Cheese Consumption and Human Microvascular Function

Microvascular Dysfunction Clinical Trial

Official title:

Cheese Consumption and Human Microvascular Function

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03376555
• Other study ID #: STUDY4340
• Secondary ID: 129552
• Status: Completed
• Phase: Phase 1/Phase 2
• Start date: March 2016
• Est. completion date: March 1, 2021

Study information

• Verified date: March 2021
• Source: Penn State University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Increased dairy intake is associated with improved measures of blood vessel health. Dairy cheese, however, is often high in sodium. Dietary sodium can impair blood vessel function. The researchers examine if and how natural cheese may protect against impairments in blood vessel function caused by sodium. For this study, participants complete four 8-day controlled feeding periods in which they eat cheese (6 oz/day) or no cheese during a low-sodium or high-sodium base-diet. The participants complete baseline experiments while on their normal personal diet and then repeat experiments at the end of each controlled feeding period. In some of our experiments, the researchers use a technique called "microdialysis" (MD). With MD, the researchers perfuse some research drugs into the skin on the forearm through tiny tubing that mimics capillaries. These MD drugs mimic or block substances the body naturally makes to control the small blood vessels in the skin. The drugs remain in nickel-sized areas around the tubing and do not go into the rest of the body. The researchers also use a standard technique called "flow mediated dilation" (FMD) that uses blood pressure cuffs and ultrasound to look at the health of larger blood vessels in the body. FMD includes placing a small tablet of nitroglycerin under the tongue during part of the test.

Description:

Subject screening will be performed by the Penn State Clinical Translational Research Center (CTRC) medical staff and will include a physical exam by a clinician, anthropometry, and a chemical and lipid profile, liver and renal function. Participants meet with a registered dietitian to determine their caloric energy requirements and identify food preferences. The interview includes surveying the subject's physical activity over the previous 7 days.

Subjects will undergo baseline microdialysis experiments to examine the function of the blood vessels in the skin microcirculation. Subjects will also go through a baseline assessment of conduit vessel endothelial and vascular smooth muscle function with brachial artery flow-mediated vasodilation (FMD), and sublingual nitroglycerin. Following baseline experiments, subjects participate in 4 controlled feeding periods, each 8 days in duration. The controlled feeding periods are assigned in a randomized order. At the end of each 8-day controlled dietary period, subjects will repeat microdialysis experiments, brachial artery FMD, and responsiveness to sublingual nitroglycerin.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 15
• Est. completion date: March 1, 2021
• Est. primary completion date: March 1, 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 55 Years to 75 Years

Eligibility

Inclusion Criteria:

• Seated systolic pressure 120-140 mmHg

• Seated diastolic pressure 70-90 mmHg.

• Normoglycemic (HbA1C <5.7%)

Exclusion Criteria:

• Taking pharmacotherapy that alters peripheral vascular control

• Pregnancy

• Breastfeeding

• Females taking contraceptives (pills, patches, shots, etc.) or hormone replacement therapy

• Taking illicit and/or recreational drugs

• Use of nicotine containing-products (e.g. smoking, chewing tobacco, etc.)

• Known allergy to latex or investigative substances

Related Conditions & MeSH terms

• Microvascular Dysfunction

Intervention

Drug:
• Acetylcholine (ACh) Dose Response
Probe 1. Lactated Ringer's only (control) Probe 2. Lactated Ringer's + N-G-nitro-L-arginine methyl ester (LNAME) Probe 3. Lactated Ringer's + Ascorbate Probe 4. Lactated Ringer's + Tempol Probe 5. Lactated Ringer's + Apocynin
• Local Heating (LH)
Probe 1. Lactated Ringer's only (control) Probe 2. Lactated Ringer's + Ascorbate Probe 3. Lactated Ringer's + Tempol Probe 4. Lactated Ringer's + Apocynin
• Flow Mediated Dilation with nitroglycerin
BP cuff on a forearm, gel on the upper arm just above the elbow, and a Doppler ultrasound probe on the gel. The ultrasound measures vessel size and blood velocity. After a 3-minute "resting" measurement, the cuff inflates for 5 minutes to occlude forearm blood flow (BF). After the cuff deflates, we perform a second reading. Sublingual nitroglycerin: The subject is supine. We measure blood pressure. Also, we perform ultrasonography at the brachial artery at the elbow during the procedure. Nurse places a 0.4 mg nitroglycerin tablet under the subject's tongue. The subject remains supine for 20 minutes following the nitroglycerin administration.

Locations

Country	Name	City	State
United States	Pennsylvania State University	University Park	Pennsylvania

Sponsors (2)

Lead Sponsor	Collaborator
Lacy M. Alexander	National Dairy Council

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	laser Doppler blood flow	This measurement is performed using a laser Doppler flow meter. The flow meter produces a non-invasive qualitative and dimensionless index of blood flow in blood vessels.	8 weeks
Secondary	Systolic Blood Pressure	Blood pressure is measured via brachial auscultation manually or with a critical care monitor. The peak blood pressure during a cardiac cycle when the heart contracts.	8 weeks
Secondary	Diastolic Blood Pressure	Blood pressure is measured via brachial auscultation manually or with a critical care monitor. The lowest blood pressure during a cardiac cycle when the heart is between beats.	8 weeks
Secondary	Flow Mediated Dilation	Flow mediated dilation is measured through Doppler ultrasound probe placed at brachial artery.	8 weeks