Glycemic levels, glucose tolerance test, and paw withdrawal threshold of control and diabetic rats. (a) Glycemic levels, (b) glucose tolerance test, and (c) paw withdrawal threshold in the 12th week of control (), near-normoglycemic (), and hyperglycemic groups (). The * symbol indicates statistical difference related to control ( Student’s -test), and # symbol indicates statistical difference between two curves (, two-way ANOVA followed by Holm-Sidak multiple comparison test).