VIVID: Vascular Function, Insulin Sensitivity, and Vitamin D

Sponsor

University of Alabama at Birmingham (Other)

Overall Status

Completed

CT.gov ID

NCT01041547

Collaborator

(none)

Enrollment

Location

Duration (Months)

1.3

Patients Per Site Per Month

Study Details

Study Description

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).

Condition or Disease	Intervention/Treatment	Phase
Insulin Sensitivity Flow-mediated Dilation Arterial Stiffness

Study Design

Study Type:

Observational

Actual Enrollment :

63 participants

Observational Model:

Cohort

Time Perspective:

Cross-Sectional

Official Title:

Vitamin D, Vascular Function, and Insulin Sensitivity in Adults [The VIVID Study

Study Start Date :

Dec 1, 2009

Actual Primary Completion Date :

Dec 1, 2012

Actual Study Completion Date :

Dec 1, 2013

Arms and Interventions

Arm	Intervention/Treatment
Healthy adults healthy adults with BMI below 32, between ages 19-60 yrs, both males and females

Outcome Measures

Primary Outcome Measures

Insulin sensitivity [Cross sectional study: at first study visit]

Secondary Outcome Measures

Vascular function [Cross sectional study: at second study visit, within 2 weeks of first study visit]

Eligibility Criteria

Criteria

Ages Eligible for Study:

19 Years to 60 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

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