INS and diabetes mellitus: Based on the different etiologies underlying the disease, diabetes is classified into four categories, including 1) type 1 diabetes, which results from an insulin-synthesis deficiency of beta cells out of autoimmune disorders; 2) type 2 diabetes, which is due to cellular insulin-resistance activities; 3) gestational diabetes, which indicates the presence of glucose intolerance during pregnancy; and 4) the fourth group, which involves other types of diabetes (Deshpande et al., 2008; American Diabetes Association, 2011).