https://www.selleckchem.com/products/pifithrin-u.html 21) and THIM sleep onset latency (mean = 3.65 minutes, SD = 2.18) (P = .25). There was strong correspondence between the two devices [r > .73, P < .001], narrow levels of agreement on Bland-Altman plots, and significantly fewer trials where PSG sleep onset had not occurred (10.24%), P = .04. THIM showed a high degree of correspondence and agreement with PSG for estimating sleep onset latency. Future research will investigate whether THIM is accurate with an insomnia sample for clinical purposes. THIM showed a high degree of correspondence and agreement with PSG for estimating sleep onset latency. Future research will investigate whether THIM is accurate with an insomnia sample for clinical purposes. Restless legs syndrome (RLS) is known to be a risk factor for cardiovascular disease. However, there are no electrophysiological biomarkers to assess this risk. This study aimed to evaluate heart rate variability (HRV) and cardiovascular reflexes in the supine and standing positions during wakefulness in patients with RLS. Fourteen drug-naïve patients with RLS (12 women and 2 men, mean age, 42.14 ± 7.81 years) and 10 healthy control patients underwent tests for blood pressure, heart rate when in the supine and standing positions, and deep breathing and handgrip tests in controlled laboratory conditions. Data on 5-minute R-R intervals at each position were collected and analyzed for HRV. Expected cardiovascular reflexes were within the normal range and were similar between the 2 groups. In HRV analysis, the normalized unit of the low-frequency component and the low-frequency/high-frequency ratio during standing were lower in patients with RLS than in the control patients. The low-frequency/high-frequencyuting factor for autonomic nervous system dysfunction. This case-control study showed a difference in HRV response to position change in a considerably small group of patients with RLS. The relevance of this finding is