Fred Hutchinson Cancer Research Center
Seattle, Washington, 98109, United States
NCT Number: NCT01477034
Chronic, low-grade adipose tissue inflammation is a major risk factor for type 2 diabetes mellitus. The cause of adipose tissue inflammation has remained largely unclear. We hypothesize that vitamin D deficiency predisposes individuals to the development of adipose tissue inflammation, and that treatment of vitamin D deficient subjects with high dose vitamin D will reduce adipose tissue inflammation.
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Notify Me18 year–65 year
All sexes
Interventional
Not applicable
Seattle, Washington, 98109, United States
The objective of this project is to investigate whether vitamin D modulates chronic low-grade adipose tissue inflammation in overweight and obese, vitamin D deficient men and women.
Obesity is associated with insulin resistance and an increased risk for type 2 diabetes mellitus. Numerous studies, mostly conducted in mouse models of obesity, strongly suggest that chronic low-grade inflammation of adipose and other tissues is the major mechanism by which increased adiposity is linked to insulin resistance. Adipose tissue inflammation may therefore be a promising therapeutic target to reduce insulin resistance and the risk of type 2 diabetes mellitus in obese individuals.
Based on several lines of evidence, we hypothesize that vitamin D is an environmental factor that affects the course of the inflammatory response in most tissues of the body, including adipose tissue. In our previous studies, we found that circulating plasma concentrations of 25-hydroxy vitamin D (25-OH-D) and the primary degradation product 24,25-dihydroxy vitamin D (24,25-OH2-D) were significantly associated with adipose tissue expression of adiponectin and negatively with TNF-alpha, even when adjusted for body mass index. Because these previous studies were cross-sectional, it is critical to complete an intervention study in humans to determine whether the observed association of vitamin D levels and adipose tissue inflammation is causal. The objectives of this pilot study are therefore to collect relevant preliminary data, and to begin an exploration of the mechanisms underlying this association such as intestinal permeability.
Increased intestinal permeability may contribute to chronic low-grade inflammation and signaling through the vitamin D receptor plays an important role in the maintenance of intestinal integrity. We will assess whether normalization of vitamin D status is associated with changes in intestinal permeability.
Healthy volunteers accepted: Yes
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
Exclusion criteria
2,000 or 4,000 IU/day vitamin D3 for 3 or 6 months.
Other names: Carlson Labs Vitamin D3 capsules (2,000/4,000 IU/capsule)
Time frame: Change from baseline to the 6 month visit
Total RNA will be extracted from whole adipose tissue. TNF alpha mRNA will be quantified using PCR, and normalized using a normalization factor based on three housekeeping genes. We will compute the change in adipose tissue TNF alpha mRNA level between baseline and the 6 month visit.
Time frame: Change from baseline to the 3 month visit
Total RNA will be extracted from whole adipose tissue. TNF alpha mRNA will be quantified using PCR, and normalized using a normalization factor based on three housekeeping genes. We will compute the change in adipose tissue TNF alpha mRNA level between baseline and the 3 month visit.
Time frame: Change from baseline to the 6 month visit
The concentration of 24,25(OH)2D will be measured in fasting plasma using high performance liquid chromatography-tandem mass spectometry (LC/MS/MS).
Time frame: Change from baseline to the 6 month visit
Adipose tissue 25(OH)D will be measured using high performance liquid chromatography-tandem mass spectometry (LC/MS/MS.)
Time frame: Change from baseline to the 6 month visit
The number or CD16+ macrophages in adipose tissue, normalized to the total number of CD14+CD206+ macrophages or the total number of CD45+ cells, will be measured using multi-parameter flow cytometry.
Time frame: Change from baseline to the 6 month visit
The number of CD8+ T cells in adipose tissue, normalized to the total number of CD3+ cells, will be measured using multi-parameter flow cytometry.
Time frame: Change from baseline to the 6 month visit
Plasma 25(OH)D will be measured by high performance liquid chromatography-tandem mass spectometry (LC/MS/MS).
Time frame: Change from baseline to the 6 month visit
Adipose tissue concentrations of cholecalciferol will be measured by high performance liquid chromatography-tandem mass spectometry (LC/MS/MS)
Time frame: Change from baseline to the 6 month visit
The number of CD11c+ macrophages in adipose tissue, normalized to the total number of CD45+ cells, will be measured by multi-parameter flow cytometry.
Time frame: Change from baseline to the 6 month visit
The number of CD4+CD25+ T cells in adipose tissue, normalized to the total number of CD4+ T cells, will be measured by multi-parameter flow cytometry.
Time frame: Change from baseline to 6 month clinic visit.
Intestinal permeability will be assessed at each clinic visit by administering 2g of mannitol and 5 g of lactulose to the oral glucose tolerance test beverage followed by collection of urine for 5 hours afterwards. Recovery of mannitol and lactulose in urine will be measured by gas chromatography, and will be indicative of the degree of intestinal permeability.
Time frame: Change from baseline to 6 month clinic visit
Zonulin concentrations will be measured by enzyme-linked immunosorbent assay in fasting plasma collected at all clinic visits. Plasma zonulin is a marker of intestinal permeability.
Time frame: Change from baseline to 6 month clinic visit
Lipopolysaccharide binding protein (LBP) will be measured by enzyme-linked immunosorbent assay in fasting plasma collected at all clinic visits. LBP is an acute phase protein secreted by the liver in response to endotoxin (lipopolysaccharide) exposure.
Time frame: Change from baseline to the 3 month visit
The concentration of 24,25(OH)2D will be measured in fasting plasma using high performance liquid chromatography-tandem mass spectometry (LC/MS/MS).
Time frame: Change from baseline to the 3 month visit
Adipose tissue 25(OH)D will be measured using high performance liquid chromatography-tandem mass spectometry (LC/MS/MS.)
Time frame: Change from baseline to the 3 month visit
The number or CD16+ macrophages in adipose tissue, normalized to the total number of CD14+CD206+ macrophages or the total number of CD45+ cells, will be measured using multi-parameter flow cytometry.
Time frame: Change from baseline to the 3 month visit
The number of CD8+ T cells in adipose tissue, normalized to the total number of CD3+ cells, will be measured using multi-parameter flow cytometry.
Time frame: Change from baseline to the 3 month visit
Plasma 25(OH)D will be measured by high performance liquid chromatography-tandem mass spectometry (LC/MS/MS).
Time frame: Change from baseline to the 3 month visit
Adipose tissue concentrations of cholecalciferol will be measured by high performance liquid chromatography-tandem mass spectometry (LC/MS/MS)
Time frame: Change from baseline to the 3 month visit
The number of CD11c+ macrophages in adipose tissue, normalized to the total number of CD45+ cells, will be measured by multi-parameter flow cytometry.
Time frame: Change from baseline to the 3 month visit
The number of CD4+CD25+ T cells in adipose tissue, normalized to the total number of CD4+ T cells, will be measured by multi-parameter flow cytometry.
Time frame: Change from baseline to 3 month clinic visit.
Intestinal permeability will be assessed at each clinic visit by administering 2g of mannitol and 5 g of lactulose to the oral glucose tolerance test beverage followed by collection of urine for 5 hours afterwards. Recovery of mannitol and lactulose in urine will be measured by gas chromatography, and will be indicative of the degree of intestinal permeability.
Time frame: Change from baseline to 3 month clinic visit
Zonulin concentrations will be measured by enzyme-linked immunosorbent assay in fasting plasma collected at all clinic visits. Plasma zonulin is a marker of intestinal permeability.
Time frame: Change from baseline to 3 month clinic visit
Lipopolysaccharide binding protein (LBP) will be measured by enzyme-linked immunosorbent assay in fasting plasma collected at all clinic visits. LBP is an acute phase protein secreted by the liver in response to endotoxin (lipopolysaccharide) exposure.
Fred Hutchinson Cancer Center
Other
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