Risk Factors for Sleep Apnea
The most important risk factors for developing obstructive sleep apnea include male sex, older age (40-70 years), obesity (particularly BMI ≥35 kg/m²), increased neck circumference (>17 inches in men, >16 inches in women), postmenopausal status in women, and craniofacial/upper airway abnormalities. 1
Demographic Risk Factors
Age and Sex
- Male sex is a primary risk factor, with men having significantly higher prevalence than women until menopause 1, 2
- Age 40-70 years represents peak risk, with prevalence increasing substantially in this age range 1
- Postmenopausal status in women dramatically increases risk, approaching male prevalence rates 1
- Older adults (≥65 years) have exceptionally high prevalence: up to 70% in men and 56% in women 3
Age-Related Considerations
- OSA prevalence increases with age, though severity and associated mortality may paradoxically decrease in elderly populations 2
- Patients under age 50 with severe untreated OSA face significantly increased mortality risk 3
- Elderly patients may present without obesity, leading to frequent underdiagnosis 3, 4
Anthropometric and Physical Risk Factors
Obesity Metrics
- BMI ≥35 kg/m² is a critical threshold for screening and referral 1
- BMI ≥40 kg/m² alone warrants immediate sleep medicine evaluation 5
- BMI ≥33 kg/m² combined with hypertension requiring ≥2 medications or type 2 diabetes necessitates urgent referral 5
- The obesity epidemic is driving increasing OSA prevalence globally 6
Anatomical Measurements
- Neck circumference >17 inches (men) or >16 inches (women) is a key screening parameter 1, 5
- Craniofacial and upper airway abnormalities that narrow the airway increase risk 1, 2
- Anatomical factors include altered upper airway structure equilibrium and increased airflow resistance 7
Medical Comorbidities as Risk Factors
Cardiovascular Conditions
- Hypertension, particularly resistant or refractory hypertension, is both a risk factor and consequence of OSA 1, 5
- Atrial fibrillation is strongly associated with OSA development 1, 3
- Pre-existing cardiovascular disease increases OSA risk 8, 9
- Heart failure patients have bidirectional risk relationship with OSA 3
Metabolic Disorders
- Diabetes mellitus is a significant risk factor, with OSA worsening insulin resistance 1, 5, 8
- Hyperlipidemia is commonly associated with OSA 1
- Hypothyroidism, particularly in women, increases OSA risk 3, 5
Lifestyle and Behavioral Risk Factors
Modifiable Factors
- Physical inactivity contributes to OSA development 6
- Alcohol consumption has sparse but suggestive evidence as a risk factor 1
- Smoking shows mixed evidence but is considered a potential risk factor 1
- Sedative use may contribute to OSA, though evidence is limited 1
Other Factors
- Family history of sleep apnea increases risk 2
- Nasal congestion shows sparse or mixed evidence as a risk factor 1
Clinical Screening Priorities
The American Academy of Sleep Medicine advocates screening high-risk patients, which include those with: 1
- Stroke risk factors (AF, refractory hypertension)
- History of stroke
- BMI ≥35 kg/m²
- Neck circumference exceeding gender-specific thresholds
Secondary screening criteria include: 5
- Age ≥42 years
- Resistant hypertension
- Established cardiovascular disease
- Hypothyroidism
Important Clinical Pitfalls
- 70-80% of patients with sleep apnea remain undiagnosed and untreated 1
- Nocturia in males is commonly misattributed to prostatic hypertrophy rather than recognized as an OSA symptom 3, 4
- Elderly patients without obesity are frequently missed because clinicians fail to consider OSA in non-obese presentations 3, 4
- Preoperative patients have exceptionally high undiagnosed OSA rates: 67.6% of major noncardiac surgery patients and 82.1% of high-risk surgical patients may have undiagnosed OSA 3