0923 Impact of Respiratory Events on Periodic Limb Movement Activity Throughout the Night

Abstract Introduction Obstructive sleep apnea (OSA) can frequently occur concurrently with elevated periodic limb movements index (PLMI). A limited number of studies have assessed whether PLMS are more prevalent in certain sleep stages or sleeping positions. Our aim was to identify the correlation of PLMs distribution in different sleep stages and body positions, in children with and without OSA. Methods This study was a single-center retrospective analysis of children under 18 years old who had elevated PLMI > 5 event/hr. Respiratory event and PLMs in different sleep stages and body positions report regenerated. OSA severity was categorized by obstructive apnea-hypopnea index (OAHI) as normal (< 1.5 event/hr), mild (1.5–4.9 events/h), moderate (5–9.9 events/h), and severe (≥ 10 events/h). Results A total of 95 children who had elevated PLMI > 5 event/hr were analyzed for differences in PLMs and respiratory events between the first and second half of the night. Primary snoring, mild, moderate, and severe OSA made up 26.3%, 25.3%, 23.2%, and 25.2% of the patient population respectively. The overall PLMI decreased from the first to the second half of the night in the non-OSA (-2.1 ± 14.8), mild (-2.2 ± 12.5), and moderate (-2.3 ± 18.3) groups, while it slightly increased in the severe group (2.1 ± 17.0), but these results were not statistically significant, indicating that OSA severity does not significantly influence how the PLMI evolves over the course of the night (p = 0.727). Similarly, none of the other PLM metrics showed a significant difference in night-to-night changes across OSA groups. PLMI in sleep stages N1, N2, N3, and REM all had p values > 0.09, indicating no correlation with OSA severity. Similarly, PLMI for different body positions did not have a significant difference in night-to-night changes across OSA groups (all p > 0.53). Conclusion There was no statistically significant effect of OSA severity on intra-night changes in PLMs metrics. Similarly, no significant differences were observed in the night-half change for sleep stage-specific or position-specific PLM metrics across OSA categories. This suggests that the dynamics of PLMs activity throughout the night are not substantially modulated by the presence or severity of OSA. Support (if any)