Postprandial Hypotension

A decline in arterial blood pressure that occurs after a meal.

In clinically stable, unmedicated elderly persons, blood pressure decreases significantly after morning and noon meals; such decreases do not occur in younger persons. In up to one third of elderly persons, blood pressure decreases >= 20 mm Hg within 75 minutes of eating a meal. The incidence of postprandial hypotension is greatest among elderly persons with hypertension or autonomic nervous system dysfunction. In one study of institutionalized elderly persons, postprandial hypotension accounted for 8% of syncopal episodes.

Postprandial hypotension is thought to be due to impaired baroreflex compensation for splanchnic blood pooling during digestion. Alterations in autonomic control of heart rate and vascular resistance are probably underlying causes of this syndrome. Patients with postprandial hypotension and autonomic dysfunction have impaired forearm vasoconstriction, reduced systemic vascular resistance, and abnormal sympathetic nervous system control of heart rate after a meal.

Blood pressure should be measured once before meals and again at 30 and 60 minutes after meals in elderly patients who have postprandial dizziness, falls, syncope, or other cerebral or cardiac ischemic symptoms.

Treatment

Symptomatic patients should not take hypotensive drugs before meals and should lie down after meals. Reducing the dose of hypotensive drugs and eating small, frequent meals may also help. Walking after a meal helps restore normal circulation in some patients; however, hypotension may recur when the activity is stopped.

Low doses of a nonsteroidal anti-inflammatory drug, caffeine 200 to 250 mg with or without dihydroergotamine 6 to 10 µg/kg sc, or octreotide 12 to 16 µg sc before a meal may help. Caffeine should be taken only in the morning so that the effect wears off by evening, allowing sleep and preventing drug tolerance.