Identification of the Region of Vitamin D Responsiveness

Hypertension Clinical Trial

— GRH-PN01  

Official title:

A Novel Approach Localizes the Association of Vitamin D Status With Insulin Resistance to One Region of the 25(OH)D Continuum.

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01692028
• Other study ID #: GRH-PN01
• Status: Completed
• Phase: N/A
• First received: September 13, 2012
• Last updated: September 21, 2012
• Start date: February 2012
• Est. completion date: February 2012

Study information

• Verified date: September 2012
• Source: Creighton University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Federal Government
• Study type: Observational

Clinical Trial Summary

Hypothesis: low vitamin D status is associated with increased insulin resistance and increased blood pressure.

Approach: Multiple regression analysis of information extracted from a large database accumulated by a Canadian health foundation, specifically evaluating statistical associations between serum 25(OH)D levels and insulin responsiveness measures as well as blood pressure, after adjusting these variables for BMI, age, sex, and waist circumference.

Description:

Data obtained from the entry records of 4,116 adult men and women in Calgary,Alberta previously enrolled in the Pure North S'Energy Foundation's health program. Individuals with a clinical diagnosis of diabetes mellitus or a HOMA-IR value above 16 were excluded. Standard statistical analyses carried out. An association between 25(OH)D and the endpoints of interest was first established. The residual values after adjusting HOMA-IR, serum insulin, QUICKI, and blood pressure for BMI, age, sex, and waist circumference were then regressed against serum 25(OH)D using 40-percentile data blocks, stepping upward from the lowest 25(OH)D values by 5 percentile increments through the 7th decile. Regression coefficients are then computed for each data block and each outcome variable. The location (along the 25(OF)D continuum) of the largest and most statistically significant coefficients is noted, and regions of null response noted as well.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 4116
• Est. completion date: February 2012
• Est. primary completion date: February 2012
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 95 Years

Eligibility

Inclusion Criteria:

• Age > 18

Exclusion Criteria:

• Diabetes

• Elevated HOMA-IR (>16)

Study Design

Observational Model: Ecologic or Community, Time Perspective: Cross-Sectional

Related Conditions & MeSH terms

• Diabetes
• Hypertension

Locations

Country	Name	City	State
Canada	Pure North S'Energy Foundataion	Calgary	Alberta

Sponsors (1)

Lead Sponsor	Collaborator
Creighton University

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	HOMA-IR	A composite measure of insulin resistance (HOMA-IR)	Observational/cross-sectional study	No
Secondary	Blood pressure	Blood Pressure	cross-sectional study	No