Cortisol Receptor Gene Linked to Binge Eating DisorderThursday, May 6, 2010
Not only do patients on high doses of cortisone regularly develop a typical Cushingoid phenotype (with abdominal obesity, moon face and buffalo hump) but patients also develop a ravenous hunger and appetite with an often dramatic increase in food intake.
Given this impact of the glucocorticoid system on ingestive behaviour, it may be reasonable to ask whether genetic differences in this system can perhaps also play a role in eating disorders?
This question was now addressed by Cellini and colleagues from the University of Florence, Italy, in a paper just published online in Psychiatric Genetics.
The authors studied the distribution of various variants of the glucocorticoid receptor gene in 572 Italian patients: 118 patients with anorexia nervosa, 108 patients with bulimia nervosa, 62 patient with binge eating disorder, 177 obese non-binge eating disorder patients, and 107 unrelated, normal, age-matched controls.
While there were no significant relationships between any of the receptor polymorphisms and other eating disorders, there was a significant association between one variant (rs6198) and binge eating disorder.
In addition, irrespective of eating behaviour, individuals with another genetic variant of this receptor (N363S) tended to have higher a BMI.
While it is always wise to treat such findings, especially when they come from a single, relatively small study, with caution, these results are certainly compatible with the notion that the glucocorticoid system (perhaps not unexpectedly) may well play a role in the development of obesity and binge eating disorder (at least in a subset of patients).
Although it is highly unlikely that finding these genetic variants will lead to a genetic diagnostic test anytime soon, people with this problem may find some comfort in the idea that their genetic makeup may well be a factor that determines their susceptibility to this disorder.
Fortunately, binge-eating disorder is highly responsive to treatment, and professional psychological counseling (sometimes in combination with pharmacotherapy) can lead to the resolution of binge-eating behaviours in the vast majority of patients.
Cellini E, Castellini G, Ricca V, Bagnoli S, Tedde A, Rotella CM, Faravelli C, Sorbi S, & Nacmias B (2010). Glucocorticoid receptor gene polymorphisms in Italian patients with eating disorders and obesity. Psychiatric genetics PMID: 20440229