BACKGROUND: Although esophageal hypomotility is prevalent in obese patients, its cause remains unknown. Leptin, a hormone derived from adipose tissue, may be involved in this phenomenon because it has been shown to decrease gastric and intestinal motility in animals. It has been hypothesized that elevated plasma leptin concentration is a risk factor for esophageal dysmotility in obese patients.OBJECTIVE: To determine whether plasma leptin concentrations are higher in obese patients with esophageal hypomotility than in obese patients with a normal motility profile.METHOD: Fasting plasma leptin concentration (assessed by radioimmuoassay) was measured in all patients who were included in a study protocol investigating esophageal manometry before bariatric surgery. The patients completed standardized surveys regarding epidemiological data, upper gastrointestinal symptoms, medical history and medication(s). Basal levels of leptin, as well as corrected leptin scores adjusted for sex and body mass index, were compared in patients with and without esophageal dysmotility.RESULTS: Nine patients without dysmotility and eight with dysmotility were included. Both groups were comparable with regard to age (42±9 versus 38±9 years), sex (78% versus 75% women) and body mass index (49±10 kg/m2 versus 42±7 kg/m2). There were no significant differences regarding medication(s) and comorbidities between the two groups. When compared with normal predicted values, the corrected leptin scores were 30% higher in patients with dysmotility than in the control group with normal motility (P≤0.05).CONCLUSION: Obese patients with esophageal dysmotility exhibited elevated plasma leptin concentrations, suggesting a role for leptin in promoting esophageal hypomotility.