Method optimization to assess endothelial function in females-duration of glyceryl trinitrate effect

Area of Science:

• Cardiovascular Physiology
• Pharmacology
• Vascular Biology

Background:

• Endothelial function assessment often utilizes pulse-wave analysis (PWA) with pharmacological agents.
• Glyceryl trinitrate (GTN) and salbutamol are used as endothelium-independent and -dependent vasodilators, respectively.
• Determining the appropriate interval between GTN administration and subsequent measurements is critical for accurate endothelial function evaluation.

Purpose of the Study:

• To establish the duration of glyceryl trinitrate (GTN) effect on pulse-wave analysis (PWA) parameters.
• To determine the optimal timing for administering salbutamol after sublingual GTN in PWA studies.
• To ensure reliable assessment of endothelial function using combined pharmacological challenges.

Main Methods:

• 11 healthy female subjects underwent baseline measurements of augmentation index (AIx) and pulse-wave velocity (PWV).
• Sublingual GTN (0.5 mg) was administered, with AIx and PWV measured at 5-minute intervals up to 20 minutes, then at 10-minute intervals up to 40 minutes.
• Statistical analysis was performed to assess changes from baseline and determine when PWA parameters returned to pre-administration levels.

Main Results:

• Maximum reduction in AIx occurred at 3 minutes post-GTN (-17.86%).
• AIx and PWV values did not significantly change from baseline after 30 minutes post-GTN.
• Significant changes in PWV were observed at 5 and 10 minutes post-GTN, but not thereafter.

Conclusions:

• A minimum of 30 minutes is required for AIx and PWV to return to baseline after sublingual GTN administration.
• Salbutamol administration for endothelial function assessment should be delayed until at least 30 minutes post-GTN.
• This timing ensures accurate interpretation of endothelium-dependent vasodilation responses in PWA.