What is diabetes mellitus?

Diabetes mellitus is a disease process that prevents proper metabolism of glucose because of insufficient production or inefficient use of the hormone insulin. Insulin is produced by the beta cells of the pancreas. The function of insulin is to regulate blood sugar (blood glucose). Glucose is “food” for the cells of the body, and insulin facilitates the diffusion of glucose from the bloodstream to the cells. If there is a deficiency of insulin, or if the insulin cannot affect transport of glucose into the cells, the cells will “starve.”

What are the two types of diabetes?

Type 1 diabetes, formerly called juvenile diabetes or insulin-dependent diabetes mellitus (IDDM), is caused by the destruction of the beta cells of the pancreas. The pancreatic beta cells are the only cells in the body that produce the hormone insulin, which is needed to regulate blood glucose. This type of diabetes typically strikes children or young adults. The susceptibility to the disease is inherited, but the actual onset of the disease is due to some environmental trigger such as a virus or allergen. The resulting autoimmune response leads to beta cell dysfunction.

Type 2 diabetes, previously known as adult-onset diabetes or non–insulin-dependent diabetes mellitus (NIDDM), accounts for more than 90% of diabetes cases in the United States. This number is increasing because of the growth in the more susceptible minority populations. In this condition, insulin requirements are greater than the supply, or the patient’s cells are insulin resistant and require help using insulin. Dietary control, exercise, and weight loss are important factors in lowering insulin requirements and increasing insulin use. Family history, obesity, hypertension, and smoking are major risk factors for this type of diabetes. African-Americans, Latinos, and Asians are at a particularly higher risk for this type of diabetes.

How is diabetes treated?

Diabetes is best managed with a multidisciplinary approach, in which the physician, nurse, and dietitian plan and implement a comprehensive plan of care. Often these professionals specialize in diabetic care and work with the primary care physician. The diabetologist (physician) determines the severity of the disease and assesses its effects. Other specialists, such as nephrologists and ophthalmologists, are consulted periodically for assessment of organ damage and for treatment. Annual visits to the ophthalmologist are necessary for all diabetic patients. A podiatrist should be consulted early to treat existing foot problems, assess risk of future problems, and recommend appropriate footwear. The medical goal is to arrest tissue and organ damage by normalizing the blood sugar. Among adults with diagnosed diabetes, 13% take both insulin and oral medications while 14% take only insulin. Oral medications alone are taken by 57% of those diagnosed with diabetes, and 16% do not take either insulin or oral hypoglycemics. (National Diabetes Information Clearinghouse, 2007). For the type 1 patient, glycemic control is achieved through diet, exercise, and insulin administration via subcutaneous injection or insulin pump. For the type 2 patient, the treatment varies and can be diet and exercise alone or may include an oral hypoglycemic agent and/or insulin injections. Monitoring of blood glucose values dictates the need for medication or dosage adjustments (Table 16-1). The dietitian creates a meal plan based on the American Diabetes Association guidelines and the individual’s lifestyle preferences. In addition, the dietitian teaches and counsels the patient about the vital role that diet and exercise play in the patient’s long-term outcomes. The nurse coordinates care, educates the patient and family about all aspects of care, and assesses all parameters of the patient’s health, including psychosocial adjustments, response to medication, diet and exercise, foot care, and other follow-up assessments as needed.

Table 16-1 Medication Monitoring in Diabetes Mellitus

How is blood sugar measured and what is normal?

There are four blood sugar tests used for diagnosing and monitoring diabetes.

What is hyperglycemia?

Hyperglycemia means high blood glucose. Signs and symptoms include frequent urination, excessive thirst, nausea and vomiting, weakness, confusion, and dehydration. If hyperglycemia is confirmed by a fingerstick test, the episode is treated with insulin and fluids (if dehydrated).

What is hypoglycemia?

Hypoglycemia means low blood glucose. Signs and symptoms include anxiety, confusion, tachycardia, diaphoresis, and tremors. The blood glucose will usually be less than 70 mg/dL, although some patients become symptomatic at higher values. The treatment is to return the blood glucose value to normal by giving glucose-containing liquids either orally or intravenously.

Both hyperglycemia and hypoglycemia can lead to coma, a life-threatening emergency. Prior to becoming comatose the patient may appear to be very drunk.

Is there a cure for diabetes?

There is no cure for diabetes at this time. Prevention of diabetes is being studied by identifying people at risk and instituting treatments designed to delay or prevent damage to the pancreas in type 1 diabetes or to the insulin receptors on the patient’s cells in type 2 diabetes. A successful pancreas transplant can restore normal insulin production, but, as with any organ transplant, the patient is immunosuppressed and at risk for adverse effects of those medicines.

What is diabetic nephropathy?

Diabetic nephropathy or diabetic kidney disease (DKD) is kidney disease caused by diabetes. It is a complication of the small blood vessels that feed the kidneys brought on by damage to the glomeruli. The pathology glomerulosclerosis is a fibrotic thickening of the glomeruli. It is thought to be caused by hyperfiltration and accumulation of glycosylated, or “caramelized,” proteins. As the disease progresses, the glomeruli lose their ability to filter blood effectively, resulting in the accumulation of waste products, such as urea and creatinine in the body.

Diabetic nephropathy occurs in five stages: