Table 4.

Advantages and disadvantages of different microvascular endothelial function assessment techniques

Method	Advantages	Disadvantages
Arterial glycocalyx	• Tracer dilution method: direct measure • OPS + SDF: simple, non-invasive, bedside performance	• Tracer dilution method: invasive and time-consuming • OPS + SDF: indirect measures
Near-infrared spectroscopy	• Non-invasive, portable • Tissue oxygen consumption measurement • Recordings during exercise	• Affected by adipose tissue thickness • Myoglobin may interfere
Laser Doppler flowmetry	• Simple, non-invasive • Continuous blood flow measurement during exercise • Coupling with reactivity tests	• Expensive equipment • Requires experienced operator for high accuracy and low variability over time • Susceptible to changes in autonomic nervous system and vasomotor tone • Temperature dependent
Laser speckle contrast analysis	• Simple, non-invasive • Real-time recording of blood flow changes	• Expensive equipment • Requires experienced operator for high accuracy and low variability over time • Movement artefacts • No recordings in absolute flow units

OPS, orthogonal polarization spectral; SDF, sidestream darkfield