Clinical Psychiatry

Obstructive sleep apnoea (OSA)

ICD-10G47.3Sleep apnoea
DSM-5-TRG47.33Obstructive Sleep Apnea Hypopnea

1. Definition and nosology

Obstructive Sleep Apnea (OSA; ICD-11: 7A41; DSM-5-TR: G47.33) — recurrent complete (apnea) or partial (hypopnea) obstruction of the upper airway during sleep; daytime sleepiness, cognitive impairment, increased cardiovascular mortality.

2. History

  • Gastaut H. (1965) — classic description of OSA.
  • Sullivan C.E. (1981) — invented CPAP.
  • AASM Practice Parameters (update).

3. Epidemiology

  • In adults: approximately 13% in men, approximately 6% in women (moderate-to-severe OSA).
  • Increases with age and BMI.
  • Comorbidity: hypertension (50%), cardiovascular disease, stroke, atrial fibrillation, diabetes.

4. Etiology and pathogenesis

  • Anatomical — adipose tissue in the upper airway, small mandible, enlarged tonsils/adenoids.
  • Genetic and family history.
  • Posture — worsens in supine position.
  • Alcohol, sedatives — worsen.

5. Clinical features

  • Waking up with loud snoring, observed apnea, or choking sensation.
  • Daytime sleepiness (dangerous while driving), fatigue.
  • Morning headache, dry mouth.
  • Concentration, memory problems.
  • Sexual dysfunction, depressive symptoms.

6. Diagnosis

6.1 Unified diagnostic criteria

Polysomnography (PSG) — AHI (Apnea-Hypopnea Index) ≥ 5/hour + symptoms; AHI ≥ 15 irrespective of symptoms.

6.2 Differences between sources

  • AASM Clinical Practice Guideline for Diagnostic Testing (2017).
  • Home Sleep Apnea Test (HSAT) — appropriate for moderate-to-severe OSA.

6.3 Diagnostic algorithm

  • STOP-BANG screening (Snoring, Tiredness, Observed apnea, BP, BMI, Age, Neck, Gender).
  • Epworth Sleepiness Scale.
  • Polysomnography or HSAT.
  • Cardiovascular evaluation.

6.4 Differential diagnosis

Condition Distinguishing feature
Insomnia (7A00) Sleeping and retention problems; no snoring.
Central sleep apnea Respiratory effort absent.
Narcolepsy (7A20) Cataplexy, MSLT.
RLS Restless legs.

7. Examination and assessment

  • STOP-BANG, Epworth.
  • Polysomnography or Home Sleep Apnea Testing.
  • BMI, neck circumference.

8. Treatment

  • CPAP — Continuous Positive Airway Pressure is first-line. For moderate-to-severe OSA; AHI significantly reduced; effect on cardiovascular mortality has not been confirmed in randomized trials (SAVE, NEJM 2016).
  • BiPAP — in refractory cases or CPAP non-response.
  • Weight loss — mild OSA; bariatric surgery in severe obesity.
  • Mandibular advancement device (MAD) — mild-to-moderate OSA, CPAP non-responsive.
  • Postural therapy — supine-avoidant.
  • Surgery (UPPP, hypoglossal nerve stimulation — Inspire) — in selected cases.
  • Withdrawal from alcohol and sedatives.

8.1 Treatment methods

  • CPAP — First-line; adherence main problem.
  • Mandibular Advancement Device (MAD) — Mild-moderate OSA; when CPAP fails.
  • Hypoglossal Nerve Stimulation (Inspire) — New surgical option; in selected cases.
  • STOP-BANG, Epworth, PSG — Screening and diagnosis.

8.2 Differences between sources

  • AASM CPAP standard, MAD selective.
  • NICE NG202 (OSA-COPD-overlap).

9. Prognosis

  • CPAP reliably reduces symptoms and AHI and improves quality of life; its effect on cardiovascular mortality is unproven (observational studies — Marin 2005 — linked it to reduced mortality, but randomized trials — SAVE, NEJM 2016 — did not confirm this, likely due to poor adherence in trials).
  • Without treatment — stroke, atrial fibrillation, diabetes, increased mortality.

10. Myths and misconceptions

Myth 1: “OSA only occurs in obese people”

Evidence: Possible in normal-weight patients as well (anatomical factors).

Myth 2: “Snoring is the main sign of OSA, nothing more is needed”

Evidence: snoring alone not proof; AHI measurement required; untreated OSA high mortality and morbidity.

Myth 3: “CPAP only reduces symptoms, does not affect mortality”

Evidence: The truth is more nuanced. Observational data (Marin, Lancet 2005) linked CPAP to reduced mortality, but subsequent randomized trials (SAVE, NEJM 2016) did not confirm reduced cardiovascular mortality — likely due to poor adherence in trials (mean ~3.3 h/night vs. the recommended ~4 h). CPAP reliably reduces symptoms and AHI and improves quality of life; its mortality effect remains unproven.

Myth 4: “Central sleep apnea and OSA are treated the same”

Evidence: Different intervention (ASV — Adaptive Servo-Ventilation for central apnea; contraindicated in chronic heart failure with LVEF ≤45%); differentiation is critical.

11. Sources

  • WHO. ICD-11. 7A41 Obstructive sleep apnoea. 2024.
  • APA. DSM-5-TR. 2022.
  • Kapur V.K. et al. AASM Clinical Practice Guideline for Diagnostic Testing for Adult OSA. J Clin Sleep Med 2017;13(3):479–504.
  • Marin J.M. et al. Long-term cardiovascular outcomes in men with OSA-hypopnoea with or without treatment with CPAP. Lancet 2005;365(9464):1046–1053.