Diabetes Mellitus Clinical Chemistry Review 84
TYPE CAUSE CHARACTERISTICS
Type 1
(formerly type I juvenile-onset
diabetes, insulin-dependent
diabetes mellitus)
Type 2
(formerly type II, adult-onset
diabetes, non–insulin-dependent
diabetes mellitus)
Gestational diabetes
mellitus (GDM)
Autoimmune destruction of beta cells.
Absolute insulin deficiency. Genetic predis-
position (HLA-DR 3/4).
Insulin resistance in peripheral tissue.
Insulin secretory defect of beta cells.
Associated with obesity.
Placental lactogen inhibits action of insulin.
Acute onset. Most develop before age 25 yr.
Dependency on injected insulin. Prone to
ketoacidosis & diabetic complications.
Most common type. Usual onset was after age 40 yr
but being seen in obese youth. Not dependent on
exogenous insulin. Not prone to ketoacidosis or
diabetic complications.
Usually Dx during latter half of pregnancy. Some
develop type 2 diabetes years later. Risk of
intrauterine death or neonatal complications
(macrosomia, hypoglycemia, hypocalcemia,
polycythemia, hyperbilirubinemia).
