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Goulet N, McCormick JJ, King KE, Notley SR, Goldfield GS, Fujii N, Amano T, Kenny GP. Elevations in serum brain-derived neurotrophic factor following occupational heat stress are not influenced by age or common chronic disease. Temperature (Austin) 2023; 10:454-464. [PMID: 38130657 PMCID: PMC10732602 DOI: 10.1080/23328940.2023.2176107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/30/2023] [Indexed: 02/09/2023] Open
Abstract
With global warming, workers are increasingly exposed to strenuous occupations in hot environments. Given age- and disease-associated declines in thermoregulatory function, older workers are at an elevated risk of developing heat-related injuries. Brain-derived neurotrophic factor (BDNF) is thought to confer neuroprotection during acute exercise, however, the influence of environmental heat on BDNF responses during prolonged work remains unclear. Therefore, we evaluated serum BDNF concentrations before and after 180 min of moderate-intensity treadmill walking (200 W/m2) and after 60 min of post-exercise recovery in temperate (wet-bulb globe temperature (WBGT) 16°C) and hot (WBGT 32°C) environments in 13 healthy young men (mean [SD; 22 [3] years), 12 healthy older men (59 [4] years), 10 men with hypertension (HTN) (60 [4] years), and 9 men with type 2 diabetes (T2D) (60 [5] years). In the temperate condition, all but one participant (1 HTN) completed the 180 min of exercise. While exercise tolerance in the heat was lower in older men with HTN (117 min [45]) and T2D (123 min [42]) compared to healthy older men (159 min [31]) (both p ≤ 0.049), similar end-exercise rectal temperatures (38.9°C [0.4]) were observed across groups, paralleled by similar elevations in serum BDNF across groups at end-exercise (+1106 pg/mL [203]) and end-recovery (+938 pg/mL [146]; all p ≤ 0.01) in the heat. No changes in serum BDNF were observed in the temperate condition. Our findings indicate similar BDNF responses in individuals with HTN or T2D compared to their healthy counterparts, despite exhibiting reduced tolerance to heat.
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Affiliation(s)
- Nicholas Goulet
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ontario, Canada, Canada
- Behavioural and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ontario, Canada, Canada
| | - James J. McCormick
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ontario, Canada, Canada
| | - Kelli E. King
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ontario, Canada, Canada
| | - Sean R. Notley
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ontario, Canada, Canada
| | - Gary S. Goldfield
- Healthy Active Living and Obesity Research Group, Children’s Hospital of Eastern Ontario Research Institute, Ontario, Canada, Canada
| | - Naoto Fujii
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | - Tatsuro Amano
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata, Japan
| | - Glen P. Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ontario, Canada, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ontario, Canada, Canada
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Walsh EI, Smith L, Northey J, Rattray B, Cherbuin N. Towards an understanding of the physical activity-BDNF-cognition triumvirate: A review of associations and dosage. Ageing Res Rev 2020; 60:101044. [PMID: 32171785 DOI: 10.1016/j.arr.2020.101044] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 02/06/2020] [Accepted: 03/10/2020] [Indexed: 12/17/2022]
Abstract
Physical activity has received substantial research attention due to its beneficial impact on cognition in ageing, particularly via the action of brain-derived neurotrophic factor (BDNF). It is well established that physical activity can elevate circulating levels of BDNF, and that BDNF has neurotrophic, neuroprotective and cognitively beneficial properties. Yet, practical implementation of this knowledge is limited by a lack of clarity on context and dose-effect. Against a shifting backdrop of gradually diminishing physical and cognitive capacity in normal ageing, the type, intensity, and duration of physical activity required to elicit elevations in BDNF, and more importantly, the magnitude of BDNF elevation required for detectable neuroprotection remains poorly characterised. The purpose of this review is to provide an overview of the association between physical activity, BDNF, and cognition, with a focus on clarifying the magnitude of these effects in the context of normative ageing. We discuss the implications of the available evidence for the design of physical activity interventions intended to promote healthy cognitive ageing.
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Sheahen BL, Fell JW, Zadow EK, Hartley TF, Kitic CM. Intestinal damage following short-duration exercise at the same relative intensity is similar in temperate and hot environments. Appl Physiol Nutr Metab 2018; 43:1314-1320. [PMID: 29874478 DOI: 10.1139/apnm-2018-0057] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Increasing temperature and exercise disrupt tight junctions of the gastrointestinal tract although the contribution of environmental temperature to intestinal damage when exercising is unknown. This study investigated the effect of 2 different environmental temperatures on intestinal damage when exercising at the same relative intensity. Twelve men (mean ± SD; body mass, 81.98 ± 7.95 kg; height, 182.6 ± 7.4 cm) completed randomised cycling trials (45 min, 70% maximal oxygen uptake) in 30 °C/40% relative humidity (RH) and 20 °C/40%RH. A subset of participants (n = 5) also completed a seated passive trial (30 °C/40%RH). Rectal temperature and thermal sensation (TSS) were recorded during each trial and venous blood samples collected at pre- and post-trial for the analysis of intestinal fatty acid-binding protein (I-FABP) level as a marker of intestinal damage. Oxygen uptake was similar between 30 °C and 20 °C exercise trials, as intended (p = 0.94). I-FABP increased after exercise at 30 °C (pre-exercise: 585 ± 188 pg·mL-1; postexercise: 954 ± 411 pg·mL-1) and 20 °C (pre-exercise: 571 ± 175 pg·mL-1; postexercise: 852 ± 317 pg·mL-1) (p < 0.0001) but the magnitude of damage was similar between temperatures (p = 0.58). There was no significant increase in I-FABP concentration following passive heat exposure (p = 0.59). Rectal temperature increased during exercise trials (p < 0.001), but not the passive trial (p = 0.084). TSS increased more when exercising in 30 °C compared with 20 °C (p < 0.001). There was an increase in TSS during the passive heat trial (p = 0.03). Intestinal damage, as measured by I-FABP, following exercise in the heat was similar to when exercising in a cooler environment at the same relative intensity. Passive heat exposure did not increase I-FABP. It is suggested that when exercising in conditions of compensable heat stress, the increase in intestinal damage is predominantly attributable to the exercise component, rather than environmental conditions.
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Affiliation(s)
- Brodie L Sheahen
- Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania.,Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania
| | - James W Fell
- Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania.,Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania
| | - Emma K Zadow
- Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania.,Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania
| | - Thomas F Hartley
- Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania.,Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania
| | - Cecilia M Kitic
- Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania.,Sports Performance Optimisation Research Team, School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Newnham, Launceston 7250, Tasmania
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