<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT01692028</url>
  </required_header>
  <id_info>
    <org_study_id>GRH-PN01</org_study_id>
    <nct_id>NCT01692028</nct_id>
  </id_info>
  <brief_title>Identification of the Region of Vitamin D Responsiveness</brief_title>
  <acronym>GRH-PN01</acronym>
  <official_title>A Novel Approach Localizes the Association of Vitamin D Status With Insulin Resistance to One Region of the 25(OH)D Continuum.</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Creighton University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Creighton University</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      Hypothesis: low vitamin D status is associated with increased insulin resistance and&#xD;
      increased blood pressure.&#xD;
&#xD;
      Approach: Multiple regression analysis of information extracted from a large database&#xD;
      accumulated by a Canadian health foundation, specifically evaluating statistical associations&#xD;
      between serum 25(OH)D levels and insulin responsiveness measures as well as blood pressure,&#xD;
      after adjusting these variables for BMI, age, sex, and waist circumference.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Data obtained from the entry records of 4,116 adult men and women in Calgary,Alberta&#xD;
      previously enrolled in the Pure North S'Energy Foundation's health program. Individuals with&#xD;
      a clinical diagnosis of diabetes mellitus or a HOMA-IR value above 16 were excluded. Standard&#xD;
      statistical analyses carried out. An association between 25(OH)D and the endpoints of&#xD;
      interest was first established. The residual values after adjusting HOMA-IR, serum insulin,&#xD;
      QUICKI, and blood pressure for BMI, age, sex, and waist circumference were then regressed&#xD;
      against serum 25(OH)D using 40-percentile data blocks, stepping upward from the lowest&#xD;
      25(OH)D values by 5 percentile increments through the 7th decile. Regression coefficients are&#xD;
      then computed for each data block and each outcome variable. The location (along the 25(OF)D&#xD;
      continuum) of the largest and most statistically significant coefficients is noted, and&#xD;
      regions of null response noted as well.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date>February 2012</start_date>
  <completion_date type="Actual">February 2012</completion_date>
  <primary_completion_date type="Actual">February 2012</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Ecologic or Community</observational_model>
    <time_perspective>Cross-Sectional</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>HOMA-IR</measure>
    <time_frame>Observational/cross-sectional study</time_frame>
    <description>A composite measure of insulin resistance (HOMA-IR)</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Blood pressure</measure>
    <time_frame>cross-sectional study</time_frame>
    <description>Blood Pressure</description>
  </secondary_outcome>
  <enrollment type="Actual">4116</enrollment>
  <condition>Diabetes</condition>
  <condition>Hypertension</condition>
  <eligibility>
    <study_pop>
      <textblock>
        Healthy adults living in or near Calgary and associated with the oil and gas industries&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Non-Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Age &gt; 18&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Diabetes&#xD;
&#xD;
          -  Elevated HOMA-IR (&gt;16)&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>95 Years</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <location>
    <facility>
      <name>Pure North S'Energy Foundataion</name>
      <address>
        <city>Calgary</city>
        <state>Alberta</state>
        <country>Canada</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Canada</country>
  </location_countries>
  <verification_date>September 2012</verification_date>
  <study_first_submitted>September 13, 2012</study_first_submitted>
  <study_first_submitted_qc>September 21, 2012</study_first_submitted_qc>
  <study_first_posted type="Estimate">September 25, 2012</study_first_posted>
  <last_update_submitted>September 21, 2012</last_update_submitted>
  <last_update_submitted_qc>September 21, 2012</last_update_submitted_qc>
  <last_update_posted type="Estimate">September 25, 2012</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <keyword>vitamin D</keyword>
  <keyword>Associational study</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Hypertension</mesh_term>
  </condition_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT01692028
org study id: GRH-PN01
nct id: NCT01692028
lead sponsor: 
has dmc: No
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.
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.
observational model: Ecologic or Community
time perspective: Cross-Sectional
measure: HOMA-IR
time frame: Observational/cross-sectional study
description: A composite measure of insulin resistance (HOMA-IR)
measure: Blood pressure
time frame: cross-sectional study
description: Blood Pressure
study pop: 
sampling method: Non-Probability Sample
criteria: 
gender: All
minimum age: 18 Years
maximum age: 95 Years
healthy volunteers: Accepts Healthy Volunteers
facility: 
country: Canada
responsible party type: Sponsor
mesh term: Hypertension