Combined Influences of Gradual Changes in Room Temperature and Light around Dusk and Dawn on Circadian Rhythms of Core Temperature, Urinary 6-Hydroxymelatonin Sulfate and Waking Sensation Just after Rising

The present experiment aimed at knowing how a gradual changes of room temperature (Ta) and light in the evening and early morning could influence circadian rhythms of core temperature (Tcore), skin temperatures, urinary 6-hydroxymelatonin sulfate and waking sensation just after rising in humans. Two kinds of room environment were provided for each participant: 1) Constant room temperature (Ta) of 27 °C over the 24 h and LD-rectangular light change with abrupt decreasing from 3,000 lx to100 lx at 1800,abrupt increasing from 0 lx to 3,000 lx at 0700. 2) Cyclic changes of Ta and with gradual decrease from 3,000 lx to 100 lx onset at 1700 (twilight period about 2 h), with gradual increasing from 0 lx to 3,000 lx onset at 0500 (about 2 h). Main results are summarized as follows: 1) Circadian rhythms of nadir in the core temperature (Tcore) significantly advanced earlier under the influence of gradual changes of Ta and light than no gradual changes of Ta and light. 2) Nocturnal fall of Tcore and morning rise of Tcore were greater and quicker, respectively, under the influence of gradual changes of Ta and light than no gradual changes of Ta and light. 3) Urinary 6-hydroxymelatonin sulfate during nocturnal sleep was significantly greater under the influence of gradual changes of Ta and light. 4) Waking sensation just after rising was significantly better under the influence of gradual changes of Ta and light. We discussed these findings in terms of circadian and thermoregulatory physiology

Influences of Twilight on Diurnal Variation of Core Temperature, Its Nadir, and Urinary 6-Hydroxymelatonin Sulfate during Nocturnal Sleep and Morning Drowsiness

This study aimed at elucidating the physiological significance of dusk and dawn in the circadian rhythm of core temperature (Tcore) and urinary 6-hydroxymelatonin sulfate in humans during sleep and the waking sensation just after rising. Seven female and four male students served as participants. Participants retired at 2300 h and rose at 0700 h. They were requested to sit on a chair and spend time as quietly as possible during wakefulness, reading a book or listening to recorded light music. Two lighting conditions were provided for each participant: 1) Light-Dark (LD)-rectangular light change with abrupt decrease from 3,000 lx to100 lx at 1800 h, abrupt increase from 0 lx to 3,000 lx at 0700 h. 2) LD-twilight light change with gradual decrease from 3,000 lx to 100 lx starting at 1700 h (twilight period about 2 h), with gradual increase from 0 lx to 3,000 lx starting at 0500 h (twilight period about 2 h). The periods of 0 lx at night were from 2300 h to 0700 h on the first day and from 2300 to 0500 h on the second day. Nadir time advanced significantly under the influence of the LD-twilight condition. The amount of 6-hydroxymelatonin sulfate in urine collected at 0200 h was significantly higher under LD-twilight in comparison with LD-rectangular light. Morning drowsiness tended to be lower under LD-twilight. Our results suggest that in architectural design of indoor illumination it is important to provide LD-twilight in the evening and early morning for sleep promotion in healthy normal people and/or light treatment in elderly patients with advanced dementia

睡眠時無呼吸症候群患者の睡眠に関連した生活習慣の調査

SAS患者は日中の眠気や倦怠感などの疾患に起因する症状を紛らわすために睡眠にとって悪い習慣を取ってしまっている可能性が指摘されている。しかしSAS患者の生活実態は明らかになっていない。そこで本研究はSAS患者の生活習慣の実態を明らかにし、Apnea Hypopnea Index (AHI)、Epworth Sleepiness Scale (ESS)、Pittsburgh Sleep Quality Index (PSQI)、Body Mass Index(BMI)との関連を検討することを目的として行った。方法は質問紙およびAHIのデータをカルテより転載し、分析を行った。対象者は睡眠時無呼吸症候群と診断され治療前の方、56名を対象として行い、回収率は86%であった。AHI、ESS、PSQI、BMIと喫煙、飲酒、カフェインの摂取、睡眠時間などとの関連をみたところ、飲酒とBMIとの間に有意な関連がみられた。また喫煙とPSQIに有意な関連がみられ、睡眠の質が低いと評価している人ほど喫煙本数が多かった。睡眠時間とESSおよび希望睡眠時間と睡眠時間の差とESSの間に相関がみられ、SASによる睡眠障害だけでなく、睡眠時間の不足も問題である可能性があると考えられた。ベッドパートナーの有無が睡眠を阻害する因子になりうる可能性が示唆された。今回の対象者では治療開始前であったが、SASの治療の第一選択であるCPAP療法には家族のサポートも重要である。そのため今後ベッドパートナーの有無がCPAP療法にどのような影響を及ぼすのかについても検討していくことが重要であると考える。It has been pointed out that Sleep Apnea Syndrome (SAS) patients may have adopted life-styles which are poor for their sleep in order to alleviate symptoms that originate in disorders such as sleepiness and fatigue during the day. However, there is no clear evidence of what kind of maladaptive life-styles have been adopted by SAS patients. This research was therefore conducted with the aim of revealing the life-styles of SAS patients, and exploring the relationships between those life-styles and their correlation with the Apnea Hypopnea Index (AHI) data, the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI) and the Body Mass Index (BMI). It was conducted on 56 pre-treated patients diagnosed with SAS via analysis of questionnaires and AHI data from their medical records. The response-rate was 86%. An analysis of the relationships between the data derived from AHI, ESS, PSQI, and BMI to smoking, alcohol consumption, caffeine intake and sleeping hours showed a significant relationship between alcohol consumption and BMI data. Furthermore, a significant relationship was evident between smoking and PSQI data, with those who evaluated their sleep quality as poor smoking the most. A correlation could also be seen between sleeping time and the ESS data, and the difference between desired hours of sleep and actual sleeping time and the ESS data, indicating that not only sleep disturbance was caused by SAS, but also the lack of sleep time could be a problem. In addition, it was also suggested that the existence of a bed partner could be one factor disturbing sleep. While the subjects of this research had not yet been treated, family support is important to CPAP treatment. For this reason, it will also be essential to study the effect of a bed partner on CPAP treatment in the future

Seasonal effects on the continuous positive airway pressure adherence of patients with obstructive sleep apnea.

[Objective] This study examined seasonal differences in continuous positive airway pressure (CPAP) therapy adherence among patients with obstructive sleep apnea (OSA). [Methods] Patients aged ≥20 years with OSA who had used CPAP devices on the automatic setting for >12 consecutive months (n = 141) were included in this retrospective study from December 2015–2016. The information of CPAP use (pressure, hours of actual use) was extracted from database downloaded from patients’ CPAP devices. Patients were divided into adherent and non-adherent groups using the cutoff point of 70% CPAP use for ≥4 h daily over the 1-year study period. CPAP use data were averaged for each season. [Results] Patients in the adherent group were significantly older than those in the non-adherent group (p < 0.001). In the adherent group, the rate of ≥4 h daily CPAP use was significantly lower, the daily duration of CPAP use was significantly shorter, and the residual apnea–hypopnea index (AHI; events/hour) was significantly higher in summer than in other seasons (all p < 0.001). In the non-adherent group, the duration of daily CPAP use and the AHI differed significantly between winter and summer (p = 0.008 and p < 0.001, respectively). [Conclusions] Seasonal changes were associated with the CPAP adherence of patients with OSA. The study findings suggest that there is possibility of increasing the duration of CPAP use by adjusting the bedroom environment in hot and humid seasons

Effects of Body Position during an Afternoon Nap on Body Temperature and Heart Rate Variability in Healthy Young Japanese Adults

Objective : To examine the effect of body position during an afternoon nap on body temperature and heart rate variability in young healthy Japanese participants. Method : Within-subject laboratory experiment with two sessions. After sleep had been restricted the previous night, the participants were required to take a nap (60 min.) in a semi-recumbent position on a reclining chair at either 60 degrees (A) or 30 degrees (B) from the horizontal. The experiment was performed from 13 : 00 to 16 : 00 in the laboratory of Nursing Science in the School of Health Sciences, Faculty of Medicine, Kyoto University. An electrocardiogram (ECG), Polysomnography (Sleep electroencephalogram), core body temperature (rectal) and skin temperatures of the leg and foot were measured. Autonomic nervous function was evaluated by heart rate variability. Participants : Eight healthy Japanese men aged 19 to 24 yrs. Results : The decrease in rectaltemperature during the first 20 minutes was greater in B than in A. There were no significant differences in parasympathetic function between A and B, while the sympathetic function in B was more activated after the nap. In B sleepiness declined significantly after the nap. Conclusion : Napping in a posture similar to that when lying in bed deepened sleep adversely, with the possibility of a more prolonged phase delay

Can tryptophan supplement intake at breakfast enhance melatonin secretion at night?

[Background]Tryptophan (TRP) is an essential amino acid, and it has been suggested that TRP intake at breakfast combined with daytime bright light exposure can increase nocturnal melatonin secretion. However, the mechanisms involved are not yet clear. The aim of this study was to examine the effect of TRP supplement intake at breakfast on nocturnal melatonin secretion under different daytime light intensities in humans. [Method]Twelve subjects (aged 21.3 ± 3.0 years, mean ± standard deviation) participated in a random order in experimental sessions lasting 3 days under four conditions in a laboratory setting. The four conditions were TRP*Bright, Placebo*Bright, TRP*Dim, and Placebo*Dim. A TRP capsule (1000 mg) or a placebo starch capsule (1000 mg) were taken at breakfast. In addition, during the daytime (07:00–18:00), the subjects were asked to stay under different light intensities: >5000 lx (bright) or <50 lx (dim). Saliva samples were collected for measuring the concentration of melatonin. The time courses of melatonin concentration and dim light melatonin onset (DLMO) were compared among the four conditions using repeated measurements analysis of variance (ANOVA). [Result] Nocturnal melatonin concentrations in the bright light condition tended to be higher than in the dim light condition (main effect of light: p = .099). Moreover, in the bright light condition, the change in DLMO between baseline and after the intervention was significantly higher than that in the dim light condition (main effect of light: p <.001). However, the ANOVA results indicated no significant effect of TRP intake on melatonin secretion. [Conclusion]Our findings indicated that intake of 1000 mg of TRP at breakfast on 1 day did not change nocturnal melatonin secretion, even though TRP is the precursor of melatonin. In contrast, daytime bright light exposure increased nocturnal melatonin secretion and advanced the phase of melatonin onset. Therefore, TRP supplementation, unlike exposure to daytime bright light, does not acutely affect biological rhythm and sleep in humans. [Trial registration]UMIN Clinical Trial Registry: UMIN00002412

Tokura H., A preliminary study on influence of negative air ions generated from pajamas on core body 84 Effect of Negative Air Ionization Exposure on Ontogenetic

Abstract. Objectives: This study was conducted to examine whether negative air ions generated from pajamas would influence the rectal temperature and the immune system during night sleep. Materials and Methods: Nine females (aged 18-23 years) served as participants. They slept during the night in their homes, wearing the pajamas with generation of negative air ions (1260 ions/cm 3 ) and with normal standard (520 ions/cm 3 ). The sequence of wearing the pajamas was: first, standard pajamas; second, pajamas with negative air ions; and third, standard pajamas again, each being worn for three consecutive days. Results: Rectal temperature in the pajamas with negative air ions tended to fall more significantly during the nighttime (p = 0.068). Salivary IgA tended to be higher on waking when wearing pajamas with negative air ions (p = 0.094) and its effect continued even after standard pajamas were worn again during last three days. Conclusion: These results suggest that the rectal temperature could possibly be more reduced and the elevation of salivary IgA more marked if the pajamas with negative air ions are worn during nocturnal sleep

Effects of Body Position during an Afternoon Nap on Body Temperature and Heart Rate Variability in Healthy Young Japanese Adults

Objective : To examine the effect of body position during an afternoon nap on body temperature and heart rate variability in young healthy Japanese participants. Method : Within-subject laboratory experiment with two sessions. After sleep had been restricted the previous night, the participants were required to take a nap (60 min.) in a semi-recumbent position on a reclining chair at either 60 degrees (A) or 30 degrees (B) from the horizontal. The experiment was performed from 13 : 00 to 16 : 00 in the laboratory of Nursing Science in the School of Health Sciences, Faculty of Medicine, Kyoto University. An electrocardiogram (ECG), Polysomnography (Sleep electroencephalogram), core body temperature (rectal) and skin temperatures of the leg and foot were measured. Autonomic nervous function was evaluated by heart rate variability. Participants : Eight healthy Japanese men aged 19 to 24 yrs. Results : The decrease in rectaltemperature during the first 20 minutes was greater in B than in A. There were no significant differences in parasympathetic function between A and B, while the sympathetic function in B was more activated after the nap. In B sleepiness declined significantly after the nap. Conclusion : Napping in a posture similar to that when lying in bed deepened sleep adversely, with the possibility of a more prolonged phase delay

Sleep disordered breathing and metabolic comorbidities across gender and menopausal status in East Asians; the Nagahama Study

生活習慣病に睡眠時無呼吸症候群がひそむことを解明 --アジア最大資料数のながはまコホートより--. 京都大学プレスリリース. 2020-05-19.It is well known that the prevalence of sleep disordered breathing (SDB) is increased in patients with obesity or metabolic comorbidities. However, the way in which the prevalence of SDB increases in relation to comorbidities according to the severity of obesity remains unclear. This cross-sectional study evaluated 7713 community participants with nocturnal oximetry ≥2 nights. SDB was assessed by the 3% oxygen desaturation index corrected for sleep duration obtained by wrist actigraphy (Acti-ODI3%). SDB severity was defined by Acti-ODI3%. Obesity was defined as body mass index ≥25 kg·/m−2. The prevalence of SDB was 41.0% (95% CI 39.9–42.1), 46.9% (45.8–48.0), 10.1% (9.5–10.8), and 2.0% (1.7–2.3) in normal, mild, moderate, and severe SDB, respectively, with notable sex differences evident (men >post-menopausal women >pre-menopausal women). Comorbidities such as hypertension, diabetes, and metabolic syndrome were independently associated with the prevalence of moderate-to-severe SDB, and coincidence of any one of these with obesity was associated with a higher probability of moderate-to-severe SDB (OR 8.2, 95% CI 6.6–10.2; 7.8, 5.6–10.9; 6.7, 5.2–8.6, respectively). Dyslipidemia in addition to obesity was not additively associated with the prevalence of moderate to-severe SDB. The number of antihypertensive drugs was associated with SDB (p for trend <0.001). Proportion of a high cumulative percentage of sleep time with SpO2 <90% increased even among moderate-to-severe SDB with increases in obesity. Metabolic comorbidities contribute to SDB regardless of the degree of obesity. We should recognise the extremely high prevalence of moderate-to-severe SDB in patients with obesity and metabolic comorbidities