The Effect of Ipomoea batatas (Caiapo) on Glucose Metabolism and Serum Cholesterol in Patients With Type 2 Diabetes

There is considerable and growing interest in neutraceutical products for the treatment of diabetes (1). Recently, it has been shown that caiapo, the extract of white-skinned sweet potato ( Ipomoea batatas ), improves glycemic control in rodents by reducing insulin resistance (2). The aim of our study was to assess the effect of caiapo on glucose metabolism and its tolerability and mode of action in male Caucasian type 2 diabetic patients in a randomized, double-blind prospective study in parallel groups controlled with placebo. A total of 18 male type 2 diabetic patients (age: 58 ± 8 years; weight: 88 ± 3 kg; BMI: 27.7 ± 2.7 kg/m2; means ± SEM) treated by diet alone were randomized to receive placebo or 2 (low dose) or 4 g (high dose) caiapo (four tablets each containing 168 or 336 mg powdered white-skinned sweet potato [ I. batatas ], respectively) before breakfast, lunch, and dinner for 6 weeks. The study protocol was approved by the Ethics Committee of the University of Vienna, and informed consent was obtained from all patients before inclusion into the study. Safety parameters (hematology and blood chemistry, including hepatic enzymes and urinanalysis) were controlled before and at the end of the study, and patients were asked to report any adverse events. Patients were seen weekly during the 6-week trial, and fasting blood glucose was measured. Each subject underwent a frequently sampled intravenous glucose tolerance test (FSIGT) …