Abstract 3619: Alpha-Glucosidase Inhibition Unmasks the Role of Insulin in Postprandial Hypotension in Autonomic Failure
Postprandial hypotension (PPH), is an important clinical condition associated with syncope, fall, angina and cerebrovascular events. Those at greater risk are elderly and patients with autonomic dysfunction. Because the enteric glucose availability has been proposed to contribute to the pathophysiology of postprandial hypotension (PPH). We hypothesized that acarbose, an alpha-glucosidases inhibitor that decrease the glucose absorption in the small intestine would improve PPH. The effect of 100 mg of acarbose was studied in 7 patients ( 5 females, 2 males, age 65.1 ± 6.6 years, BMI 24.2 ± 4.9 Kg/m2) with pure autonomic failure in a double blind, randomized, crossover study. All participants had severe PPH, defined as a decrease in systolic blood pressure of at least 20 mm Hg within 2 hours of meal ingestion. Baseline measurements were taken for 30 minutes every 5 minutes on supine position. The study medication (Acarbose/Placebo) was administered 20 minutes previous the ingestion of a standard mixed meal consisted of 423 Kcal. Blood pressure and heart rate were monitored for 90 minutes. Neurohumoral parameters were measured at baseline, 15, 30, 45, 60 and 90 minutes of meal ingestion. During placebo, the fall in systolic blood pressure was 42±9 mm Hg as compared to 20±6 mm Hg with acarbose, P<0.05 (Figure 1⇓). Acarbose significantly reduced plasma levels of insulin as compared to placebo, at 60 minutes (19± 3 vs 28±5 pg/ml with placebo, P=0.028). We conclude that acarbose 100 mg successfully improved postprandial hypotension in patients with severe autonomic failure, at least in part by reducing insulin levels a known vasodilator in patients with autonomic failure.