Acute heat exposure protects against endothelial ischemia-reperfusion injury in aged humans.

Abstract

Nonpharmacological therapies that protect against endothelial ischemia-reperfusion injury (I/R) remain limited in aged adults. Acute heat exposure protects against endothelial I/R injury in young adults, but its efficacy has never been explored in aged adults. Therefore, we tested the hypothesis that acute heat exposure would prevent the attenuation of endothelium-dependent vasodilation after I/R injury in aged adults. Nine (2 men, 69 ± 8 yr) aged adults were exposed to a thermoneutral control condition or whole body passive heating (water-perfused suit) sufficient to increase body core temperature by 1.2°C. Experiments were separated by at least 7 days. Heat exposure was always performed first to time match the thermoneutral control condition. Endothelium-dependent vasodilation was assessed via flow-mediated dilation of the brachial artery before (pre-I/R) and after I/R injury (post-I/R), which was induced by 20 min of arm ischemia followed by 20 min of reperfusion. Flow-mediated dilation was reduced following I/R injury for the thermoneutral control condition (pre-I/R, 4.5 ± 2.9% vs. post-I/R, 0.9 ± 2.8%, P < 0.01), but was well maintained with prior heat exposure (pre-I/R, 4.4 ± 2.8% vs. post-I/R, 3.5 ± 2.8%, P = 0.5). Taken together, acute heat exposure protects against endothelial I/R injury in aged adults. These results highlight the therapeutic potential of heat therapy to prevent endothelial dysfunction associated with I/R injury in aged adults who are most at risk for an ischemic event.

• Authors: Holden W Hemingway, Rauchelle E Richey, Amy M Moore, Albert H Olivencia-Yurvati, Geoffrey P Kline, Steven A Romero
• Journal: American journal of physiology. Regulatory, integrative and comparative physiology (Am J Physiol Regul Integr Comp Physiol) Vol. 322 Issue 5 Pg. R360-R367 (05 01 2022) ISSN: 1522-1490 [Electronic] United States
• PMID: 35200050 (Publication Type: Journal Article)

Topics

• Aged
• Body Temperature
• Brachial Artery
• Endothelium, Vascular
• Female
• Hot Temperature
• Humans
• Male
• Middle Aged
• Reperfusion Injury (prevention & control)
• Vasodilation