Ascorbic acid prevents vascular dysfunction induced by oral glucose load in healthy subjects

Area of Science:

• Cardiovascular Physiology
• Microcirculation Research
• Endothelial Function

Background:

• Oral glucose loads can impact circulatory regulation.
• Endothelial dysfunction is a concern in metabolic health.
• Oxidative stress may play a role in glucose-induced circulatory changes.

Purpose of the Study:

• To investigate the effects of an oral glucose load on forearm circulatory regulation.
• To assess the potential protective role of ascorbic acid (vitamin C) against glucose-induced circulatory impairment.
• To evaluate changes in microcirculation and hyperemic responses.

Main Methods:

• Employed laser Doppler and strain gauge plethysmography to measure microcirculatory function.
• Assessed forearm hyperemia following ischemia, acetylcholine, and nitroprusside administration.
• Administered oral glucose (75g) and randomized subjects to ascorbic acid (1g BID) or placebo for 10 days.

Main Results:

• Oral glucose load reduced hyperemic peak flow and flux recovery time, indicating impaired microcirculation.
• Ascorbic acid administration prevented the glucose-induced reduction in hyperemia and improved the response to acetylcholine.
• Placebo treatment did not alter the observed effects of glucose on circulation.

Conclusions:

• Oral glucose load impairs endothelium-dependent vasodilation and microcirculatory hyperemia, likely mediated by oxidative stress.
• Ascorbic acid demonstrates a protective effect, preventing glucose-induced microcirculatory dysfunction.
• Findings suggest a therapeutic potential for ascorbic acid in mitigating adverse vascular effects of glucose.