Diabetes Mellitus

IntroductionDiabetes mellitus (DM) refers to a group of common metabolic disorders that share the phenotype of hyperglycemia. Several distinct types of DM are caused by a complex interaction of genetics and environmental factors. Depending on the etiology of the DM, factors contributing to hyperglycemia include reduced insulin secretion, decreased glucose utilization, and increased glucose production. The metabolic dysregulation associated with DM causes secondary pathophysiologic changes in multiple organ systems that impose a tremendous burden on the individual with diabetes and on the health care system.

Defining Glucose and Its Uses in the Body Glucose is a sugar and is one of the

energy sources of the body. The two hormones that are

particularly important in diabetes are insulin and glucagon.

Screening for Diabetes

Start screening at the age of 45. If the test is normal, repeat every three years.

Screen adults younger than 45 if they are overweight and have one or more of the following risk factors:

Abbreviations: BMI, body mass index; GDM, gestational diabetes mellitus; HDL, high-density lipoprotein; IFG, impaired fasting glucose; IGT, impaired glucose tolerance.

There are two screening tests for diabetes

• A fasting glucose level after an overnight fast

• An oral glucose tolerance test (OGTT), in which you drink 75 grams of glucose after an overnight fast and your glucose level is measured two hours later

Spectrum of glucose homeostasis and diabetes mellitus (DM).

Classification of diabetes

● Type 1 diabetes (results from cell destruction, usually leading to absolute insulin deficiency)

● Type2diabetes(results from a progressive insulin secretory defect on the background of insulin resistance)

● Other specific types of diabetes due to other causes, e.g., genetic defects in cell function, genetic defects in insulin action, diseases of the exocrine pancreas(cysticfibrosis),and drug or chemical-induced (the treatment of HIV/AIDS or after organ transplantation)

● Gestational diabetes mellitus (GDM)

aRandom is defined as without regard to time since the last meal. bFasting is defined as no caloric intake for at least 8 h. cThe test should be performed in laboratory certified according to A1C standards of the Diabetes Control and Complications Trial. dThe test should be performed using a glucose load containing the equivalent of 75 g anhydrous glucose dissolved in water, not recommended for routine clinical use. Note: In the absence of unequivocal hyperglycemia and acute metabolic decompensation, these criteria should be confirmed by repeat testing on a different day.

aAs recommended by the ADA; goals should be individualized for each patient (see text). Goals may be different for certain patient populations. bA1C is primary goal. cNormal range for A1C: 4.0–6.0% (DCCT-based assay). dOne–two hours after beginning of a meal. eIn decreasing order of priority.

HOW IS TYPE 1 DIABETES TREATED?Type 1 diabetes is treated using insulin injections. Oral medicines that are used to treat type 2 diabetes do not work in people with type 1 diabetes because they depend on having the pancreas still making signifi cant amounts of insulin.

HOW IS TYPE 2 DIABETES TREATED?

The most important thing before prescribing any medicines, is to lose weight by exercising and reducing the calories in your diet. These two things will reduce the insulin resistance significantly.

Diabetic ketoacidosis (DKA)

In people who have a severe insulin deficiency.

A person who is in DKA has a characteristic appearance: the eyes are sunken, the skin flushed but dry and cool, the tongue is dry, and the breath smells of acetone (like nail polish remover or a room in which apples are kept).

Long-Term Complications

• Microvascular complications relate to the small blood vessels and capillaries and lead to kidney, eye, and nerve disease.

• Macrovascular complications relate to disease of medium-sized and large blood vessels and lead to heart attacks, circulation problems in the legs, and strokes. People with type 2 diabetes are more prone to the macrovascular complications, because in addition to having elevated glucose values, they often have hypertension, high cholesterol and triglycerides, and low HDL cholesterol.

Long-Term Complications

• Diabetic eye disease—retinopathy, macular edema, cataracts, glaucoma. Untreated diabetic eye disease can lead to blindness.

• Kidney failure, which if severe may lead to dialysis.

• Neuropathy—peripheral neuropathy; autonomic neuropathy with resting fast heart rate and gastroparesis. Diabetic peripheral neuropathy increases the risk of foot injuries and infections. The nerve damage and circulatory problems of the penis can cause erectile dysfunction.

• Circulatory problems: heart disease, strokes, impaired blood flow to the legs.

General Insulin Dosing Recommendations1. Type 1 DM - insulin is necessary at all times (even when NPO).

• Must continue basal/scheduled insulin and add mealtime insulin for caloric needs.

2. Individualize Insulin Dose

• Use outpatient dose for baseline and increase (infection, steroids) or decrease (fewer calories ingested than when at home) as needed.

• Resume outpatient regimen If blood glucose is well controlled unless patient is NPO.

3. Never previously on insulin - estimate dose based on patient's body weight.

• Type 1 DM - 0.6 units/kg dose to start; ½ dose as basal insulin and ½ dose as mealtime insulin. Adjust to maintain glucose between 100-150 mg/dL. For example, a 70 kg man eating the average hospital meal will require approximately 42 (0.6 units/kg x 70 kg) units of insulin per day. One half or 21 units as a basal insulin (e.g. Glargine 21 units qhs or Ultralente 10 units bid), and the other half as mealtime insulin (Lispro 7 units with each meal). This should be adjusted accordingly, to maintain glucose levels between 100-150 mg/dL.

• Type 2 DM - usually require higher doses - more than 1 unit/kg per day.

4. Important!! Evaluate insulin dose daily. Adjust if needed to prevent hyper or hypoglycemia.

5. Type 2 DM - some oral agents may need to change.

• Sulfonylureas; risk for hypoglycemia if NPO; Metformin; lactic acidosis risk with renal insufficiency. Glitazones; risk for fluid overload and exacerbation of CHF.

Hypoglycemia Decision Tree ProtocolI. Assessment

• Symptoms of hypoglycemia are reported or observed; If on insulin drip, turn off insulin drip.

• Blood glucose test performed. Results reported to RN.

II. Intervention

A. Blood glucose <40 mg/dL with or without symptoms

• Unconscious without IV –Give 1 mg glucagon subcutaneously once and start IV of normal saline with saline lock. If no response in 10 minutes, give 25 mL

D50W slow IV push once. Note: glucagon is located in PYXIS.

• Unconscious or NPO with IV – Give 25 mL D50W slow IV push once. Check blood glucose in 15 minutes. Follow protocol based on blood glucose reading.

• Conscious – Repeat blood glucose test. Give 6 glucose tabs or 8 ounces of juice.

Hypoglycemia Decision Tree ProtocolB. Blood glucose 40-60 mg/dL with or without symptoms Give 3 glucose tablets or 4 ounces of juice. Check blood glucose in 15 minutes.

If blood glucose < 60 mg/dL or symptomatic, follow decision tree for unconscious patient. If blood glucose < 60 mg/dL and no symptoms, follow with snack

C. Blood glucose >60 mg/dL without symptoms DO NOT TREAT. There is no hypoglycemia.

D. Blood glucose 61-80 mg/dL with symptoms. Initial treatment: Give 3 glucose tablets or 4 ounces of juice. Check blood glucose in 15 minutes.

If blood glucose < 60 mg/dL or symptomatic, follow decision tree for unconscious patient.

If blood glucose < 60 mg/dL and no symptoms, follow with snack of peanut butter or give next meal tray.

Recheck glucose 1 hour after snack.

Hypoglycemia Decision Tree ProtocolIII. Following episode Assess for cause of hypoglycemia (e.g.,

missed or delayed meal, extra insulin). Document episode and instruct

patient/family re: avoiding hypoglycemia. Notify physician. Complete adverse drug

reaction form, if applicable.