ObjectivesPostprandial hypotension (PPH) is a unique clinical phenomenon in the elderly, but its underlying pathogenesis has not been completely elucidated, and drug treatment is still in clinical exploratory stage. The aim of the study was to evaluate the relationship between the fall in postprandial blood pressure and splanchnic blood flow, and to provide a theoretical basis for the treatment of PPH by taking acarbose.Patients and methodsThe study included 20 elderly inpatients diagnosed with PPH concomitant with abnormal glucose metabolism at stable condition. They were treated with 50mg acarbose with their meal to observe the changes in blood pressure, heart rate, and blood glucose level, and to monitor the hemodynamics of the superior mesenteric artery (SMA) before and after treatment.ResultsWithout acarbose treatment, patients after a meal had significantly decreased systolic and diastolic blood pressure, faster postprandial heart rate, higher postprandial glucose level at each period, and increased postprandial SMA blood flow compared with that at fasting state (P<0.05). Acarbose treatment significantly attenuated the decrease of postprandial systolic blood pressures from 35.5012.66 to 22.25 +/- 6.90mmHg (P=0.000), the increase of heart rate from 9.67 +/- 5.94 to 5.33 +/- 3.20beats/min (P=0.016), the increase of postprandial blood glucose from 3.55 +/- 1.69 to 2.28 +/- 1.61mmol/l (P=0.000), the increase of postprandial SMA blood flow from 496.80 +/- 147.15 to 374.55 +/- 97.89ml/min (P=0.031), and the incidence of PPH, syncope, falls, dizziness, weakness, and angina pectoris (P<0.05). The maximal decrease of postprandial systolic blood pressure was positively associated with the maximal increase in postprandial SMA blood flow (r=0.351, P=0.026). Acarbose treatment showed no significant side effects.ConclusionThe increase in postprandial splanchnic perfusion is one of the reasons for PPH formation. Acarbose may exert its role in PPH treatment by reducing postprandial gastrointestinal blood perfusion. Giving 50mg acarbose with a meal to treat PPH concomitant with abnormal glucose metabolism is effective and safe in very old patients.