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

NCT ID: NCT03008525

Last Updated: 2023-07-27

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-03-17
• Study Completion Date: 2026-09-13

Brief 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

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

obese patients (group OB)

patients with body mass index ≥ 35 kg/m²

Group Type: EXPERIMENTAL

subcutaneous and visceral adipose tissue biopsies

Intervention Type: BIOLOGICAL

Subcutaneous and visceral adipose tissue biopsies during operation

blood samples analysis

Intervention Type: BIOLOGICAL

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.

non-obese patients (group NO)

patients with body mass index \< 30 kg/m²

Group Type: ACTIVE_COMPARATOR

subcutaneous and visceral adipose tissue biopsies

Intervention Type: BIOLOGICAL

Subcutaneous and visceral adipose tissue biopsies during operation

blood samples analysis

Intervention Type: BIOLOGICAL

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.

Interventions

subcutaneous and visceral adipose tissue biopsies

Subcutaneous and visceral adipose tissue biopsies during operation

Intervention Type: 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.

Intervention Type: BIOLOGICAL

Eligibility Criteria

Inclusion Criteria

• Subject with a BMI greater than 35 kg / m2 (group OB) or less than 30 kg / m² (group NO)
• Subject undergoing bariatric surgery (OB group) or abdominal surgery (group NO)

Exclusion Criteria

• Regular intake of dietary supplements or vitamin supplements in the last three months
• For the subjects of the group NO:

• Malnourished patient (BMI <18.5 kg / m2, weight loss greater than 5% in 1 month or 10% in 6 months)
• Subject with an infection or inflammatory syndrome (CRP> 10 mg / L and / or white blood cells> 12000 / mm3)
• Non-cancerous subject

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Assistance Publique Hopitaux De Marseille

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Urielle Desalbres

Role: STUDY_DIRECTOR

Assistance Publique Hôpitaux de Marseille

Locations

Assistance Publique Hôpitaux de Marseille

Marseille, , France

Site Status: RECRUITING

Countries

France

Central Contacts

Rene VALERO

Role: CONTACT

rene.valero@ap-hm.fr

0491383393 ext. 33

Facility Contacts

Rene VALERO

Role: primary

rene.valero@ap-hm.fr

Other Identifiers

2016-23

Identifier Type: -

Identifier Source: org_study_id