💉 GLP-1 Gastric Emptying Delay Satiety Simulator

Normal Gastric Emptying After a Meal

Placeholder: stomach fills, antral pump pushes chyme through pylorus at baseline rate.

• ~28%/hr: Baseline emptying rate (placeholder half-emptying pace)
• ~90 min: Half-emptying time (placeholder typical meal)
• Open/closed cycling: Pyloric sphincter (placeholder gating rhythm)
• ~3/min: Antral contractions (placeholder pacesetter rate)

Antral pump and pyloric gating

Placeholder: antrum contracts rhythmically, pylorus regulates chyme release downstream.

GLP-1 Agonist Acts on Gastric Smooth Muscle

Placeholder: agonist binds GLP-1 receptors on antral and pyloric smooth muscle.

• GLP-1R: Receptor target (placeholder smooth muscle site)
• Minutes–hours: Onset of motility effect (placeholder dose dependent)
• Increased: Pyloric tone (placeholder sphincter narrowing)
• Suppressed: Antral motility (placeholder reduced contractions)

Receptor binding and motility suppression

Placeholder: agonist raises pyloric tone and dampens antral contraction strength.

Emptying Rate Falls — Stomach Stays Distended

Placeholder: chyme lingers, gastric wall stretch and distension persist longer.

• Up to 70%: Emptying slowdown (placeholder at high dose)
• Extended: Distension duration (placeholder longer than baseline)
• Elevated: Wall stretch (placeholder mechanoreceptor load)
• Prolonged: Bolus residence time (placeholder hours not minutes)

Distension kinetics under slowed emptying

Placeholder: slower outflow keeps volume and wall tension high for longer.

Stretch Receptors Signal the Brainstem via Vagus

Placeholder: mechanoreceptors fire, vagal afferents carry fullness signal upward.

• Vagal afferents: Signal pathway (placeholder gut-to-brain route)
• NTS (brainstem): Target nucleus (placeholder relay center)
• Increased: Firing rate (placeholder with distension)
• With CCK, PYY: Signal integration (placeholder co-signals)

Vagal relay to brainstem satiety centers

Placeholder: nucleus tractus solitarius integrates stretch signal into fullness perception.

Prolonged Fullness, Smaller Meals, Nausea Risk

Placeholder: sustained distension reduces intake but risks delayed-emptying side effects.

• Up to ~30%: Meal size reduction (placeholder at high dose)
• Reduced: Meal frequency (placeholder fewer eating episodes)
• Dose dependent: Nausea risk (placeholder high-dose side effect)
• Gradual dose ramp: Titration strategy (placeholder tolerance building)

Balancing satiety benefit against GI side effects

Placeholder: clinicians titrate dose slowly to limit nausea while preserving satiety gain.

Placeholder: excess delay in emptying can tip benefit into nausea and discomfort.