Antioxidant vitamin C improves endothelial dysfunction in chronic smokers

Area of Science:

• Cardiovascular Research
• Vascular Biology
• Oxidative Stress

Background:

• Chronic smoking is linked to endothelial dysfunction, a precursor to atherosclerosis.
• Endothelial dysfunction in smokers may stem from increased nitric oxide degradation due to free radicals.
• This study investigates the role of antioxidant vitamin C in smokers' endothelial function.

Purpose of the Study:

• To evaluate the effect of vitamin C on endothelium-dependent responses in chronic smokers.
• To determine if vitamin C can mitigate smoking-induced endothelial dysfunction.

Main Methods:

• Measured forearm blood flow using venous occlusion plethysmography in 10 smokers and 10 controls.
• Administered acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) via brachial artery infusion.
• Assessed responses before and during intra-arterial vitamin C infusion (18 mg/min).

Main Results:

• Vitamin C did not affect blood flow responses in control subjects.
• In smokers, vitamin C significantly improved attenuated forearm blood flow responses to acetylcholine.
• Vitamin C had no impact on sodium nitroprusside-induced vasodilation in smokers.

Conclusions:

• Antioxidant vitamin C markedly enhances endothelium-dependent responses in chronic smokers.
• Findings support the hypothesis that oxidative stress contributes to endothelial dysfunction in smokers.
• Vitamin C may offer a therapeutic strategy for smoking-related vascular impairment.