Effects of L-citrulline Supplementation on Vascular Function in Metabolic Syndrome

Effects of L-Citrulline Supplementation on Vascular Function During Fasted and Acute Hyperglycemia in Middle-aged and Older Women With Metabolic Syndrome

The objective of this project is to provide evidence that L-Citrulline (CIT) supplementation can improve vascular function in the fasted and acute hyperglycemia conditions in middle-aged and older women with metabolic syndrome.

Using a double-blind, randomized, placebo-controlled, and parallel design, middle-aged and older women with metabolic syndrome will be randomized into receiving either CIT supplementation (10g/day) or placebo (Microcrystalline Cellulose) for 4 weeks.

The first visit will be approximately 1hr and 30 minutes. The 2nd and 3rd visits will each be approximately 2hrs and 30 minutes, separated by 4 weeks in between each visit. During visits 2 and 3, vascular measurements will be assessed in the fasted state and 30, 60, and 90 minutes after acute glucose ingestion (75g).

Inclusion Criteria:

Must present at least 3 of the following 5 cardiometabolic risk factors

• Waist circumference ≥88 cm
• Fasting glucose between 100-125 mg/dL or HbA1c between 5.7-6.4%.
• Blood pressure ≥130 mm Hg
• Triglyceride ≥ 150 mg/dL
• HDL <50 mg/dL

The following are also inclusion criteria's:

• Women aged 45-79 years old
• Body mass index ≤ 39.9 kg/m2
• Sedentary (defined as < 120 min/week of exercise)
• Abstain from any dietary supplements with vascular effects for one month prior to the beginning of the study and until participation in study has terminated.

Exclusion Criteria:

• < 45 and > 79 years of age
• Use of medications and/or any supplements that may affect outcome variables (such as arginine-containing supplements, nitroglycerin, statin drugs, biguanides, insulin, beta blockers, statins, verapamil)
• Systolic blood pressure ≥ 160 mmHg
• BMI > 40 kg/m2
• Recent changes in medication (3 months)
• Current smoking any tobacco use
• Cardiovascular disease, diabetes (Type 1 or 2), and other metabolic or chronic diseases
• More than 7 alcoholic drinks/week of consumption