Research Article Details

Article ID: A19954
PMID: 26242295
Source: Trials
Title: The link between obesity and vitamin D in bariatric patients with omega-loop gastric bypass surgery - a vitamin D supplementation trial to compare the efficacy of postoperative cholecalciferol loading (LOAD): study protocol for a randomized controlled trial.
Abstract: BACKGROUND: Beyond its classical role in calcium homoeostasis and bone metabolism, vitamin D deficiency has been found to be associated with several diseases, including diabetes, non-alcoholic fatty liver disease, and even obesity itself. Importantly, there are limited data on therapeutic strategies for vitamin D deficiency in bariatric patients, and the procedure-specific guidelines may not be sufficient. To improve long-term outcomes, nutritional screening and appropriate supplementation to prevent nutrient deficiencies are urgently needed. Therefore, the aim of this study is to examine effects and safety of a forced dosing regimen of vitamin D versus conventional dose supplementation on vitamin D levels and other parameters in bariatric patients. METHODS/DESIGN: The study includes loading plus repeat dosing compared with repeated administration of vitamin D without a loading dose, according to guidelines, in a prospective, double-blind, randomized controlled trial. Up to a triple oral loading dose is given on day 1, then 2 and 4 weeks after surgery (100,000 IU dose each time), followed by an oral maintenance dose (3420 IU/day). The control group (n = 25) will receive placebo, followed by administration of a standard dose (3420 IU/day). We hypothesize that a significant increase in vitamin D levels will occur in patients in the treatment group (n = 25) by 24 weeks after surgery. Further measurements are aimed at evaluating changes in inflammation, bone turnover, insulin resistance, blood pressure, liver, mental health, and gut microbiota of patients undergoing omega-loop gastric bypass surgery. Furthermore, possible associations between concentrations of vitamin D, the involved enzymes, or vitamin D receptor in adipose and/or liver tissues will be determined. DISCUSSION: To our knowledge, this trial is the first of its kind with this type of vitamin D supplementation in bariatric patients. Its major strength is the design and implementation of evaluation of influencing factors such as liver function, bone health, inflammation, insulin resistance, blood pressure, symptoms of depression, or microbiota. This alternative vitamin D dosing regimen has the potential to be a safe, fast, evidence-based treatment of vitamin D deficiency in bariatric patients. Owing to the increasing number of bariatric patients, it is also of interest to elucidate the link between obesity and vitamin D. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02092376 . Registered on 17 March 2014.
DOI: 10.1186/s13063-015-0877-9

Strategy ID Therapy Strategy Synonyms Therapy Targets Therapy Drugs
S01 Improve insulin resistance insulin sensitizer; insulin resistance; glucose tolerance Biguanide: increases 5-AMP activated protein kinase signaling; SGLT-2 inhibitor; Thiazalidinedione: selective PPAR-γ agonists; GLP-1 agonist Metformin; Empagliflozin; Canagliflozin; Rosiglitazone; Pioglitazone; Liraglutide Details
S06 Regulating intestinal flora intestine gut microbiota; gut microbiota farnesoid X receptor (FXR); fibroblast growth factor-19 (FGF19) Probiotics; Prebiotics; Rifaximin; Yaq-001; Cilofexor; EDP-305; EYP001a; INT-767 Details

Target ID Target Name GENE Action Class UniProtKB ID Entry Name
T18 Acetyl-CoA carboxylase 1 ACACA inhibitor Enzyme Q13085 ACACA_HUMAN Details
T20 Fatty acid synthase FASN inhibitor Enzyme P49327 FAS_HUMAN Details
T07 Bile acid receptor NR1H4 agonist Nuclear hormone receptor Q96RI1 NR1H4_HUMAN Details

Diseases ID DO ID Disease Name Definition Class
I17 1596 Mental depression Mental depression disease of mental health/ cognitive disorder/ mood disorder Details
I02 5113 Nutritional deficiency disease A nutrition disease that is characterized by deficiency of a nutritional element, such as a vitamin, mineral, carbohydrate, protein, fat, or general energy content. https://medlineplus.gov/malnutrition.html disease of metabolism/acquired metabolic disease/nutrition disease Details
I05 9352 Type 2 diabetes mellitus A diabetes that is characterized by chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both. A diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. http://en.wikipedia.org/wiki/Diabetes, http://en.wikipedia.org/wiki/Diabetes_mellitus_type_2 disease of metabolism/inherited metabolic disorder/ carbohydrate metabolic disorder/glucose metabolism disease/diabetes/ diabetes mellitus Details
I14 9970 Obesity An overnutrition that is characterized by excess body fat, traditionally defined as an elevated ratio of weight to height (specifically 30 kilograms per meter squared), has_material_basis_in a multifactorial etiology related to excess nutrition intake, decreased caloric utilization, and genetic susceptibility, and possibly medications and certain disorders of metabolism, endocrine function, and mental illness. https://en.wikipedia.org/wiki/Obesity disease of metabolism/acquired metabolic disease/ nutrition disease/overnutrition Details

Drug ID Drug Name Type DrugBank ID Targets Category Latest Progress
D387 Vitamin D Supplement DB11094 -- Vitamin source drug Under clinical trials Details
D083 CLA Chemical drug DB01211 KCNH2; SLCO1B1; SLCO1B3 -- Under clinical trials Details
D182 Insulin Biological drug DB00030 INSR agonist; CPE modulator&product of -- Under clinical trials Details
D055 Calcium Chemical drug DB01373 CAST; COMP; CP; BMP4; MGP -- Under clinical trials Details
D094 Cysteamine Chemical drug DB00847 GSS stimulant Renal drug Under clinical trials Details
D095 Cysteamine bitartrate Chemical drug DB00847 -- -- Under clinical trials Details