Abstract
Purpose: Exertional heat stress can cause damage to the intestinal epithelium and disrupt gastrointestinal barrier integrity, leading to microbial translocation (MT) linked to the development of heat stroke. This study aimed to assess age-related differences in markers of intestinal epithelial injury and MT following non-heat stress and high-heat stress exercise in healthy young and older men.
Methods: Markers of intestinal epithelial injury (intestinal fatty acid-binding protein—‘IFABP’) and MT (soluble cluster of differentiation 14—‘sCD14’; and lipopolysaccharide-binding protein—‘LBP’) were assessed in healthy young (18–30 y, n = 13) and older (50–70 y) men (n = 12). Blood samples were collected before, after 180 min of moderate-intensity (metabolic rate: 200 W/m 2) walking and following 60 min recovery in either a non-heat stress [temperate: 21.9 °C, 35% relative humidity (RH)] or high-heat stress (hot: 41.4 °C, 35% RH) environment.
Results: There were no differences in IFABP and sCD14 between the young and older groups in the temperate condition, while LBP was greater in the older group (+ 0.66 ug/mL; + 0.08 to + 1.24 ug/mL). In the hot condition, the older group experienced greater increases in IFABP compared to the young group (+ 712 pg/mL/hr; + 269 to + 1154 pg/mL/hr). However, there were no clear between-group differences for sCD14 (+ 0.24 ug/mL/hr, − 0.22 to + 0.70 ug/mL/hr) or LBP (+ 0.86 ug/mL/hr, − 0.73 to + 2.46 ug/mL/hr).
Conclusion: While older men may experience greater intestinal epithelial injury following exercise in the heat; this did not lead to a greater magnitude of microbial translocation relative to their younger counterparts.
| Original language | English |
|---|---|
| Pages (from-to) | 1049-1062 |
| Number of pages | 14 |
| Journal | European Journal of Applied Physiology |
| Volume | 124 |
| Issue number | 4 |
| Early online date | 10 Oct 2023 |
| DOIs | |
| Publication status | Published - Apr 2024 |
Bibliographical note
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Funder
This project was supported by the Government of Ontario (all funds held by G.P.K.). J.J.M. and K.E.K. were supported by Mitacs Accelerate and the Human and Environmental Physiology Research Unit. G.P.K. is supported by a University of Ottawa Research Chair.Funding
This project was supported by the Government of Ontario (all funds held by G.P.K.). J.J.M. and K.E.K. were supported by Mitacs Accelerate and the Human and Environmental Physiology Research Unit. G.P.K. is supported by a University of Ottawa Research Chair.
| Funders | Funder number |
|---|---|
| Government of Ontario | |
| Mitacs Accelerate | |
| Human and Environmental Physiology Research Unit | |
| University of Ottawa |
Keywords
- Heat stress
- Physical activity
- Ageing
- LBP
- IFABP
- sCD14