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OBJECTIVE: This study aims to prospectively examine the association between temperatures and the occurrence of type 2 diabetes (T2D). METHODS: We used the CPH models to analyze 103,215 non-diabetic participants in the UK Biobank cohort who answered questions about workplace temperature, to evaluate the survival relationship, and the interaction effects of working environmental temperature and T2D-related genetic risk scores (GRS) on the occurrence of T2D. The occurrence of T2D was assessed by hospital inpatient records. The weighted T2D-related GRS were calculated. RESULTS: During 1,355,200.6 person-years follow-up, a total of 2436 participants were documented as having diagnosed T2D. After adjustment, compared to the comfortable group, the participants working in non-comfortable environmental temperature had greater risk of T2D (HR: 1.27, 95â¯%CI: 1.04 to 1.55, for cold; HR: 1.32, 95â¯%CI: 1.17 to 1.48 for hot; HR: 1.51, 95â¯%CI: 1.38 to 1.65 for alternate). Similarly, individuals exposed to different levels of genetic risk scores in alternating hot and cold work environments had a higher risk of developing type 2 diabetes. CONCLUSIONS: This study found working in single non-comfortable environmental temperatures was associated with greater risk of T2D occurrence, and exposure to alternating environmental temperatures had the highest risk of range and severity.
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Astragalus is a medicinal plant with obvious rhizosphere effects. At present, there are many Astragalus plants with high application value but low recognition and resource reserves in the northwestern area of Yunnan province, China. In this study, metagenomics was used to analyze the microbial diversity and community structure of rhizosphere soil of A. forrestii, A. acaulis, and A. ernestii plants grown in a special high-cold environment of northwestern Yunnan, China, at different altitudes ranging from 3225 to 4353 m. These microbes were taxonomically annotated to obtain 24 phyla and 501 genera for A. forrestii, 30 phyla and 504 genera for A. acaulis, as well as 39 phyla and 533 genera for A. ernestii. Overall, the dominant bacterial phyla included Proteobacteria, Actinobacteria, and Acidobacteria, while the dominant fungal ones were Ascomycota and Basidiomycota. At the genus level, Bradyrhizobium, Afipia, and Paraburkholderia were the most prevalent bacteria, and Hyaloscypha, Pseudogymnoascus, and Russula were the dominant fungal genera. Some of them are considered biocontrol microbes that could sustain the growth and health of host Astragalus plants. Redundancy analysis revealed that pH, TN, and SOM had a significant impact on the microbial community structures (p < 0.05). Finally, triterpene, flavonoid, polysaccharide, and amino acid metabolisms accounted for a high proportion of the enriched KEGG pathways, which possibly contributed to the synthesis of bioactive constituents in the Astragalus plants.
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Objectives. This study aimed to determine the impact of low temperature (-1 °C, +5 °C) on manual dexterity and hand skin temperature after 1 h of exposure when using two types of protective gloves. Methods. Ten male participants wore double gloves or single gloves, when spending 1 h in a climatic chamber at -1, +5 or +20 °C. Before and after the cold exposure, measurements of mean weighted body skin temperature, hand skin temperature, the Purdue Pegboard Test and hand grip strength were performed. Results. There were statistically significant differences in the values of mean weighted body skin temperature and left and right hand skin temperature between the study variants. Conclusion. No effect of cold exposure (-1 °C, +5 °C) on manual dexterity was observed, but there was an effect of -1 °C temperature change on weighted mean skin temperature and hand skin temperature during 1 h of exposure. The decrease in both right and left hand skin temperature after cold exposure was the largest for -1 °C while using single gloves, and differed significantly from the other variants.
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Fuerza de la Mano , Mano , Humanos , Masculino , Temperatura , Frío , Temperatura CutáneaRESUMEN
The plateau hypoxic environment can affect the thermoregulation process of the human body, and due to the different acclimatization ability to the hypoxic environment, the thermal requirements among the people who enter Xizang at different times may be different. Accordingly, this study aims to clarify how plateau hypoxic environments influence the physiological and subjective responses of people entering Xizang at different times. And field experiments were conducted in Xi'an and Lhasa, respectively, to compare the thermal responses and oxygen responses of the subjects under different temperature conditions on the plain, the first day of entering Xizang and the 15th day of entering Xizang. The results showed that under the hypoxic environment, the thermal sensation of the subjects decreased. With the extension of the time entering Xizang, the influence of the hypoxic environment on thermal comfort was gradually weakened, but under the low temperature environment, the effect of hypoxia on thermal response was not significantly reduced. The results of this study can help to reveal how plateau hypoxic environments affect human thermal comfort and provide a theoretical basis for the design of indoor thermal environment parameters suitable for sojourners entering Xizang at different times.
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Aclimatación , Regulación de la Temperatura Corporal , Humanos , Regulación de la Temperatura Corporal/fisiología , Frío , Sensación Térmica , Hipoxia , TemperaturaRESUMEN
BACKGROUND: Yakuts are one of the indigenous populations of the subarctic and arctic territories of Siberia characterized by a continental subarctic climate with severe winters, with the regular January average temperature in the regional capital city of Yakutsk dipping below - 40 °C. The epigenetic mechanisms of adaptation to such ecologies and environments and, in particular, epigenetic age acceleration in the local population have not been studied before. RESULTS: This work reports the first epigenetic study of the Yakutian population using whole-blood DNA methylation data, supplemented with the comparison to the residents of Central Russia. Gene set enrichment analysis revealed, among others, geographic region-specific differentially methylated regions associated with adaptation to climatic conditions (water consumption, digestive system regulation), aging processes (actin filament activity, cell fate), and both of them (channel activity, regulation of steroid and corticosteroid hormone secretion). Further, it is demonstrated that the epigenetic age acceleration of the Yakutian representatives is significantly higher than that of Central Russia counterparts. For both geographic regions, we showed that epigenetically males age faster than females, whereas no significant sex differences were found between the regions. CONCLUSIONS: We performed the first study of the epigenetic data of the Yakutia cohort, paying special attention to region-specific features, aging processes, age acceleration, and sex specificity.
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Metilación de ADN , Epigénesis Genética , Humanos , Masculino , Femenino , Siberia , Regiones ÁrticasRESUMEN
The ClimApp smartphone application was developed to merge meteorological forecast data with personal information for individualized and improved thermal warning during heat and cold stress and for indoor comfort in buildings. For cold environments, ClimApp predicts the personal thermal stress and strain by the use of the Insulation REQuired model that combines weather and personal physiological data with additional consideration of the Wind Chill index based on the local weather forecast. In this study, we validated the individualized ClimApp index relative to measurements and compared it with the Universal Temperature Climate Index (UTCI). To this aim, 55 participants (27 females) were exposed to at least 1 h in an outdoor environment of 10 °C or below (average 1.4 °C air temperature, 74.9% relative humidity, and 4.7 m/s air velocity) inputting their activity level and clothing insulation as instructed by ClimApp. The UTCI and ClimApp indices were calculated and compared to the participants' perceived thermal sensation. The ClimApp index root mean square deviation (RMSD) was below the standard deviation of the perceived thermal sensation which indicates a valid prediction and the UTCI RMSD was higher than the standard deviation which indicates an invalid prediction. The correlation of ClimApp and UTCI to the perceived thermal sensation was statistically significant for both models.
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Clima , Teléfono Inteligente , Femenino , Humanos , Temperatura , Tiempo (Meteorología) , Viento , Sensación Térmica/fisiologíaRESUMEN
BACKGROUND: Whereas outdoor temperature is linked to both mortality and hydration status, the hormone vasopressin, measured through the surrogate copeptin, is a marker of cardiometabolic risk and hydration. We recently showed that copeptin has a seasonal pattern with higher plasma concentration in winter. Here, we aimed to investigate the association between outdoor temperature and copeptin. METHODS: Copeptin was analysed in fasting plasma from five cohorts in Malmö, Sweden (n = 26,753, 49.7% men, age 18-86 years). We utilized a multivariable adjusted non-linear spline model with four knots to investigate the association between short-term temperature (24 h mean apparent) and log copeptin z-score. FINDINGS: We found a distinct non-linear association between temperature and log copeptin z-score, with both moderately low and high temperatures linked to higher copeptin concentration (p < 0.0001). Between 0 °C and nadir at the 75th temperature percentile (corresponding to 14.3 °C), log copeptin decreased 0.13 z-scores (95% CI 0.096; 0.16), which also inversely corresponded to the increase in z-score log copeptin between the nadir and 21.3 °C. INTERPRETATION: The J-shaped association between short-term temperature and copeptin resembles the J-shaped association between temperature and mortality. Whereas the untangling of temperature from other seasonal effects on hydration warrants further study, moderately increased water intake constitutes a feasible intervention to lower vasopressin and might mitigate adverse health effects of both moderately cold and hot outdoor temperatures. FUNDING: Swedish Research Council, Å Wiberg, M Stephen, A Påhlsson, Crafoord and Swedish Heart-Lung Foundations, Swedish Society for Medical Research and Swedish Society of Medicine.
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Biomarcadores , Glicopéptidos , Temperatura , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Biomarcadores/sangre , Biomarcadores/metabolismo , Frío , Glicopéptidos/sangre , Glicopéptidos/metabolismo , Calor , Estaciones del Año , Vasopresinas/sangre , Vasopresinas/metabolismo , Estado de Hidratación del Organismo , Estudios de CohortesRESUMEN
Military personnel during combat or peacekeeping operations are exposed to extreme climates of hot or cold environments for longer durations. Spinal cord injury is quite common in military personnel following central nervous system (CNS) trauma indicating a possibility of altered pathophysiological responses at different ambient temperatures. Our previous studies show that the pathophysiology of brain injury is exacerbated in animals acclimated to cold (5 °C) or hot (30 °C) environments. In these diverse ambient temperature zones, trauma exacerbated oxidative stress generation inducing greater blood-brain barrier (BBB) permeability and cell damage. Extracts of Ginkgo biloba EGb-761 and BN-52021 treatment reduces brain pathology following heat stress. This effect is further improved following TiO2 nanowired delivery in heat stress in animal models. Several studies indicate the role of EGb-761 in attenuating spinal cord induced neuronal damages and improved functional deficit. This is quite likely that these effects are further improved following nanowired delivery of EGb-761 and BN-52021 with cerebrolysin-a balanced composition of several neurotrophic factors and peptide fragments in spinal cord trauma. In this review, TiO2 nanowired delivery of EGb-761 and BN-52021 with nanowired cerebrolysin is examined in a rat model of spinal cord injury at cold environment. Our results show that spinal cord injury aggravates cord pathology in cold-acclimated rats and nanowired delivery of EGb-761 and BN-52021 with cerebrolysin significantly induced superior neuroprotection, not reported earlier.
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Bilobálidos , Ginkgo biloba , Fármacos Neuroprotectores , Traumatismos de la Médula Espinal , Animales , Ratas , Frío , Sistemas de Liberación de Medicamentos , Nanocables , Fármacos Neuroprotectores/uso terapéutico , Extractos Vegetales/uso terapéutico , Traumatismos de la Médula Espinal/tratamiento farmacológico , Traumatismos de la Médula Espinal/fisiopatología , ChinaRESUMEN
With the outbreak of the Ukrainian crisis, extremely cold environment warfare has once again become the focus of international attention. People exposed to extremely cold environments may suffer from cold damage, further aggravate trauma, trigger high disability and mortality rates, and even cause serious sequelae. To declare the effects and mechanisms of the extremely cold environment on the body after trauma, this paper reviews, firstly, physiological reaction of human body in an extremely cold environment. Then, the post-traumatic body response in an extremely cold environment was introduced, and finally, the sequelae of trauma in extremely cold environment was further summarized in the paper. The results indicated that extremely cold environment can cause a series of damage to the body, especially the body after trauma. The extremely cold factor is a double-edged sword, showing a favorable and unfavorable side in different aspects. Moreover, in addition to the trauma suffered by the body, the subsequent sequelae such as cognitive dysfunction, anxiety, depression and even post-traumatic stress disorder may also be induced. The paper summarizes the human body's physiological response in an extremely cold environment, and declares the effects and mechanisms of the extremely cold environment on the body after trauma, which may provide a theoretical basis for effectively improving the level of combat trauma treatment in extremely cold regions.
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Trastornos por Estrés Postraumático , Humanos , Trastornos por Estrés Postraumático/psicología , Trastornos por Estrés Postraumático/terapia , AnsiedadRESUMEN
Background: Hypoxic and cold environments have been shown to improve the function and performance of athletes. However, it is unclear whether the combination of subalpine conditions and cold temperatures may have a greater effect. The present study aims to investigate the effects of 6 weeks of training in a sub-plateau cold environment on the physical function and athletic ability of elite parallel giant slalom snowboard athletes. Methods: Nine elite athletes (four males and five females) participated in the study. The athletes underwent 6 weeks of high intensity ski-specific technical training (150 min/session, six times/week) and medium-intensity physical training (120 min/session, six times/week) prior to the Beijing 2021 Winter Olympic Games test competition. The physiological and biochemical parameters were collected from elbow venous blood samples after each 2-week session to assess the athletes' physical functional status. The athletes' athletic ability was evaluated by measuring their maximal oxygen uptake, Wingate 30 s anaerobic capacity, 30 m sprint run, and race performance. Measurements were taken before and after participating in the training program for six weeks. The repeated measure ANOVA was used to test the overall differences of blood physiological and biochemical indicators. For indicators with significant time main effects, post-hoc tests were conducted using the least significant difference (LSD) method. The paired-samples t-test was used to analyze changes in athletic ability indicators before and after training. Results: (1) There was a significant overall time effect for red blood cells (RBC) and white blood cells (WBC) in males; there was also a significant effect on the percentage of lymphocytes (LY%), serum testosterone (T), and testosterone to cortisol ratio (T/C) in females (p < 0.001 - 0.015, η p 2 = 0 . 81 - 0 . 99 ). In addition, a significant time effect was also found for blood urea(BU), serum creatine kinase (CK), and serum cortisol levels in both male and female athletes (p = 0.001 - 0.029, η p 2 = 0 . 52 - 0 . 95 ). (2) BU and CK levels in males and LY% in females were all significantly higher at week 6 (p = 0.001 - 0.038), while WBC in males was significantly lower (p = 0.030). T and T/C were significantly lower in females at week 2 compared to pre-training (p = 0.007, 0.008, respectively), while cortisol (C) was significantly higher in males and females at weeks 2 and 4 (p (male) = 0.015, 0.004, respectively; p (female) = 0.024, 0.030, respectively). (3) There was a noticeable increase in relative maximal oxygen uptake, Wingate 30 s relative average anaerobic power, 30 m sprint run performance, and race performance in comparison to the pre-training measurements (p < 0.001 - 0.027). Conclusions: Six weeks of sub-plateau cold environment training may improve physical functioning and promote aerobic and anaerobic capacity for parallel giant slalom snowboard athletes. Furthermore, male athletes had a greater improvement of physical functioning and athletic ability when trained in sub-plateau cold environments.
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Rendimiento Atlético , Frío , Acondicionamiento Físico Humano , Femenino , Humanos , Masculino , Atletas , Hidrocortisona , Oxígeno , Deportes , Testosterona , Deportes de NieveRESUMEN
In cold environments, the low temperature slows down microbial metabolisms, such as the biodegradation processes of hydrocarbons, which are often stimulated by the addition of dispersants in oil spill disasters. In this study, we investigated the effects of hydrocarbon water-accommodated fraction (WAF) prepared with and without dispersant on benthic microbial communities in a microcosm experiment in which hydrocarbon removal was observed. Both WAFs contained similar polycyclic aromatic hydrocarbon (PAH) content. The microcosm experiment, set up with either pristine or contaminated sediments, was conducted for 21 days at 4 °C under WAF and WAF + dispersant conditions. The behavior of bacterial communities in response to WAF and WAF + dispersant was examined at both DNA and RNA levels, revealing the effect of WAF and WAF + dispersant on the resident and active communities respectively. The contaminated sediment showed less taxa responsive to the addition of both WAF and WAF + dispersant than the pristine sediment, indicating the legacy effect by the presence hydrocarbon-degrading and dispersant-resistant taxa inhabiting the contaminated sediment.
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Microbiota , Contaminación por Petróleo , Petróleo , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Agua , Petróleo/análisis , Contaminantes Químicos del Agua/análisis , Hidrocarburos , Contaminación por Petróleo/análisis , Hidrocarburos Policíclicos Aromáticos/análisisRESUMEN
Hypothermia caused by cold water immersion is one of the main causes of death in marine accidents. Immersion suit is a kind of protective clothing when implementing flying tasks over the sea in cold seasons, with the main function to slow down the loss of human heat in water and prolong the survival time. In this study, the thermal properties and wearing types of immersion suit and underwear were analyzed. The subjects with internal- and external-wear immersion suit exposed to the experimental environments for 2 h in five working conditions. The core temperature, weighted average skin temperature, and average body temperature were measured and calculated. Both internal- and external-wear immersion suits could fulfil the cold protection requirements under the experimental conditions. The results of clothing parameter tests and physiological experiments both exhibit that the external-wear immersion suit has better thermal insulation effect. And the tolerance time in low-temperature water was predicted, which is crucial for effective and efficient rescue during shipwreck in adverse thermal scenarios. In future research, a comprehensive evaluation and analysis of the thermal insulation performance of immersion suit could be completed in combination with the water ingress of the clothing, the subjects' thermal comfort, and flexibility of the clothing.
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Cuerpo Humano , Hipotermia , Humanos , Inmersión/efectos adversos , Hipotermia/etiología , Hipotermia/prevención & control , Temperatura Corporal , Frío , Ropa de Protección/efectos adversos , Agua , Regulación de la Temperatura CorporalRESUMEN
An electric heating glove can protect the health of workers without affecting flexibility of the hand in a cold environment. A heat transfer model of an electric heating glove with a function of intelligent temperature control was established. The model was verified by a test device for simulating cold-contact exposure. The results showed good agreement between the simulated values and the experimental values. Based on the numerical model, the basic parameters of the electric heating glove were analyzed. It was found that the pressure, thickness and thermal conductivity of the outer fabric were the key factors affecting the thermal regulative performance of the electric heating glove. The power consumption of the electric heating glove was mainly determined by the thickness of the outer fabric. The developed model provides a theoretical basis for the design of an electric heating glove for a thermal regulative effect and energy saving.
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Calefacción , Calor , Humanos , Temperatura , Mano , ElectricidadRESUMEN
Working in cold environments can have a variety of negative consequences on health, efficiency, quality, safety, and performance. The present study investigates the risk of cold stress in petroleum transfer centers in Iran's northwestern cold regions. The proposed method by ISO-15743 (E) was used to assess the risk of cold stress. The activity level (M) was calculated using the ISO 8996:2021 standard. The evaluation of local cooling, contact of cold surfaces, and hand and face temperature was performed using ISO 11079, ISO 13732-3, and ISO 9886, respectively. During their work, 28 outdoor site men and mechanics as a case group and 8 operators as a control group put through subjective analysis. According to the findings, the mean Icl,r, IREQmin, and IREQneutral were 1.59 ± 0.33, 2.1 ± 0.44, and 2.43 ± 0.45, respectively. The mean equivalent chill temperature was -13.83 ± 5.45, and workers were at risk of local cooling stress at levels 1 and 2. The case group showed greater losses in finger skin temperatures after short term exposure to extremely cold environments than the control group (P < 0.001). Based on the questionnaire results a significant percentage of workers performing the activity during the winter have more difficulty. Prolonged general and local cold exposure can cause pain, numbness, and frostbite in site men and mechanics. Careful planning, training, extensive distribution of cold protective clothing, rest periods, a relatively short stay in the cold environment, and proper equipment can greatly reduce these hazards.
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Respuesta al Choque por Frío , Petróleo , Masculino , Humanos , Irán , Medición de Riesgo , FríoRESUMEN
A 7-segment and 29-node numerical hand-glove/mitten model was developed to simulate human hand physiological responses in various cold environments. To validate the model, simulated skin temperatures were compared to data from published literature and human trials conducted at -20, -40, and -60 °C. Results demonstrated that the model could reasonably predict cold-induced vasodilation (CIVD) responses at 0 °C temperature. At -20 °C, the model predicted skin temperature with the root mean square deviation (RMSD) falling within the measurement standard deviation (SD) for both the entire and local hand except for the posterior hand. At -40 and -60 °C, the model could predict the trend of the skin temperatures of the whole/local hand, but the RMSD was larger than the SD for the majority of predictions. A parametric analysis revealed that the palm and posterior hand had higher skin temperatures than the fingers, while the thumb had the lowest skin temperature of the fingers in all simulated cases except the case with a 3.5 clo mitten at -60 °C. The proposed numerical hand-glove/mitten model could reasonably predict local hand physiological responses in three extremely cold environments and provides fundamental knowledge for cold stress prediction and protective glove development, thereby improving the safety and health of industrial workers, firefighters, first responders, and troops.
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Frío , Temperatura Cutánea , Humanos , Mano/fisiología , Guantes Protectores , Dedos/fisiología , Vasodilatación/fisiologíaRESUMEN
The genome of the basidiomycete yeast Dioszegia hungarica strain PDD-24b-2 isolated from cloud water at the summit of puy de Dôme (France) was sequenced using a hybrid PacBio and Illumina sequencing strategy. The obtained assembled genome of 20.98 Mb and a GC content of 57% is structured in 16 large-scale contigs ranging from 90 kb to 5.56 Mb, and another 27.2 kb contig representing the complete circular mitochondrial genome. In total, 8,234 proteins were predicted from the genome sequence. The mitochondrial genome shows 16.2% cgu codon usage for arginine but has no canonical cognate tRNA to translate this codon. Detected transposable element (TE)-related sequences account for about 0.63% of the assembled genome. A dataset of 2,068 hand-picked public environmental metagenomes, representing over 20 Tbp of raw reads, was probed for D. hungarica related ITS sequences, and revealed worldwide distribution of this species, particularly in aerial habitats. Growth experiments suggested a psychrophilic phenotype and the ability to disperse by producing ballistospores. The high-quality assembled genome obtained for this D. hungarica strain will help investigate the behavior and ecological functions of this species in the environment.
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Basidiomycota , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Agua , Basidiomycota/genética , Análisis de Secuencia de ADNRESUMEN
Cold climates may be a risk to the health and welfare of lambs during winter because cold environments alter the physiological processes of lambs, and we used cold environments with three different temperature gradients-an indoor heating control group (IHC) using electric heating; an indoor temperature group (IT) with intermittent and slight degrees of stimulation of coldness; an outdoor temperature group (OT) exposed to cold environments in an external natural environment. The results showed that the lambs in the OT group had a greater decrease in the average daily gain (ADG) and increase in the average daily feed intake (ADFI) and the feed-to-gain ratio (F:G) compared to the other two groups. The decrease in immunoglobulin A (IgA) and interleukin 2 (IL-2) contents and IL-2 gene expression, and the increase in tumor necrosis factor α (TNF-α) content and TNF-α and nuclear factor kappa-B p65 (NF-κB p65) gene expressions in the OT group suggested that the lambs had a compromised immune status in cold environments. Moreover, the decrease in catalase (CAT), glutathione peroxidase (GPx), total superoxide dismutase (T-SOD), and total antioxidant capacity (T-AOC) levels, and CAT, GPx, SOD1, SOD2, and nuclear factor-erythroid 2-related factor 2 (Nrf2) gene expressions, and the increase in malondialdehyde (MDA) in the OT group suggested that the lambs had a lower antioxidant defense capacity in cold environments. Thus, in extreme cold, lambs kept outdoors could reduce growth, immune function and antioxidant status. However, shelter feeding in winter could relieve the stress of cold environments on lambs, and housing with heating equipment was more conducive to the improve growth, immune, and antioxidant function of the lambs.
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A numerical human thermo-physiological model is developed with the consideration of characteristics of exercising people in cold environments. The developed model is characterized by: 1) the concept of net exercise efficiency which is used to correct the calculation of metabolic heat production by excluding mechanical energy; 2) the effects of low temperature on basal metabolic rate and basal blood flow rate; 3) the integration with a multi-layer clothing model to calculate the heat and moisture transfer through the clothing system, which takes into account the air gaps between the clothing layers to reflect the ventilation and air penetration effect from the ambient wind. Human subject experiment is conducted in a climate chamber to validate the proposed model. The human subject experiment is also carried out in a cold environment (-5 °C) combined with different air velocity conditions (still air, 2 m/s), taking into account the activities of different intensities (standing statically, 2 km/h walking and 7 km/h running). Thermo-physiological parameters including the core temperature, 8-point local skin temperatures and the clothing layer temperatures, are measured during the experiment. Comparison between the predicted and experimental results gives the root mean squared error (RMSE) of core temperature and mean skin temperature of 0.06-0.10 °C and 0.17-0.27 °C, respectively. RMSE values for local skin and clothing layer temperatures are no higher than 1.5 °C and most within 0.8 °C. The model is also validated with published data under various ambient temperature and activity intensity conditions. The proposed model is shown to be capable of predict the thermo-physiological responses of people exposed and exercising in cold environments.
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Regulación de la Temperatura Corporal , Vestuario , Regulación de la Temperatura Corporal/fisiología , Frío , Humanos , Temperatura Cutánea , TemperaturaRESUMEN
Background: Musculoskeletal conditions are major contributors to years lived with disability. Cold exposure can be a risk factor, but any conclusion is obscure. Aim: The aim of the present scoping review was to identify the existing evidence of an association between cold exposure and musculoskeletal conditions. The aim also included to consider pain in different regions and their assessment, as well as different measures of cold exposure, effect sizes, and to assess the feasibility of future systematic reviews and meta-analyses. Eligibility criteria: The studies must have: an epidemiological design, defined cold exposure to come prior to the health outcome, defined exposure and outcome(s), existence of effect estimate(s) or data that made it possible to calculate such an estimate. Further, studies were required to be in English language and published in peer-reviewed journals. Studies that had a specific goal of studying cold exposure as an aggravator of already existing health problems were excluded. Sources: We searched Ovid MEDLINE(R) and Epub Ahead of Print, In-Process and Other Non-Indexed Citations, Daily and Versions(R), and Embase Classic + Embase for original studies. Charting method: The included studies were reviewed for study population, measurement of exposure and outcome, and effect size. Each publication was assessed for risk of bias. Results: The included studies were heterogeneous in populations, measures of cold exposure and musculoskeletal conditions. Most studies used self-reported data. They were mostly cross-sectional studies, only two were prospective and one was a case-control study. Associations were found for different cold exposures and regional musculoskeletal conditions, but the heterogeneity and lack of studies impeded valid synthesis of risk magnitude, or meta-analyses. Conclusion: The studies identified in this review indicate that cold exposure increases the risk of musculoskeletal conditions. However, there is a need for studies that better assess temporality between exposure and outcome. Future studies should also include better exposure assessment, including both objective measurements and measures of subjective experience of cold exposure. The heterogeneity in measurement of exposure and outcome impeded any meta-analysis.
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The endothelial glycocalyx maintains vascular structure and may be subject to shedding during inflammation and also during high-intensive exercise. There are no studies on shedding during ultra-endurance exercise. The "Yukon Arctic Ultra" (YAU) is one of the longest and coldest ultramarathons and its impact on glycocalyx shedding was investigated. Thirteen adults (38.92 ± 8.67 yr, 6 females) of YAU editions 2015-2019 completed 657.03 ± 71.65 km at a moving velocity of 4.17 ± 0.62 km/h. Mean daily temperatures ranged from -12.6°C to -30.5°C. Glycocalyx elements heparan sulfate, hyaluronan, and syndecan CD-138 were quantified from serum at start, 277 km, 383 km, and 690 km. Cortisol, C-reactive protein, creatine kinase, and N-terminal-prohormone of brain natriuretic peptide were also quantified. Seven YAU volunteers (36.14 ± 11.04 yr, 5 females) served as control. There were no time-changes among the control. Among finishers, there was a significant increase for hyaluronan and a significant decrease for syndecan CD-138. Values were greater among female finishers for heparan sulfate at start, 383 km, and 690 km, and among male finishers for hyaluronan at 277 km. Values for syndecan CD-138 were greater among older finishers at all timepoints. There were weak significant correlations (R2 < 0.215) between hyaluronan and distance, creatine kinase, and NT-Pro BNP, respectively. Shedding of glycocalyx elements is shown among participants of the YAU. Greater shedding of heparan sulfate among female, greater increases of hyaluronan among male, and greater shedding of syndecan CD-138 among older athletes indicate complex glycocalyx shedding during ultra-endurance exercise.NEW & NOTEWORTHY This is the first study to investigate changes in glycocalyx elements in an endurance footrace and first study to investigate exercise-induced shedding in both sexes. This study comprised of an athlete group who finished the ultra-long distance of up to 690 km during the Yukon Arctic Ultra as well as a control group. Results indicate relevant and different shedding of glycocalyx elements heparan sulfate, hyaluronan, and syndecan CD-138. Sex, age, BMI, and covered distance appear to have an influence on the shedding. Other serum parameters indicative of stress appear to be associated with shedding.