Bariatric Surgery Candidate
Conditions
Keywords
Bariatric surgery, vitamin D, supplementation
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.
Interventions
DRUGCholecalciferol
DRUGPlacebo
Sponsors
Maria Luger
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| Prevalence of vitamin D deficiency | 24 weeks postoperatively | Prevalence of vitamin D deficiency |
| Co-morbidities | 24 weeks postoperatively | Prevalence of Co-morbidities |
| 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 |
| Blood pressure | 24 weeks postoperatively | Change of vital signs (blood pressure) |
| 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 |
| 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). |
| Depression symptoms | 24 weeks postoperatively | Prevalence of depression symptoms assessed by Beck Depression Inventory Questionnaire |
Countries
Austria
Outcome results
None listed