Insulin-dependent DM (T1DM)

Non-insulin dependent DM (T2DM)

Epidemiology

Patients are:

-Younger

-Usually lean

-European

-Seasonal incidence (spring /summer)

Patients are:

-Older

-Often overweight

-All racial groups

Heredity

-HLA-DR3 or DR4 in >90%

-35% concordance in monozygotic twins

-No HLA links

-90% concordance in monozygotic twins

-Glucokinase gene abnormalities in some families

Pathogenesis

Autoimmunity:

-Islet cell antibody

-Autoantibody to insulin

-Insulinitis

-No evidence of autoimmunity

Clinical

-Insulin deficiency

-May develop ketoacidosis

-Always need insulin

-Partial insulin deficiency /insulin resistance

-May develop non-ketotic hyperosmolar state

-Sometimes need insulin

Biochemical

Eventual disappearance of C-peptide

C-peptide persists