Chapter 47: Management of Patients with Diabetes

Prevalence and Impact

Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels due to defects in insulin secretion, insulin action, or both. It is a major public health concern in the United States, affecting millions and contributing to significant morbidity, mortality, and economic burden.

• Prevalence: Over 37 million Americans have diabetes, with a substantial proportion undiagnosed.

• Prediabetes: Affects approximately 38% of adults, indicating a high risk for progression to diabetes.

• Economic Impact: Annual costs exceed $327 billion, including medical expenses and lost productivity.

• Disparities: Higher prevalence among certain ethnic and racial groups, including Black Americans, Native Americans, Hispanic/Latino, Asian Americans, and Pacific Islanders.

Classification of Diabetes

Major Types

Diabetes is classified based on etiology and clinical presentation:

• Type 1 Diabetes: Autoimmune destruction of pancreatic beta cells, leading to absolute insulin deficiency. Typically presents in childhood or adolescence but can occur at any age.

• Type 2 Diabetes: Progressive loss of insulin secretion on the background of insulin resistance. Most common in adults but increasingly seen in youth due to obesity.

• Gestational Diabetes: Glucose intolerance first recognized during pregnancy, usually in the second or third trimester.

• Other Specific Types: Result from genetic defects, diseases of the exocrine pancreas, or drug-induced diabetes.

• Prediabetes: Intermediate state with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT).

Risk Factors for Diabetes

Key Risk Factors

Multiple factors increase the risk of developing diabetes, particularly type 2 diabetes.

• Age >45 years for type 2; <30 years for type 1

• Low HDL cholesterol or high triglycerides

• History of gestational diabetes

• Hypertension

• Family history of diabetes

• Obesity (preclinical and clinical)

• Physical inactivity

• History of cardiovascular disease

• Polycystic ovary syndrome

• Previously identified impaired fasting glucose or glucose tolerance

• Race/ethnicity (e.g., African American, Latino, Native American, Asian American, Pacific Islander)

Pathophysiology of Diabetes

Role of Insulin

Insulin is an anabolic hormone produced by pancreatic beta cells. It facilitates glucose uptake into muscle, liver, and adipose tissue, promotes glycogen synthesis, and inhibits the breakdown of fat and protein.

• Stimulates glucose transport and metabolism for energy

• Signals the liver to stop glucose production

• Enhances fat storage and amino acid uptake

• Suppresses breakdown of glycogen, protein, and fat

Clinical Manifestations of Diabetes

Classic Symptoms

Diabetes presents with a range of symptoms, often related to hyperglycemia and metabolic disturbances.

• Polyuria: Increased urination

• Polydipsia: Increased thirst

• Polyphagia: Increased appetite

• Fatigue, weakness, vision changes, tingling/numbness, slow-healing wounds, recurrent infections

• Type 1 specific: Sudden weight loss, nausea, vomiting, abdominal pain

Assessment and Diagnostic Findings

Diagnostic Criteria

Diagnosis is based on blood glucose measurements and clinical assessment.

• Fasting plasma glucose (FPG) ≥ 126 mg/dL

• Random plasma glucose ≥ 200 mg/dL

• A1C ≥ 6.5%

• 2-hour postload glucose ≥ 200 mg/dL during an oral glucose tolerance test

Medical Management of Diabetes

Goals and Components

The primary goal is to normalize blood glucose and insulin activity to prevent complications. Management includes:

• Nutritional therapy

• Physical activity

• Blood glucose monitoring

• Pharmacologic therapy (insulin and/or oral agents)

• Patient education and self-management

Nutritional Therapy and Meal Planning

Principles of Nutrition Management

Nutrition is foundational in diabetes care. Individualized meal planning considers preferences, lifestyle, and cultural background. Consistency in carbohydrate intake and meal timing is important for glycemic control.

• Control caloric intake and achieve/maintain healthy weight

• Normalize blood glucose, lipid, and blood pressure levels

• Promote healthy eating patterns and provide practical meal planning tools

Pharmacologic Management of Diabetes

Insulin Therapy

Insulin is essential for type 1 diabetes and may be required for type 2 diabetes. Various formulations differ in onset, peak, and duration of action.

Insulin Administration

Insulin can be administered via syringes, pens, or pumps. Prefilled insulin syringes and pens are commonly used for convenience and accuracy.

Oral and Noninsulin Injectable Antidiabetic Medications

Several classes of oral and injectable agents are used in type 2 diabetes management. Selection depends on patient characteristics, efficacy, side effects, and comorbidities.

Acute Complications of Diabetes

Hypoglycemia

Defined as blood glucose <70 mg/dL. Symptoms range from adrenergic (sweating, tremor, tachycardia) to neuroglycopenic (confusion, seizures, loss of consciousness). Immediate treatment with 15 g of fast-acting carbohydrates is essential.

Diabetic Ketoacidosis (DKA)

A life-threatening complication of insulin deficiency, primarily in type 1 diabetes. Characterized by hyperglycemia, ketosis, acidosis, and dehydration. Management includes IV fluids, insulin, and electrolyte replacement.

Hyperglycemic Hyperosmolar Syndrome (HHS)

Occurs mainly in type 2 diabetes. Marked by severe hyperglycemia, dehydration, and altered mental status, but minimal ketosis. Management is similar to DKA but with less emphasis on acidosis correction.

Long-Term Complications of Diabetes

Macrovascular Complications

Involve large blood vessels and include coronary artery disease, cerebrovascular disease, and peripheral vascular disease. Risk factors include hypertension, dyslipidemia, and smoking. Aggressive risk factor modification is essential.

Microvascular Complications

Affect small blood vessels, leading to retinopathy (eye), nephropathy (kidney), and neuropathy (nerves). Chronic hyperglycemia is a major contributing factor.

Diabetic Retinopathy

• Leading cause of blindness in adults

• Nonproliferative and proliferative stages

• Diagnosis by retinal examination and fluorescein angiography

• Prevention: Glycemic, blood pressure, and lipid control; regular eye exams

Diabetic Nephropathy

• Chronic kidney disease due to glomerular damage

• Screening: Annual urinary albumin and eGFR

• Management: Glycemic and blood pressure control, ACE inhibitors/ARBs, dietary modifications

Diabetic Neuropathy

• Peripheral neuropathy: Paresthesias, loss of sensation, risk of foot ulcers

• Autonomic neuropathy: Affects cardiovascular, gastrointestinal, and genitourinary systems

• Management: Optimize glucose control, manage symptoms, prevent complications

Foot and Leg Problems in Diabetes

Diabetic Foot Ulcers

Neuropathy and peripheral vascular disease increase the risk of foot ulcers, infections, and amputations. Daily foot inspection and proper foot care are essential for prevention.

• High-risk features: Poor glycemic control, neuropathy, arterial disease, foot deformities, history of ulcers or amputation

• Routine foot exams and multidisciplinary care are recommended for high-risk patients

Diabetes Management in Special Situations

Hospitalization and Surgery

Stress, illness, and surgery can destabilize glucose control. Frequent monitoring, adjustment of insulin, and prevention of hypo- and hyperglycemia are critical. Hospitalization is an opportunity for patient education and self-care skill reinforcement.

Older Adults with Diabetes

Older adults may have unique challenges, including comorbidities, cognitive impairment, and functional limitations. Treatment goals should prioritize quality of life and independence. Education should be tailored to individual needs and abilities.