Vascular Function, Insulin Sensitivity, and Vitamin D

NCT01041547 | Completed DMC

• 1 other identifier: F091023002
• Study Type: observational
• Target: 63
• Locations: 1 country
• Sites: 1

Brief Summary

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).

Conditions

Insulin Sensitivity; Flow-mediated Dilation; Arterial Stiffness

Keywords

Insulin sensitivity; Vascular function; Flow-mediated dilation; Arterial stiffness; Glucose tolerance; Hypertension

Outcome Measures

Primary Outcomes (1)

• Insulin sensitivity

  Cross sectional study: at first study visit

Secondary Outcomes (1)

• Vascular function

  Cross sectional study: at second study visit, within 2 weeks of first study visit

Study Arms (1)

Healthy adults

healthy adults with BMI below 32, between ages 19-60 yrs, both males and females

Eligibility Criteria

• Age: 19 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

* Healthy adults with BMI below 32 * Both males and females * Ages 19-60 years * Race: African Americans, White Hispanics, European Americans

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Alabama at Birmingham: lead

Study Sites (1)

University of Alabama

Birmingham, Alabama, 35243, United States

Location

Related Publications (1)

• 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.

  PMID: 22719806 DERIVED

Biospecimen

Retention: SAMPLES WITHOUT DNA

Seum

MeSH Terms

Conditions

Insulin Resistance; Hypertension

Condition Hierarchy (Ancestors)

Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Vascular Diseases; Cardiovascular Diseases

Study Officials

• Ambika Ashraf, MD

  University of Alabama at Birmingham

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: December 28, 2009
• First Posted: December 31, 2009
• Study Start: December 1, 2009
• Primary Completion: December 1, 2012
• Study Completion: December 1, 2013
• Last Updated: January 14, 2014

Record last verified: 2014-01

Locations

US (1)