Navigation Links
Genes influence effectiveness of weight-loss drug

Bethesda, MD (Oct. 1, 2008) Obese patients with a specific genetic make-up lose more weight when taking the weight loss drug sibutramine and undergoing behavioral therapy compared to those without this genetic make-up, reports a new study in Gastroenterology, the official journal of the American Gastroenterological Association (AGA) Institute.

The obesity epidemic continues to be an increasingly global problem: an estimated 1.6 billion adults worldwide are overweight (body mass index [BMI]>25) and 400 million are obese (BMI>30). In addition, the incidences of diabetes and other debilitating diseases attributable to obesity continue to rise.

While there are numerous options for the treatment of obesity, this study examined sibutramine, a medication approved for the long-term treatment of obesity. The drug creates a feeling of fullness, prevents decline in metabolic rate associated with low calorie diets and causes weight loss, especially when combined with behavioral therapy. However, weight loss with the drug is highly variable. Therefore, a research team at the Mayo Clinic assessed the influence of specific markers of candidate genes controlling serotonergic and adrenergic mechanisms (α2A-receptor, 5-HTTLPR and GNβ3) on weight loss/body composition in response to sibutramine or placebo.

"We found significantly lower values for weight, BMI and proportion of body fat in patients taking sibutramine. The candidate gene variations provided useful markers of enhanced response to the drug," said Michael Camilleri, MD, AGAF, of the Mayo Clinic and lead author of the study. "Gene variations may help select obese patients who are more likely to experience improved outcome with this treatment. Since the different markers were present in almost 50 percent of patients, inclusion of screening for these genetic markers before prescribing the medication may even be cost-effective from a public health perspective."

In this randomized, double-blind, pharmacogenetic study, Dr. Camilleri and colleagues evaluated behavioral therapy and sibutramine (10 or 15 mg daily) or placebo for 12 weeks in 181 overweight or obese participants. They measured body weight, BMI, body composition, gastric emptying and genetic variation.

Study results showed that sibutramine at both doses, given in combination with behavioral therapy, caused significant weight loss (p = 0.009). The drug resulted in lower values for weight, BMI and proportion of body fat compared to placebo (p<0.01, p<0.001 and p=0.05, respectively). Weight loss at four weeks was a predictor of weight loss achieved at 12 weeks.

There was a statistically significant gene-by-dose interaction for GNβ3 genotype. This gene determines the function of G proteins, which are involved in translating the message from surface receptors that bind the transmitters serotonin and norepinephrine (e.g. of cells controlling appetite). Those surface receptors are indirectly influenced by sibutramine, which blocks the reuptake of the two transmitters. For each candidate gene, treatment effects were observed at 12 weeks (p<0.017) for all specific genotype variants. The research showed gene pairs (e.g. for GNβ3and α2A-receptor) resulted in greater sibutramine treatment effects on weight (both p<0.002). However, there was no evidence of synergism between combinations of two genotypes on the response to sibutramine therapy compared to the effect on weight loss associated with individual genotypes.

"Our results suggest the genetic make-up of patients could predispose their responsiveness to a drug. This could have important implications for the future of personalized molecular-based or individualized medicine," added Dr. Camilleri. As new and exciting research like this study continues into the causes, prevention and treatments for obesity, the role played by the GI tract is becoming more defined. This understanding has the potential to lead to novel endoscopic, pharmacological and nutritional therapies for obesity as well as changes in policies and societal practices related to obesity.


Contact: Alissa Cruz
American Gastroenterological Association

Related medicine news :

1. Genes affect weight loss drug effectiveness
2. UNC study: Parenting can override effect of genes in how babies respond to stress
3. Type 1 diabetes may result from good genes behaving badly
4. Nanomedical approach targets multiple cancer genes, shrinks tumors more effectively
5. Genesis Pharmaceuticals Received New Purchase Orders Worth $12 Million
6. The first autism disease genes
7. Neurogenesis in the adult brain: The association with stress and depression
8. Beyond PTEN: Alternate genes linked to breast, thyroid and kidney cancer predisposition
9. Researchers Find Genes That Influence West Nile Virus
10. ThermoGenesis Announces 10 New BioArchive(R) System Distributors
11. Genesis Pharmaceuticals Announces New Board Member and Forms Committees
Post Your Comments:
(Date:11/26/2015)... ... November 26, 2015 , ... Pixel ... self-animating trailer titles with ProTrailer: Vintage. This newly styled ProTrailer pack comes with ... work with any font, giving users limitless opportunities to stylize and create designs ...
(Date:11/25/2015)... , ... November 25, 2015 , ... ... where preparing the perfect dish and pleasing the palates of attendees is of ... bringing a dish to a seasonal get-together, give these recipes a try this ...
(Date:11/25/2015)... ... 2015 , ... Ministers, senior government and UN agencies, representatives ... of Excellence, and public R&D institutions, civil societies and other partners gathered today ... African Network for Drugs and Diagnostics Innovation, ANDI, Stakeholders Meeting. The three- day ...
(Date:11/25/2015)... ... November 25, 2015 , ... Dental professionals who would like to become ... invited to attend Dr. Mark Iacobelli’s Advanced Implant Mentoring (AIM) CE course. Courses will ... , As the co-founders of Advanced Implant Mentoring (AIM), Dr. Iacobelli and Dr. D’Orazio ...
(Date:11/25/2015)... ... ... Smiles by Stevens is pleased to announce the addition of Botox® ... are aware of the benefits of Botox® in the treatment of moderate facial wrinkling, ... soreness, and pain as a result of Jaw Tension, TMJ (temporo-mandibular joint) disorder, and ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... YORK , November 25, 2015 ... market of self-monitoring blood glucose devices was valued at ... grow with a CAGR of 5.7% during 2015 - ... geriatric population and increasing prevalence of diabetes. In addition, ... diabetes care is also contributing to the growth of ...
(Date:11/25/2015)... China , Nov. 25, 2015 ... the "Company") (NYSE: MR ), ... of medical devices worldwide, today announced ... annual general meeting of shareholders at ... 11/F, Grand Century, 193 Prince Edward West ...
(Date:11/25/2015)... - Will Also Offer Point ... (CME) --> - Will Also Offer ... (CME) --> - Will ... Education (CME) Elsevier , a world-leading ... feature latest diagnostic imaging textbooks and decision support tools, as well ...
Breaking Medicine Technology: