Effects of L-Citrulline Supplementation on Endothelial Function, Arterial Stiffness, and Blood Glucose Level in the Fasted and Acute Hyperglycemic States in Middle-Aged and Older Adults with Type 2 Diabetes.

L-citrulline supplementation improved brachial artery flow-mediated dilation (FMD) in the fasted state compared to placebo in patients with T2DM.

• 16 patients with T2DM were randomized to CIT (6 g/day) or placebo for 4 weeks
• Mean age of participants was 62 ± 6 years
• FMD improvement in fasted state reached statistical significance (p < 0.05)
• FMD measures endothelial function via brachial artery response to increased blood flow

L-citrulline supplementation reduced femoral-ankle pulse wave velocity (PWV) in the fasted state compared to placebo.

• Femoral-ankle PWV was used as a measure of leg arterial stiffness
• Reduction in femoral-ankle PWV reached statistical significance (p < 0.05)
• Both aortic and leg arterial stiffness (PWV) were assessed in the study
• The study also assessed carotid-femoral PWV as a measure of aortic arterial stiffness

L-citrulline supplementation reduced aortic systolic blood pressure in the fasted state compared to placebo.

• Aortic systolic blood pressure reduction was statistically significant (p < 0.05)
• Both brachial and aortic blood pressure were assessed
• Participants consumed either CIT (6 g/day) or placebo for 4 weeks
• Assessments were performed in the fasted state

L-citrulline supplementation reduced fasting blood glucose concentration compared to placebo in patients with T2DM.

• Blood glucose concentration was assessed in the fasted state
• Reduction in fasting glucose reached statistical significance (p < 0.05)
• This finding is consistent with prior literature showing CIT decreases fasting glucose in those with T2DM
• 16 patients with T2DM participated in the randomized design

During acute hyperglycemia induced by glucose ingestion, L-citrulline supplementation increased FMD compared to placebo.

• Acute hyperglycemia was induced 60 minutes following glucose ingestion
• FMD increase during acute hyperglycemia was statistically significant (p < 0.05)
• This finding addresses a previously unknown question of whether CIT improves vascular function during acute hyperglycemic states in T2DM
• Assessments were performed at 60 min post-glucose ingestion

During acute hyperglycemia, L-citrulline supplementation reduced femoral-ankle PWV, aortic systolic blood pressure, and blood glucose levels compared to placebo.

• All three outcomes during acute hyperglycemia reached statistical significance (p < 0.05)
• Acute hyperglycemia was assessed 60 minutes following glucose ingestion
• Reduction in blood glucose during acute hyperglycemia suggests a role for CIT in modulating postprandial glycemia
• These findings collectively indicate CIT benefits both vascular function and metabolic control in the acute hyperglycemic state