Vitamin D, Insulin Sensitivity, and Vascular Associations in Adolescents

Completed

• Conditions: Flow-mediated Dilation; Insulin Sensitivity; Arterial Stiffness

• Registration Number: NCT01041365
• Lead Sponsor: University of Alabama at Birmingham

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 AA is responsible for ethnic differences in insulin sensitivity and hypertension in AA and 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 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), Serum 25-hydroxy vitamin D (25()H)D, Body mass index (BMI), Alabama (AL).

Detailed Description

Not available

Study Timeline

• Study Start: 2009-12
• Study First Submitted: 2009-12-28
• Study First Submitted QC: 2009-12-30
• Study First Posted: 2009-12-31
• Primary Completion: 2012-12
• Study Completion: 2013-12
• Status Verified: 2014-01
• Last Update Submitted: 2014-01-13
• Last Update Posted: 2014-01-14

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 62

Inclusion Criteria

• African American or Caucasian ethnicity
• Ages 14-18 yrs
• Healthy

Exclusion Criteria

• BMI-for age and -sex higher than 95th centile on the Centers for Disease Control and Prevention Growth Charts
• Use of medication(s) known to influence body composition, vascular function, or glucose metabolism
• Pregnancy
• Diabetes or any chronic diseases

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Insulin Sensitivity	Cross sectional study: at the first study visit

Secondary Outcome Measures

Name	Time	Method
Vascular Function	Cross sectional study: at the second study visit, within 2 weeks of first study visit

Trial Locations

Locations (1)

University of Alabama; 🇺🇸 Birmingham, Alabama, United States