The human plasma lipidome response to exertional heat tolerance testing

Journal Article · 15 November 2024 · Lipids in Health and Disease

DOI: https://doi.org/10.1186/s12944-024-02322-7 · OSTI ID:2526576

Estevao, Igor L. ^[1]; Kazman, Josh B. ^[2]; Bramer, Lisa M. ^[1]; Nicora, Carrie ^[1]; Ren, Ming Qiang ^[2]; Sambuughin, Nyamkhishig ^[2]; Munoz, Nathalie ^[1]; Kim, Young-Mo ^[1]; Bloodsworth, Kent ^[1]; Richert, Maile ^[3]; Teeguarden, Justin ^[1]; Burnum-Johnson, Kristin ^[1]; Deuster, Patricia A. ^[3]; Nakayasu, Ernesto S. ^[1]; Many, Gina ^[1]

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1. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
2. Uniformed Services University of the Health Sciences, Bethesda, MD (United States); Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD (United States)
3. Uniformed Services University of the Health Sciences, Bethesda, MD (United States)

The year of 2023 displayed the highest average global temperatures recorded in history— the duration and severity of extreme heat are projected to increase. Rising global temperatures represent a major public health threat, especially to occupations exposed to hot environments, such as construction and agricultural workers, and first responders. Despite efforts of the scientific community, there is still a need to characterize the pathophysiological processes leading to heat related illness and develop biomarkers that can predict its onset. Here, we performed a plasma lipidomic analysis on male and female subjects who underwent heat tolerance testing (HTT), consisting of a 2-h treadmill walk at 5 km/h with 2% inclination at a controlled temperature of 40oC. We identified 995 lipids from 27 classes, with nearly half of all detected lipids being responsive to HTT. Lipid classes related to substrate utilization were predominantly affected by HTT, with a downregulation of triacylglycerols and upregulation of free fatty acids and acyl-carnitines. We additionally examined correlations between changes in plasma lipids by using the even chain acyl-carnitines is physiological strain index (PSI). Here, even chain acyl-carnitines, bi-products of incomplete beta oxidation, and diacylglycerols displayed the highest correlation to PSI. PSI did not correlate with plasma lactate levels, which suggests that correlations with related to metabolic efficiency versus physical exertion. Overall, our results show that HTT has a strong impact on the plasma lipidome and that incomplete beta oxidation may underlie heat intolerance.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: National Institutes of Health (NIH); US Department of the Navy, Office of Naval Research (ONR); USDOE
• Grant/Contract Number: AC05-76RL01830
• OSTI ID: 2526576
• Report Number(s): PNNL-SA--199090
• Journal Information: Lipids in Health and Disease, Journal Name: Lipids in Health and Disease Journal Issue: 1 Vol. 23; ISSN 1476-511X
• Publisher: Springer NatureCopyright Statement
• Country of Publication: United States
• Language: English