Diabetes Part I

This is a very broad subject so I plan to write this in several parts. For starters, I'm going to write down the nomenclature generally followed by clinicians at present so that it would be easier to follow the subject matter as the article goes along. The present classification of diabetes follows the etiological classification of disorders of glycemia. Simply put, that means your doctors will call it according to its pathological cause. As a side note, this was adopted because the previous way of categorizing the disease into insulin dependent and non-insulin dependent was deemed confusing. This is due to the fact that patients with any form of diabetes may require insulin treatment at some stage of their disease.

So to start off, we start with Type 1 diabetes. Type 1 (formerly known as IDDM or insulin dependent diabetes mellitus in the previous nomenclature) is the type of diabetes that is generally due to beta-cell destruction that usually leads to absolute insulin deficiency. Type 2 (formerly known as NIDDM or non-insulin dependent diabetes mellitus in the previous nomenclature) is the type that has an etiological cause ranging from predominantly insulin resistance with relative insulin deficiency to a predominantly secretory defect with or without insulin resistance.

The third type is a collective of diabetes mellitus from various known etiologies and is grouped together to form the classification called "other specific types." This group includes persons with genetic defects of beta-cell function (this type of diabetes was formerly called MODY or maturity-onset diabetes in youth) or with defects of insulin action; persons with diseases of the exocrine pancreas, such as pancreatitis or cystic fibrosis; persons with dysfunction associated with other endocrinopathies (e.g., acromegaly); and persons with pancreatic dysfunction caused by drugs, chemicals or infections.

The fourth type is known as gestational diabetes (can usually be read as the acronym GDM or gestational diabetes mellitus). Among the types, this is the only one not following the etiologic basis of diabetes nomenclature. By reason of customary practice, it remained in its operational classification and did not use the etiological basis of nomenclature. Thus, it identifies all women who develop diabetes mellitus during gestation, regardless of pathological etiology, as having GDM. That is to say, women who develop type 1 diabetes mellitus during pregnancy and women with undiagnosed asymptomatic type 2 diabetes mellitus that is discovered during pregnancy are classified as having gestational diabetes mellitus, just the same.

Apart from type 1, type 2, other specific types and GDM, we will sometimes encounter the terms impaired glucose tolerance (IGT) and impaired fasting glucose (IFG). These basically refers to recognized forms of hyperglycemia in an intermediate group of subjects whose glucose levels, although not meeting the criteria for diabetes, are nevertheless too high to be considered normal.

Well, there you have it. These are the nomenclature basics that we need to further delve into DM. I will leave this topic for now and continue next time on this. For my next posting, I plan to go into specifics. So I will most probably go discussing 1 type per post. Until then, ciao for now!