General Characteristics of Types 1 and 2 Diabetes Mellitus
Characteristic | Type 1 | Type 2 |
|---|---|---|
Age at onset | Most commonly < 30 years | Most commonly > 30 years |
Associated obesity | Uncommon | Very common |
Propensity to ketoacidosis requiring insulin treatment for control | Yes | No |
Plasma levels of endogenous insulin | Extremely low to undetectable | Variable; may be low, normal, or elevated depending on degree of insulin resistance and insulin secretory defect |
Twin concordance | ≤ 50% | > 90% |
Associated with specific HLA-D antigens | Yes | No |
Pancreatic autoantibodies at diagnosis | Yes, but may be absent | No |
Islet pathology | Insulitis, selective loss of most beta cells | Smaller, normal-appearing islets; amyloid (amylin) deposition common |
Prone to develop diabetic complications (retinopathy, nephropathy, neuropathy, atherosclerotic cardiovascular disease) | Yes | Yes |
Hyperglycemia responds to non-insulin antihyperglycemic medications | No | Yes, initially in many patients |