Sleep in Medical Disorders

On this page

Cardiovascular Disorders & Sleep - Heart's Night Watch

  • OSA's Cardiovascular Impact:
    • Hypertension: OSA ↑ risk & severity. Screen in resistant HTN.
    • Coronary Artery Disease (CAD): OSA linked to ↑ adverse events.
    • Heart Failure (HF): OSA worsens HFrEF & HFpEF.
    • Arrhythmias: Strong link with Atrial Fibrillation (AF); screen OSA in AF.
  • Key Mechanisms:
    • Intermittent hypoxia → oxidative stress.
    • Sympathetic overactivity (↑HR, ↑BP).
    • Systemic inflammation (↑CRP).
  • Screening for OSA: Indicated in resistant HTN, AF.
  • CPAP Therapy:
    • ↓ Blood pressure.
    • Improves cardiac function (LVEF in some HF).
    • ↓ AF recurrence.

⭐ OSA is an independent risk factor for hypertension, stroke, and heart failure, highlighting a bidirectional relationship with cardiovascular diseases.

OSA consequences and cardiovascular diseasesoka

Respiratory Disorders & Sleep - Lungs' Lullaby Lost

  • Chronic Obstructive Pulmonary Disease (COPD): Nocturnal desaturation common, especially during REM sleep due to ↓ventilatory drive & V/Q mismatch. Can lead to ↑pulmonary hypertension risk.
  • Nocturnal Asthma:
    • Triggers: Allergens, GERD, circadian rhythm (e.g., ↓cortisol, ↑vagal tone at night).
    • Impact: Cough, wheeze, dyspnea → sleep fragmentation, daytime fatigue.
    • Rx: Optimize asthma control (ICS/LABA), address triggers.
  • Obesity Hypoventilation Syndrome (OHS):
    • Criteria: Obesity (BMI >30 kg/m²), daytime hypercapnia (PaCO2 >45 mmHg), sleep-disordered breathing (after excluding other causes like neuromuscular disease).
    • Key: Daytime hypercapnia differentiates from simple OSA.
  • Overlap Syndrome (COPD + OSA):
    • Leads to more profound nocturnal hypoxemia & hypercapnia than either alone.
    • Rx: Crucial to treat both; CPAP/BiPAP for OSA, optimize COPD therapy.
    • ⭐ Overlap Syndrome (COPD coexisting with OSA) significantly worsens prognosis, leading to more severe hypoxemia and hypercapnia than either condition alone.

Neurological Disorders & Sleep - Mind's Midnight Maze

  • Parkinson's Disease (PD):
    • REM Sleep Behavior Disorder (RBD) often prodromal; insomnia, RLS, sleep fragmentation.
    • Dopaminergic pathway degeneration disrupts sleep.
  • Alzheimer's Disease (AD):
    • Sundowning, severe sleep fragmentation (↓ SWS, ↓ REM).
    • Circadian rhythm dysregulation common.
  • Stroke:
    • Obstructive Sleep Apnea (OSA) is a significant risk factor.
    • Post-stroke: insomnia, hypersomnia, new-onset Sleep-Disordered Breathing (SDB).
  • Epilepsy:
    • Nocturnal seizures, interictal epileptiform activity during sleep.
    • Sleep deprivation lowers seizure threshold.
    • Anti-epileptic drugs (AEDs) have varied effects on sleep (e.g., sedation, insomnia).

⭐ REM Sleep Behavior Disorder (RBD) is a strong predictor for future development of α-synucleinopathies like Parkinson's disease or Lewy Body Dementia.

  • Endocrine Disorders & Sleep:
    • Diabetes Mellitus: ↑ OSA risk. Poor sleep worsens glycemic control, insulin resistance.

      ⭐ Patients with Type 2 Diabetes Mellitus have a significantly higher prevalence of Obstructive Sleep Apnea, which can worsen insulin resistance and glycemic control.

    • Thyroid Disorders:
      • Hyperthyroidism: Insomnia, ↓ sleep time.
      • Hypothyroidism: Hypersomnia, OSA.
    • PCOS: ↑ OSA risk (hormonal changes, obesity).
  • Psychiatric Conditions & Sleep:
    • Depression: Insomnia or hypersomnia.
    • Anxiety Disorders: Insomnia (difficulty initiating/maintaining).
    • Bipolar Disorder: Circadian disruption; ↓ sleep (mania), ↑ sleep (depression).
  • Bidirectional Link: Poor sleep worsens endocrine/psychiatric issues & vice-versa.
  • Screening: Essential for sleep disorders in these patients.

High‑Yield Points - ⚡ Biggest Takeaways

  • COPD causes nocturnal hypoxemia and fragmented sleep, worsening pulmonary hypertension.
  • Restless Legs Syndrome (RLS) is linked to iron deficiency, uremia, and pregnancy.
  • OSA significantly increases risk for hypertension, arrhythmias, and stroke.
  • Insomnia is prevalent in psychiatric disorders (depression, anxiety) and chronic pain syndromes.
  • GERD often worsens at night, leading to sleep disruption and awakenings.
  • Thyroid dysfunction: Hyperthyroidism causes insomnia; hypothyroidism causes somnolence and ↑OSA.

Practice Questions: Sleep in Medical Disorders

Test your understanding with these related questions

A 56-year-old woman with diabetes, hypertension, and hyperlipidemia is found to have an A1C of 11 despite her best attempts at diet and faithfully taking her metformin and glyburide. She reports severe fatigue and sleepiness in the daytime, which has limited her ability to exercise. On examination, she is obese, has a full appearing posterior pharynx, clear lungs, a normal heart examination, and trace bilateral edema. Her TSH is 2.0 m/L (normal). Before adding another oral agent or switching to insulin, what is the best next step?

1 of 5

Flashcards: Sleep in Medical Disorders

1/8

_____ is associated with loss of orexin from lateral hypothalamus.

TAP TO REVEAL ANSWER

_____ is associated with loss of orexin from lateral hypothalamus.

Narcolepsy

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial