Diabetes Mellitus: An Overview

Introduction to Diabetes Mellitus

• Diabetes mellitus (DM) is a systemic metabolic disorder
• DM is characterized by improper metabolism of carbohydrates, fats, and proteins
• The chronic, multi-system disease is related to decreased or absent insulin production
• This is caused by beta cells of the islets of Langerhans in the pancreas, impaired insulin use, or both
• Hyperglycemia is the primary clinical sign of all types of DM

Anatomy and Physiology

• The pancreas is an elongated gland located posterior to the stomach
• It contains both endocrine and exocrine tissue
• Islets of Langerhans are tiny clusters of cells within the endocrine tissue of the pancreas
• Beta cells secrete insulin in response to increased blood glucose levels
• Alpha cells secrete glucagon in response to decreased blood glucose levels
• Insulin and glucagon play a major role in carbohydrate, fat, and protein metabolism
• Insulin enables the body’s cells to absorb glucose from the bloodstream
• Insulin secretion peaks about 30 minutes after meals, returning to normal in 2-3 hours
• Adults secrete 40-50 units of insulin every 24 hours, maintaining blood glucose between 70 and 100 mg/dL

Types of Diabetes Mellitus

• Type 1 DM is an autoimmune disease resulting in the destruction of beta cells in the pancreatic islets
• The destruction of beta cells, leads to deficient insulin production
• Type 1 DM patients retain normal sensitivity to insulin action
• Type 1 DM comprises 5-10% of all DM cases and is usually diagnosed before age 30
• Rapid onset of hyperglycemic symptoms are typical of Type 1 DM
• Type 2 DM is characterized by abnormal resistance to insulin action
• Type 2 DM comprises 90% of all DM cases, with a higher incidence among certain ethnicities
• Type 2 DM is often diagnosed after the age of 35, with many patients being older than 55 at diagnosis
• 80-90% of patients with type 2 DM are overweight at the time of diagnosis

Etiology and Risk Factors

• Genetic predisposition
• Viral infections (e.g., Coxsackievirus B, rubella, mumps)
• Aging process
• Diet and lifestyle
• Ethnicity
• Obesity is a major contributing factor
• Autoimmune factors such as T lymphocytes may attack beta cells

Clinical Manifestations of Type 1 DM

• Polydipsia: Abnormal thirst due to high blood glucose
• Polyuria: Frequent urination as the kidneys try to dilute and remove excess glucose
• Polyphagia: Increased food intake
• Weight loss: Despite increased food consumption
• The body burns fat and protein instead of glucose for energy

Clinical Manifestations of Type 2 DM

• Signs and symptoms may not be apparent until later in the disease progression
• May present with complications such as kidney involvement, retinopathy, impotence, neuropathy, or gangrene

General Assessment Findings

• Subjective: Hunger, thirst, nausea, frequent urination, weakness, fatigue, blurred vision, cold extremities, cramping pain, decreased sensation, numbness, delayed stomach emptying
• Objective: Slow wound healing, frequent infections, weight loss (Type 1), obesity (Type 2), shiny and thin skin on lower extremities, decreased hair, cool skin temperature

Diagnostic Tests

• Random Blood Glucose: Requires further evaluation above 200 mg/dL
• Fasting Plasma Glucose (FBG): Normal is 60-100 mg/dL, Abnormal is 126 mg/dL or greater
• Oral Glucose Tolerance Test (OGTT): Blood samples taken periodically for 3 hours after consuming a glucose-containing fluid
• Serum Insulin: Absent in type 1 DM, normal to high in type 2 DM
• Postprandial Blood Glucose (PPBG): Glucose over 160 mg/dL may indicate DM

Self-Monitoring and Glycosylated Hemoglobin

• Self-Monitoring of Blood Glucose (SMBG) is recommended by ADA for accurate glucose level monitoring
• Glycosylated Hemoglobin (HbA1c) shows average glucose levels over the past 120 days
• Normal HbA1c: 4-6%, diabetics should aim for below 7% to reduce complications
• HbA1c result greater than 8% represents an average blood glucose level of approximately 200 mg/dL

C-Peptide Test and Urine Testing

• C-Peptide Test indicates whether any insulin is being produced
• Urine Testing for Ketonuria is recommended for type 1 DM patients experiencing hyperglycemia or acute illness

Medical Management Goals

• Improve metabolic control through nutrition and exercise
• Maintain near-normal blood glucose levels
• Achieve optimal serum lipid levels
• Prevent acute and long-term complications
• Improve overall health through optimal nutrition

Education and Diet

• Education is essential for newly diagnosed patients, covering diet, medication routines, home testing, and exercise
• Diet should aim to achieve a normal blood glucose level (less than 126 mg/dL), HbA1c of 4% to 6%, and maintaining a reasonable body weight

Meal Planning

• Quantitative: 45-50% of total kilocalories from carbohydrates, 10-20% of total kilocalories from protein, No more than 30% of total kilocalories from fats
• Qualitative meal planning emphasizes moderation and reduces simple carbohydrates, saturated fats, and alcohol

Exercise, Stress, and Medications

• Exercise reduces insulin resistance, increases glucose uptake, lowers cholesterol and triglyceride levels, decreases blood pressure, and helps control weight
• Stress of acute illness and surgery increases blood glucose levels therefore monitor blood glucose every 1-2 hours
• Medications include insulin, which is necessary for all patients with type 1 DM and oral hypoglycemic drugs

Other Treatments for Diabetes

• Use of Insulin-enhancing drugs (e.g., Pramlintide, Exenatide)
• Pancreas transplant for selected patients with type 1 DM and end-stage renal disease

Nursing Interventions and Patient Education

• Encourage a daily routine of accurate monitoring of blood glucose levels
• Careful attention to the amount of food eaten at each meal
• Consider conditions affecting blood glucose such as illness, stress, and surgery
• Good skin care: Is essential due to poor circulation, which can lead to skin problems and poor healing
• Special foot care is crucial due to poor circulation and decreased nerve sensation:
  • Seek podiatrist services, wash and dry feet thoroughly daily
  • Inspect feet daily for lesions, avoid soaking feet, powders, or lotion and clip toenails straight across
• Eye Exams: Encourage exams every 6-12 months
• Medication Education: Proper administration of insulin or oral hypoglycemic medications and their side effects
• Recognize Hyperglycemia and Hypoglycemia: Educate on the signs and symptoms
• Plan for travel by taking extra supplies and arranging for self-monitoring of blood glucose
• Suggest regular medical checkups and stress the importance of these
• Social Aspects: Lifestyle adjustments and support via a medical alert bracelet or necklace, and medical information wallet cards

Acute Complications

• Diabetic Ketoacidosis (DKA) occurs in type 1 DM patients due to inadequate insulin
  • Symptoms include elevated blood glucose (300-800 mg/dL), weakness, drowsiness, vomiting, thirst, abdominal pain, dehydration, Kussmaul's breathing, fruity odor on breath
  • Managed using Intravenous insulin, fluid and electrolyte replacement
• Hyperglycemic Hyperosmolar Nonketotic Coma (HHNC) occurs in type 2 DM patients due to insufficient insulin or oral hypoglycemic agents
  • Symptoms include elevated blood glucose (600-2000 mg/dL), dehydration, dry mouth, lethargy, decreased consciousness, glucosuria without ketones
  • Managed with Intravenous insulin, fluid and electrolyte replacement
• Hypoglycemia is indicated by low blood glucose level (below 60 mg/dL)
  • Symptoms : Nervousness, irritability, tremors, tachycardia, diaphoresis, hunger, headache, difficulty speaking, visual disturbances, altered consciousness
  • Managed with rapid-acting, simple carbohydrates for conscious patients; glucose gel or glucagon for unconscious patients
• Infections: Hyperglycemia and ketonemia hinder the phagocytic action of leukocytes

Chronic Complications

• Angiopathy: Damage to blood vessels secondary to chronic hyperglycemia
• Diabetic Retinopathy: Microvascular changes affect retinal capillaries, leading to aneurysms, hemorrhages, and exudates, sometimes leading to blindness
• Cardiovascular Issues: Accelerated arteriosclerosis, hypertension, myocardial infarction, stroke, gangrene
• Nephropathy: Capillary changes contribute to renal sclerosis and end-stage renal disease
• Neuropathy: Pain and decreased sensation in the extremities, may result in gastroparesis
• Other Chronic Complications: Impotence and erectile dysfunction

Nursing Process

• Insufficient Knowledge: Related to self-injections and SMBG
  • Goals: Patient will independently self-administer insulin and perform SMBG accurately
  • Interventions: Support patient in self-injecting insulin, observe SMBG technique, review the effect of activity, dietary intake, and insulin on blood glucose, instruct on frequency and timing of SMBG
• Compromised Maintenance of Health: Related to ineffective coping skills
  • Goals: Patient will state at least one change that will improve blood glucose control
  • Interventions: Teach the effects of stress, lack of exercise, and activity pattern on blood glucose levels. Explore the patient's willingness and ability to change behaviors. Explore sources for long-term support in learning more effective coping skills; suggest support groups