The Link Between Obesity And Vitamin D in Bariatric Patients With Omega-loop Bypass Surgery

Phase 4

Completed

• Conditions: Bariatric Surgery Candidate
• Interventions: Drug: Placebo; Drug: Cholecalciferol

• Registration Number: NCT02092376
• Lead Sponsor: Maria Luger

Brief Summary

The aim of the study is to increase vitamin D concentrations or to keep it on high level, respectively, by supplementing with vitamin D3 in a different dose regime, and to improve the overall health status in bariatric patients. In this project, the vitamin D status, the parameters of inflammation, bone turnover, insulin resistance, liver and depression score of bariatric patients are expected to improve, due to supplementation of a loading dose compared to the standard therapy.

Detailed Description

Not available

Study Timeline

• Study Start: 2014-03
• Study First Submitted: 2014-03-17
• Study First Submitted QC: 2014-03-19
• Study First Posted: 2014-03-20
• Primary Completion: 2015-10
• Study Completion: 2016-06
• Status Verified: 2016-07
• Last Update Submitted: 2016-07-13
• Last Update Posted: 2016-07-14

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 50

Inclusion Criteria

• Planned omega loop bypass surgery
• 25-hydroxy vitamin D < 75 nmol/l
• BMI >40 or ≥35 kg/m2 with co-morbidities e.g. diabetes mellitus, hypertension
• Body weight <140 kg (due to limitation of DEXA measurement)
• Capability to consent

Exclusion Criteria

• Another planned form of bariatric surgery
• Hypercalcemia (calcium >2.63 mmol/l) or hypocalcemia (<1.75 mmol/l)
• Renal insufficiency (creatinine >133 μmol/l or GFR <50 ml/min)
• Primary hyperparathyroidism
• Malignancy
• Infection e.g. human immunodeficiency virus
• Medical conditions requiring daily calcium supplements or antacid use
• Known hypersensitivity to cholecalciferol
• No capability to consent
• Imprisoned persons

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	The placebo loading dose (oil) is divided into three administrations and will be given over the first months. All patients in the placebo group will receive the first placebo loading dose at day of discharge. After the last placebo loading dose a maintenance dose of 3420 IU per day should maintain the 25-hydroxy vitamin D concentration. It should be administered for up to 46 weeks (until follow-up).
Intervention	Cholecalciferol	The loading dose of 300 000 IU is divided into three doses (100 000 IU) and will be given over the first months. All patients in the intervention group will receive the first loading dose of 100 000 IU at day of discharge. The second (2 weeks) and third (4 weeks postoperative) administration will be given based on the 25-hydroxy vitamin D concentration. After the last respectively third loading dose a maintenance dose of 3420 IU per day should maintain the high 25-hydroxy vitamin D concentration. It should be administered for up to 46 weeks (until follow-up visit)

Primary Outcome Measures

Name	Time	Method
25-hydroxy vitamin D levels	24 weeks postoperatively	25-hydroxy vitamin D levels after 24 weeks measured in intervention and placebo group, adjusting for the baseline value as covariate

Secondary Outcome Measures

Name	Time	Method
Co-morbidities	24 weeks postoperatively	Prevalence of Co-morbidities
Prevalence of vitamin D deficiency	24 weeks postoperatively	Prevalence of vitamin D deficiency
Laboratory parameters	24 weeks postoperatively	Change in laboratory parameters compared to baseline: vitamin D status, bone turnover markers, calcium homeostasis, parathyroid hormone, inflammation, insulin resistance
Prevalence of sufficient vitamin D	24 weeks postoperatively	Number of patients reaching 25-hydroxyvitamin D levels above 75 nmol/l
Blood pressure	24 weeks postoperatively	Change of vital signs (blood pressure)
Depression symptoms	24 weeks postoperatively	Prevalence of depression symptoms assessed by Beck Depression Inventory Questionnaire
Prescribed medication	24 weeks postoperatively	Change in prescribed medication
Body weight, body composition	24 weeks postoperatively	Change in body weight and body composition by bioelectrical impedance analysis
Bone mineral density and body fat content	24 weeks postoperatively	Assessment of bone mineral density and total body fat content by DEXA
Liver condition	24 weeks postoperatively	Measurement of liver stiffness and fat content by FibroScan and CAP
Dietary assessment	24 weeks postoperatively	Dietary assessment will be documented with a 5-day food record to calculate vitamin D intake and the Mediterranean Score (questionnaire with calculated score)
Gut microbiota composition	24 weeks postoperatively	Association between vitamin D, gut microbiota and surgery-induced weight loss, by collecting stool samples
Vitamin D in adipose and liver tissue	during surgery	For instance, for the purposes of describing adipose depot vitamin D concentrations and expression of enzymes in subcutaneous, visceral adipose and liver tissue samples will be collected during the omega loop gastric bypass surgery. Furthermore, the liver tissue samples should be used in addition for a histological examination as extended diagnostics (NAFLD/ NASH).

Trial Locations

Locations (1)

Medical University of Vienna; 🇦🇹 Vienna, Austria