- The effect of Ipomoea batatas (Caiapo) on glucose metabolism and serum cholesterol in patients with type 2 diabetes: a randomized study. Ludvik, B.H., Mahdjoobian, K., Waldhaeusl, W., Hofer, A., Prager, R., Kautzky-Willer, A., Pacini, G. Diabetes Care (2002)