MedicineWorld.Org
Your gateway to the world of medicine
Home
News
Cancer News
About Us
Cancer
Health Professionals
Patients and public
Contact Us
Disclaimer

Medicineworld.org: Genes influence effectiveness of weight-loss drug

Back to weightwatch Blogs list Cancer blog  


Subscribe To Weightwatch RSS Feed  RSS content feed What is RSS feed?

Genes influence effectiveness of weight-loss drug




Obese patients with a specific genetic make-up lose more weight when taking the weight loss drug sibutramine and undergoing behavioral treatment in comparison 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.



Genes influence effectiveness of weight-loss drug

While there are numerous options for the therapy of obesity, this study examined sibutramine, a medicine approved for the long-term therapy of obesity. The drug creates a feeling of fullness, prevents decline in metabolic rate linked to low calorie diets and causes weight loss, particularly when combined with behavioral treatment. 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 therapy. Since the different markers were present in almost 50 percent of patients, inclusion of screening for these genetic markers before prescribing the medicine may even be cost-effective from a public health perspective".

In this randomized, double-blind, pharmacogenetic study, Dr. Camilleri and his colleagues reviewed behavioral treatment 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 treatment, caused significant weight loss (p = 0.009). The drug resulted in lower values for weight, BMI and proportion of body fat in comparison 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, therapy 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 therapy effects on weight (both p<0.002). However, there was no evidence of synergism between combinations of two genotypes on the response to sibutramine treatment in comparison to the effect on weight loss linked to 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 therapys 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 correlation to obesity.


Posted by: JoAnn    Source




Did you know?
Obese patients with a specific genetic make-up lose more weight when taking the weight loss drug sibutramine and undergoing behavioral treatment in comparison to those without this genetic make-up, reports a new study in Gastroenterology, the official journal of the American Gastroenterological Association (AGA) Institute.

Medicineworld.org: Genes influence effectiveness of weight-loss drug

Asthma| Hypertension| Medicine Main| Diab french| Diabetes drug info| DruginfoFrench| Type2 diabetes| Create a dust free bedroom| Allergy statistics| Cancer terms| History of cancer| Imaging techniques| Cancer Main| Bladder cancer news| Cervix cancer news| Colon cancer news| Esophageal cancer news| Gastric cancer news| Health news| Lung cancer news| Breast cancer news| Ovarian cancer news| Cancer news|

Copyright statement
The contents of this web page are protected. Legal action may follow for reproduction of materials without permission.