Takaubu Takemura

Acute effects of zolpidem on daytime alertness, psychomotor and physical performance

In a double-blind cross-over study, seven athletes received zolpidem (10mg) or placebo in two sessions over two nights. Residual effects on subsequent daytime functions were evaluated objectively by measuring psychomotor and physical performance using a combined test of finger dexterity, a simple discriminatory reaction test, critical flicker fusion test (CFF), vertical jump, and 50-m sprint, as well as subjectively, by visual analog scales. Zolpidem shortened self-estimated sleep latency and increased total sleep at nighttime. There was no change in alertness and fatigue scales on the following day in the zolpidem session, but realm of daytime well-being was slightly worsened. The CFF test showed significantly better results in the zolpidem group than in the placebo group. Zolpidem did not have effects in athletic evaluation. Zolpidem has a hypnotic activity without disturbing psychomotor and physical performance on the following day when given to healthy adults, suggesting zolpidem may be used in healthy athletes to adjust their extrinsic sleep disturbances and their consecutive psychomotor and physical impairments.

Sleep habits of students attending elementary schools, and junior and senior high schools in Akita prefecture.

Abstract It is widely accepted that students in Japan sleep fewer hours than what they actually need. However, epidemiological data on sleep habits among students are scarce. The sleep habits and related problems among 1650 students in Akita prefecture were studied. The results revealed that schoolchildren attending elementary schools seemed to sleep for a sufficient number of hours, whereas students attending junior or senior high schools were not sleeping enough. In particular, approximately half of the students attending senior high schools answered that they slept 6 h or less on weekdays and nodded off during classes more than twice a week.

A psychological study on patients with masticatory muscle disorder and sleep bruxism.

Abstract Sleep bruxism (SB) has been believed to be related to stress and psychosocial factors, however their implicit relationship has remained unclear. This study was conducted on patients visiting our clinic with SB and masticatory muscle disorders (MMD) for the purpose of clarifying personality and behavioral traits. This study was conducted on patients of MMD visiting our clinic. The Rosenzweig Picture-Frustration study was performed on each patient. Twenty-seven (27) patients were divided into two groups: 17 patients with SB and 10 patients without. The SB group showed a significantly lower level of E (extrapunitive) reaction than the nonSB group. SB patients showed a significantly higher level of M (impunitive) reaction than those without SB. Concerning the directions of aggression, the percentage of E-A (extraaggression) was significantly lower in SB patients than in those without. On the other hand, the percentage of I-A (intraaggression) was significantly higher in patients with SB than those without. Our study found a new aspect of the patients with MMD and SB: they are not only intraaggressive, but are also unable to be extrapunitive and extraaggressive. Consequently, they are unable to demonstrate adequate self-assertiveness in stressful situations.

Alcohol has a dose-related effect on parasympathetic nerve activity during sleep

BACKGROUND The aim of this study was to identify the acute effects of ethanol on the relationship between sleep and heart rate variability (HRV) during sleep. METHODS Ten healthy male university students were enrolled in this study. An alcoholic beverage was given to each subject at a dosage of 0 (control), 0.5 (low dose: LD), or 1.0 g (high dose: HD) of pure ethanol/kg of body weight. All experiments were performed at 3-week intervals. On the day of the experiment, a Holter electrocardiogram was attached to the subject for a 24-hour period, and the subject was instructed to drink the above-described dosage of alcoholic beverage 100 minutes before going to bed; polysomnography was then performed for 8 hours. Power spectral analysis of the HRV was performed using the maximum entropy method, and the low- (LF: 0.04 to 0.15 Hz) and high-frequency (HF: 0.15 to 0.4 Hz) components along with LF/HF ratio were calculated. RESULTS As alcohol consumption increased, the heart rate increased and the spectral power of HRV measured at each frequency range decreased. Higher doses of ethanol also increased the LF/HF ratio compared with the measured ratio of the control group. CONCLUSIONS Acute ethanol intake inhibits parasympathetic nerve activity and results in predominance of sympathetic nerve activity during sleep, in a dosage-dependent manner. The results of this study suggest that ethanol interferes with the restorative functions of sleep.

CHADS2 and CHA2DS2-VASc scores as bleeding risk indices for patients with atrial fibrillation: the Bleeding with Antithrombotic Therapy Study.

The CHADS2 and CHA2DS2-VASc scores, that is, ischemic stroke risk indices for patients having atrial fibrillation (AF), may also be useful as bleeding risk indices. Japanese patients with AF, who routinely took oral antithrombotic agents were enrolled from a prospective, multicenter study. The CHADS2 and CHA2DS2-VASc scores were assessed based on information at entry. Scores of 0, 1 and ⩾2 were defined as the low, intermediate and high ischemic risk categories, respectively, for each index. Of 1221 patients, 873 took warfarin, 114 took antiplatelet agents and 234 took both. The annual incidence of ischemic stroke was 0.76% in the low-risk category, 1.46% in the intermediate-risk category and 2.90% in the high-risk category by CHADS2 scores, and 1.44, 0.42 and 2.50%, respectively, by CHA2DS2-VASc scores. The annual incidence of major bleeding in each category was 1.52, 2.19 and 2.25% by CHADS2, and 1.44, 1.69 and 2.24% by CHA2DS2-VASc. After multivariate adjustment, the CHADS2 was associated with ischemia (odds ratio 1.76, 95% confidence interval 1.03–3.38 per 1−category increase) and the CHA2DS2-VASc tended to be associated with ischemia (2.18, 0.89–8.43). On the other hand, associations of the indices with bleeding were weak. In conclusion, bleeding risk increased gradually as the CHADS2 and CHA2DS2-VASc scores increased in Japanese antithrombotic users, although the statistical impact was rather weak compared with their predictive power for ischemic stroke.