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Completed

NCT Number: NCT02482675

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

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.

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Key information

Conditions

PreDiabetes Diabetes Mellitus Endocrine System Diseases Glucose Metabolism Disorders Hyperglycemia Metabolic Diseases Nutritional and Metabolic Diseases Prediabetic State

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

The Ohio State University

Columbus, Ohio, 43210, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

Exclusion criteria

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

Treatment and study plan

Glucose

Other

Following baseline measurements, participants will consume a 75 g glucose solution within five minutes.

Glucose with Non-fat Milk

Other

Following baseline measurements, participants will consume 75 g glucose dissolved in two cups of non-fat milk within five minutes.

Glucose with Whey Protein Isolate

Other

Following baseline measurements, participants will consume 75 g glucose and whey protein isolate dissolved in 2 cups water within five minutes.

Glucose with Sodium Caseinate

Other

Following baseline measurements, participants will consume 75 g glucose and sodium caseinate dissolved in 2 cups water within five minutes.

Primary outcomes

  1. Vascular Endothelial Function

    Time frame: Area under curve for FMD for three hours (0, 30, 60, 90, 120, 180 minutes)

    Flow mediated dilation (FMD) of the brachial artery, calculated as FMD AUC for 0-180 minutes (change from baseline)

Secondary outcomes

  1. Nitrite/Nitrate (NOx)

    Time frame: Area under curve for nitrite/nitrate for three hours (0, 30, 60, 90, 120, 180 min) (change from baseline)

    NOx AUC for 0-180 minutes

  2. Plasma Glucose

    Time frame: Area under the curve for glucose for three hours (0, 30, 60, 90, 120, 180 minutes) (change from baseline)

    Plasma glucose concentration from 0-180 minutes

  3. Malondialdehyde (MDA)

    Time frame: Area under curve for MDA for three hours (0, 30, 60, 90, 120, 150, 180 min.) (change from baseline)

    Plasma MDA measured as MDA AUC from 0-180 minutes

  4. Arginine (ARG)

    Time frame: ARG area under the curve for 3 hours (0, 30, 60, 90, 120, 150, 180 minutes) (change from baseline)

    Plasma arginine concentration, calculated as ARG AUC from 0-180 minutes

  5. Asymmetric Dimethylarginine/Arginine (ADMA/ARG)

    Time frame: ADMA/ARG area under the curve for 3 hours (0, 30, 60, 90, 120, 150, 180 minutes) (change from baseline)

    Plasma ADMA/arginine concentration, calculated as ADMA/ARG AUC from 0-180 minutes

  6. Symmetric Dimethylarginine/Arginine (SDMA/ARG)

    Time frame: SDMA/ARG area under the curve for 3 hours (0, 30, 60, 90, 120, 150, 180 minutes) (change from baseline)

    Plasma SDMA/arginine concentration, calculated as SDMA/ARG AUC from 0-180 minutes

  7. Tetrahydrobiopterin/Dihydrobiopterin (BH4/BH2)

    Time frame: Plasma BH4/BH2 concentration area under the curve for 3 hours (0, 30, 60, 90, 120, 150, 180 minutes) (change from baseline)

    Plasma BH4/BH2 concentration, calculated as BH4/BH2 AUC from 0-180 minutes

  8. Insulin

    Time frame: Insulin area under the curve for 3 hours (0, 30, 60, 90, 120, 150, 180 minutes) (change from baseline)

    Plasma insulin concentration, calculated as insulin AUC from 0-180 minutes

  9. Cholecystokinin (CCK)

    Time frame: CCK area under the curve for 3 hours (0, 30, 60, 90, 120, 150, 180 minutes) (change from baseline)

    Plasma CCK concentration, calculated as CCK AUC from 0-180 minutes

  10. 8-isoprostaglandin-F2a

    Time frame: 8-isoprostaglandin-F2a area under the curve for 3 hours (0, 30, 60, 90, 120, 150, 180 minutes) (change from baseline)

    Plasma 8-isoprostaglandin-F2a concentration, calculated as 8-isoprostaglandin-F2a AUC from 0-180 minutes

  11. 8-isoprostaglandin-F2a/Arachidonic Acid

    Time frame: 8-isoprostaglandin-F2a/Arachidonic acid area under the curve for 3 hours (0, 30, 60, 90, 120, 150, 180 minutes) (change from baseline)

    Plasma 8-isoprostaglandin-F2a/Arachidonic acid concentration, calculated as 8-isoprostaglandin-F2a/Arachidonic acid AUC from 0-180 minutes

  12. Arachidonic Acid

    Time frame: Arachidonic acid area under the curve for 3 hours (0, 30, 60, 90, 120, 150, 180 minutes) (change from baseline)

    Arachidonic acid concentration, calculated as Arachidonic acid AUC from 0-180 minutes

Sponsors and collaborators

Lead sponsor

Ohio State University

Other

Registry information

Important dates

Study start
2015
Primary completion
2016
Study completion
2018
First posted
Jun 26, 2015
Registry last updated
May 14, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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