Clinical Trial: To Study the Nutri-Genomic Response of Vit-D Supplementation in African-Americans

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional

Official Title: An Eight Week Double Blinded Randomized, Placebo-controlled Trial to Assess the Effect of Two Doses of 100,000 IU Vitamin D3 by Mouth on Select Genetic Responses in Overweight, Hypertensive African-Am

Brief Summary:

Three hundred thirty (330) overweight, pre-hypertensive/controlled hypertensive, African-American participants will be enrolled in a 8 week study to assess the effect of two administrations of Vitamin D3 on Vitamin D serum responsiveness as a function of clinical, biologic and genetic factors. The investigators anticipate that at least 300 participants will complete this study.

Written, signed and dated informed consent to participate in the study will be given by the participant or a legally acceptable representative, in accordance with the International Conference on Harmonization (ICH) Good Clinical Practice (GCP) Guideline E6 and applicable regulations, before completing any study-related activities/procedures. The original signed and dated consent will be kept in the subject's research file and a copy given to the subject. A copy will also be placed in their medical record.


Detailed Summary:

DETAILED DESCRIPTION OF STUDY PROCEDURES Three hundred thirty (330) overweight, pre-hypertensive/controlled hypertensive, African-American participants will be enrolled in a 8 week study to assess the effect of two administrations of Vitamin D3 on Vitamin D serum responsiveness as a function of clinical, biologic and genetic factors. The investigators anticipate that at least 300 participants will complete this study.

Written, signed and dated informed consent to participate in the study will be given by the participant or a legally acceptable representative, in accordance with the International Conference on Harmonization (ICH) Good Clinical Practice (GCP) Guideline E6 and applicable regulations, before completing any study-related activities/procedures. The original signed and dated consent will be kept in the subject's research file and a copy given to the subject. A copy will also be placed in their medical record.

Blood Pressure Control Controlled High blood pressure is entry criteria, but not an outcome. However, the investigators want to exclude potential participants who are likely to have poor BP control during the study. Therefore, although patients with pre-hypertension or hypertension are eligible to be entered into the study, the protocol only allows enrollment of participants with well-controlled hypertension as defined by SBP≥ 120 mmHg or DBP ≥ 80 mmHg if not on treatment, and SBP <160 mmHg or DBP < 100 mmHg regardless of whether on treatment or not. BP care will be managed by the participants' primary or other provider. All participants being actively treated for hypertension with pharmacotherapy will receive direction to adhere to their medication and to follow-up with their Primary Care Physician. Patients with poorly controlled diabetes as defined by hemoglobin A1c > 8.5% or advanced
Sponsor: Charles Drew University of Medicine and Science

Current Primary Outcome: Plasma PTH Level [ Time Frame: 8 weeks ]

Building upon our hypothesis above, this aim exploits the fact that the nuclear Vit-D Receptor (VDR) regulates parathyroid hormone (PTH) gene transcription. Therefore the plasma PTH level serves as a sensitive biomarker of the Vit-D nutri-genomic response. This aim will define the multivariate determinants (covariates such as age, BMI, baseline Vit-D level and dietary calcium) of the Vit-D-PTH level relationship (the primary outcome variable) in African-Americans. It is anticipated that the Vit-D supplementation trial will document a wide variance of Vit-D-PTH level relationships that will identify patients at the upper and lower quartiles of the distribution that are either 'nutrient-responsive' or 'nutrient-resistant'. These studies should help identify the 'clinical' characteristics of the sub-set of African-Americans that exhibit the poorest response to Vit-D supplementation.


Original Primary Outcome: Same as current

Current Secondary Outcome: Biomarkers of Inflammation: C-reactive protein, IL-6 and Adiponectin [ Time Frame: 8 weeks ]

This aim will focus on defining the molecular determinants of the Vit-D response of immune cells of African-Americans. Recent studies have documented that the VDR and other elements of Vit-D metabolism are expressed in a wide spectrum of tissues. Moreover, Vit-D has pleiotropic effects on a variety of cellular pathways that extend beyond PTH-calcium metabolism. Specifically, it has been shown that immune cells are capable of metabolizing Vit-D. Furthermore, Vit-D has been shown to exert a potent anti-inflammatory influence on leukocyte biology. The tissue-level response to Vit-D supplementation in African-Americans remains poorly defined. In accordance with the parent grant, the supplementary study will also test the working hypothesis by examining the effect of Vit-D supplementation on circulating biomarkers of inflammation (i.e. C-reactive protein, IL-6, and Adiponectin) as well as gene expression


Original Secondary Outcome: Same as current

Information By: Charles Drew University of Medicine and Science

Dates:
Date Received: April 8, 2016
Date Started: September 2013
Date Completion: July 2018
Last Updated: April 18, 2017
Last Verified: June 2016