Periodic limb movements during sleep and progression of sleep apnea: a longitudinal analysis from the Wisconsin sleep cohort.

PURPOSE: To explore whether Periodic Limb Movements during Sleep (PLMS) are an intrinsic feature of sleep physiology or influenced by the progression of sleep apnea using longitudinal data.

METHODS

This study analyzed data from 39 participants in the Wisconsin Sleep Cohort who transitioned from no or mild (Apnea-Hypopnea Index - AHI < 10) to moderate-to-severe sleep apnea (AHI > 15). Polysomnographic recordings measured PLMS and related leg movement indices, including respiratory-related limb movements (RRLM), at baseline and follow-up.

RESULTS

AHI increased significantly between baseline and follow-up, while the PLMS index remained stable. Predictors of follow-up PLMS index were limited to baseline PLMS index, with no significant effects from AHI or other confounding factors. Increased indices of short-interval and isolated leg movements were observed but did not impact the PLMS index.

CONCLUSION

PLMS appear to be a relatively consistent feature of individual sleep patterns, independent of respiratory disturbances. This novel approach, examining pre-apnea recordings, provides unique insights into the interplay of limb movements and respiratory events in sleep-disordered breathing.