Postprandial blood pressure reduction.

Recently it has been shown that, after a meal, blood pressure may fall in the elderly, in patients with autonomic failure and in patients on haemodialysis. This review deals with the available data on postprandial blood pressure reduction, the clinical significance and some pathophysiological hypotheses. The mechanism is not fully understood, but postprandial blood pressure reduction seems to be related to glucose related factors, since blood pressure only falls after oral glucose loading, but not after oral fructose, fat or protein loading. Vasoactive gastrointestinal peptides may play a role in the glucose induced vasodilation of splanchnic vasculature, but attempts to identify such peptides have been unsuccessful. The role of insulin in postprandial blood pressure reduction remains to be elucidated, but it does not appear to have any influence on systemic vasodilation or baroreflex response. Although the clinical significance of postprandial blood pressure reduction remains uncertain, patients can be advised in several ways on how to avoid this symptom. Treatment of hypertension, small carbohydrate meals, caffeine and treatment with the somatostatin analogue SMS 201-995 may have a beneficial effect. Patients on haemodialysis with symptomatic hypotension should not consume meals during the procedure.