Postprandial hypotension

🍽️ Postprandial hypotension is diagnosed by measuring blood pressure changes after ingestion of high-carbohydrate meals. It is especially relevant in the elderly and those with neurological or cardiovascular comorbidities. ⚠️ Important because it may cause falls, syncope, and reduced quality of life, yet can often be overlooked in clinical practice.

📖 About

• ⬇️ Defined as a drop in BP (with or without standing) after meals.
• 👵 Common in older adults, particularly with neurological disease.
• 🧠 Associated with Parkinson’s disease, diabetes mellitus, heart failure, and CKD.
• Often asymptomatic, detected on review of unexplained dizziness or falls.

🧬 Aetiology

• 🍲 Gastric/oesophageal distension after meals.
• 🧩 Vasodilatory peptides released in the gut.
• 🩸 ↑ Splanchnic blood pooling post-meal.
• ⚡ Impaired baroreflex function (ageing, hypertension).
• 📉 Inadequate sympathetic firing or vascular responsiveness to noradrenaline.
• 🧪 Insulin-mediated vasodilation in high-CHO meals.

🩺 Clinical Features

• ⏱️ Symptoms occur within 2 hours of eating.
• 🍞 Triggered by large carbohydrate meals or 🍷 alcohol.
• 😵 May cause dizziness, weakness, blurred vision, near-syncope.
• 🚶 Often reported in public or social settings, raising fall risk.

🔎 Investigations

• 🩸 Bloods: FBC, U&E, LFTs, glucose, cortisol (if suspicion of Addison’s).
• 📉 Supine & standing/after-meal BP monitoring (look for ≥20 mmHg systolic drop).
• 🫀 ECG, CXR to exclude other causes of hypotension.

💊 Management

• 🍽️ Dietary: Avoid large high-CHO meals ± alcohol; prefer smaller, low-CHO meals.
• 🚶 Postural: Stand slowly after eating; avoid sudden post-meal activity.
• 💧 Water bolus: 400–500 mL within 5 min before meals can ↑ BP.
• 🩱 Abdominal binders: May reduce venous pooling before outings/events.
• 💦 Ensure good hydration.
• 💊 Pharmacological (specialist): – Caffeine ☕ (stimulates sympathetic system) – Somatostatin analogues (e.g. octreotide) – Vasopressin analogues – NSAIDs (rare, not first-line due to side effects)

📚 References

• Orthostatic Hypotension: Management of a Complex, but Common, Medical Problem

🧾 Clinical Case Examples – Postprandial Hypotension

Case 1 – The Fainting Lunch 🥪 An 82-year-old woman with Parkinson’s disease faints in a café shortly after lunch. Paramedics find her BP 90/50 mmHg, recovering to 130/70 mmHg after lying down. 👉 Likely diagnosis: Postprandial hypotension. 👉 Management: Education on smaller, low-carbohydrate meals, hydration, and gradual mobilisation after eating.

Case 2 – Recurrent Falls 👵 A 76-year-old man with type 2 diabetes reports dizziness and unsteadiness after meals. He has had three unexplained falls in the past 2 months. Supine BP is 145/80 mmHg, but 30 minutes after a carbohydrate-rich meal it falls to 110/65 mmHg. 👉 Likely diagnosis: Postprandial hypotension in diabetes with autonomic neuropathy. 👉 Management: Postprandial water bolus, diet modification, consider abdominal binder for outings.

Case 3 – The Cardiology Follow-Up ❤️ A 70-year-old man with heart failure on beta-blockers reports lightheadedness after Sunday roasts. No symptoms otherwise. Clinic BP is 135/75 mmHg, but ambulatory monitoring shows repeated systolic drops of 25 mmHg within 1 hour of eating. 👉 Likely diagnosis: Postprandial hypotension, medication- and meal-related. 👉 Management: Adjust beta-blocker timing, encourage smaller meals, optimise hydration.

Case 4 – Asymptomatic Drop 📉 A 68-year-old woman with CKD attends for routine geriatric assessment. During post-meal monitoring, her systolic BP falls by 25 mmHg, but she denies any dizziness or syncope. 👉 Likely diagnosis: Asymptomatic postprandial hypotension. 👉 Management: Education and monitoring; intervene if symptoms or falls develop.