Clinical trial NCT06016478: The Effect of 4 Weeks of L-Citrulline Supplementation on Macro- and Microvascular Function in Type 2 Diabetes
Official title: The Effect of 4 Weeks of L-Citrulline Supplementation on Macro- and Microvascular Function in Type 2 Diabetes
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Type 2 Diabetes
Keywords: Endothelial function
Arterial stiffness
Hyperglycemia
Oral glucose tolerance test
Aortic blood pressure
Blood glucose
Lean mass
Lead sponsor: Texas Tech University
Sponsor class: OTHER
First posted: 2023-08-29
Enrollment: 36
Sex: ALL
Minimum age (years): 40
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Double-blind (subject, investigator), randomized, cross-over, placebo-controlled
Primary purpose: BASIC_SCIENCE

Brief summary: The purpose of this study is to examine the effect of 4 weeks of Citrulline supplementation on macro- and microvascular function during acute hyperglycemia in middle-aged and older adults with type 2 diabetes.

Detailed description: Using a double-blind, randomized, placebo-controlled, and cross-over design, middle-aged and older adults with type 2 diabetes will be randomized to receive either CIT supplementation (6g/day) or placebo (Microcrystalline Cellulose, 6g/day) for 4 weeks.

There will be a total of 5 laboratory visits. Visit 1 (screening visit) will take approximately 1 hour and 30 minutes, visit 2 will take approximately 2 hours and 30 minutes, and visits 3-5 will be approximately 3 hours each.

Visit 1 will measure blood pressure, blood glucose and lipid levels, anthropometry, body composition, and muscle strengths. Visits 2-5 will assess vascular function and glucose control during fasted and acute hyperglycemia conditions induced by 75g of glucose ingestion.

Eligibility criteria: Inclusion Criteria:

* Middle-aged and older women and men between 40-75 years old
* A physician diagnosed type 2 diabetes at least 3 months ago
* Treated with an oral hypoglycemic medication
* Body mass index \< 40 kg/m2
* Systolic blood pressure \< 160 mmHg
* Sedentary (defined as \< 120 min/week of exercise)
* Not currently participating in exercise or dietary interventions for at least 2 months prior the present study and willing to abstain from participating in those strategies during the duration of this study.

Exclusion Criteria:

* \< 40 years of age and \> 65 years of age
* Use of medications and/or any supplements that may affect outcome variables (such as arginine- or citrulline-containing supplements, nitrates, and nitroglycerin)
* Body mass index ≥ 40 kg/m2
* Systolic blood pressure ≥ 160 mmHg
* Recent changes in medications within 3 months
* Current smoking any tobacco use
* Type 1 diabetes, severe cardiovascular/renal/pulmonary diseases
* More than 7 alcoholic drinks/week of consumption
* Premenopausal women with an irregular menstrual cycle (oligomenorrhea) or pregnancy

Primary outcomes:
measure: Change in macrovascular endothelial function in the fasted condition
timeFrame: 4 weeks
measure: Change in macrovascular endothelial function during acute hyperglycemia
timeFrame: 4 weeks
measure: Change in microvascular endothelial function in the fasted condition
timeFrame: 4 weeks
measure: Change in microvascular endothelial function in the fasted condition
timeFrame: 4 weeks
measure: Change in microvascular endothelial function during acute hyperglycemia
timeFrame: 4 weeks
measure: Change in blood glucose levels in the fasted condition
timeFrame: 4 weeks
measure: Change in blood glucose levels during acute hyperglycemia
timeFrame: 4 weeks
measure: Change in central and peripheral arterial stiffness in the fasted condition
timeFrame: 4 weeks
measure: Change in central and peripheral arterial stiffness during acute hyperglycemia
timeFrame: 4 weeks
measure: Change in blood pressure in the fasted condition
timeFrame: 4 weeks
measure: Change in blood pressure during acute hyperglycemia
timeFrame: 4 weeks
measure: Change in stroke volume in the fasted condition
timeFrame: 4 weeks
measure: Change in stroke volume during acute hyperglycemia
timeFrame: 4 weeks
measure: Change in total peripheral resistance in the fasted condition
timeFrame: 4 weeks
measure: Change in total peripheral resistance during acute hyperglycemia
timeFrame: 4 weeks
Secondary outcomes:
measure: Change in body composition
timeFrame: 4 weeks
measure: Change in muscle strength
timeFrame: 4 weeks
measure: Change in insulin levels
timeFrame: 4 weeks
measure: Change in serum arginine levels
timeFrame: 4 weeks
measure: Change in serum arginase activity levels
timeFrame: 4 weeks
measure: Change in 24-hour ambulatory blood pressure monitoring
timeFrame: 4 weeks
Other outcomes:
Locations:
city: Lubbock
country: United States
facility: TTU Kinesiology and Sport Management Building
state: Texas
Study officials:
affiliation: Texas Tech University
name: Arturo Figueroa, Ph.D, MD
role: PRINCIPAL_INVESTIGATOR
References: