Psychobiology of purging disorder: reduction in circulating leptin levels in purging disorder in comparison with controls.

OBJECTIVE: Purging disorder (PD), a recently recognized eating disorder syndrome, is differentiated from bulimia nervosa (BN) based on the absence of objectively large binge episodes. BN has been associated with low serum leptin levels. This study examined whether PD is also characterized by low serum leptin.

METHOD: Participants included women with PD (n = 20) or BN (n = 37), and non-eating disorder controls (n = 33). Blood samples for measurement of leptin and total ghrelin were obtained after overnight fast.

RESULTS: In comparison with control values, leptin levels were significantly decreased in PD (p < .01), as well as in BN (p < .02). Plasma ghrelin levels did not differ significantly across groups.

DISCUSSION: These results provide the first evidence that PD is associated with alteration in a neurobiological pathway influencing eating patterns and body weight. Further research is needed to assess whether low leptin levels in PD and BN are associated with restrained eating and weight suppression.