Oral Vitamin C Supplementation and its Impact on Endothelial Function in Obstructive Sleep Apnea Patients

Abstract

Background – Obstructive Sleep Apnea (OSA) is a prevalent condition associated with endothelial dysfunction, a precursor to cardiovascular disease. Passive Leg Movement (PLM) has emerged as a simple method to assess endothelial function. The role of oral vitamin C in improving endothelial function in OSA patients, however, has been underexplored.

Materials and Methods

This study recruited 26 male subjects, 13 with OSA and 13 healthy controls, aged 18-55 years. PLM was utilized to assess endothelial function by measuring femoral artery blood flow (FBF) and velocity (FBV) using Doppler ultrasound, pre- and post-administration of 1000mg of oral vitamin C. The intervention aimed to compare endothelial function responses between OSA patients and healthy controls, and to evaluate the impact of oral vitamin C on these responses.

Results

Baseline comparisons revealed a significant difference in FBF between OSA patients (76.6 ml/min) and healthy controls (162.1 ml/min, p < 0.05), indicating endothelial dysfunction in OSA. Post-vitamin C intervention, the peak FBF responses in OSA patients showed no significant difference (Pre-vitamin C: 76.6 ml/min, Post-vitamin C: 79.9 ml/min, p > 0.05), suggesting that oral vitamin C did not significantly improve endothelial function in OSA patients.

Conclusion

PLM effectively distinguished between healthy subjects and those with OSA through differences in FBF, confirming its utility as a diagnostic tool for endothelial dysfunction. However, oral vitamin C supplementation did not significantly enhance endothelial function in OSA patients, indicating the need for further research into alternative or adjunctive therapies.