Impact of Body Composition on Sleep and Its Relationship with Sleep Disorders: Current Insights.

Sleep is involved in many physiological processes and is essential for both physical and mental health. Obesity and sleep deprivation due to sleep disorders are major public health issues. Their incidence is increasing, and they have a wide range of adverse health-related consequences, including life-threatening cardiovascular disease. The impact of sleep on obesity and body composition is well-known, and many studies have shown an association between insufficient or excessive sleep duration and obesity, body fat percentage, and weight gain. However, there is growing evidence of the effects of body composition on sleep and sleep disorders (particularly sleep disordered breathing) through anatomical and physiological mechanisms (nocturnal fluid shift, core body temperature, or diet). Although some research has been conducted on the bidirectional effects of sleep-disordered breathing and body composition, the specific effects of obesity and body composition on sleep and the underlying mechanisms that explain these effects remain unclear. Therefore, this review summarizes the findings on the effects of body composition on sleep and draws conclusions and proposals for future research in this field.

Evaluation of Sleep Parameters and Sleep Staging (Slow Wave Sleep) in Athletes by Fitbit Alta HR, a Consumer Sleep Tracking Device.

Purpose: Sleep is an essential factor for athletes, and it is important to intervene in sleep to manage it. We need a device that can evaluate sleep easily and constantly. Consumer wearable devices can be useful tools for athletes. In order to use consumer wearable devices in clinical research, it is essential to conduct a validation study. Thus, we conducted a validation study to assess the Fitbit Alta HRTM (FBA)- a consumer wearable device with an accelerometer and a heart rate monitor to detect sleep stages and quality against electroencephalographic (EEG) studies in athletes. Patients and Methods: Forty college athletes participated in the study. EEG was applied to participants simultaneously while wearing FBA. Results: Regarding sleep parameters, there was a strong correlation between the total sleep time (TST)-EEG and the TST-Fitbit (r = 0.83; p < 0.001). Regarding the sleep stages, there was a modest correlation between the N3 sleep-EEG and the N3 sleep-Fitbit (r = 0.68; p < 0.001). In addition, there was a strong correlation between the percentage of N3 sleep in between sleep onset and initial rapid eye movement sleep-EEG and those on Fitbit (r = 0.73; p < 0.001). Conclusion: These results demonstrate that FBA facilitates sleep monitoring and exhibits acceptable agreement with EEG. Therefore, FBA is a useful tool in athletes' sleep management.

The relationship between body composition and sleep architecture in athletes.

Sleep is essential for athletes to recover physical fitness. It has been suggested that sleep is affected by muscle volume. Compared to female athletes, male athletes with greater muscle volume may have inferior objective sleep quality. This study aimed to assess the relationship between body composition and objective sleep parameters in male and female athletes. The body composition of 17 male and 19 female collegiate athletes were measured, and they underwent overnight home sleep monitoring. Compared with female athletes, male athletes had more muscle mass and less fat mass. Moreover, male athletes had lower sleep efficiency, longer sleep onset latency, higher arousal index, less rapid eye movement (REM) sleep, and lower percentage of slow-wave (N3) sleep in the initial non-REM sleep. Furthermore, the percentage of muscle mass was inversely related, whereas fat mass or percentage of fat mass was directly related to the percentage of N3 sleep in the initial non-REM sleep. Overall, there were no significant association between sex and sleep parameters. However, a significant correlation was found within both subgroups. Objective sleep quality was suggested to be worse in male athletes than in female athletes, implying that sleep architecture may be related to the muscle volume.

Susceptibility of subregions of prefrontal cortex and corpus callosum to damage by high-dose oxytocin-induced labor in male neonatal mice.

Induction and augmentation of labor is one of the most common obstetrical interventions. However, this intervention is not free of risks and could cause adverse events, such as hyperactive uterine contraction, uterine rupture, and amniotic-fluid embolism. Our previous study using a new animal model showed that labor induced with high-dose oxytocin (OXT) in pregnant mice resulted in massive cell death in selective brain regions, specifically in male offspring. The affected brain regions included the prefrontal cortex (PFC), but a detailed study in the PFC subregions has not been performed. In this study, we induced labor in mice using high-dose OXT and investigated neonatal brain damage in detail in the PFC using light and electron microscopy. We found that TUNEL-positive or pyknotic nuclei and Iba-1-positive microglial cells were detected more abundantly in infralimbic (IL) and prelimbic (PL) cortex of the ventromedial PFC (vmPFC) in male pups delivered by OXT-induced labor than in the control male pups. These Iba-1-positive microglial cells were engulfing dying cells. Additionally, we also noticed that in the forceps minor (FMI) of the corpus callosum (CC), the number of TUNEL-positive or pyknotic nuclei and Iba-1-positive microglial cells were largely increased and Iba-1-positive microglial cells phagocytosed massive dying cells in male pups delivered by high-dose OXT-induced labor. In conclusion, IL and PL of the vmPFC and FMI of the CC, were susceptible to brain damage in male neonates after high-dose OXT-induced labor.

Oxytocin induced labor causes region and sex-specific transient oligodendrocyte cell death in neonatal mouse brain.

AIM: Previous reports showed associations between oxytocin induced labor and mental disorders in offspring. However, those reports are restricted in epidemiological analyses and its mechanism remains unclear. In this study, we hypothesized that induced labor directly causes brain damage in newborns and results in the development of mental disorders. Therefore we aimed to investigate this hypothesis with animal model. METHODS: The animal model of induced labor was established by subcutaneous oxytocin administration to term-pregnant C57BL/6J mice. We investigated the neonatal brain damage with evaluating immediate early gene expression (c-Fos, c-Jun and JunB) by quantitative polymerase reaction and TdT-mediated dUTP nick end labeling staining. To investigate the injured brain cell types, we performed double-immunostaining with TdT-mediated dUTP nick end labeling staining and each brain component specific protein, such as Oligo2, NeuN, GFAP and Iba1. RESULTS: Brain damage during induced labor led to cell death in specific brain regions, which are implicated in mental disorders, in only male offspring at P0. Furthermore, oligodendrocyte precursors were selectively vulnerable compared to the other cell types. This oligodendrocyte-specific impairment during the perinatal period led to an increased numbers of Olig2-positive cells at P5. Expression levels of oxytocin and Oxtr in the fetal brain were not affected by the oxytocin administered to mothers during induced labor. CONCLUSION: Oligodendrocyte cell death in specific brain regions, which was unrelated to the oxytocin itself, was caused by induced labor in only male offspring. This may be an underlying mechanism explaining the human epidemiological data suggesting an association between induced labor and mental disorders.

Cold-induced metabolic conversion of haptophyte di- to tri-unsaturated C37 alkenones used as palaeothermometer molecules.

The cosmopolitan marine haptophyte alga Emiliania huxleyi accumulates very long-chain (C37-C40) alkyl ketones with two to four trans-type carbon-carbon double bonds (alkenones). These compounds are used as biomarkers of haptophytes and as palaeothermometers for estimating sea-surface temperatures in biogeochemistry. However, the biosynthetic pathway of alkenones in algal cells remains enigmatic, although it is well known that the C37 tri-unsaturated alkenone (K37:3) becomes dominant at low temperatures, either by desaturation of K37:2 or by a separate pathway involving the elongation of tri-unsaturated alkenone precursors. Here, we present experimental evidence regarding K37:3 synthesis. Using the well-known cosmopolitan alkenone producer E. huxleyi, we labelled K37:2 with 13C by incubating cells with 13C-bicarbonate in the light at 25 °C under conditions of little if any K37:3 production. After stabilisation of the 13C-K37:2 level by depleting 13C-bicarbonate from the medium, the temperature was suddenly reduced to 15 °C. The 13C-K37:2 level rapidly decreased, and the 13C-K37:3 level increased, whereas the total 13C-K37 level-namely [K37:2 + K37:3]-remained constant. These 13C-pulse-chase-like experimental results indicate that 13C-K37:2 is converted directly to 13C-K37:3 by a desaturation reaction that is promoted by a cold signal. This clear-cut experimental evidence is indicative of the existence of a cold-signal-triggered desaturation reaction in alkenone biosynthesis.

Detection of AU(III) ions using a poly(N,N-dimethylacrylamide)-coated QCM sensor.

A polymer-coated quartz crystal microbalance (QCM) sensor has been developed for the detection of Au(III) ions in a HCl aqueous solution. Poly(N,N-dimethylacrylamide) (poly(DMAA)) gel was used as a sensing material. The poly(DMAA) gel adsorbs Au(III) ions in the HCl aqueous solution, whereas it is inactive toward most other metal ions. The equilibrium adsorption of Au(III) ions onto the poly(DMAA) gel can be expressed by the Henry-type isotherm. The oscillation behavior of the poly(DMAA)-coated QCM sensor was investigated, and linear relationships between the resonance frequency shift and the concentration of Au(III) ions were obtained for concentrations of less than 0.032 mol/m(3) (6.3 mg/m(3)) in the single and multicomponent metal systems. The poly(DMAA)-coated QCM sensor detects Au(III) ions successfully with high selectivity and sensitivity even in the presence of other metal ions and organic compounds.

CT localisation of small pulmonary nodules prior to thorascopic resection: Evaluation of a point marker system.

PURPOSE: To evaluated the utility of a 5-mm long point marker system for CT localisation of small pulmonary nodules prior to thorascopic resection. MATERIALS AND METHODS: Percutaneous localisation of 57 pulmonary nodules was performed with computed tomographic (CT) guidance in 52 patients. The size of the nodules ranged from 3mm to 20mm (mean: 9mm, median: 8mm). The mean distance of the outer rim to the pleura ranged from 3mm to 55mm (mean: 19mm, median: 15mm). A stainless steel, 5-mm long point marker with a 30-cm long nylon suture and introducer system (21-gauge) was firmly attached to the funnel at the proximal end of the marker. RESULTS: The point marker system was successfully placed without being dislodged in 56 out of the 57 lesions (98%) and served as a clear guide during thoracoscopy. In 10 out of 52 patients (19%), non-symptomatic pneumothorax cases were observed. In 6 out of 52 patients (10%), haemorrhages into the lung parenchyma were observed. In no case did insertion of the point marker system cause strong pain and require an analgesic agent to be added. No patients produced hemopysis or air emboli. All nodules, including a dislodgment case, were successfully resected and the suture served as a clear guide during thoracoscopy. Pathologic findings of nodules included 37 malignancies and 20 non-malignancies. CONCLUSION: The marker system used for thoracoscopic resection was a safe and useful procedure.

Sonographic diagnosis of biliary atresia in pediatric patients using the "triangular cord" sign versus gallbladder length and contraction.

OBJECTIVE: A retrospective review was performed to evaluate the importance of the "triangular cord" sign in comparison with gallbladder length and contraction for the diagnosis of biliary atresia in pediatric patients. MATERIALS AND METHODS: Fifty-five fasting infants with cholestatic jaundice were examined on sonography. The examinations focused on the visualization of the triangular cord sign and assessment of gallbladder length and contraction. The diagnosis of neonatal hepatitis or of other causes of infantile cholestasis was made if symptom resolution occurred during follow-up. RESULTS: A triangular cord sign was found in 27 of 29 infants with biliary atresia and in one of 26 infants with neonatal hepatitis or other causes of infantile cholestasis. The diagnostic accuracy was 95%, sensitivity was 93%, and specificity was 96%. The gallbladder was thought to be abnormal if it was less than 1.5 cm long, was not detectable, or was detectable but had no lumen. The gallbladder was abnormal in 21 of 29 infants with biliary atresia, whereas it was abnormal in eight of 26 infants with neonatal hepatitis or other causes of infantile cholestasis. The diagnostic accuracy was 71%, sensitivity was 72%, and specificity was 69%. The gallbladder was detectable on sonography in 13 infants with biliary atresia and 26 infants with neonatal hepatitis or other causes of infantile cholestasis. Gallbladder contraction was not confirmed in 11 of 13 infants with biliary atresia and seven of 26 infants with neonatal hepatitis or other causes of infantile cholestasis. The diagnostic accuracy was 77%, sensitivity was 85%, and specificity was 73%. CONCLUSION: The triangular cord sign was a more useful sonographic finding for diagnosing biliary atresia than gallbladder length and contraction.