S. U. Ito’s research while affiliated with Akita University and other places

Introduction We have been studying sleep facilitation of chloride spring and artificially carbonated spring (ACS). ACS are known to increase peripheral blood flow. We concluded that ACS caused great body temperature change and promoted sleep. On the other hand, ACS are also known to have an effect on the autonomic nervous system, but no one examined simultaneously the effects on sleep and autonomic nerves. Methods We evaluated the effects of bathing in ACS (Awakomachi, Danrei Co., Japan), and a plain hot bath (PH) on sleep. 11 healthy subjects submerged in a bath (40 °C) for 15 min at 22:00. From 23:00 to the next morning at 7:00, we measured their core body temperature, distal skin temperature, proximal skin temperature, distal-proximal temperature gradient (DPG), electroencephalogram (EEG), and autonomic nervous activity (LF/HF). Subjects were evaluated for subjective parameters (sleepiness, mood, fatigue) and underwent a critical flicker fusion (CFF) test before and after bathing and sleep. They were instructed to sleep from 24:00 to 7:00. Results The core body temperature during sleep in ACS was significantly lower than that in PH. DPG during sleep in ACS showed significantly higher value than that in PH. This indicated the heat dissipation due to the increase the skin blood flow and the skin vasodilator action of the ACS as in the previous study. In the subjective evaluation, ACS bath was significantly higher value in mood. The autonomic nervous activity (LF / HF) in ACS was stable low values compered with PH, but it did not reach a significant level (p = 0.06). Conclusion In ACS bath, good quality sleep can be obtained by deep body temperature falling during sleep, but the relaxing effect was insufficient. Support (If Any) N/A.

Hypnotics may be used by athletes to avoid sleep disturbance or insufficient sleep the night before sports events. However, in the past, taking hypnotics for sleep disturbances resulted in an unsuccessful attempt due to residual effects. The purpose of this study is to assess the residual effects of eszopiclone (2 mg), one of the non-benzodiazepine hypnotics, on physical performance, psychomotor function and subjective evaluations in 12 healthy athletes. Eszopiclone did not have serious side effects in athletic evaluations. This medication significantly improved short-term memory test rather than placebo and did not impair any other objective evaluations in athletes. There was no change in well-being and fatigue scales on the following day in the eszopiclone session, but daytime alertness was significantly worsened in the subjective evaluations. Eszopiclone has a hypnotic activity without disturbing psychomotor and physical performance on the following day when given to healthy adults, suggesting eszopiclone may be used in healthy athletes to adjust their extrinsic sleep disturbances and their consecutive psychomotor and physical impairments.

Introduction Next-day residual effects are a common problem with current hypnotic agents. The purpose of the present study was to evaluate the residual effects of the new agent - suvorexant that doesn’t have the muscle relaxation effect - on the physical and cognitive functions of healthy elderly people in the early morning and the day following drug administration. In this study, the next-day residual effects of suvorexant, zolpidem and ramelteon following bedtime dosing in elderly subjects were evaluated. Methods Six men and eight women aged 63–75 years received a single tablet (at 23:00), suvorexant 10 mg, zolpidem 5mg, ramelteon 4mg or placebo in a randomized, double-blind and crossover design. Measures of objective parameters (Timed up and Go test, Functional Reach Test, body sway test, critical flicker fusion test, simple discrimination reaction test and short-term memory test) and subjective ratings were obtained every 2 hour from 4:00 to 16:00. Akita University Ethics Committee approved the protocol. Written informed consent was obtained from all subjects. Results During our study, no subjects showed serious side effects, since physical observations and vital sign checks were done before and after hypnotics were taken. Furthermore, safety management was ensured such as by having a standby physician at all times. For the body sway test (closed eye), we find the main effects of the drug (p=0.012) with R-ANOVA and zolpidem was significant better than suvorexant and ramelteon in a multiple comparison using Bonferroni. The other parameters showed no significant differences. Conclusion Based on the above results, the changes of physical and cognitive functions in healthy elderly after taking hypnotics, it would be recognized that hypnotics are likely to be suitable for the elderly people with insomnia. Support (If Any) This study was funded by Grants-and-Aid for Scientific Research ‘Scientific Research (C) (General)’ (16K01496).