Dopamine Action on Metabolism Depending on Genetic Heterogeneity - a Randomized, Placebo-controlled Double Blind Study
Overview
- Phase
- Phase 2
- Intervention
- Placebo
- Conditions
- Obesity
- Sponsor
- University Hospital Tuebingen
- Enrollment
- 120
- Locations
- 3
- Primary Endpoint
- Interaction between FTO genotype and treatment on change in body weight.
- Status
- Completed
- Last Updated
- 5 months ago
Overview
Brief Summary
Obesity is a widespread disease with increasing prevalence and associated with serious secondary complications. So far, the origin of the disease, regardless of an existing positive energy balance, is not fully understood. In addition to environmental factors, the genetic background plays an important role in the pathogenesis of obesity. Of common genetic polymorphisms, variants in the fat mass and obesity associated gene (FTO) locus have the highest effect size on body weight. Animal and first clinical studies indicate that FTO variants interact with dopamine signaling in the brain, thus influencing the risk of overweight. In fact, preliminary results indicate that enhancing dopamine signaling with the dopamine agonist bromocriptine, depending on the FTO genotype, either induces weight loss or has a neutral effect on body weight.
The planned clinical trial serves to develop a genotype-specific and thus individualized therapy approach for obesity. The influence of dopamine agonist therapy on weight loss as a function of the FTO (rs8050136) genotype is to be tested.
Here, the greatest weight loss is expected to occur in subjects carrying the homozygous risk-allele (AA).
So far, there are only a few established conservative therapy forms of obesity, so that bariatric interventions with an increasing rate are necessary to achieve weight loss and thus a reduction in overall morbidity and mortality. Among the approved drug therapies for obesity, bromocriptine is commonly used. In addition, some interventions require injections. An early, conservative individualized, genotype-specific treatment with little side-effects would enable simple treatment of obesity.
Study design: 150 obese (BMI > 30) subjects (50 / study center) will be enrolled in the study. The subjects will be stratified according to their FTO genotype (rs8050136). Subjects will be randomized into placebo or bromocriptine treatment group. Treatment will last for 18 weeks and a follow-up will be performed 30 weeks after baseline.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Body mass index (BMI) between \>30 kg/m².
- •Understand and voluntarily sign an informed consent document prior to any study related assessments/procedures.
- •Females of childbearing potential (FCBP) must agree to utilize a reliable form of contraception simultaneously or practice complete abstinence from heterosexual contact while participating in the study.
- •Males must agree to use a latex condom during any heterosexual contact while participating in the study and to refrain from donating semen or sperm while participating in this study.
Exclusion Criteria
- •Women during pregnancy and lactation.
- •History of hypersensitivity to the investigational medicinal product or to any drug with similar chemical structure or to any excipient present in the pharmaceutical form of the investigational medicinal products.
- •Participation in other clinical trials or observation period of competing trials up to 30 days prior to this study.
- •Diabetes mellitus
- •Treatment with Methyldopa, levodopa, dopamine agonists, metoclopramid, domperidon, glycerol nitrate, griseofulvin, azol-antimycotic drugs, macrolide-antibiotics, octreotide, orlistat, tamoxifen, liraglutide
- •Any relevant cardiovascular disease, e.g. myocardial infarction, acute coronary syndrome, unstable angina pectoris, Percutaneous transluminal coronary angioplasty (PTCA), heart failure (NYHA III-IV), stroke or transient ischemic attack (TIA)
- •Acute or chronic viral hepatitis or liver cirrhosis
- •Impaired renal function, defined as estimated Glomerular Filtration Rate (eGFR) ≤ 60 ml/min (MDRD formula) as determined during screening.
- •Medical history of cancer and/or treatment for cancer within the last 5 years.
- •Claustrophobia
Arms & Interventions
FTO SNP rs8050136 (AA), Placebo
Participants with FTO SNP rs8050136 AA receiving matching Placebo
Intervention: Placebo
FTO SNP rs8050136 (AA), Bromocriptine
Participants with FTO SNP rs8050136 AAreceiving Bromocriptine up to 5 mg
Intervention: Bromocriptine
FTO SNP rs8050136 (CA), Placebo
Participants with FTO SNP rs8050136 CA receiving matching Placebo
Intervention: Placebo
FTO SNP rs8050136 (CA), Bromocriptine
Participants with FTO SNP rs8050136 CA receiving Bromocriptine up to 5 mg
Intervention: Bromocriptine
FTO SNP rs8050136 (CC), Placebo
Participants with FTO SNP rs8050136 CC receiving matching Placebo
Intervention: Placebo
FTO SNP rs8050136 (CC), Bromocriptine
Participants with FTO SNP rs8050136 CC receiving Bromocriptine up to 5 mg
Intervention: Bromocriptine
Outcomes
Primary Outcomes
Interaction between FTO genotype and treatment on change in body weight.
Time Frame: 18 weeks
Interaction between FTO (single nucleotide peptide) SNP rs8050136 genotype and treatment (bromocriptine or placebo) on change in body weight.
Secondary Outcomes
- Effect of bromocriptine vs. placebo on body weight(18 weeks)
- Effect of bromocriptine vs. placebo on dietary intake(18 weeks)
- Effect of bromocriptine vs. placebo on whole body insulin sensitivity(18 weeks)
- Effect of bromocriptine vs. placebo on processing of food cues in the brain(18 weeks)
- Effect of bromocriptine vs. placebo on brain insulin sensitivity(18 weeks)
- Effect of bromocriptine vs. placebo on body fat distribution(18 weeks)
- Effect of bromocriptine vs. placebo on insulin secretion(18 weeks)
- Effect of bromocriptine vs. placebo on physical activity(18 weeks)
- Effect of bromocriptine vs. placebo on serum prolactin concentrations(18 weeks)
- Effect of bromocriptine vs. placebo on glucose tolerance(18 weeks)
- Effect of bromocriptine vs. placebo on resting energy expenditure(18 weeks)