Improved metabolic control by Ipomoea batatas (Caiapo) is associated with increased adiponectin and decreased fibrinogen levels in type 2 diabetic subjects. The effect of Ipomoea batatas (Caiapo) on glucose metabolism and serum cholesterol in patients with type 2 diabetes: a randomized study. Efficacy of Ipomoea batatas (Caiapo) on diabetes control in type 2 diabetic subjects treated with diet.
The extract of the white-skinned sweet potato Ipomoea batatas (Caiapo) has been shown to ameliorate glucose control by improving insulin sensitivity in patients with type 2 diabetes mellitus (T2DM). The present study was designed to further evaluate its mode of action on insulin sensitivity over an extended period of time as well as the effects on fibrinogen and other markers of low-grade inflammation.
                In this randomized trial, 27 patients with T2DM on diet only received 4 g of Caiapo daily for 5 months; 34 patients placebo. Before and after therapy, insulin sensitivity [oral glucose insulin sensitivity (OGIS), as glucose clearance from oral glucose tolerance test], parameters of diabetes control, lipids, plasma adiponectin, high-sensitivity C-reactive protein (hs-CRP) and fibrinogen were measured.
                Following Caiapo, we observed an increase in OGIS (293 +/- 15 vs. 321 +/- 12 ml/m(2)/min, p = 0.0072) and adiponectin (5.97 +/- 0.65 to 6.63 +/- 0.70 microg/ml, p = 0.013), while fibrinogen decreased from 3.83 +/- 0.16 to 3.64 +/- 0.18 mg/ml (p = 0.02). This was associated with an improvement in glycated haemoglobin (HbA1c: 6.46 +/- 0.12 vs. 6.25 +/- 0.11%, p = 0.008), fasting glucose (138 +/- 4 vs. 128 +/- 5 mg/dl, p = 0.039) and triglycerides (2.36 +/- 0.22 vs. 2.07 +/- 0.25 mmol/l, p = 0.032). Body weight, lipid levels and hs-CRP were not altered. No changes were observed in the placebo group except for HbA1c, which significantly increased from 6.25 +/- 0.10 to 6.50 +/- 0.12% (p = 0.0001).
                This study confirms the beneficial effects of Caiapo on glucose and HbA1c control in patients with T2DM after 5 months follow-up. Improvement of insulin sensitivity was accompanied by increased levels of adiponectin and a decrease in fibrinogen. Thus, Caiapo can be considered as natural insulin sensitizer with potential antiatherogenic properties. nan To investigate the tolerability, efficacy, and mode of action of Caiapo, an extract of white sweet potatoes, on metabolic control in type 2 diabetic patients.
                A total of 61 type 2 diabetic patients treated by diet were given 4 g Caiapo (n = 30; mean age 55.2 +/- 2.1 years; BMI 28.0 +/- 0.4 kg/m(2)) or placebo (n = 31; mean age 55.6 +/- 1.5 years; BMI 27.6 +/- 0.3 kg/m(2)) once daily for 12 weeks. Each subject underwent a 75-g oral glucose tolerance test (OGTT) at baseline and after 1, 2, and 3 months to assess 2-h glucose levels. Additionally, fasting blood glucose, HbA(1c), total cholesterol, and triglyceride levels were measured.
                After treatment with Caiapo, HbA(1c) decreased significantly (P < 0.001) from 7.21 +/- 0.15 to 6.68 +/- 0.14%, whereas it remained unchanged (P = 0.23) in subjects given placebo (7.04 +/- 0.17 vs. 7.10 +/- 0.19%). Fasting blood glucose levels decreased (P < 0.001) in the Caiapo group (143.7 +/- 1.9 vs. 128.5 +/- 1.7 mg/dl) and did not change in the placebo group (144.3 +/- 1.9 vs. 138.2 +/- 2.1 mg/dl; P = 0.052). A decrease in body weight was observed in both the placebo group (P = 0.0027) and in the Caiapo group (P < 0.0001), probably due to a better- controlled lifestyle. In the Caiapo group, body weight was related to the improvement in glucose control (r = 0.618; P < 0.0002). Two-hour glucose levels were significantly (P < 0.001) decreased in the Caiapo group (193.3 +/- 10.4 vs. 162.8 +/- 8.2 mg/dl) compared with the placebo group (191.7 +/- 9.2 vs. 181.0 +/- 7.1 mg/dl). Mean cholesterol at the end of the treatment was significantly lower in the Caiapo group (214.6 +/- 11.2 mg/dl) than in the placebo group (248.7 +/- 11.2 mg/dl; P < 0.05). No significant changes in triglyceride levels or blood pressure were observed, and Caiapo was well tolerated without significant adverse effects.
                This study confirms the beneficial effects of Caiapo on plasma glucose as well as cholesterol levels in patients with type 2 diabetes. For the first time, the long-term efficacy of Caiapo on glucose control was demonstrated by the observed decrease in HbA(1c). Thus, the neutraceutical Caiapo seems to be a useful agent in the treatment of type 2 diabetes.
There is insufficient evidence to recommend sweet potato for type 2 diabetes mellitus. Improvement in trial methodology as well as addressing the issues of standardization and the quality control of preparations of other varieties of sweet potato are required. For medical nutritional therapy, further observational trials and RCTs evaluating the effects of sweet potato are needed to guide any recommendations in clinical practice.