Diabetes Mellitus

1. Diabetes Mellitus Debbie Hogan RN NUR 112

2. Definition • A chronic multisystem disease related to • Abnormal insulin production • Impaired insulin utilization • Or both

3. Definition (Cont’d) • Leading cause of • End-stage renal disease • Adult blindness • Nontraumatic lower limb amputations • Major contributing factor • Heart disease • Stroke

4. Definition (Cont’d) • 73% of adults with diabetes have hypertension • 20.8 million people with diabetes in the U.S. • 41 million people with prediabetes

5. Etiology and Pathophysiology • Theories link cause to single/ combination of these factors • Genetic • Autoimmune • Viral • Environmental

6. Etiology and Pathophysiology (Cont’d) • Two most common types • Type 1 • Type 2 • Other types • Gestational • Prediabetes • Secondary diabetes

7. Etiology and Pathophysiology (Cont’d) • Normal insulin metabolism • Produced by the  cells • Islets of Langerhans • Released continuously into bloodstream in small increments with larger amounts released after food intake • Stabilizes glucose range to 70-120 mg/dl • Average daily secretion 0.6 units/kg body weight

8. Normal Insulin Secretion Fig. 49-1

9. Type 1 Diabetes MellitusEtiology and Pathophysiology • End result of long-standing process • Progressive destruction of pancreatic  cells by body’s own T cells • Autoantibodies cause a reduction of 80% to 90% of normal  cell function before manifestations occur

10. Prediabetes • Known as impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) • IGT: Fasting glucose levels higher than normal (>100 mg/dl but <126 mg/dl) • IFG: 2-hour plasma glucose higher than normal (between 140 and 199 mg/dl)

11. Prediabetes • Not high enough for diabetes diagnosis • Increase risk for developing type 2 diabetes • If no preventive measure taken—usually develop diabetes within 10 years

12. Prediabetes (Cont’d) • Long-term damage already occurring • Heart, blood vessels • Usually present with no symptoms • Must watch for diabetes symptoms • Polyuria • Polyphagia • Polydipsia

13. Type 2 Diabetes Mellitus • Most prevalent type of diabetes • Over 90% of patients with diabetes • Usually occurs in people over 35 years of age • 80% to 90% of patients are overweight

14. Type 2 Diabetes • Prevalence increases with age • Genetic basis • Greater in some ethnic populations • Increased rate in African Americans, Asian Americans, Hispanic Americans, and Native Americans • Native Americans and Alaskan Natives: Highest rate of diabetes in the world

15. Type 2 Diabetes MellitusEtiology and Pathophysiology • Pancreas continues to produce some endogenous insulin • Insulin produced is either insufficient or poorly utilized by tissues

16. Type 2 Diabetes MellitusEtiology and Pathophysiology (Cont’d) • Obesity (abdominal/visceral) • Most powerful risk factor • Genetic mutations • Lead to insulin resistance • Increased risk for obesity

17. Type 2 Diabetes MellitusEtiology and Pathophysiology (Cont’d) • Four major metabolic abnormalities • 1. Insulin resistance • Body tissues do not respond to insulin • Insulin receptors either unresponsive or insufficient in number • Results in hyperglycemia

18. Type 2 Diabetes MellitusEtiology and Pathophysiology (Cont’d) • 2. Pancreas ↓ ability to produce insulin • β cells fatigued from compensating • β-cell mass lost • 3. Inappropriate glucose production from liver • Liver’s response of regulating release of glucose is haphazard • Not considered a primary factor in development of type 2

19. Type 2 Diabetes MellitusOnset of Disease • Gradual onset • Person may go many years with undetected hyperglycemia • Osmotic fluid/electrolyte loss from hyperglycemia may become severe • Hyperosmolar coma

20. Gestational Diabetes • Develops during pregnancy • Detected at 24 to 28 weeks of gestation • Usually normal glucose levels at 6 weeks postpartum

21. Increased risk for cesarean delivery, perinatal death, and neonatal complications • Increased risk for developing type 2 in 5 to 10 years • Therapy: First nutritional, second insulin

22. Secondary Diabetes • Results from • Another medical condition • Cushing syndrome • Hyperthyroidism • Pancreatitis • Parenteral nutrition • Cystic fibrosis • Hematochromatosis

23. Clinical ManifestationsType 1 Diabetes Mellitus • Classic symptoms • Polyuria (frequent urination) • Polydipsia (excessive thirst) • Polyphagia (excessive hunger) • Weight loss • Weakness • Fatigue

24. Clinical ManifestationsType 2 Diabetes Mellitus • Nonspecific symptoms • May have classic symptoms of type 1 • Fatigue • Recurrent infections • Recurrent vaginal yeast or monilia infections • Prolonged wound healing • Visual changes

25. Diabetes MellitusDiagnostic Studies • Three methods of diagnosis • Fasting plasma glucose level >126 mg/dl • Random or casual plasma glucose measurement ≥200 mg/dl plus symptoms • Two-hour OGTT level ≥200 mg/dl using a glucose load of 75 g

26. Diabetes MellitusDiagnostic Studies (Cont’d) • Hemoglobin A1C test • Useful in determining glycemic levels over time • Not diagnostic, but monitors success of treatment • Shows the amount of glucose attached to hemoglobin molecules over RBC life span • 90 to 120 days

27. Diabetes MellitusDiagnostic Studies (Cont’d) • Hemoglobin A1C test (cont’d) • Regular assessments required • Ideal goal • ADA ≤7.0% • American College of Endocrinology <6.5% • Normal A1C reduces risk of retinopathy, nephropathy, and neuropathy

28. Diabetes MellitusCollaborative Care • Goals of diabetes management • Decrease symptoms • Promote well-being • Prevent acute complications • Delay onset and progression of long-term complications

29. Diabetes MellitusCollaborative Care (Cont’d) • Patient teaching • Self-monitoring of blood glucose • Nutritional therapy • Drug therapy • Exercise

30. Drug TherapyInsulin • Exogenous insulin • Insulin from an outside source • Required for type 1 diabetes • Prescribed for patient with type 2 diabetes who cannot control blood glucose by other means

31. Drug TherapyInsulin (Cont’d) • Types of insulin • Human insulin • Only type used today • Prepared through genetic engineering • Common bacteria (Escherichia coli) • Yeast cells using recombinant DNA technology

32. Drug TherapyInsulin (Cont’d) • Types of insulin (cont’d) • Insulins differ in regard to onset, peak action, and duration • Characterized as rapid-acting, short-acting, intermediate-acting, long-acting • Different types of insulin may be used for combination therapy

33. Drug TherapyInsulin (Cont’d) • Types of insulin (cont’d) • Rapid-acting: Lispro (Humalog), aspart (Novolog), and glulisine (Apidra) • Short-acting: Regular • Intermediate-acting: NPH • Long-acting: Glargine (Lantus), detemir (Levemir)

34. Drug TherapyInsulin (Cont’d) • Regimen that closely mimics endogenous insulin production is basal-bolus • Long-acting (basal) once a day • Rapid/short-acting (bolus) before meals

35. Drug TherapyInsulin (Cont’d) • Insulin preparations • Rapid-acting (bolus) • Lispro, aspart, glulisine • Injected 0 to 15 minutes before meal • Onset of action 15 minutes • Short-acting (bolus) • Regular • Injected 30 to 45 minutes before meal • Onset of action 30 to 60 minutes

36. Drug TherapyInsulin (Cont’d) • Insulin preparations (cont’d) • Long-acting (basal) • Injected once a day at bedtime or in the morning • Released steadily and continuously • No peak action • Cannot be mixed with any other insulin or solution

38. Drug TherapyInsulin • Storage of insulin • Do not heat/freeze • In-use vials may be left at room temperature up to 4 weeks • Lantus only for 28 days • Extra insulin should be refrigerated • Avoid exposure to direct sunlight

39. Administration of insulin • Cannot be taken orally • Subcutaneous injection for self-administration • IV administration

40. Drug TherapyInsulin (Cont’d) • Administration of insulin (cont’d) • Fastest absorption from abdomen, followed by arm, thigh, buttock • Abdomen • Preferred site • Rotate injections within one particular site • Do not inject in site to be exercised

41. Subcutaneous Injection Sites Fig. 49-6

42. Drug TherapyInsulin (Cont’d) • Administration of insulin (cont’d) • Usually available as U100 • 1 ml contains 100 units of insulin • No alcohol swab on site needed before injection

43. Drug TherapyInsulin (Cont’d) • Administration of insulin (cont’d) • Hand washing with soap adequate • Do not recap needle • 45- to 90-degree angle depending on fat thickness of patient • Insulin pens preloaded with insulin now available

44. Drug TherapyInsulin • Insulin pump • Continuous subcutaneous infusion • Battery-operated device • Connected via plastic tubing to a catheter inserted into subcutaneous tissue in abdominal wall • Potential for tight glucose control

45. Drug TherapyInsulin (Cont’d) • Problems with insulin therapy • Hypoglycemia • Allergic reactions • Lipodystrophy • Somogyi effect • Dawn phenomenon

46. Drug TherapyInsulin (Cont’d) • Problems with insulin therapy • Somogyi effect • Rebound effect in which an overdose of insulin causes hypoglycemia • Usually during hours of sleep • Counterregulatory hormones released • Rebound hyperglycemia and ketosis occur

47. Drug TherapyInsulin (Cont’d) • Problems with insulin therapy • Dawn phenomenon • Characterized by hyperglycemia present on awakening in the morning • Due to release of counterregulatory hormones in predawn hours • Growth hormone/cortisol possible factors

48. Drug TherapyOral Agents • Not insulin • Work to improve mechanisms by which insulin and glucose are produced and used by the body

49. Drug TherapyOral Agents (Cont’d) • Work on three defects of type 2 diabetes • Insulin resistance • Decreased insulin production • Increased hepatic glucose production

50. Drug TherapyOral Agents (Cont’d) • Sulfonylureas • Meglitinides • Biguanides • α-Glucosidase inhibitors • Thiazolidinediones