'REM-related OSA': a forgotten diagnostic? Possible path to under-diagnosing sleep apnea

Restrictive criteria are proposed to define the disorder 'REM-related OSA' disorder, and questions remain about its nosological transcendence and clinical management.

To evaluate the criteria proposed to define 'REM-related OSA', its relationship with cardio-metabolic comorbidity, and aspects related to it diagnostic.

Retrospective observational study of clinical and polysomnographic data from outpatients. 525 patients over 18 years old who had an Apnea Hypopnea Index (AHI) = 5 (total, or partial, in REM and/or NREM) were included.

'Phase-dependent' subgroups were formed using a criterion based on the 'ratio = 2' and another 'strict' criterion based on a partial AHI = 5 compared to another partial AHI <5 (in REM or in NREM). In the 'strict REM-related OSA' subgroup, half of the patients showed an overall AHI < 5, with less severity in the respiratory parameters, but with lower comorbidity percentages. With the current diagnostic criteria, these patients would be excluded from the sleep apnea diagnosis.

The application of the strict criterion to detect 'REM-related OSA' makes it possible to filter milder forms of sleep apnea associated with percentages of cardiovascular and/or metabolic comorbidity that are not significantly different from other more severe forms of sleep apnea. To avoid under-diagnosis, it would be advisable to review the sleep apnea diagnostic criteria and the indications of the reduced sleep apnea diagnostic techniques.