Vascular Function, Insulin Sensitivity, and Vitamin D

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

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT01041547

Acronym

VIVID

Enrollment

Registered

2009-12-31

Start date

2009-12-31

Completion date

2013-12-31

Last updated

2014-01-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Arterial Stiffness, Flow-mediated Dilation, Insulin Sensitivity

Keywords

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

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).

Interventions

None listed

Study design

Observational model

COHORT

Time perspective

CROSS_SECTIONAL

Eligibility

Sex/Gender

ALL

Age

19 Years to 60 Years

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

Design outcomes

Primary

Measure	Time frame
Insulin sensitivity	Cross sectional study: at first study visit

Secondary

Measure	Time frame
Vascular function	Cross sectional study: at second study visit, within 2 weeks of first study visit

Countries

United States

Outcome results