DIVA: Vitamin D, Insulin Sensitivity, and Vascular Associations in Adolescents

Sponsor

University of Alabama at Birmingham (Other)

Overall Status

Completed

CT.gov ID

NCT01041365

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 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).

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

Study Design

Study Type:

Observational

Actual Enrollment :

62 participants

Observational Model:

Cohort

Time Perspective:

Cross-Sectional

Official Title:

Serum 25-hydroxyvitamin D, Vascular Functioning, and Insulin Sensitivity in Adolescent Girls [The DIVA Study (Vitamin D, Insulin, and Vascular Associations)] (Pediatric Physician Training in Translational Research)

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 adolescents Healthy adolescent African American and Caucasian females, ages 14-18

Outcome Measures

Primary Outcome Measures

Insulin Sensitivity [Cross sectional study: at the first study visit]

Secondary Outcome Measures

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

Eligibility Criteria

Criteria

Ages Eligible for Study:

14 Years to 18 Years

Sexes Eligible for Study:

Female

Accepts Healthy Volunteers:

Yes

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