Table 1.

Comparison of type 1, type 2 and surgically induced diabetes mellitus

	Type 1 DM	Type 2 DM	Type 3 DM
Pathogenesis	Chronic autoimmune disorder; the immune system attacks endogenous pancreatic β-cells	Progressive metabolic disorder characterized by insulin resistance	Chronic disorder induced by partial or total pancreatectomy
Prevalence	5% to 10% of diagnosed diabetics	90% to 95% percent of diagnosed diabetics	1% of diagnosed diabetics
Onset	Abrupt	Gradual	Shortly after surgery
Age of onset	Varies (commonly in childhood or puberty)	Commonly over 35 yr	Commonly over 50 yr
Genetic predisposition	Moderate	Very strong	Moderate
Body habitus	Thin or normal	Often obese	Normal, overweight or obese
Ketoacidosis	Common	Rare	Rare
β-cell depletion	Severe (over 80%)	Mild (24% to 65%)	Mild to total (up to 100%)
Plasma insulin	Low to absent	Normal or increased	Low to absent

DM: Diabetes mellitus.