Pharmacogenetic Study of Neurofunctional Brain Areas Related to Food Craving in Obese Patients With Binge Eating Disorder Treated With Topiramate

Obesity has been declared the number one illness of the 21st Century in industrialized countries, and is reaching epidemic proportions. Adoption, twin and family studies have reported that obesity has a strong heritable component and in particular, it has been suggested that BMI in adults is due to genetic influence rather than shared family environment. Binge eating in obese patients was escribed. Therefore, it has been proposed that binge eating disorder (BED) may contribute to obesity in some individuals. Subjects with BED are frequently obese. Conversely, BED is often observed in obese populations, especially the severely obese. Therefore, these findings suggest that BED is a major public health problem and a contributor to the obesity epidemic.

Evidence from twin studies suggests a significant contribution of genetic factor in binge eating. Interestingly, it was reported that relatives of patients with BED displayed a higher prevalence of obesity, particularly of severe obesity than relatives of probands without BED. Adoption and twin studies have consistently shown that, regardless of the population studied, genetic factors play an important role in determining the risk of developing binge eating.

Pharmacological studies reported that topiramate plays an important role in the treatment of binge eating disorder. It has been observed improvement of co-occurring binge eating disorder in patients receiving topiramate for treatment of mood disorder. In addition, topiramate was associated with anorexia and weight loss in clinical trials with epilepsy patients. Also, topiramate has been demonstrated efficacy in pilot and controlled studies for binge eating disorder (BED) associated with obesity. A paper review showed that topiramate weigtht loss was reported in 21 of 32 studies analyzed.

Recently, it was approved on 4/6/2012 the use of topiramate in combination with phentermine (QNEXA) in the Meeting of the Endocrinologic and Metabolic Drugs Advisory Committee of the Food and Drug Administration, as an adjunct to diet and exercise for weight management in patients with a body mass index (BMI) equal to or greater than 30 kilograms (kg) per square meter or a BMI equal to or greater than 27 kg per square meter if accompanied by weight-related co-morbidities.

Finally, animal studies have shown that stimulation of the lateral hypothalamus by glutamate and glutamate agonists, including kainite/AMPA agonists, causes an intense, rapid, dose-dependent increase in food intake.