Vascular Function, Insulin Sensitivity, and Vitamin D (VIVID)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01041547
Recruitment Status : Completed
First Posted : December 31, 2009
Last Update Posted : January 14, 2014
Information provided by (Responsible Party):
Ambika Ashraf, M.D., University of Alabama at Birmingham

December 28, 2009
December 31, 2009
January 14, 2014
December 2009
December 2012   (Final data collection date for primary outcome measure)
Insulin sensitivity [ Time Frame: Cross sectional study: at first study visit ]
Same as current
Complete list of historical versions of study NCT01041547 on Archive Site
Vascular function [ Time Frame: Cross sectional study: at second study visit, within 2 weeks of first study visit ]
Same as current
Not Provided
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Vascular Function, Insulin Sensitivity, and Vitamin D
Vitamin D, Vascular Function, and Insulin Sensitivity in Adults [The VIVID Study

The overall objectives of this study are to examine the relationships between circulating vitamin D, insulin sensitivity, and multiple indices of vascular function and to examine whether vitamin D deficiency in African Americans (AA) and White Hispanics (WH) is responsible for ethnic differences in insulin sensitivity and hypertension in AA, WH and European Americans (EA), as well as mechanisms underlying the association between insulin resistance and blood pressure. We hypothesize that 1) serum 25(OH)D is associated with insulin sensitivity and vascular functioning, independent of adiposity, 2) lower insulin sensitivity and vascular functioning in AA and WH relative to EA is due to lower circulating 25(OH)D in AA, and 3) the relationship between insulin resistance and vascular dysfunction is mediated by 25(OH)D.

Acronyms: African American (AA), European American (EA), White Hispanics (WH), Serum 25-hydroxy vitamin D (25()H)D, Body mass index (BMI), Alabama (AL).

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Observational Model: Cohort
Time Perspective: Cross-Sectional
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Retention:   Samples Without DNA
Non-Probability Sample
  • Healthy adults with BMI below 32
  • Both males and females
  • Ages 19-60 years
  • Race: African Americans, White Hispanics, European Americans
  • Insulin Sensitivity
  • Flow-mediated Dilation
  • Arterial Stiffness
Not Provided
Healthy adults
healthy adults with BMI below 32, between ages 19-60 yrs, both males and females
Alvarez JA, Gower BA, Calhoun DA, Judd SE, Dong Y, Dudenbostel T, Scholl J, Ashraf AP. Serum 25-hydroxyvitamin D and Ethnic Differences in Arterial Stiffness and Endothelial Function. J Clin Med Res. 2012 Jun;4(3):197-205. doi: 10.4021/jocmr965w. Epub 2012 May 15.

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Same as current
December 2013
December 2012   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • African American (AA), White Hispanic (WH), and European American (EA) race
  • Ages 19-60 years
  • Negative urine pregnancy test
  • No evidence of diabetes
  • Not on medications that can affect vascular functioning or insulin sensitivity

Exclusion Criteria:

  • BMI > 32 kg/m2
  • Diabetes or any chronic diseases
  • Use of medication(s) known to influence body composition, vascular function, or glucose metabolism
  • Regular smoking
  • Regular use of illegal drugs and pregnancy
Sexes Eligible for Study: All
19 Years to 60 Years   (Adult)
Contact information is only displayed when the study is recruiting subjects
United States
Not Provided
Not Provided
Ambika Ashraf, M.D., University of Alabama at Birmingham
University of Alabama at Birmingham
Not Provided
Principal Investigator: Ambika Ashraf, MD University of Alabama at Birmingham
University of Alabama at Birmingham
January 2014