🩺 1.0 Diabetes Mellitus (DM)

📘 1.1 What Is Diabetes Mellitus?

• Diabetes Mellitus is a group of metabolic disorders characterized by chronic hyperglycemia (elevated blood glucose levels).
• Hyperglycemia occurs due to:
• Insufficient insulin production
• Impaired insulin action (insulin resistance)
• Or a combination of both
• Long-term hyperglycemia leads to damage of blood vessels, nerves, and organs.

📊 1.2 Why Diabetes Matters (Epidemiology & Impact)

• Over 34 million adults in the U.S. have diabetes.
• Approximately 1.7 million new cases are diagnosed each year.
• If trends continue, 1 in 3 U.S. adults may have diabetes by 2050.
• Diabetes causes:
• High healthcare costs
• Loss of productivity
• Increased disability
• It is the leading cause of non-traumatic amputations and end-stage kidney disease, and a major contributor to cardiovascular death.

🧠 1.3 Normal Glucose & Insulin Regulation

🧪 1.3.1 Key Hormones

• Insulin (released by pancreatic beta cells):
• Lowers blood glucose by allowing glucose to enter cells.
• Glucagon (released by pancreatic alpha cells):
• Raises blood glucose by stimulating glucose release from the liver.

🍞 1.3.2 Sources of Blood Glucose

• Digestion of dietary carbohydrates
• Breakdown of glycogen stores (glycogenolysis)
• Production of new glucose by liver and kidneys (gluconeogenesis)

⚠️ 1.4 Pathophysiology of Diabetes

• When insulin is absent or ineffective:
• Glucose cannot enter cells.
• Cells are starved for energy.
• Glucose accumulates in the bloodstream → hyperglycemia.
• Persistent hyperglycemia is the hallmark of diabetes.
• Two primary forms exist:
• Type 1 Diabetes
• Type 2 Diabetes

🧬 1.5 Other Forms of Diabetes

• Gestational diabetes: glucose intolerance during pregnancy.
• Diabetes due to pancreatic disease or surgery.
• Medication-induced hyperglycemia (e.g., corticosteroids).
• Genetic defects affecting insulin secretion or action.

🔵 2.0 Type 1 Diabetes Mellitus

🧾 2.1 Overview

• Type 1 DM is an autoimmune disease.
• The immune system destroys insulin-producing beta cells.
• Results in absolute insulin deficiency.
• Patients require lifelong insulin therapy.

🧠 2.2 Pathophysiology

• Combination of:
• Genetic predisposition
• Environmental triggers (viruses, toxins)
• Autoimmune destruction
• Insulin production becomes minimal or absent.
• Without insulin, glucose cannot enter cells → rapid hyperglycemia.

🚨 2.3 Risk Factors

• Family history of autoimmune disease
• Genetic susceptibility
• Presence of other autoimmune conditions (thyroid disease, celiac disease)

🩻 2.4 Clinical Manifestations

🔑 Classic “3 P’s”

• Polyuria: excessive urination due to glucosuria.
• Polydipsia: excessive thirst due to dehydration.
• Polyphagia: increased hunger due to cellular starvation.

➕ Additional Findings

• Weight loss despite increased appetite
• Fatigue
• Weakness

💉 2.5 Management of Type 1 DM

• Insulin therapy (subcutaneous or inhaled adjuncts)
• Nutrition management
• Self-management education
• Monitoring for complications
• Goal: maintain blood glucose as close to normal as possible while avoiding hypoglycemia.

🟠 3.0 Type 2 Diabetes Mellitus

📈 3.1 Overview

• Type 2 DM accounts for 90–95% of diabetes cases.
• Strongly associated with obesity, physical inactivity, and genetics.
• Increasingly seen in children and adolescents.

🧠 3.2 Pathophysiology

• Cells become resistant to insulin.
• Pancreas compensates by producing more insulin.
• Over time, beta cells fail → insulin deficiency develops.
• Many patients eventually require insulin therapy.

⚠️ 3.3 Risk Factors

🟡 Modifiable

• Obesity (BMI ≥ 26; higher risk ≥ 30)
• Physical inactivity
• Dyslipidemia
• Metabolic syndrome

🔴 Non-Modifiable

• Family history of diabetes

• History of gestational diabetes

🧪 3.4 Clinical Manifestations

• Slow, often silent onset
• Fatigue
• Recurrent infections
• Poor wound healing
• Visual changes

💊 3.5 Management of Type 2 DM

• Lifestyle modification is foundational.

• Additional oral agents or injectables as needed.
• Insulin added when glycemic targets are not met.

🧪 4.0 Diagnostic & Monitoring Tools

📊 4.1 Laboratory Testing

• OGTT: evaluates glucose response to a glucose load.

📈 4.2 Glycemic Monitoring

• Finger-stick blood glucose testing.
• Continuous glucose monitoring (CGM) for real-time trends.
• Frequent monitoring required during illness or therapy changes.

🧪 4.3 Ketone Monitoring

• Ketones indicate fat breakdown.

• Essential in Type 1 DM and during illness.

💉 5.0 Insulin Therapy

⚙️ 5.1 What Insulin Does

• Enables glucose uptake into cells.
• Promotes glycogen storage.
• Prevents fat and protein breakdown.
• Maintains metabolic balance.

🧴 5.2 Administration & Safety

• Delivered via syringe, pen, or pump.
• Administered subcutaneously.

🥗 6.0 Nutrition & Physical Activity

🍞 6.1 Nutrition Therapy

• Focus on carbohydrate control.
• Emphasize non-starchy vegetables.
• Even distribution of meals to avoid glucose spikes.

⚖️ 6.2 Weight Management

• Weight loss of 5–10% improves insulin sensitivity.
• BMI <25 associated with lowest cardiovascular risk.

🏃 6.3 Physical Activity

• At least 150 minutes/week of moderate exercise.
• Improves insulin sensitivity and cardiovascular health.
• Monitor for exercise-induced hypoglycemia.

🚑 7.0 Acute Complications

⚠️ 7.1 Hypoglycemia

• Blood glucose <65 mg/dL.
• Caused by excess insulin, missed meals, or increased activity.
• Treated with oral glucose, IV dextrose, or glucagon.

🔥 7.2 Diabetic Ketoacidosis (DKA)

• Seen primarily in Type 1 DM.
• Caused by severe insulin deficiency.
• Features: hyperglycemia, ketosis, metabolic acidosis.
• Requires IV fluids, insulin, and electrolyte correction.

🧪 Diagnostic Criteria

• Blood glucose >250 mg/dL
• Positive ketones (blood or urine)
• Arterial pH ≤7.3
• Serum bicarbonate ≤18 mEq/L
• Elevated anion gap

💧 7.3 Hyperosmolar Hyperglycemic State (HHS)

• Seen primarily in Type 2 DM.
• Severe hyperglycemia and dehydration without ketoacidosis.
• Profound dehydration and high mortality risk.

⚙️ Pathophysiology (Why there is no ketones??)

The body has enough residual insulin to prevent significant lipolysis (fat breakdown) and the production of ketone bodies (ketogenesis). However, this amount of insulin is inadequate to manage blood glucose levels

• Extreme hyperglycemia causes:
• Severe dehydration
• Markedly increased serum osmolality
• Brain cells shrink due to fluid shifts → neurological symptoms

🚨 Common Triggers

• Infection (most common)
• Inadequate fluid intake
• Missed medications
• Acute illness (stroke, MI)

7.4 ⚔️ DKA vs HHS

🧠 Exam Pearl

• DKA = acid + ketones
• HHS = dehydration + confusion
• If you see fruity breath or Kussmaul respirations → think DKA
• If you see extreme glucose + altered mental status → think HHS

🧠 8.0 Chronic Complications

❤️ 8.1 Macrovascular

• Coronary artery disease
• Stroke
• Peripheral vascular disease

👁️ 8.2 Microvascular

• Retinopathy
• Nephropathy
• Nephropathy

🦶 8.3 Neuropathy & Foot Care

Proper diabetes foot care involves daily inspection, gentle washing in warm (not hot) water, thorough drying (especially between toes), moisturizing dry skin (but not between toes), and always wearing well-fitting shoes and socks to prevent injuries, as nerve damage and poor circulation can mask problems, leading to serious complications like ulcers or infections, requiring regular professional podiatrist checkups.