Regulation of Postprandial Nitric Oxide Bioavailability and Vascular Function By Dairy Milk

The Ohio State University

Status: Completed

Conditions: Prediabetes

Treatments: Other: Glucose with Sodium Caseinate; Other: Glucose with Non-fat Milk; Other: Glucose; Other: Glucose with Whey Protein Isolate

Study type: Interventional

Funder types: Other

Identifiers

NCT02482675

2015H0088

Details and patient eligibility

About

Cardiovascular disease (CVD) is the leading cause of death in the United States. Short-term increases in blood sugar, or postprandial hyperglycemia (PPH), affect blood vessel function and increase the risk of CVD. Greater intakes of dairy foods have been associated with a lower risk of CVD, but whether these effects occur directly or indirectly by displacing foods in the diet that might increase CVD risk is unclear. The health benefits of dairy on heart health are at least partly attributed to its ability to limit PPH and resulting PPH-mediated responses leading to vascular dysfunction. This provides rationale to further investigate dairy as a dietary strategy to reduce PPH and risk for CVD. The objective of this study is to define the extent to which dairy milk, and its whey and casein protein fractions, protect against postprandial vascular dysfunction by reducing oxidative stress responses that limit nitric oxide bioavailability to the vascular endothelium in adults with prediabetes.

Full description

This study consists of four, 3-hour postprandial trials in response to consuming the following dietary treatments: 1. oral glucose challenge, 2. oral glucose challenge in combination with non-fat milk, 3. oral glucose challenge in combination with whey protein isolate, and 4. oral glucose challenge in combination with sodium caseinate. For three days preceding each trial, participants will be provided all meals to standardize physiologic responses to test meals. On each trial day, vascular function will be assessed and blood samples collected prior to and at 30 minute intervals for 3 hours following test meal ingestion.

Enrollment: 23 patients

Sex: All

Ages: 18 to 50 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. hemoglobin A1c 5.7-6.4%
2. non-dietary supplement user
3. no medications affecting vasodilation, inflammation, or energy metabolism
4. no CVD
5. nonsmokers
6. individuals having blood pressure <140/90 mmHg and total cholesterol <240 mg/dL

Exclusion criteria

1. unstable weight (±2 kg)
2. vegetarian or dairy allergy
3. alcohol intake >3 drinks/day or >10 drinks/week
4. ≥7 hours/week of aerobic activity

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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23 participants in 4 patient groups

Glucose

Active Comparator group

Description:

This study day will last approximately three hours and will be separated from the other arms by four days for men and one month for women.

Treatment:

Other: Glucose

Glucose with Non-fat Milk

Experimental group

Description:

This study day will last approximately three hours and will be separated from the other arms by four days for men and one month for women.

Treatment:

Other: Glucose with Non-fat Milk

Glucose with Whey Protein Isolate

Experimental group

Description:

This study day will last approximately three hours and will be separated from the other arms by four days for men and one month for women.

Treatment:

Other: Glucose with Whey Protein Isolate

Glucose with Sodium Caseinate

Experimental group

Description:

This study day will last approximately three hours and will be separated from the other arms by four days for men and one month for women.

Treatment:

Other: Glucose with Sodium Caseinate