The occurrence of respiratory events in young subjects with a frequent rhythmic masticatory muscle activity: a pilot study.

PURPOSE: Concomitant occurrence of respiratory events can be often overlooked in the clinical practice of SB. This study assessed physiological characteristics of rhythmic masticatory muscle activity (RMMA) and concomitant respiratory events in young sleep bruxism (SB) subjects asymptomatic to obstructive sleep apnea (OSA). METHODS: Twenty-two subjects (age: 24.1±1.9years; F 8: M 14; BMI: 20.2±1.9kg/m2) were polysomnographically diagnosed as moderate-severe SB. Sleep architecture, oromotor (RMMA and non-specific masseter activity [NSMA]) and apnea/hypopnea events were scored. RESULTS: All subjects showed normal sleep architecture whereas 6 exhibited respiratory events at a mild level of OSA. In all subjects, RMMA predominantly occurred in Stage N1+N2 while NSMA occurred in Stage N1+N2 (approximately 60 %) and in Stage R (up to 30 %). Up to 50% of respiratory events were scored in Stage R. RMMA occurred more frequently in close association (e.g., within 10s) with respiratory events in 6 subjects with OSA than those without. The percentage of RMMA occurring closely to respiratory events was positively correlated with apnea-hypopnea index (AHI) in Stage N1+N2 only while that of NSMA was positively correlated with AHI in Stage N1+N2 and Stage R. A sub-analysis in 6 subjects with OSA, RMMA after respiratory events was followed to arousals while those before respiratory events were mostly associated with central apnea. CONCLUSIONS: A subpopulation of young SB subjects can show concomitant respiratory events. Further large sample studies are needed to demonstrate that the occurrence of subclinical respiratory events represents a clinical subtype of SB.

Subjective oropharyngeal symptoms for abnormal swallowing in Japanese patients with obstructive sleep apnea syndrome: a descriptive questionnaire study.

OBJECTIVES: This study aimed to investigate the prevalence of clinical symptoms related to abnormal swallowing in a large sample of obstructive sleep apnea syndrome (OSAS) patients. METHODS: Oropharyngeal symptoms for abnormal swallowing were assessed by a self-administered questionnaire in 507 consecutive patients (females: 65, males: 442; mean age: 49.6 ± 12.6 years old) with clinical symptoms of OSAS, enrolled for cardiorespiratory evaluation. RESULTS: Overall, 16.2% of patients (82/507) had at least one symptom for abnormal swallowing and 6.3% (32/507) had two or more symptoms. The most frequent symptom was difficulty with coughing up phlegm during or after a meal (8.3%). Demographic, sleep, and clinical variables did not differ between the patients with and without abnormal symptoms. CONCLUSIONS: The results of the current study showed that 16% of middle-aged OSAS patients reported pharyngeal symptoms related to abnormal swallowing, regardless of the severity of OSAS.

Sleep duration and its association with sleepiness and depression in "ronin-sei" preparatory school students.

PURPOSES: The Japanese word "ronin-sei" refers to a student who has failed their university entrance examination and is preparing to re-take the examination in the following year. We aimed to determine how sleep duration is associated with daytime sleepiness or depression in ronin-sei because impaired daytime performance is known to result from sleep deprivation. METHODS: The participants in this cross-sectional study were 1075 ronin-sei and 285 university students. Sleepiness and depressive symptoms were assessed using the Epworth Sleepiness Scale (ESS) and the Center for Epidemiologic Studies Depression Scale (CES-D), respectively. RESULTS: Ronin-sei had significantly shorter sleep duration and earlier bed- and rise-times than university students. There was no significant difference in CES-D between the groups; however, the ESS score of university students was significantly higher than that of ronin-sei. Ronin-sei who slept for 5 to <6h had higher ESS scores than those who slept for 6 to <7h. The mean CES-D score in ronin-sei who slept <5h was significantly higher than in those who slept for 5 to <6h, from 6 to <7h, and from 7 to <8h. Ronin-sei who slept for more than 8h also had higher depression scores. CONCLUSIONS: Sleep deprivation appears to be common among ronin-sei. Furthermore, a U-shaped relationship was found between sleep duration and depressive symptoms, revealing that ronin-sei who had too little or too much sleep were more likely to exhibit an increase in depressive symptoms.

Sense of coherence, health problems, and presenteeism in Japanese university students.

AIM: Sense of coherence (SOC) is thought to be a major determinant in maintaining health. SOC gained attention recently in the fields of psychiatry after it was reported to be associated with a lowered risk of various health problems. However, the effect of SOC as a buffer against performance impairment caused by health problems is not well known. Thus, we aimed to examine the relationships among health problem, the degree of presenteeism (performance loss due to health problems), and SOC in adolescents. METHODS: Participants were 2824 university students (1855 males, mean age; 18.35±0.84 years). SOC and self-reported health problems were assessed using an SOC scale (29 items) and the presenteeism scale for students, respectively. RESULTS: SOC scores differed between students with and without health problems (t(2822)=5.75, P<0.001). The effect size (Cohen's d) was 0.22 for this difference. In a multiple logistic regression analysis, male gender (odds ratio [OR]=0.62; 95% confidence interval [CI]=0.53-0.73), moderate SOC (within ±1 SD; OR=0.59; 95% CI=0.47-0.72), and high SOC (>1 SD; OR=0.43; 95% CI=0.33-0.58) were independently associated with a lower frequently of health problems. In addition, SOC showed a significant inverse correlation with presenteeism (r=-0.27, P<0.001). CONCLUSION: These results suggest that application of the concept of SOC might aid in the prevention of health problems among university students. Students with a strong SOC might be less prone to a decline in performance when health problems arise.

Responsiveness of jaw motor activation to arousals during sleep in patients with obstructive sleep apnea syndrome.

OBJECTIVES: We aimed to characterize the association between jaw muscle contractions and respiratory events in patients with obstructive sleep apnea syndrome (OSAS) and to investigate the responsiveness of the contractions to respiratory events in comparison with that of leg muscles in terms of arousal types and sleep states. METHODS: Polysomnographic (PSG) recordings were performed in 19 OSAS patients (F/M: 2/17; 53.1 ± 13.7 years; AHI: 31.8 ± 19.9/h) with no concomitant sleep bruxism or other sleep-related movement disorders. Muscle contractions of unilateral masseter (MAS) and anterior tibialis (AT) muscles were scored during sleep in association with graded arousals (microarousals and awakenings) related or unrelated to apneahypopnea events. RESULTS: Arousals were scored for 68.2% and 52.3% of respiratory events during light NREM and REM sleep, respectively. Respiratory events with arousals were associated with longer event duration and/or larger transient oxygen desaturation than those without (ANOVAs: p < 0.05). Median response rates of MAS events to respiratory events were 32.1% and 18.9% during NREM and REM sleep. During two sleep states, MAS muscle was rarely activated after respiratory events without arousals, while its response rate increased significantly in association with the duration of arousals (Friedman tests: p < 0.001). A similar response pattern was found for AT muscle. Motor responsiveness of the two muscles to arousals after respiratory events did not differ from responsiveness to spontaneous arousals in two sleep stages. CONCLUSION: In patients with OSAS, the contractions of MAS and AT muscles after respiratory events can be nonspecific motor phenomena, dependent on the duration of arousals rather than the occurrence of respiratory events.

Can we predict arterial lactate from venous lactate in the ED?

OBJECTIVE: We aimed to generate equation to predict arterial lactate (a-Lac) using venous lactate (v-Lac) and other lab data. METHODS: A prospective cross-sectional study was conducted on emergency patients in the emergency department for 6 months at a general hospital in Tokyo, Japan. We collected arterial and venous gas analysis data. Patients were eligible for entry into the study if an arterial blood gas analysis was required for appropriate diagnostic care by the treating physician. Univariate linear regression analysis was conducted to generate an equation to calculate a-Lac incorporating only v-Lac. A multivariate forward stepwise logistic regression model (p-value of 0.05 for entry, 0.1 for removal) was used to generate an equation including v-Lac and other potentially relevant variables. Bland-Altman plot was drawn and the two equations were compared for model fitting using R-squares. RESULTS: Seventy-two arterial samples from 72 participants (61% male; mean age, 58.2 years) were included in the study. An initial regression equation was derived from univariate linear regression analysis:"(a-Lac) = -0.259 + (v-Lac) × 0.996". Subsequent multivariate forward stepwise logistic regression analysis, incorporating v-Lac and Po2, generated the following equation:"(a-Lac) = -0.469+(venous Po2) × 0.005 + (v-Lac) × 0.997". Calculated R-squares by single and multiple regression were 0.94 and 0.96, respectively. CONCLUSION: v-Lac estimates showed a high correlation with arterial values and our data provide two clinically useful equations to calculate a-Lac from v-Lac data. Considering clinical flexibility, "Lac = -0.259 + v-Lac × 0.996" might be more useful while avoiding a time-consuming and invasive procedure.

Negative association between self-reported jaw symptoms and apnea-hypopnea index in patients with symptoms of obstructive sleep apnea syndrome: a pilot study.

OBJECTIVES: Prior to oral appliance therapy for snoring and obstructive sleep apnea syndrome (OSAS), patients are screened for jaw symptoms (e.g., pain). However, the presence of jaw symptoms in a large spectrum of OSAS patients remains unknown. This study aimed to assess the distribution of subjective jaw symptoms in patients with symptoms of OSAS. METHODS: Five hundred and eleven consecutive patients (66 female, 445 male; mean age 49.6 ± 12.6 years) with clinical symptoms of OSAS were enrolled for cardiorespiratory evaluation. Self-administered questionnaires were used to assess jaw symptoms, tooth grinding and clenching during sleep, morning oral dryness, morning heartburn sensation, and pain in the neck and back. RESULTS: The mean apnea-hypopnea (AHI) index was 32.5 ± 30.6 per hour of sleep. Nineteen percent of patients (n = 96) reported at least one jaw symptom. The presence of jaw symptoms was more frequently reported by patients with AHI less than 15 (25 %) than those with AHI of 15 and more (15 %, p = 0.012). In the crude analyses, jaw symptoms were associated with tooth grinding, tooth clenching, morning oral dryness, morning heartburn sensation, and neck/back pain. Multiple logistic regression analysis confirmed that jaw symptoms were associated with AHI less than 15 (odds ratio (OR) 1.99, p = 0.009), tooth clenching (OR 1.79, p = 0.006), morning oral dryness (OR 2.17, p = 0.02), and neck/back pain (OR 1.99, p = 0.005). CONCLUSIONS: Jaw symptoms can be found in 19 % of patients with symptoms of OSAS and are more frequently reported in patients with lower AHI, a patient population for whom oral appliances are often prescribed.

Efficacy and tolerability of ramelteon in a double-blind, placebo-controlled, crossover study in Japanese patients with chronic primary insomnia.

The aim of this study was to evaluate the efficacy and safety of ramelteon 4, 8, 16 or 32 mg and placebo in Japanese patients with chronic insomnia using a randomized, double-blind, five-period crossover design. A total of 65 Japanese patients with chronic primary insomnia received ramelteon or placebo for two nights each in sleep laboratories. Changes in sleep parameters were assessed objectively by polysomnography and subjectively by postsleep questionnaires. Safety and tolerability was evaluated by assessment of the occurrence of adverse events, next-day residual effects and laboratory and ECG investigations. Ramelteon 8 and 32 mg significantly shortened the mean latency to persistent sleep in comparison with placebo, and there was a statistically significant trend for linear dose-response for this sleep parameter. Overall changes in sleep architecture were modest (<3% changes vs placebo), with increases in stage 1 and decreases in stage 3/4. Ramelteon was well tolerated, the most common adverse effect being somnolence, which was similar to placebo at doses up to 8 mg, but increased with higher doses. Next-day residual effects occurred no more frequently with ramelteon at any dose than with placebo. When compared with sleep latency data from a similarly-designed US study, there was no evidence of any ethnic differences in the efficacy of ramelteon between Japanese and US patients. Overall, ramelteon 8 mg showed the most favorable balance between sleep-promoting effects and tolerability. The unique efficacy profile of ramelteon, promoting sleep initiation without affecting other sleep parameters, may be due to its circadian shifting effect.

Presenteeism in college students: reliability and validity of the Presenteeism Scale for Students.

OBJECTIVE: Presenteeism is the impaired work performance due to health problems. We aimed to develop a Presenteeism Scale for Students (PSS), and to reveal the existence of presenteeism among students. METHODS: Students (n = 5,701) in 4 national universities in Japan were recruited via the school-based health examination. Moreover, 122 students participated in a 2-week interval test-retest to examine the reliability and criterion-related validity of the PSS. RESULTS: Of the students, 59.2% indicated some health problems. Allergy was most prevalent health problems, affecting 35.7% of the whole students. Students with emotional problems had higher degree of presenteeism than those with the other problems. The Cronbach's α of the work impairment score of the PSS was 0.90. The Spearman's coefficient for the test-retest score was 0.80 (P < 0.001). Regarding criterion-related validity, Spearman's coefficient between the work impairment score of the PSS and summary score of the SF-36 was -0.60 (P < 0.001). CONCLUSIONS: These findings suggest that the PSS can be expected to be useful for assessment of students with presenteeism. Furthermore, we found that the majority of students have some health problems, and proposed that the issue of presenteeism on campus should be addressed.

Anxiety, neuroticism and oxidative stress: cross-sectional study in non-smoking college students.

AIMS: Oxidative stress has gained attention recently in psychiatric medicine and has been reported to be associated with various diseases. However, the psychosocial factors involved in oxidative stress are still not well understood. Thus, the aim of this study was to examine whether anxiety levels and neuroticism were associated with serum oxidative and anti-oxidative status in healthy college students. METHODS: Participants in this cross-sectional study were 54 non-smoking college students. Their serum oxidative status was determined by reactive oxygen metabolites (ROM) and the biological anti-oxidant potential. Anxiety levels and neuroticism were assessed using the State-Trait Anxiety Inventory and the NEO Five-Factor Inventory, respectively. RESULTS: Correlation analysis showed an association of increased ROM concentration with elevated anxiety levels (State, rho = 0.39, P = 0.046; Trait, rho = 0.44, P = 0.024) and the personality trait of neuroticism (rho = 0.47, P = 0.016) in female students. However, the ROM concentration in male students was not associated with the anxiety level or any personality trait. CONCLUSION: Although these findings suggest that neurotic and anxious female students tend to be exposed to oxidative stress, these linkages should be confirmed by multivariate analysis in future research.

Do depressive symptoms correlate with oxidative stress in a sample of healthy college students?

Background and Objectives: Major depression and sub-threshold depressive symptoms are associated with health crisis. Oxidative stress may be a mechanism for major depression. In the present study, we examined the relationship between the degree of depressive symptoms and oxidative status using a reliable and inexpensive method that evaluates endogenous hydroperoxides. Methods: We conducted a cross-sectional study in 54 non-smoking college students and measured serum reactive oxygen metabolites (ROMs) and the biological antioxidant potential (BAP) as an index of oxidative status. Depressive symptoms were assessed by the Beck Depression Inventory (BDI). Results: The concentrations of ROMs did not differ between the lower BDI group (BDI < 14) and the higher BDI group (BDI > 14) (282.7 - 59.84 U.CARR vs 307.7 - 67.51 U.CARR, z = -1.19, P = 0.239). We did find a significant relationship between ROM concentration values and higher BDI scores (rho = 0.30, P = 0.042). BAP levels in the higher BDI group were not significantly greater than those in the lower BDI group (z = -0.108, P = 0.287). There was no significant correlation between BAP and depressive symptoms (rho = 0.22, P = 0.140). Moreover, we conducted a multiple regression analysis to control for gender difference and difference in sleep perception of the previous night between the two BDI groups. However, depressive symptoms were not significantly predicted by ROM concentrations (b = 0.28, P = 0.076). Conclusions: While results of the present study demonstrated a slight correlation between depressive symptoms and oxidative stress, this linkage could not be confirmed after controlling for significant confounding factors. This result should be verified in a larger sample (AU)

Electrogastrography abnormality in eating disorders.

Eating disorders are common psychiatric disorders in young women. The aim of the present study was to evaluate the gastric electrical activity of patients with eating disorders and its relation to their symptoms. The electrogastrography (EGG) was performed before and after a water load test for outpatients with eating disorders (n = 36; 14 anorexia nervosa, 14 bulimia nervosa, eight eating disorder not otherwise specified) and healthy women (n = 19). A structured interview (Eating Disorder Examination) was used to assess clinical symptoms. The percentage of normal gastric myoelectrical power was significantly smaller in the eating disorder patients (44.5% vs 74.2%; P < 0.05), while the percentage of bradygastric power was significantly greater, both before and after the water load test compared with the control subjects (30.4% vs 10.4%; P < 0.05). In addition, moderate correlation was found between the duration of illness and the percentage of bradygastria (P < 0.05). In conclusion, it is suggested that longstanding abnormal eating in patients with eating disorders may induce disturbances to gastric motor function, resulting in their abnormal, eating-related behavior, and form a symptomatic vicious circle. The EGG may be a promising method for determining the pathophysiology of eating disorders and for developing effective therapeutic approaches.

Sleep characteristics of menopausal insomnia: a polysomnographic study.

Although menopausal insomnia is of clinical significance, the essential features of this form of disrupted sleep are poorly understood. The aim of the present study was to identify the sleep characteristics of menopausal insomnia by using overnight polysomnography (PSG). Twenty-one subjects with menopausal insomnia (MI) and 13 sex- and age-matched normal control (NC) subjects without sleep complaints took part in the present study. All MI and NC subjects underwent PSG on two consecutive nights. In comparison with NC, MI subjects had non-specific findings such as significantly shorter total sleep time, longer sleep latency, higher wake time after sleep onset, and lower sleep efficiency. As for rapid eye movement (REM) sleep variables, MI subjects had significantly shorter total REM sleep time, fewer numbers of REM sleep periods, longer REM latency, and higher REM density than did the NC subjects. As for the time course of REM density, REM density during the first 3 h period of nocturnal sleep was significantly higher for MI than for NC subjects. Unlike NC subjects, REM density for MI subjects did not tend to rise progressively during nocturnal sleep. The MI subjects had objective evidence of disrupted sleep and the most striking characteristics of this dysfunction were observed in REM sleep variables. The sleep characteristics of MI subjects were found to differ in REM sleep variables from those of patients with major depression (except for REM density). Menopausal insomnia patients appear to be similar to patients with generalized anxiety disorder accompanied by severe sleep disruption. These data lend support to the clinical distinction between menopausal insomnia and insomnia associated with major psychiatric disorders.

Clinical significance of pulse rate rise during sleep as a screening marker for the assessment of sleep fragmentation in sleep-disordered breathing.

OBJECTIVE: To assess the clinical utility of the frequencies of transient increases of pulse rate, non-invasively measured with a pulseoximeter, as an indirect indication of the degree of cortical arousal, measured conventionally on an electroencephalogram (EEG), in obstructive sleep apnea-hypopnea syndrome (OSAHS) patients. PATIENTS AND METHODS: Thirty-three consecutive patients referred with suspected OSAHS were studied. Polysomnography (PSG) with determination of esophageal pressure (Pes) and pulseoximetry was monitored to identify breathing-related EEG arousal (B-Ar) associated with apnea, hypopnea or respiratory effort and the frequencies of pulse rate increases. We also assessed the association of B-ArI (defined as the number of B-Ar per hour) with the pulse rate rise index (PRRI)-X(X=4-10) (defined as the number of pulse rate increases per hour). In addition, the sensitivity and specificity of PRRI for the assessment of a B-ArI cutoff point of 30 were calculated. RESULTS: The sensitivity and specificity of pulseoximetry for different thresholds of PRRI-X(X=4-10) demonstrated that the greatest diagnostic accuracy for detecting frequent arousal (B-ArI > or =30) occurs at a cutoff point of 40 PRRI-6 with a sensitivity of 0.88 and specificity of 0.86. This point shows a significant area under the curve of 0.84. In addition, a statistically significant correlation between PRRI-6 and B-ArI (r=0.68, P<0.0001) was observed. CONCLUSIONS: The transient increases in pulse rate measured by pulseoximetry during sleep may be a useful clinical marker for predicting the degree of arousal in OSAHS patients, and may, in addition, prevent cases with frequent respiratory effort related arousals from being overlooked. However, further studies are required to improve the confidence level of the PRRI and to investigate the causes of overestimation of EEG arousals.

Three components of obstructive sleep apnea/hypopnea syndrome.

The aims of this study were to calculate the apnea-hypopnea index (AHI), which represented as the number of apnea-hypopnea occurrences per hour, the 4% oxygen desaturation index (ODI4) and the breathing-related arousal index (B-ArI) in polysomnographic studies of obstructive sleep apnea/hypopnea syndrome (OSAHS) patients and to investigate whether there was any relationship between each pair of scoring schemes. Thirty-four cases of OSAHS were studied. Total OSAHS patients were subdivided into those with a high AHI (> 25), and those with a low AHI (< 25). The correlation between each pair of scoring schemes for OSAHS with a high AHI showed high value. The correlation between AHI and ODI4 for OSAHS with a low AHI was 0.18 and that between AHI and B-ArI showed a weak correlation of 0.59, while that between ODI4 and B-ArI was only -0.078. Our results mean that oxygen desaturation and arousal occur separately in mild or moderate OSAHS patients, even though they are diagnosed with the same level of OSAHS by means of AHI. Breathing-related arousal without oxygen desaturation often occurs in mild or moderate OSAHS patients. We previously reported that AHI does not accurately reflect the severity of the increase in negativity of esophageal pressure manifested as respiratory efforts. We consider that the comprehension and assessment of OSAHS can be improved by the systematic differentiations among the three components: oxygen desaturation, arousals and respiratory efforts.