Classification of Diabetes Mellitus

WHO Definition of Diabetes Mellitus

A state of chronic hyperglycaemia which may result from genetic or environmental factors often acting jointly. Hyperglycaemia may be due to a lack of insulin or an excess of one or more factors that oppose the action of insulin.

Classification

Primary

1. Type 1: Insulin dependent diabetes mellitus (IDDM) – severe, labile, occurs usually at younger age but can occur at any age, liable to develop ketoacidosis.
2. Type 2: Non-insulin dependent diabetes mellitus (NIDDM) – not prone to ketoacidosis, patients are often obese, and is of maturity onset.

Secondary

1. Pancreatic disorders:

- Chronic pancreatitis

- Pancreatectomy/trauma

- Neoplasia

- Cystic fibrosis

- Hemachromatosis

- Fibrocalculous pancreatopathy

- Chronic pancreatitis

2. Endocrine disorders :

- Acromegaly

- Cushing syndrome

- Hyperthyroidism

- pheochromocytoma.

- glucagonoma.

3. Genetic disorders:

- hemochromatosis,

- syndrome X (metabolic syndrome),

- maturity onset diabetes of die young (MODY)

4. Drug induced:

- Glucocorticoids

- Thyroid hormone

- Interferon-α

- Protease inhibitors

- β-adrenergic agonists

- Thiazides

- Nicotinic acid

- Phenytoin (Dilantin)

5. Infections:

- Mumps

- Congenital rubella,

- Cytomegalovirus (AIDS patients)

Gestational

Glucose intolerance that develops during pregnancy.

Comparison between Type I and Type II Diabetes Mellitus

TYPE-1 TYPE-2

Age: < 40 Years >40years

Duration: Weeks Months To Years

Ketonuria: Common Rare

Insulin- Dependent Yes No

Autoantibody: Yes No

Family History: No Yes

Insulin Levels: Very Low Normal To High

Islets: Insulinitis Normal/Exaustion

Complications: Acute & Metabolic Late And Vascular

Ketoacidosis Microangiopathies