Passive Leg Movement as a Diagnostic Tool for Distinguishing Healthy Individuals from Those with Obstructive Sleep Apnea

Abstract

Background – Obstructive Sleep Apnea (OSA) is linked with endothelial dysfunction, posing a significant risk for cardiovascular diseases. The non-invasive assessment of endothelial function through passive leg movement (PLM) offers a novel diagnostic avenue. This study explores PLM's efficacy in differentiating between healthy individuals and those with OSA, alongside evaluating the impact of oral vitamin C on endothelial function within these groups.

Materials and Methods:

The study enrolled 26 male subjects, divided equally into healthy and OSA groups. PLM was performed using an isokinetic machine to assess femoral artery blood flow (FBF) and blood velocities (FBVs) via Doppler ultrasound. Subjects consumed 1000mg of oral vitamin C, with measurements repeated post-consumption. Data analysis involved repeated measures ANOVA to evaluate the diagnostic capability of PLM and the effect of vitamin C on FBF responses.

Results:

A significant difference in FBF was observed between OSA and healthy groups (healthy: 162.1 ml/min, OSA: 76.6 ml/min; p < 0.05), confirming PLM's diagnostic potential. However, vitamin C administration did not significantly alter FBF responses in OSA patients (pre-vitamin C: 76.6 ml/min, post-vitamin C: 79.9 ml/min; p > 0.05), challenging the anticipated benefits of oral vitamin C on endothelial function.

Conclusion:

PLM effectively distinguishes between healthy individuals and those with OSA, highlighting its diagnostic utility. Nonetheless, oral vitamin C did not improve endothelial dysfunction in OSA patients, suggesting the need for further research on alternative administration methods or dosages.