NCT03008525

Vitamin D and Its Metabolites Quantification in Adipose Tissues of Obese and Non-obese Patients.

Vitamin D and Its Metabolites Quantification in Adipose Tissues of Obese and Non-obese

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 60 (estimated)
• Sponsor: Assistance Publique Hopitaux De Marseille · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Not accepted

Summary

Vitamin D (VD) is a pleiotropic hormone, involved in many physiological processes including calcium and phosphorus absorption. The VD metabolism begin to be well-known and involves a hepatic hydroxylation (mediated by enzymes, which belong to the cytochrome P450 family) leading to the production of the 25(OH)D, which corresponds to the circulating form of the VD. After circulation in blood, the 25(OH)D is submitted to a second hydroxylation in the kidney resulting to the generation of 1,25(OH)2D, the active metabolite of VD. Numerous epidemiological studies reported an inverse relationship between obesity and circulation level of 25(OH)D. Several mechanisms could explain the low level of 25(OH)D observed in obese subjects, the more classical evoked being based on sequestration and/or dilution of VD in adipose tissue (AT), the main VD storage site. However, this mechanism has never been demonstrated. In order to confirm this hypothesis, the concentration of VD and its metabolites in adipose tissue need to be quantified. The objective of this study is to determine the concentration of VD and its metabolites in adipose tissue as well as adipose tissue mass quantification and distribution (visceral or subcutaneous) to highlight putative difference of VD and its metabolites quantities between obese and non-obese patients. A quantification of VD metabolism, inflammation and lipid metabolism gene expression will be realized on biopsies. Correlations between gene expression and quantity of VD in tissue will be carrying out.

Conditions

• Obesity; Endocrine

Interventions

Type	Name	Description
BIOLOGICAL	subcutaneous and visceral adipose tissue biopsies	Subcutaneous and visceral adipose tissue biopsies during operation
BIOLOGICAL	blood samples analysis	Blood sampling is required to measure plasma cholecalciferol, calcidiol and calcitriol concentrations, as well as biological parameters of interest. Another plasma/serum tube is used to measure pro- and anti-inflammatory cytokines and adiponectin.

Timeline

• Start date: 2017-03-17
• Primary completion: 2025-09-13
• Completion: 2026-09-13
• First posted: 2017-01-02
• Last updated: 2023-07-27

Locations

1 site across 1 country: France