Altered endothelial function in high-performance military fighter pilots.

High-performance fighter pilots are routinely subjected to extreme mechanical and physiological stressors, including exposure to high +Gz accelerations that may impact vascular health. In this short report, we evaluated endothelial function in 20 Eurofighter Typhoon (F-2000A) pilots and 19 matched control pilots flying nonhigh-G aircraft (KC-767A). Flow-mediated dilation (FMD) of the brachial artery was measured before and after flight sorties to assess vascular response. FMD values were lower after flight compared with preflight measurements, reflecting a significant main effect of time across the entire cohort (P < 0.05). Within-group analyses revealed a larger absolute reduction in FMD in F-2000A pilots (median = 10.02%-6.45%) compared with controls (9.40%-8.80%). However, the absence of a significant time × group interaction indicates that this response was not statistically different between pilot groups. In addition, F-2000A pilots exhibited smaller arterial diameters at rest and a significant postflight increase in baseline vessel caliber (3.81-4.13 mm; P < 0.001), suggesting a transient vasodilatory response potentially related to thermal or hemodynamic stress. These findings suggest an acute endothelial response to the high-performance flight environment. This study underscores the need for continued cardiovascular surveillance in high-performance aviators and supports further investigation of FMD as a noninvasive marker of vascular function within structured aeromedical follow-up programs.NEW & NOTEWORTHY This study is the first to evaluate endothelial function in fighter pilots exposed to high Gz (up to +9). Results indicate a postflight reduction in flow-mediated dilation (FMD) and time-dependent vascular changes associated with high-performance flight exposure. These findings highlight the potential value of FMD as a noninvasive tool for monitoring cardiovascular health and developing targeted aeromedical follow-up strategies for high-performance aircrew.