Clinical trial NCT03376555: Cheese Consumption and Human Microvascular Function
Official title: Cheese Consumption and Human Microvascular Function
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
PHASE2
Conditions: Microvascular Dysfunction
Keywords: Sodium
Hypertension
Blood Pressure
Cardiovascular Disease
Nitric Oxide
Skin
Dairy
Cheese
Oxidative Stress
Diet
Flow Mediated Vasodilation
Nitroglycerin
Superoxide
Microcirculation
Lead sponsor: Penn State University
Sponsor class: OTHER
Collaborators: name: National Dairy Council
First posted: 2017-12-18
Enrollment: 13
Sex: ALL
Minimum age (years): 55
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: All subjects participate in 4 diets in randomized order. The diets differ in the amount of sodium and dairy cheese content. Each diet is consumed for 8 days. Minimum washout of 1 week between diets. Baseline experiment is conducted prior to first dietary intervention, and the experiment is repeated after each dietary intervention.
Primary purpose: BASIC_SCIENCE

Brief 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.

Detailed 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.

Eligibility criteria: 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

Primary outcomes:
measure: Microvascular Reactivity to Acetylcholine
timeFrame: 1 hour
Secondary outcomes:
measure: Systolic Blood Pressure
timeFrame: 8 days
measure: Diastolic Blood Pressure
timeFrame: 8 days
measure: Flow Mediated Dilation
timeFrame: 8 days
Other outcomes:
Locations:
city: University Park
country: United States
facility: Pennsylvania State University
state: Pennsylvania
Study officials:
affiliation: Penn State University
name: Lacy M Alexander, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Alba BK, Stanhewicz AE, Dey P, Bruno RS, Kenney WL, Alexander LM. Controlled Feeding of an 8-d, High-Dairy Cheese Diet Prevents Sodium-Induced Endothelial Dysfunction in the Cutaneous Microcirculation of Healthy, Older Adults through Reductions in Superoxide. J Nutr. 2020 Jan 1;150(1):55-63. doi: 10.1093/jn/nxz205.