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Tochihara Y, Yamashita K, Fujii K, Kaji Y, Wakabayashi H, Kitahara H. Thermoregulatory and cardiovascular responses in the elderly towards a broad range of gradual air temperature changes. J Therm Biol 2021; 99:103007. [PMID: 34420637 DOI: 10.1016/j.jtherbio.2021.103007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/08/2021] [Accepted: 05/18/2021] [Indexed: 11/19/2022]
Abstract
This study aimed to determine age-related differences in thermoregulatory and cardiovascular responses to a wide range of gradual ambient temperature (Ta) changes. Morphologically matched normotensive elderly and young males participated. The participants wearing only shorts rested during the 3-h experiment. After 30 min of baseline at 28 °C, Ta increased linearly to 43 °C in 30 min (warming) and then gradually decreased to 13 °C in 60 min (cooling). Ta was rewarmed to 28 °C in 30 min (rewarming), and that temperature was maintained for an additional 30 min (second baseline). During the warming phase, there were no age-related differences in blood pressure (BP) and rectal temperature (Tre), despite a significantly lower cutaneous vascular conductance and heart rate in the elderly (P < 0.05). At the end of the cooling phase, systolic blood pressure (SBP) in the elderly was significantly higher than the young (155.8 ± 16.1 and 125.0 ± 12.5 mmHg, P < 0.01). There was a consistent age group difference in SBP during rewarming. Mean skin temperature was significantly lower in the elderly during rewarming (P < 0.05). Tre decreased more in the elderly and was significantly lower at the end of the experiment than the younger participants (36.78 ± 0.34 and 37.01 ± 0.15 °C, P < 0.05). However, there were no age group differences in thermal sensation. In conclusion, even normotensive elderly participants have a greater and more persistent BP response to cold than younger adults, suggesting that the elderly might be at a higher risk of cardiac events during cooling and subsequent rewarming.
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Affiliation(s)
- Yutaka Tochihara
- Environmental Ergonomics Laboratory, Department of Human Science, Faculty of Design, Kyushu University, Fukuoka, Japan
| | - Kazuaki Yamashita
- Environmental Ergonomics Laboratory, Department of Human Science, Faculty of Design, Kyushu University, Fukuoka, Japan; Toa, Kitakyushu, Japan
| | - Kenji Fujii
- Yamaguchi Prefectural Industrial Technology Institute, Ube, Japan
| | - Yumi Kaji
- Assisted Living Facility La Paz, Fukuoka, Japan
| | - Hitoshi Wakabayashi
- Environmental Ergonomics Laboratory, Department of Human Science, Faculty of Design, Kyushu University, Fukuoka, Japan; Laboratory of Environmental Ergonomics, Faculty of Engineering, Hokkaido University, Sapporo, Japan.
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Maeda T. Relationship between maximum oxygen uptake and peripheral vasoconstriction in a cold environment. J Physiol Anthropol 2017; 36:42. [PMID: 29212523 PMCID: PMC5719941 DOI: 10.1186/s40101-017-0158-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 11/28/2017] [Indexed: 11/25/2022] Open
Abstract
Background Various individual characteristics affect environmental adaptability of a human. The present study evaluates the relationship between physical fitness and peripheral vasoconstriction in a cold environment. Methods Seven healthy male students (aged 22.0 years) participated in this study. Cold exposure tests consisted of supine rest for 60 min at 28 °C followed by 90 min at 10 °C. Rectal and skin temperatures at seven sites, oxygen consumption, and the diameter of a finger vein were measured during the experiment. Metabolic heat production, skin heat conductance, and the rate of vasoconstriction were calculated. Individual maximum oxygen consumption, a direct index of aerobic fitness, was measured on the day following the cold exposure test. Results Decreases in temperature of the hand negatively correlated with the changes in rectal temperature. Maximum oxygen consumption and the rate of vasoconstriction are positively correlated. Furthermore, pairs of the following three factors are also significantly correlated: rate of metabolic heat production, skin heat conductance, and the rate of vasoconstriction. Conclusion The results of this study suggested that the capacity for peripheral vasoconstriction can be improved by physical exercise. Furthermore, when exposed to a cold environment, fitter individuals could maintain metabolic heat production at the resting metabolic level of a thermoneutral condition, as they correspondingly lost less heat.
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Affiliation(s)
- Takafumi Maeda
- Department of Human Science, Faculty of Design, Kyushu University, 4-9-1, Shiobaru, Minami-ku, Fukuoka, 815-8540, Japan. .,Physiological Anthropology Research Center, Faculty of Design, Kyushu University, 4-9-1, Shiobaru, Minami-ku, Fukuoka, 815-8540, Japan.
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Botonis PG, Geladas ND, Kounalakis SN, Cherouveim ED, Koskolou MD. Effects of menthol application on the skin during prolonged immersion in swimmers and controls. Scand J Med Sci Sports 2016; 27:1560-1568. [PMID: 27859725 DOI: 10.1111/sms.12799] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2016] [Indexed: 12/16/2022]
Abstract
We hypothesized that menthol application on the skin would enhance vasoconstriction of subjects immersed in cool water, which would reduce heat loss and rectal temperature (Tre) cooling rate. Furthermore, it was hypothesized that this effect would be greater in individuals acclimatized to immersion in 24 °C water, such as swimmers. Seven swimmers (SW) and seven physical education students (CON) cycled at 60% VO2 max until Tre attained 38 °C, and were then immediately immersed in stirred water maintained at 24 °C on two occasions: without (NM) and with (M; 4.6 g per 100 mL of water) whole-body skin application of menthol cream. Heart rate, Tre, proximal-distal skin temperature gradient, oxygen uptake (VO2 ), electromyographic activity (EMG), and thermal sensation were measured. Tre reduction was similar among SW and CON in NM and CON in M (-0.71±0.31 °C in average), while it was smaller for SW in M (-0.37±0.18 °C, P < 0.01). VO2 and heart rate were greater in M compared with NM condition (P = 0.01). SW in M exhibited a shift of the threshold for shivering, as reflected in increased VO2 and EMG activity, toward a higher Tre compared with the other trials. Menthol application on the skin before immersion reduces heat loss, but defends Tre decline more effectively in swimmers than in non-swimmers.
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Affiliation(s)
- P G Botonis
- Department of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, University of Athens, Athens, Greece.,Department of Aquatic Sports, School of Physical Education and Sports Science, University of Athens, Athens, Greece
| | - N D Geladas
- Department of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, University of Athens, Athens, Greece
| | - S N Kounalakis
- Department of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, University of Athens, Athens, Greece
| | - E D Cherouveim
- Department of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, University of Athens, Athens, Greece
| | - M D Koskolou
- Department of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, University of Athens, Athens, Greece
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Kounalakis SN, Botonis PG, Koskolou MD, Geladas ND. The effect of menthol application to the skin on sweating rate response during exercise in swimmers and controls. Eur J Appl Physiol 2010; 109:183-9. [DOI: 10.1007/s00421-009-1345-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2009] [Indexed: 10/20/2022]
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Maeda T, Fukushima T, Ishibashi K, Higuchi S. Involvement of basal metabolic rate in determination of type of cold tolerance. J Physiol Anthropol 2007; 26:415-8. [PMID: 17641462 DOI: 10.2114/jpa2.26.415] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
This study aimed to assess the relationship between basal metabolic rate (BMR) and metabolic heat production, and to clarify the involvement of BMR in determining the phenotype of cold tolerance. Measurements of BMR, maximum oxygen uptake, and cold exposure test were conducted on ten males. In the cold exposure test, rectal (T(rec)) and mean skin temperatures (T(ms)), oxygen uptake, and blood flow at forearm (BF(arm)) were measured during exposure to cold (10 degrees C) for 90 min. Significant correlations were observed between BMR and increasing rate of oxygen uptake, as well as between decreasing rate of BF(arm) and increasing rate of oxygen uptake at the end of cold exposure. These findings suggested that individuals with a lower BMR were required to increase their metabolic heat production during cold exposure, and that those with a higher BMR were able to moderate increased metabolic heat production during cold exposure because they were able to reduce heat loss. This study showed that BMR is an important factor in determining the phenotype of cold tolerance, and that individuals with a low BMR showed calorigenic-type cold adaptation, whereas subjects with a high BMR exhibited adiabatic-type cold adaptation by peripheral vasoconstriction.
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Affiliation(s)
- Takafumi Maeda
- Department of Hygiene and Preventive Medicine, Fukushima Medical University.
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Maeda T, Sugawara A, Fukushima T, Higuchi S, Ishibashi K. Effects of lifestyle, body composition, and physical fitness on cold tolerance in humans. ACTA ACUST UNITED AC 2005; 24:439-43. [PMID: 16079594 DOI: 10.2114/jpa.24.439] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In the present study, we attempted to clarify the effects of lifestyle and body compositions on basal metabolism and to clarify the effects of physical training on thermoregulatory responses to cold. Basal metabolism, body compositions, and questionnaires regarding lifestyle were evaluated in 37 students. From multiple linear regression analysis, sex, muscle weight, fat intake, and diurnal temperature were selected as significant explanatory variables. In a second experiment, rectal and the skin temperature at 7 different points as well as the oxygen uptake of eight males were measured at 10 degrees C for 90 min before and after training. The decline in rectal temperature that was observed before training was not observed after training. In addition, rectal temperature was significantly higher at post-training than at pre-training. These results suggest that some lifestyle factors affect cold tolerance; in particular, daily activity might improve our ability to control heat radiation and basal heat production.
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Affiliation(s)
- Takafumi Maeda
- Department of Hygiene and Preventive Medicine, Fukushima Medical University School of Medicine, Fukushima, Japan.
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Maeda T. Perspectives on environmental adaptability and physiological polymorphism in thermoregulation. ACTA ACUST UNITED AC 2005; 24:237-40. [PMID: 15930813 DOI: 10.2114/jpa.24.237] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The environmental adaptability of human beings has progressed according to various environments experienced in the course of evolution. Therefore, various phenotypes for environmental adaptability exist and are considered to be physiological polymorphism. Physiological polymorphism in thermoregulation is influenced by genotype, individual characteristics, environmental factors, cultural factors, etc. Moreover, it is thought that physiological polymorphism is evidenced more clearly in physiological responses to extreme situations and/or changing conditions than in environments where homeostasis is easily maintained. In the field of physiological anthropology, I think that it is important not only to discover the physiological responses that demonstrate polymorphism, but also to hypothesize about the mechanisms and the processes by which such polymorphisms were formed, and their meaning for human beings. Such discussions may be supposed to lead to an evaluation of the environmental adaptability of humans from the viewpoint of physiological anthropology.
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Affiliation(s)
- Takafumi Maeda
- Department of Hygiene and Preventive Medicine, Fuskushima Medical University School of Medicine, Japan.
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Steegmann AT, Cerny FJ, Holliday TW. Neandertal cold adaptation: physiological and energetic factors. Am J Hum Biol 2002; 14:566-83. [PMID: 12203812 DOI: 10.1002/ajhb.10070] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
European Neandertals employed a complex set of physiological cold defenses, homologous to those seen in contemporary humans and nonhuman primates. While Neandertal morphological patterns, such as foreshortened extremities and low relative surface-area, may have explained some of the variance in cold resistance, it is suggested the adaptive package was strongly dependent on a rich array of physiological defenses. A summary of the environmental cold conditions in which the Neandertals lived is presented, and a comparative ethnographic model from Tierra del Fuego is used. Muscle and subcutaneous fat are excellent "passive" insulators. Neandertals were quite muscular, but it is unlikely that they could maintain enough superficial body fat to offer much cold protection. A major, high-energy metabolic adaptation facilitated by modest amounts of highly thermogenic brown adipose tissue (BAT) is proposed. In addition, Neandertals would have been protected by general mammalian cold defenses based on systemic vasoconstriction and intensified by acclimatization, aerobic fitness, and localized cold--induced vasodilation. However, these defenses are energetically expensive. Based on contemporary data from circumpolar peoples, it is estimated that Neandertals required 3,360 to 4,480 kcal per day to support strenuous winter foraging and cold resistance costs. Several specific genetic cold adaptations are also proposed--heat shock protein (actually, stress shock protein), an ACP*1 locus somatic growth factor, and a specialized calcium metabolism not as yet understood.
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Affiliation(s)
- A Theodore Steegmann
- Department of Anthropology, 380 MFAC, SUNY Buffalo, Buffalo, New York 14261, USA.
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