Automatically obtained PLM biomarkers in Wisconsin Sleep Cohort.

PLM metrics are calculated from PLM classified using our detector (SNR+). PLM/h and periodicity indices are calculated for wake (PLMW/h) and sleep (PLMS/h). Patients not using CPAP and having more two hours of evaluation were grouped according to their apnea-hypopnea index (AHI). CPAP users are not excluded from the “All” category. An hour of the night effect is seen with PLM, occurring almost five times as frequently in the first half of the night compared to the second half (PLM night ratio), while leg movement activity occurs equally across the night in patients with respiratory difficulty during sleep. Note that the periodicity index is artificially affected by excluding intermittent wake and produces a statistically significant higher value in patients with AHI≤15 when examining sleep only.Data are mean ± Standard Error Mean, or percentage. The number of subject used for calculations are shown in parentheses. Periodicity is the periodicity index. Count is the total number of individual PLM or LM counted per study. Night ratio is the ratio of events classified in the first half of each study divided by the number of events classified in the second half. Heart rate is the normalized cardiac change (beats per minute) time locked to PLM as described in the text. P-values are calculated from the student t-test with significance level of 0.05. Periodicity index, heart rate, and PLM ratio is only calculated in the presence of PLM. Night ratios are only calculated in cases where PLM or LM occur during both the first and second half of the study.Automatically obtained PLM biomarkers in Wisconsin Sleep Cohort.