BMI Limitations for Home Sleep Testing
There is no specific BMI limit that precludes the use of home sleep testing (HST), but caution should be exercised in patients with higher BMIs, particularly those with obesity-hypoventilation syndrome or other comorbidities. 1
Evidence on Home Sleep Testing and BMI
The available evidence shows that home sleep testing has been successfully used in patients with varying BMI ranges:
- In the Andreu (2012) study, patients with a mean BMI of 34 ± 7 kg/m² successfully underwent home sleep testing with good outcomes 1
- The Kuna (2011) study included patients with a mean BMI of 34.6 ± 6.5 kg/m² who had successful home sleep testing with functional outcomes comparable to in-laboratory testing 1
- The Masa (2011) study included patients with a mean BMI of 31.0 ± 6.6 kg/m² 1
Considerations for Patient Selection
While there is no absolute BMI cutoff, several factors should guide the decision to use home sleep testing:
Appropriate Candidates for HST:
- Patients with high pre-test probability of moderate to severe OSA 2
- Patients without significant comorbidities 1
- Patients who can reliably set up the equipment 3
Caution or Consider In-Lab Testing for:
- Patients with obesity-hypoventilation syndrome 1
- Patients with significant pulmonary disorders (COPD, restrictive disorders) 1
- Patients with unstable heart disease 1
- Patients with other sleep disorders (parasomnias, RLS) 1
Clinical Implications and Outcomes
The evidence suggests that when appropriate patients are selected:
- Home sleep testing provides comparable diagnostic accuracy to in-lab polysomnography for moderate to severe OSA 1, 2
- CPAP adherence rates are similar between patients diagnosed via home testing versus in-lab testing (52% vs 49% of days with ≥4 hours usage) 1
- Functional outcomes (measured by FOSQ improvement) are non-inferior with home testing compared to in-lab testing 1
- Home-based testing is more cost-effective than in-lab testing 1
Potential Pitfalls
- Home sleep testing may be less reliable for diagnosing mild OSA 1
- Technical inadequacy rates may be higher in patients with extreme obesity due to sensor placement challenges 3
- Younger age, female sex, and lower BMI are associated with discordant results between home testing and in-lab polysomnography 4
- Home testing cannot detect sleep stages and may underestimate AHI by using total recording time rather than total sleep time 5
Conclusion
When selecting patients for home sleep testing, consider the overall clinical picture rather than BMI alone. While obesity is associated with higher OSA prevalence, the evidence suggests that home sleep testing can be successfully used in patients with elevated BMI when they don't have significant comorbidities that would affect respiratory function during sleep.