Abstract
Heat stress induced damage to the gastrointestinal barrier can induce local and systemic inflammatory reactions implicated in heat-stroke. Gastrointestinal barrier damage has been shown to be greater in older relative to young adults following hyperthermia. However, comparisons between young and older adults have been limited to brief exposures (3 h), which may not reflect the duration of heat stress experienced during heat waves. We therefore evaluated markers of intestinal epithelial damage (log transformed intestinal fatty acid binding protein, IFABPLOG), microbial translocation (soluble cluster of differentiation 14, sCD14LOG), and systemic inflammation (tumour necrosis factor alpha, TNF-αLOG; interleukin 6, IL-6LOG; C-reactive protein, CRP) in 19 young (interquartile range: 21–27 years; 10 females) and 37 older (68–73 years; 10 females) adults before and after 9 h of rest in 40 °C (9% relative humidity). The magnitude of the increase in IFABPLOG was 0.38 log pg/mL (95% CI, 0.10, 0.65 log pg/mL) greater in the older relative to young cohort ( P = 0.049) after 9 h heat exposure. At baseline both IL-6LOG and CRP concentrations were higher in the older (IL-6: 2.67 (1.5) log pg/mL, CRP: 0.28 (1.5) mg/mL) relative to the young (IL-6: 1.59 log pg/mL, SD 1.2; CRP: 0.11 mg/mL, SD 1.7) group (both P ≤ 0.001). The change in IL-6 and CRP was similar between groups following 9 h heat exposure (IL-6: P = 0.053; CRP: P = 0.241). Neither sCD14LOG and TNF-αLOG were different between groups at baseline nor altered after 9 h heat exposure. Our data indicate that age may modify intestinal epithelial injury following 9 h of passive heat exposure.
| Original language | English |
|---|---|
| Pages (from-to) | 1241-1251 |
| Number of pages | 11 |
| Journal | Applied Physiology, Nutrition, and Metabolism |
| Volume | 49 |
| Issue number | 9 |
| Early online date | 21 May 2024 |
| DOIs | |
| Publication status | Published - 1 Sept 2024 |
Bibliographical note
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Funder
This research was funded by the Canadian Institutes for Health Research (CIHR) Research Grant (no. 399434 and PJT – 180242) and Health Canada (contract no. 4500387992; funds held by Glen P. Kenny). The funders had no role in trial design, collection, analysis, or interpretation of data, or in manuscript development. No authors received direct compensation related to the development of this article.Funding
This research was funded by the Canadian Institutes for Health Research (CIHR) Research Grant (no. 399434 and PJT – 180242) and Health Canada (contract no. 4500387992; funds held by Glen P. Kenny). The funders had no role in trial design, collection, analysis, or interpretation of data, or in manuscript development. No authors received direct compensation related to the development of this article.
| Funders | Funder number |
|---|---|
| Canadian Institutes for Health Research | no. 399434 and PJT – 180242) |
| Health Canada | contract no. 4500387992; funds held by Glen P. Kenny |
Keywords
- ageing
- climate change
- heat waves
- gastrointestinal barrier
- microbial translocation
- inflammation
