Sleep Medicine · Supplementary · from Sleep Medicine

Case 1: Obstructive Sleep Apnea with Cardiovascular Risk

Patient Presentation

Demographics: 52-year-old male construction foreman

Chief Complaint: "My wife says I stop breathing at night and she's scared I'm going to die in my sleep. I'm also falling asleep at work."

History of Present Illness: The patient presents to the sleep medicine clinic at the insistence of his wife, who has witnessed increasingly frequent and prolonged episodes of breathing cessation during sleep over the past 2-3 years. She describes loud, crescendo snoring punctuated by periods of silence lasting 20-30 seconds, followed by a choking or gasping sound and resumption of breathing. She estimates these episodes occur dozens of times per hour and reports that she has moved to a separate bedroom because of the noise.

The patient acknowledges loud snoring dating back at least 10 years but has only recently noticed daytime symptoms. He reports excessive daytime sleepiness, particularly in sedentary situations: he frequently falls asleep watching television, during meetings, and as a passenger in a vehicle. More concerning, he reports two recent near-miss incidents while driving to construction sites, where he "nodded off" briefly at the wheel. He wakes feeling unrefreshed despite 7-8 hours of time in bed and describes morning headaches 3-4 times per week that resolve within an hour of awakening. He endorses nocturia (2-3 times nightly) and reports decreased libido over the past year.

His wife also notes that he has become more irritable and forgetful. He has gained approximately 15 kg over the past 5 years. His primary care physician recently found his blood pressure to be persistently elevated despite two antihypertensive medications and referred him for sleep evaluation.

Past Medical History:

• Resistant hypertension (BP poorly controlled on two medications)
• Type 2 diabetes mellitus (diagnosed 4 years ago, HbA1c 7.9%)
• Hyperlipidemia
• Obesity (BMI 36.8)
• Gastroesophageal reflux disease (GERD)
• Atrial fibrillation — new diagnosis on recent routine ECG (paroxysmal)
• No prior sleep study

Medications:

• Amlodipine 10 mg daily
• Losartan 100 mg daily
• Metformin 1000 mg twice daily
• Atorvastatin 40 mg daily
• Omeprazole 20 mg daily
• Apixaban 5 mg twice daily (started recently for atrial fibrillation)
• Aspirin 81 mg daily

Social History:

• Construction foreman — heavy machinery exposure, early morning starts (5:00 AM)
• Married, two adult children
• Former smoker (quit 5 years ago; 25-pack-year history)
• Alcohol: 2-3 beers most evenings, more on weekends
• Diet: high-carbohydrate, large portions; frequently eats late evening meals
• Minimal exercise; previously active in construction labor but now primarily supervisory
• Sleeps supine; wife reports that snoring and apneas are worse in this position

Family History:

• Father: died of stroke at age 62; was a heavy snorer with obesity
• Mother: hypertension, type 2 diabetes, alive at age 78
• Brother: diagnosed with sleep apnea at age 48, uses CPAP

Physical Examination

• Vital Signs: BP 158/96 mmHg (despite two antihypertensives), HR 84 bpm (irregular), RR 16/min, Temp 36.7°C, Weight 118 kg, Height 179 cm, BMI 36.8 kg/m², Neck circumference 46 cm (18 inches), Waist circumference 112 cm
• General: Obese male; plethoric facies; appears fatigued; falls asleep briefly during history-taking
• Epworth Sleepiness Scale (ESS): Score 17/24 (severe excessive daytime sleepiness; >10 is abnormal)
• STOP-BANG Score: 7/8 (high risk for OSA)
• Snoring: Yes | Tired: Yes | Observed apneas: Yes | Pressure (HTN): Yes
• BMI >35: Yes | Age >50: Yes | Neck >40 cm: Yes | Gender male: Yes
• HEENT:
• Mallampati class IV (only hard palate visible; soft palate, uvula, and tonsillar pillars not visible)
• Crowded oropharynx with redundant pharyngeal tissue
• Large tongue (macroglossia)
• Retrognathia (recessed mandible)
• No nasal septal deviation; mild nasal congestion
• Neck: Thick neck with excess adipose tissue; no thyromegaly; no lymphadenopathy; neck circumference 46 cm
• Cardiovascular: Irregularly irregular rhythm (consistent with atrial fibrillation); no murmurs; mild bilateral pedal edema (1+)
• Respiratory: Clear to auscultation; no wheeze; adequate air movement; SpO2 94% on room air awake
• Abdomen: Obese, non-tender; central adiposity
• Extremities: 1+ bilateral pedal edema; no cyanosis

Workup and Results

Laboratory Studies:

Imaging/Additional Studies:

• In-laboratory polysomnography (PSG) — diagnostic study results:
• Total recording time: 462 minutes; Total sleep time: 385 minutes; Sleep efficiency: 83%
• Sleep latency: 4 minutes (shortened — consistent with excessive sleepiness)
• REM latency: 68 minutes (normal)
• Sleep architecture: Increased N1 (28%), decreased N3 (8%), decreased REM (14%); frequent arousals and sleep fragmentation
• Apnea-Hypopnea Index (AHI): 68 events/hour (Severe OSA; mild 5-15, moderate 15-30, severe >30)
• Obstructive apneas: 312; Obstructive hypopneas: 124; Central apneas: 8; Mixed apneas: 12
• Oxygen desaturation index (ODI): 62 events/hour
• Minimum SpO2: 68% (severe desaturation; sustained SpO2 <90% for 42% of total sleep time)
• Mean SpO2 during sleep: 87%
• Apneas and desaturations significantly worse in REM sleep (AHI-REM: 92/hour) and in the supine position (AHI-supine: 84/hour)
• Snoring: present >80% of recording time
• No significant periodic limb movements (PLMI <5/hour)
• ECG during PSG: Intermittent atrial fibrillation; cyclical heart rate variation with bradycardia during apneas (nadir 42 bpm) and tachycardia post-arousal (peak 118 bpm)
• Echocardiogram: Mild left ventricular hypertrophy; left atrial dilation (4.6 cm); LVEF 50% (low-normal); mild tricuspid regurgitation with estimated RVSP 38 mmHg (borderline elevated, suggesting early pulmonary hypertension)
• ECG (resting): Atrial fibrillation with controlled ventricular rate; left ventricular hypertrophy by voltage criteria

Clinical Image

Representative polysomnography tracing illustrating obstructive apneic events with cyclical oxygen desaturation, arousal responses, and associated cardiac rhythm changes in severe obstructive sleep apnea. Source: Educational illustration.

Diagnosis

Severe Obstructive Sleep Apnea (AHI 68/hour) with Cardiovascular Comorbidities

Key Diagnostic Criteria:

• AHI of 68 events/hour on diagnostic polysomnography (severe OSA: AHI >30)
• Severe nocturnal hypoxemia (nadir SpO2 68%, >42% of sleep time below 90%)
• Classic symptomatology: witnessed apneas, excessive daytime sleepiness (ESS 17), morning headaches, nocturia
• STOP-BANG score 7/8 (very high risk)
• Anatomic risk factors: obesity (BMI 36.8), neck circumference 46 cm, Mallampati IV, retrognathia, macroglossia
• Associated cardiovascular complications: resistant hypertension, paroxysmal atrial fibrillation, left ventricular hypertrophy, early pulmonary hypertension, polycythemia (secondary to chronic intermittent hypoxemia)

Treatment Plan

1. Continuous Positive Airway Pressure (CPAP) — first-line therapy:

• In-laboratory CPAP titration study to determine optimal pressure (alternative: auto-titrating CPAP/APAP with pressure range 6-16 cmH2O)
• Mask fitting session: trial nasal mask, nasal pillows, and full-face mask to optimize comfort and minimize leak (full-face may be needed if significant mouth breathing)
• Heated humidification to reduce nasal dryness and improve comfort
• Target: AHI <5 events/hour on treatment; SpO2 >90% throughout the night
• Adherence support: Sleep technologist education, scheduled 2-week and 1-month follow-up calls; download CPAP data at each visit. Medicare adherence requirement: >4 hours/night on >70% of nights in the first 90 days
• Expected benefits: reduction in blood pressure (average 5-10 mmHg drop), improved atrial fibrillation control, improved daytime alertness, improved glycemic control

1. Behavioral and lifestyle modifications:

• Weight loss: target 10% body weight reduction (12 kg); referral to structured weight management program; consider GLP-1 receptor agonist (semaglutide) which would also address diabetes and has shown independent benefit in OSA
• Positional therapy: avoid supine sleeping; consider a positional therapy device (e.g., Night Shift) given significant positional component (AHI-supine 84 vs non-supine estimated ~45)
• Alcohol cessation or significant reduction: alcohol relaxes upper airway muscles and worsens OSA severity; avoid all alcohol within 4 hours of bedtime
• Avoid sedating medications (benzodiazepines, opioids, antihistamines)
• Regular exercise program: even without weight loss, exercise reduces AHI by approximately 25%

1. Cardiovascular risk management (coordinate with cardiology and primary care):

• Blood pressure: CPAP therapy often allows reduction or improved control of antihypertensives; expect improvement within 1-3 months
• Atrial fibrillation: CPAP adherence reduces AF recurrence by 42%; essential before any consideration of cardioversion or ablation
• Optimize statin therapy: increase atorvastatin to 80 mg given elevated LDL and high cardiovascular risk
• Testosterone: re-evaluate after 3-6 months of CPAP therapy (OSA treatment often improves testosterone levels; testosterone supplementation may worsen OSA)
• BNP elevation: monitor; likely reflects diastolic dysfunction and pulmonary hypertension from OSA

1. Occupational safety:

• Driving restriction discussion: patient should not drive until excessive daytime sleepiness is adequately treated (ESS <10, no near-miss events); report requirements vary by jurisdiction
• Heavy machinery operation restriction until CPAP adherence demonstrated and sleepiness resolved
• Provide documentation for employer if accommodations needed

1. Follow-up schedule:

• CPAP titration PSG within 2 weeks
• Clinic visit at 1 month with CPAP data download
• Clinic visits at 3, 6, and 12 months; then annually
• Repeat echocardiogram in 6-12 months to reassess pulmonary pressures and cardiac function
• Repeat sleep study if symptoms recur or after significant weight change

Key Learning Points

• Obstructive sleep apnea is an independent risk factor for hypertension, atrial fibrillation, heart failure, stroke, and sudden cardiac death; OSA should be suspected in any patient with resistant hypertension (uncontrolled on 3+ medications) as it is the most common identifiable cause.
• The STOP-BANG questionnaire is the most validated screening tool for OSA (sensitivity >90% for moderate-severe OSA when score >=3); it should be used routinely in preoperative evaluations and in patients with cardiovascular risk factors.
• CPAP adherence is the greatest challenge in OSA management — approximately 50% of patients are non-adherent at 1 year; early follow-up (within 1-2 weeks), mask comfort optimization, heated humidification, and addressing side effects (nasal dryness, claustrophobia, aerophagia) are critical for long-term success.
• Secondary polycythemia (elevated hemoglobin/hematocrit) in OSA results from chronic intermittent hypoxemia stimulating erythropoietin production and is an indicator of disease severity; it typically resolves with effective CPAP therapy.
• OSA and metabolic syndrome share a bidirectional relationship: obesity worsens OSA, and untreated OSA promotes weight gain through sleep fragmentation-induced hormonal changes (increased ghrelin, decreased leptin, insulin resistance); GLP-1 receptor agonists represent a promising dual-target intervention.

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