passive exposure to extreme heat (44°C, 30% relative humidity). Metabolic heat production, dry heat gain, total heat gain (metabolic heat production + dry heat gain), evaporative heat loss, body heat storage (summation of heat gain/loss), rectal and mean skin temperatures as well as heart rate were measured continuously. No between-group differences were observed for metabolic heat production (T2D vs. Control; 53 ± 5 vs. 55 ± 7 W/m), dry heat gain (48 ± 9 vs. 47 ± 11 W/m), total heat gain (101 ± 10 vs. 102 ± 14 W/m) and evaporative heat loss (83 ± 10 vs. 85 ± 12 W/m) over the 3 h (all P > 0.05). Consequently, the changes in body heat storage (380 ± 93 vs. 358 ± 172 kJ, P = 0.67) were similar between groups. Moreover, no between-group differences in rectal and mean skin temperatures or heart rate were measured. We conclude that unacclimatized, physically active, older adults with well-controlled T2D do not experience greater hyperthermia and cardiovascular strain compared to their healthy counterparts while resting in extreme heat for a brief, 3-h period.
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http://dx.doi.org/10.1080/23328940.2020.1736760DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7575233PMC
March 2020
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