The acute effects of passive heat exposure on arterial stiffness, oxidative stress, and inflammation

Background and objective: The aim of the study was to determine the acute effect of passive heat exposure (PHE) on arterial stiffness, oxidative stress (OxS) and inflammatory parameters.
Materials and methods: Subjects were studied in thermoneutral conditions before and after PHE in a climatic chamber. Pulse wave analysis was used for assessment of central hemodynamic and arterial stiffness parameters. Venous blood samples were obtained to measure OxS and inflammatory parameters.
Results: Rectal temperature increased after PHE exposure compared to baseline: 37.01 °C ± 0.19 °C and 36.4 °C ± 0.31 °C, respectively (P < 0.001). There was a 17% (P < 0.05) decrease in large artery elasticity index (from 24.68 ± 5.53 to 20.42 ± 2.65 mL/mmHg^*10), which was predicted upon normothermic value (r = −0.878, P < 0.01). However, no significant changes were found in others arterial stiffness parameters. A 30% (P < 0.05) increase occurred in blood IL-6 concentration (from 0.43 ± 0.15 to 0.56 ± 0.23 pg/mL), but OxS parameters remained significantly unchanged.
Conclusions: This study describes for the first time acute PHE effects on arterial stiffness, inflammation and OxS. PHE significantly decreases large artery elasticity index and increases inflammatory IL-6 level. However, further larger investigations are needed for clarifying acute PHE effects on arterial function and biomarkers.