# The clinical characteristic of catathrenia: a new look at an old issue—a systematic review of existing literature

## TL;DR

This study reviews existing literature to better understand catathrenia, a sleep disorder, and finds it occurs more often during non-REM sleep and may differ by sex.

## Contribution

This paper provides a systematic review revealing sex-specific patterns and sleep stage preferences in catathrenia episodes.

## Key findings

- Catathrenia episodes occur more frequently during NREM sleep than REM sleep.
- Females and obese individuals experience shorter catathrenia episodes.
- CPAP therapy is associated with shorter episode durations, suggesting a respiratory origin.

## Abstract

The International Classification of Sleep Disorders categorized catathrenia as a respiratory disorder, but there are doubts whether episodes appear during rapid eye movement (REM) sleep or the non-rapid eye movement (NREM), their duration, and symptoms. The main objectives were to identify the most common features and relations of catathrenia.

PubMed, Embase, and Web of Science were searched according to the PRISMA 2020 guidelines. The Joanna Briggs Institute and the ROBINS-I tools were chosen to assess the risk of bias.

A total of 288 records were identified, 31 articles were included. The majority of the studies had a moderate risk of bias. 49.57% of episodes occurred during the NREM sleep, while 46% took place during REM. In 60.34% females, catathrenia was more common in the NREM, while in 59.26% of males was in REM sleep (p < 0.05). Females and obese individuals were found to have shorter episodes (p < 0.05). Age was inversely correlated with minimal episodes duration (r =  − 0.34). The continuous positive airway pressure (CPAP) therapy was inversely correlated with the maximal episode duration (r =  − 0.48).

Catathrenia occurs with similar frequency in both genders. The most frequent symptoms embraced groaning, awareness of disturbing bedpartners, and daytime somnolence—not confirmed by the Epworth Sleepiness Scale. The episodes occur more frequently in NREM than in REM sleep. Catathrenia may be considered as a sex-specific condition. The effects of CPAP treatment leading to shortening episodes duration, which may indicate the respiratory origin of catathrenia.

The online version contains supplementary material available at 10.1007/s11325-024-03033-0.