Definitions

Type 2 diabetes.  It’s certainly the most prevalent form of diabetes.  Type 2 diabetes features elements of insulin resistance and insulin insufficiency.  This form of diabetes usually starts after age 20 but can occur earlier.  Childhood type 2 diabetes is now common and associated with early obesity.  Early type 2 diabetes may be managed with major lifestyle changes, oral agents but may require insulin at any point in the disease.

Type 1 diabetes. Most people with type 1 DM have Type 1a. This diabetes occurs from an autoimmune problem in which the body’s defense system attacks the insulin producing pancreatic beta cells, eventually causing their destruction.  In this case, antibodies are generally present.  It tends to occur at an earlier age and was considered “juvenile diabetes” in the past.  Patients with type 1 diabetes are dependent upon insulin. As with everything else in medicine, some people defy the rule.  These have absolute insulin deficiency and typical type 1 diabetes but no evidence of an autoimmune process and are considered to have idiopathic (cause unknown) or type1b diabetes mellitus.

LADA or Latent Autoimmune Diabetes in Adults is like type 1a diabetes, only it occurs slowly and later in life. These individuals have antibodies. LADA patients appear to have type 2 diabetes but generally are not as much overweight and may lack the strong family history frequently seen in type 2 diabetes.  It has been stated that it occurs primarily in individuals of Scandinavian origin, but we have several African-American patients with this type of diabetes (the gene pool is diverse).  A type of diabetes may be more prevalent in some groups, but diabetes and its devastating effects are nondiscriminatory.  At first patients with LADA may respond to oral agents but eventually will become dependent on insulin like any other patient with type

Gestational Diabetes: also called GDM or type 4 diabetes results from insulin resistance caused by placental and other hormones during pregnancy. A woman with established diabetes (type I or 2) who becomes pregnant is considered to have “pre-gestational diabetes mellitus”.

Type 3 diabetes.  There is controversy in the diabetes world regarding type 3. It is well known that people with type 2 diabetes are at increased risk of Alzheimer’s disease.  In addition, a variant of the Alzheimer’s gene (AP0E 4) seems to interfere with the brain’s ability to use insulin. This causes brain cells to starve and die. This has been called type 3 diabetes.  The term is not generally accepted but has been reported in a Mayo Clinic study.

Type 3c diabetes. DM 3c refers to physical problems of the pancreas. Most DM 3c occurs from chronic pancreatitis.  The World Health Organization and several other organizations except type 3c as insulin lack from diseases of the pancreas including acute or chronic pancreatitis, cancer, cystic fibrosis, pancreatic surgery.  A British blog lists the following designations under type 3 (x)diabetes. compared to type 2 and type 1 diabetes, the categories in type 3 are very rare.

Type 3A: genetic defect in beta cells. (this includes MODY, maternally inherited diabetes and deafness))

Type 3B: genetically related insulin resistance. (Donohue syndrome [also known as Leprechaunism])

Type 3C: diseases of and trauma to the pancreas. (e.g. pancreatitis, pancreatic cancer Haemochromatosis, cystic fibrosis, pancreatectomy)

Type 3D: caused by hormonal defects. (e.g. Cushing’s disease and syndrome )

Type 3E: caused by chemicals or drugs. (e.g.  Glucocorticoids ,β-Blockers )

Type 3F caused by infections (Congenital rubella)

Type 3G Uncommon forms of immune-mediated diabetes (‘Stiff man/ person’ syndrome)

Type 3H other (Down’s syndrome)

(type 4 is gestational)

Prediabetes: a condition where blood glucose levels are higher than normal but not high enough to have a diagnosis of diabetes.  One is considered to have prediabetes if any of the below are true:

The fasting blood sugar (plasma glucose) is 100 to 125 mg/dl (5.6 to 6.9 mmol/L). IFG (Impaired Fasting Glucose.)

The blood sugar 2 hours after orally taking 75 g of glucose is 140 – 199 mg/dl (7.8 to 11.0 mmol/L) IGT (Impaired Glucose Tolerance).

A1C 5.7 to 6.4% (39 to 46 mmol/mol).

People with prediabetes are at risk of developing the full-blown disease.  Diabetes can be prevented or at least delayed by intervention.

The mainstay of intervention is lifestyle change.  This includes weight loss, increased physical activity, smoking cessation.  If these fail, medication such as metformin is used.