Assessing the Effects of Alfacalcidol Intake on Expression of Involed Gene in Metabolism in Obese Subjects
Recruitment status was: Recruiting
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Prevention
|Official Title:||Assessing the Effects of Supplementary Alfacalcidol Intake on Peroxisome Proliferator-activated Receptor-coactivator-1α, Vitamin D Receptor and Peroxisome Proliferator-activated Receptor Gamma Gene Expression in Obese Subjects|
- Expression of VDR, PPARγ and PGC1α gene [ Time Frame: Change from baseline to 8 weeks ]measurement of Relative gene expression with RT-PCR.
- Change of weight [ Time Frame: Change from baseline to 8 weeks ]measurement with Body composition device
- Body mass index change [ Time Frame: Change from baseline to 8 weeks ]calculated with BMI equation
|Study Start Date:||January 2012|
|Estimated Study Completion Date:||January 2013|
|Primary Completion Date:||December 2012 (Final data collection date for primary outcome measure)|
Dietary Supplement: Alfacalcidol
Placebo Comparator: Placebo
Corn oil pearl Capsules 1 gram: were given to the intervention group once a day for 8 weeks
Dietary Supplement: Placebo
corn oil Capsules 1 gram: were given to the placebo group once a day for 8 weeks
Increasing evidence from human population studies and animal research has established correlative as well as causative links between chronic inflammation and insulin resistance. The anti-inflammatory characteristics of vitamin D have been demonstrated in previous studies. In addition to its role in bone and calcium metabolism, vitamin D is demonstrated to be influential in the regulation of different immune system functions and glucose homeostasis pathways. Although low levels of vitamin D have shown to be in close correlation with obesity, whether vitamin D deficiency is the cause or the consequence of obesity remains unclear. It is noteworthy that several studies have demonstrated that vitamin D deficiency is associated with an increased resistance to insulin.
The biologic effects of vitamin D are primarily mediated via the nuclear transcription factor, vitamin D receptor (VDR), which triggers the expression of vitamin D responsive genes. VDR is expressed on different immune cells such as monocytes, T-lymphocytes, and granulocytes. It is documented that VDR and PGC-1α show an overlapping pattern of expression. Furthermore, as the expression of PGC-1α and PPARγ are regulated via environmental stimuli such as diet, it could be suggested that the function of VDR function can also be altered in response to external stimuli. PGC-1α was demonstrated to be of a particular importance in amelioration of increased insulin sensitivity.
Accordingly, to evaluate whether alphacalcidol treatment in obese subjects who generally suffer from a low state chronic inflammation could affect the insulin resistance, we designed the current double blind clinical trial study to compare the effect of alfacalcidol with placebo on serum glucose, 25-OH vitamin D, PTH, and lipid profile levels as well as Homeostatic model assessment (HOMA) and quantitative insulin sensitivity check index (QUICKI) indexes as a markers of insulin resistance. Furthermore, to assess the possible cross talk between VDR and PPARγ, the gene expressions of these VDR, PPARγ and PGC1α were evaluated following a course of treatment with either alphacalcidol or placebo.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01752244
|Iran, Islamic Republic of|
|Tehran, Iran, Islamic Republic of|
|Principal Investigator:||Arash Hossein-nezhad, MD, PhD||Tehran University of Medical Sciences|
|Principal Investigator:||Khadijeh Mirzaei, Ms||Tehran University of Medical Sciences|