Endocrine System NoteGuide

Gerontologic Considerations

• Decreased hormone production/secretion

• Altered metabolism/biologic activity

• Decreased responsiveness to hormones

• Disrupted circadian rhythms

• Complex assessment due to comorbidities and medications

Diabetes Mellitus Overview

Insulin Physiology

• Hormone from pancreatic beta cells

• Basal secretion + surges post-meal

• Normal glucose range: 70–100 mg/dL

• Promotes glucose uptake into cells for energy

• Stores excess glucose as glycogen in liver/muscle (anabolic hormone)

• Fasting state: insulin falls → glucose from liver, protein from muscle, fat from adipose tissue

• Counter-regulatory hormones: glucagon, epinephrine, GH, cortisol

Type 1 Diabetes

• Autoimmune destruction of beta cells → little/no insulin

• Genetic link: HLA-DR3, HLA-DR4

• Viral triggers

• Sudden onset, usually <40 years

• Requires lifelong insulin

• Latent autoimmune diabetes in adults (LADA): slower progression

Type 2 Diabetes

• Insulin resistance + impaired insulin secretion

• Gradual onset; 90–95% of cases

• Associated with obesity, inactivity, family hx

• Contributing factors: metabolic syndrome, cytokines from adipose tissue

Clinical Manifestations

Type 1

• Polyuria, polydipsia, polyphagia

• Weight loss, fatigue

• DKA risk

Type 2

• May mimic type 1 symptoms

• Fatigue, recurrent infections

• Vaginal yeast infections

• Poor wound healing

• Visual issues

Diagnostic Criteria

• Fasting BG ≥126 mg/dL (2x)

• HbA1c ≥6.5%

• OGTT: 2-hr glucose ≥200 mg/dL (2x)

• Random glucose ≥200 mg/dL + classic symptoms

Diabetes Management

• Goals: reduce symptoms, prevent complications, delay progression

• Education: diet, medication, exercise, glucose monitoring

• Type 2: may initially be controlled with lifestyle

Medications

• Type 1: insulin therapy is essential

• Type 2: oral meds (metformin, sulfonylureas), injectables (GLP-1, SGLT2 inhibitors), insulin

Insulin Types

• Rapid-acting (lispro, aspart): onset 15 min

• Short-acting (regular): onset 30 min

• Intermediate-acting (NPH): onset 1.5 hrs

• Long-acting (glargine, detemir): no peak, lasts ~24 hrs

Basal = background insulin; Bolus = mealtime

Administration Strategies

• Sliding Scale: reactive, based on BG readings

• Prandial Insulin: proactive, before meals

• Mixing NPH & Regular: draw regular before NPH

• Storage: avoid heat/freezing, refrigerate unopened, roll vials to mix

Insulin Pump

• Continuous subcutaneous delivery of rapid-acting insulin

• Adjustable basal and bolus doses

• Changed every 2–3 days

Insulin Therapy Issues

• Allergies: treat with antihistamines, switch to analogs

• Lipodystrophy: rotate sites

• Somogyi Effect: nighttime hypoglycemia → morning hyperglycemia

• Dawn Phenomenon: early AM hyperglycemia due to hormones

Type 2 Oral/Injectable Therapies

• Metformin: increases sensitivity

• Sulfonylureas: stimulate insulin release

• GLP-1 Agonists: enhance insulin post-meal, weight loss

• SGLT2 Inhibitors: glucose excretion via urine

Patient Teaching

• Nutrition: balanced, consistent carbs, low-glycemic

• Exercise: 150 min/week, resistance 3x/week

• Alcohol: moderate use, with food

• Monitoring: pre-meal, post-meal, during illness/exercise

Sick Day Rules

• Check BG q4h, ketones if >240

• Report BG >300 twice or ketones

• Continue meds, fluids

• If unable to eat, supplement with carbs

Travel & ID

• Carry ID, supplies, snacks, doctor letter

• Prepare for time zone changes

Acute Complications

DKA

• Type 1 mainly

• Symptoms: hyperglycemia >250, fruity breath, kussmaul breathing

• Treatment: airway, IV fluids, insulin, monitor K+, glucose

HHS

• Type 2 mainly

• Glucose ≥600, severe dehydration, neuro symptoms

Hypoglycemia

• Glucose <70

• Symptoms: shaky, confused, seizure

• Treatment: 15g carbs or D50 IV or glucagon IM

Chronic Complications

• Macrovascular: heart disease, stroke, PAD

• Microvascular:

  • Retinopathy: eye damage

  • Nephropathy: kidney damage

  • Neuropathy: nerve damage

Foot Care: inspect daily, podiatrist only, proper shoes

Skin Issues:

• Diabetic dermopathy

• Acanthosis nigricans

Thyroid Function

• Controls metabolism, heart, digestive, brain, bone

• Requires iodine

Hyperthyroidism

• Causes: Graves’ (autoimmune), goiter, tumor

• Labs: ↓T3/T4, ↓RAIU, ↓Total T3/T4, ↓Free T4, ↓HR, ↓BP, ↓Temp

• Symptoms: tremors, weight loss, heat intolerance, goiter, exophthalmos

Treatment:

1. Antithyroid meds (PTU, methimazole)

2. Iodine (Lugol’s)

3. Beta-blockers (propranolol)

4. Radioactive iodine therapy (RAI)

5. Surgery (subtotal thyroidectomy)

Thyroidectomy Post-Op Care

• Airway: monitor for obstruction, stridor

• Position: semi-Fowler's, support neck

• Monitor: bleeding, vitals, calcium (hypocalcemia)

• Voice: monitor for hoarseness

• Swallowing: assess difficulty

Education:

• Lifelong thyroid hormone if total thyroidectomy

• Calcium/vitamin D supplements if needed

• Emergency signs: hoarseness, tingling, cramps, fever

Thyroid Storm (Thyrotoxicosis)

• Life-threatening

• Causes: stress, surgery

• Symptoms: fever, tachycardia, delirium, coma

• Treatment: meds, fluids, oxygen, calm environment

Hypothyroidism

• Primary: gland issue

• Secondary: pituitary (TSH) or hypothalamic (TRH)

• Causes: iodine deficiency, Hashimoto’s, radiation, drugs

Symptoms: fatigue, cold intolerance, constipation, weight gain, dry skin

Labs: ↑TSH (primary), ↓T3/T4, ↑Cholesterol, ↑CK, anemia

Treatment: Levothyroxine (Synthroid), low-calorie diet

Complication: Myxedema coma — IV thyroid hormone, ICU care