Classification of Diabetes Mellitus

CLASSIFICATION

The types of diabetes are prediabetes, type 1, type 2, and gestational. Prediabetes means that the cells in the body are not using insulin properly. The diagnosis is made by a fasting blood glucose, which is more than 110 but less than 126 mg/dl. One’s lifestyle will determine when prediabetes will advance to type 2.

Type 1 diabetes develops when the body’s immune system destroysthe pancreatic beta cells. These are the only cells in the body that make the hormone insulin that regulates blood glucose. Type 1 diabetes is usually diag-nosed in children and young adults. It can account for 5% to 10% of all cases of newly diagnosed diabetes. Some risk factors include genetics, autoimmune status, and environmental factors.

Type 2 diabeteswas previously called adult-onset diabetes because itusually occurred in adults over the age of 40. Type 2 is associated with obesity, and obesity has become an epidemic, which has drastically increased the inci-dence of type 2 diabetes among adolescents and young adults. A family history of diabetes, prior history of gestational diabetes, impaired glucose tolerance, older age, physical inactivity, and race and ethnicity can predispose one to type 2 diabetes. African Americans, Hispanic and Latino Americans, Native Americans, some Asian Americans, and Native Hawaiians and other Pacific Islanders are at particularly high risk for type 2 diabetes. It is not uncommon for the client to have no symptoms of diabetes and to be totally ignorant of hisor her condition until it is discovered accidentally during a routine urine or blood test or after a heart attack or stroke. In type 2 diabetes, hypertension may be present as part of the metabolic syndrome (i.e., obesity, hypergly-cemia, and dyslipidemia) that is accompanied by high rates of cardiovascular disease. The American Diabetes Association recommends that blood pressure be controlled at >130/80 mm Hg for diabetics.

Type 2 diabetes can usually be controlled by diet and exercise, or by diet, exercise, and an oral diabetes medication. 

Table 17-1 shows six types of oral glucose-lowering medications in order from newest and most frequently used to oldest and least frequently used. The goals of medical nutri-tion therapy for clients with type 2 diabetes include maintaining healthy glucose, blood pressure, and lipid levels. Also, because approximately 80% of type 2 clients are overweight, these clients may be placed on weight reduc-tion diets after their blood glucose levels are within acceptable range. Thus, monitoring their weight loss also becomes part of their therapy. Exenatide (Byetta) injection is the first in a new class of drugs for the treatment of type 2 diabetes. The drugs are called incretin mimetics. When food is eaten, incretin hormones are released from cells located in the small intestine. In the pancreas, incretins will act on the beta cells to increase glucose-dependent insulin secretions to ensure an appropriate insulin response after a meal. This medication is used in conjunction with the nonsulfonylurea metformin to help clients lower their HgbA1c to less than 7%. HgbA1c is a blood test to determine how well blood glucose has been controlled for the last 3 months. The American Diabetes Association prefers the outcome be less than 6%.

Gestational diabetes can occur between the sixteenth and twenty-eighth week of pregnancy. If it is not responsive to diet and exercise, insulin injection therapy will be used (Figure 17-1). It is recommended that a dietitian or a diabetic educator be consulted to plan an adequate diet that will control blood sugar for mother and baby.

Concentrated sugars should be avoided. Weight gain should continue, but not in excessive amounts. Usually, gestational diabetes disappears after the infant is born. However, diabetes can develop 5 to 10 years after the pregnancy.

Secondary diabetes occurs infrequently and is caused by certain drugs or by a disease of the pancreas.