The following observations have led us to hypothesize that patients with BN have a satiety deficiency
Assessment of Gastric ComplianceAssessment of Gastric ComplianceResponse to a Meal: Gastric SensoryResponse to a Meal: Gastric SensoryMotor Function in Bulimia NervosaMotor Function in Bulimia NervosaJL Guss, HR Kissileff, E Zimmerli, M Devlin, B WalshJL Guss, HR Kissileff, E Zimmerli, M Devlin, B WalshObesity Research Center-St Lukes-RooseveltObesity Research Center-St Lukes-RooseveltHospitalHospitalColumbia UniversityColumbia University
Bulimia Nervosa (BN)-A Satiety Disturbance?Bulimia Nervosa (BN)-A Satiety Disturbance?Episodes of uncontrolled hyperphagiaEpisodes of uncontrolled hyperphagiaRate of eating does not decline during mealsRate of eating does not decline during mealsEat more than controls to reach same fullnessEat more than controls to reach same fullnessPost-prandial CCK-release is diminishedPost-prandial CCK-release is diminished
Gastric Relaxation (Accommodation)Gastric Relaxation (Accommodation)Adaptive relaxation: Postprandial gastricAdaptive relaxation: Postprandial gastricrelaxation in response to ingested nutrientrelaxation in response to ingested nutrientIncreases gastric volume relative to fastingIncreases gastric volume relative to fastingImpaired in BNImpaired in BN
Impaired Relaxation Response to FoodImpaired Relaxation Response to FoodnormalnormalImpaired accommodationImpaired accommodationfood redistributes tofood redistributes toantrumantrumFundicFundicaccommodationaccommodation(receptive relaxation)(receptive relaxation)MealMealImpairedImpairedaccommodationaccommodation
Gastric Relaxation-Healthy ControlGastric Relaxation-Healthy Control
Gastric Relaxation-Patient with BNGastric Relaxation-Patient with BN
Blunted Relaxation Response in BNBlunted Relaxation Response in BNBlunted relaxation in BNPatientsControls
Bulimia Nervosa: Gastric CapacityBulimia Nervosa: Gastric Capacity03006009001200Bulimics Normalsfrom Geliebter et al 1992from Geliebter et al 1992
Time (min)0 10 20 30 40 50 60 70 80 90PercentofInitialRemaining405060708090100Bulimia NervosaControlsGastric Emptying: Patients vs ControlsGastric Emptying: Patients vs Controls
AimAimTo determine whether meal-induced changesTo determine whether meal-induced changesin motor-sensory responses to gastricin motor-sensory responses to gastricdistension are disturbed in BN.distension are disturbed in BN.To test motor-sensory response to distensionTo test motor-sensory response to distensionby measuring gastric compliance: change inby measuring gastric compliance: change ingastric volume as a function of changinggastric volume as a function of changingpressurepressure
HypothesisHypothesisMotor and sensory responses to the fillingMotor and sensory responses to the fillingeffects of large meals are impaired in BN.effects of large meals are impaired in BN.
Gastric ComplianceGastric ComplianceVolume response to an imposed pressureVolume response to an imposed pressureVolume change at stepwise pressure incrementsVolume change at stepwise pressure incrementsbefore and after a meal:before and after a meal:Intragastric volume response plotted on y-axisIntragastric volume response plotted on y-axisImposed incrementing pressure plotted on x-axisImposed incrementing pressure plotted on x-axisCompliance = slope of pressure-volume curveCompliance = slope of pressure-volume curveMeasured by imposing isobaric stepwise distensionsMeasured by imposing isobaric stepwise distensionsA Barostat device applies fixed pressure incrementsA Barostat device applies fixed pressure incrementsand records intragastric volumeand records intragastric volume
ProcedureProcedureBalloon swallowed @ 1500 hrs, after 6 hr fastBalloon swallowed @ 1500 hrs, after 6 hr fastMDP (minimal distending pressure) obtainedMDP (minimal distending pressure) obtainedDistending pressure increased 2 mmHg every 2Distending pressure increased 2 mmHg every 2min, starting at minimal distending pressure (MDP)min, starting at minimal distending pressure (MDP)Barostat records balloon volume every secondBarostat records balloon volume every secondBefore next pressure-step, subjects rate abdominalBefore next pressure-step, subjects rate abdominalsensations on a 6-point scalesensations on a 6-point scaleDistension sequence ends at volume of 750 mL or ifDistension sequence ends at volume of 750 mL or ifsubject reports painsubject reports pain200 cc Ensure consumed p.o.200 cc Ensure consumed p.o.Procedure repeated from MDP-measurementProcedure repeated from MDP-measurement
Summary of ResultsSummary of ResultsPost meal gastric relaxation is blunted in BN.Post meal gastric relaxation is blunted in BN.Gastric compliance appears normal in BN.Gastric compliance appears normal in BN.