Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020.

The prevalence of sleep disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared in order to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Because sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020.

The prevalence of sleep-disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Since sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

Sleep disordered breathing in cardiac surgery patients: The NU-SLEEP trial.

BACKGROUND: Sleep disordered breathing (SDB) is associated with lifestyle-related diseases and its treatment influence the prognosis of cardiac disease, but little investigation of SDB has been conducted in cardiac surgery patients. METHODS AND RESULTS: A prospective study was performed in 1005 patients undergoing cardiac surgery. The primary endpoint was the severity of SDB determined from the apnea/hypopnea index. The secondary endpoints were patient background factors, cardiovascular risk factors, ejection fraction, atrial and brain natriuretic peptides, oxidative stress and inflammatory markers, and postoperative atrial fibrillation. While 227 patients (22.6%) did not have SDB, there were 361 patients (35.9%) with mild SDB, 260 patients (25.9%) with moderate SDB, and 157 patients (15.6%) with severe SDB. Patients with severe SDB had a lower ejection fraction and higher levels of atrial and brain natriuretic peptides than the other groups. Postoperative atrial fibrillation occurred in 28 patients without SDB (13.6%), 43 patients with mild SDB (13.5%), 74 patients with moderate SDB (31.9%), and 73 patients with severe SDB (52.5%), being significantly more frequent in the severe group than the other groups. CONCLUSIONS: SDB was frequent in cardiac surgery patients. Activation of the renin-angiotensin-aldosterone system, postoperative atrial fibrillation atrial, and cardiac dysfunction were associated with severe SDB. Markers of inflammation and oxidative stress also increased as SDB became more severe.

Prevalence of chronic kidney diseases in patients with chronic obstructive pulmonary disease: assessment based on glomerular filtration rate estimated from creatinine and cystatin C levels.

BACKGROUND: Cardiovascular diseases, osteoporosis, and depression are identified comorbidities of chronic obstructive pulmonary disease (COPD), but there have been few reports of chronic kidney disease (CKD) as a comorbidity of COPD. The objective of this study was to investigate the prevalence of CKD in COPD patients using estimated glomerular filtration rate (eGFR) based on creatinine (Cr) and cystatin C (Cys) levels. METHODS: The prevalence of CKD and the values of various CKD-related parameters were compared between 108 stable COPD outpatients (COPD group) and a non-COPD control group consisting of 73 patients aged 60 years or more without a history of COPD or kidney disease. CKD was defined as an eGFR less than 60 mL/min/1.73 m(2). RESULTS: The Cr level was significantly higher in the COPD group, but eGFR based on serum Cr (eGFRCr) was not significantly different between the two groups (73.3±25.3 vs 79.7±15.5 mL/min/1.73 m(2)). The Cys level was significantly higher and eGFR based on serum Cys (eGFRCys) was significantly lower in the COPD group (60.0±19.4 vs 74.0±13.5 mL/min/1.73 m(2), P<0.0001). The prevalence of CKD evaluated based on eGFRCr was 31% in the COPD group and 8% in the non-COPD group with an odds ratio of 4.91 (95% confidence interval, 1.94-12.46, P=0.0008), whereas the evaluated prevalence based on eGFRCys was 53% in the COPD group and 15% in the non-COPD group with an odds ratio of 6.30 (95% confidence interval, 2.99-13.26, P<0.0001), demonstrating a higher prevalence of CKD when based on eGFRCys rather than on eGFRCr. CONCLUSION: CKD is a comorbidity that occurs frequently in COPD patients, and we believe that renal function in Japanese COPD patients should preferably be evaluated based not only on Cr but on Cr in combination with Cys.

A cross-sectional study of the association between working hours and sleep duration among the Japanese working population.

OBJECTIVES: This study aimed to clarify the association between long working hours and short sleep duration among Japanese workers. METHODS: We selected 4,000 households from across Japan by stratified random sampling and conducted an interview survey of a total of 662 participants (372 men; 290 women) in November 2009. Logistic regression analyses were performed using "sleep duration <6 hours per day" as a dependent variable to examine the association between working hours/overtime hours and short sleep duration. RESULTS: When male participants who worked for ≥7 but <9 hours per day were used as a reference, the odds ratio (OR) for short sleep duration in those who worked for ≥ 11 hours was 8.62 (95% confidence interval [CI]: 3.94-18.86). With regard to overtime hours among men, when participants without overtime were used as a reference, the OR for those whose period of overtime was ≥ 3 hours but <4 hours was 3.59 (95% CI: 1.42-9.08). For both men and women, those with long weekday working hours tended to have a short sleep duration during weekdays and holidays. CONCLUSIONS: It is essential to avoid working long hours in order to prevent short sleep duration.

The association between sleep problems and perceived health status: a Japanese nationwide general population survey.

OBJECTIVE: Sleep problems in humans have been reported to impact seriously on daily function and to have a close association with well-being. To examine the effects of individual sleep problems on physical and mental health, we conducted a nationwide epidemiological survey and examined the associations between sleep problems and perceived health status. METHODS: Cross-sectional surveys with a face-to-face interview were conducted in August and September, 2009, as part of the Nihon University Sleep and Mental Health Epidemiology Project (NUSMEP). Data from 2559 people aged 20 years or older were analyzed (response rate 54.0%). Participants completed a questionnaire on perceived physical and mental health statuses, and sleep problems including the presence or absence of insomnia symptoms (i.e., difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], and early morning awakening [EMA]), excessive daytime sleepiness (EDS), poor sleep quality (PSQ), short sleep duration (SSD), and long sleep duration (LSD). RESULTS: The prevalence of DIS, DMS, and EMA was 14.9%, 26.6%, and 11.7%, respectively, and 32.7% of the sample reported at least one of them. At the complaint level, the prevalence of EDS, PSQ, SSD, and LSD was 1.4%, 21.7%, 4.0%, and 3.2%, respectively. Multiple logistic regression analyses revealed that DMS, PSQ, SSD, and LSD were independently associated with poor perceived physical health status; DIS, EDS, and PSQ were independently associated with poor perceived mental health status. CONCLUSIONS: This study has demonstrated that sleep problems have individual significance with regard to perceived physical or mental health status.

Arrhythmia and sleep-disordered breathing in patients undergoing cardiac surgery.

BACKGROUND: Recently, the role of sleep-disordered breathing (SDB) in cardiovascular disease has attracted attention. In this study, we investigated the influence of SDB on postoperative arrhythmias after cardiac surgery. METHODS AND RESULTS: In 89 patients undergoing cardiac surgery, postoperative portable monitoring for SDB and Holter electrocardiography were performed. The primary end-points were the apnea-hypopnea index (AHI) and occurrence of arrhythmia. The secondary end-points were: (1) patient background factors; (2) average heart rate; (3) maximum heart rate (total, daytime, and nighttime); (4) minimum heart rate (total, daytime, and nighttime); (5) minimum SaO(2) during sleep; and (6) an independent predictor for arrhythmia. Twenty-six patients (29.2%) had an AHI≥15 and they were classified into the SDB group, while patients with an AHI<15 formed the non-SDB group (70.8%). Although there was no significant difference in atrial fibrillation, frequent nocturnal premature ventricular contractions were significantly more common in the SDB group (19.2%) than the non-SDB group (3.2%) (p=0.01). Maximum daytime and nighttime heart rates were also significantly higher in the SDB group. AHI was a significant predictor for frequent nocturnal premature ventricular contractions. CONCLUSIONS: This study showed that SDB is common among patients undergoing cardiac surgery, and that SDB might be closely associated with arrhythmia in these patients.

Preferable forms of relaxation for health promotion, and the association between recreational activities and self-perceived health.

Little research has been done on the association between relaxation and health. In the present study, by conducting a nationwide cross-sectional survey, we aimed to obtain scientific data on the preferable forms of relaxation for health promotion, and to clarify the associations between specific recreational activities and self-perceived mental and physical health. We selected 4,000 households by stratified random sampling from across Japan in November 2009 and used the interview method to collect data (number of subjects: 2,206). The questionnaire contained items on sleep, recreation status, recreational activities, and self-perceived mental and physical health status. We obtained responses from 1,224 adults (response rate: 55.5%). Insufficient rest from sleep, short sleep duration (<6 h/day), ineffective use of free time, and less free time used for activities other than rest showed independent positive associations with poor mental and physical health. The results of the logistic regression analyses showed significantly low adjusted odds ratios with regard to the status of poor mental and physical health for outings/walking among men (0.33 [95% confidence interval; 0.16-0.68] and 0.49 [0.26-0.90], respectively), and for community activities among women (0.19 [0.04-0.79] and 0.27 [0.09-0.77], respectively). Relaxation for the promotion of health should include both passive relaxation (rest) and active relaxation (recreation). In addition, ensuring sufficient sleep duration is important for passive relaxation, and engaging in outings/walking for men and community activities for women are important for active relaxation.

[Exercise test and respiratory muscle function test].

Dyspnea on exertion is a chief complaint of patients with COPD, and it has a major effect on the quality of their lives. Dyspnea is, by definition, subjective, but objective approaches are needed for a comprehensive understanding of these patients' conditions. Thus, measuring changes in cardiopulmonary variables during exercise can be very helpful when evaluating patients with COPD. The main purpose of exercise testing is to evaluate exercise tolerance and to identify the factors limiting exercise. Although incremental exercise testing is ideal for these purposes, simple walking tests such as 6-minute walking test, are also useful.

Obstructive sleep apnoea is associated with risk factors comprising the metabolic syndrome.

BACKGROUND AND OBJECTIVE: Several features of OSA syndrome suggest that it is a manifestation of the metabolic syndrome (MS). In this study, we investigated the prevalence of the MS among male Japanese patients with OSA, as well as the relationship between OSA in non-obese patients and components of the MS other than obesity (hypertension, dyslipidaemia and glucose intolerance). METHODS: The study included 416 Japanese men who were diagnosed as having OSA by polysomnography. Among these, 101 non-obese patients were selected and the severity of OSA, as well as the prevalence of hypertension, dyslipidaemia and glucose intolerance, was assessed. RESULTS: The MS was associated with OSA in 218/416 patients (52.4%). A significant increase in the prevalence of the MS was associated with increased severity of OSA, as categorized according to AHI. In the non-obese patients with OSA (mean age 57.6 years, BMI 22.7 kg/m(2), AHI 34.3 events/h), hypertension, dyslipidaemia and glucose intolerance were identified in 70 (69.3%), 43 (42.6%) and 20 patients (19.8%), respectively. At least two of these factors were identified in 40 patients (39.6%). Non-obese patients with severe OSA had a significantly higher prevalence of two or more of these factors (33/59 patients, 55.9%). CONCLUSIONS: Although Asians are generally less obese than Caucasians, the prevalence of the MS was high among Japanese patients with OSA, and even among non-obese patients, OSA was associated with risk factors for the MS.

Simple four-variable screening tool for identification of patients with sleep-disordered breathing.

OBJECTIVES: To aid in the identification of patients with moderate-to-severe sleep-disordered breathing (SDB), we developed and validated a simple screening tool applicable to both clinical and community settings. METHODS: Logistic regression analysis was used to develop an integer-based risk scoring system. The participants in this derivation study included 132 patients visiting one of 2 hospitals in Japan, and 175 residents of a rural town. The participants in the present validation study included 308 employees of a company in Japan who were undergoing a health check. RESULTS: The screening tool consisted of only 4 variables: sex, blood pressure level, body mass index, and self-reported snoring. This tool (screening score) gave an area under the receiver operating characteristic curve (ROC) of 0.90, sensitivity of 0.93, and specificity of 0.66, using a cutoff point of 11. Predicted and observed prevalence proportions in the validation dataset were in close agreement across the entire spectrum of risk scores. In the validation dataset, the area under the ROC for moderate-to-severe SDB and severe SDB were 0.78 and 0.85, respectively. The diagnostic performance of this tool did not significantly differ from that of previous, more complex tools. CONCLUSION: These findings suggest that our screening scoring system is a valid tool for the identification and assessment of moderate-to-severe SDB. With knowledge of only 4 easily ascertainable variables, which are routinely checked during daily clinical practice or mass health screening, moderate-to-severe SDB can be easily detected in clinical and public health settings.

Predicting optimal continuous positive airway pressure in Japanese patients with obstructive sleep apnoea syndrome.

BACKGROUND AND OBJECTIVE: Several algorithms that predict the optimal CPAP have been developed for Caucasian patients with OSA syndrome, but these algorithms do not allow for racial differences in craniofacial anatomy. We investigated whether an equation that included data on craniofacial structure, physique and severity of OSA could more accurately predict the optimal CPAP for Japanese patients with OSA syndrome. METHODS: In 170 Japanese patients with OSA syndrome, the optimal CPAP was determined by manual titration during polysomnography. An equation predicting the optimal pressure was derived from anthropometric, polysomnographic and cephalometric data. This equation was validated in another 110 Japanese patients with OSA syndrome. RESULTS: Stepwise multiple regression analysis identified AHI, BMI, mean SaO(2) and a cephalometric parameter: the angle between a line from point B to the menton (Me) and a line from Me to the hyoid bone (H) (BMeH), as independent predictors of optimal CPAP. The following equation was constructed to predict the optimal CPAP: 27.78 + (0.041 x BMeH) + (0.141 x BMI) + (0.040 x AHI) - (0.312 x mean SaO(2)). This equation accounted for 47% of the variance in optimal pressure (R(2) = 0.47, P < 0.0001). The measured optimal pressure and the pressure calculated using this equation were very similar in the other 110 patients with OSA syndrome (9.5 +/- 3.0 and 9.2 +/- 2.1 cmH(2)O, respectively). CONCLUSION: Optimal CPAP was more accurately predicted by combining a cephalometric parameter with BMI and polysomnographic data in Japanese patients with OSA, suggesting that craniofacial structure may be important in the pathogenesis of OSA syndrome among Asians.

Clinical characteristics of obesity-hypoventilation syndrome in Japan: a multi-center study.

OBJECTIVE: To clarify the prevalence and clinical characteristics of obesity-hypoventilation syndrome (OHS) in a large number of patients with moderate to severe obstructive sleep apnea syndrome (OSAS). METHODS: Subjects comprised 611 patients with OSAS registered from 7 sleep centers and clinics and analyzed according to the definitions of the Respiratory Failure Research Group of the Japanese Ministry of Health and Welfare. Baseline characteristics, polysomnographic data during sleep, laboratory blood examinations, excessive daytime sleepiness, pulmonary functions, and arterial blood gases were compared between OHS and non-OHS patients. Determinants of daytime hypercapnia were also examined in OHS patients. RESULTS: OHS was identified in 55 of the 611 patients with OSAS (9%). OHS patients were younger, heavier, and more somnolent than non-OHS patients and displayed more severe OSAS, liver dysfunctions, higher total cholesterol, and impaired pulmonary function. However, these differences were resolved except for pulmonary function after correction for obesity. Daytime hypercapnia was associated with impaired pulmonary function. Percent vital capacity (%VC) was most closely correlated with PaCO2 in OHS. CONCLUSION: OHS patients display numerous abnormalities due to obesity compared with non-OHS patients. Impaired pulmonary function, particularly %VC, may play an important role in the development of daytime hypercapnia independent of obesity in OHS patients.

Effects of long-term nasal continuous positive airway pressure on C-reactive protein in patients with obstructive sleep apnea syndrome.

Serum levels of C-reactive protein (CRP) were measured in 96 consecutive patients with obstructive sleep apnea syndrome (OSAS) before and after nasal continous positive airway pressure treatment. CRP levels only displayed significant correlations with body mass index (BMI) before treatment. No significant changes were observed in BMI and CRP levels after 9 months of treatment. These data suggest that CRP levels in patients with OSAS may be associated with obesity rather than OSAS itself.

Nasal CPAP improves the quality of life and lessens the depressive symptoms in patients with obstructive sleep apnea syndrome.

OBJECTIVE: To assess changes in response to nasal continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea syndrome (OSAS) concerning excessive daytime sleepiness (EDS), depressive state, and quality of life (QOL). PATIENTS AND METHODS: We assessed for EDS using the Epworth sleepiness scale (ESS), for mood using The Zung self-depression scale (SDS), and for QOL using Short-Form 36 (SF-36) in 132 patients with obstructive sleep apnea syndrome (OSAS) and control subjects. Patients had severe OSAS (apnea-hypopnea index, 59.4+/-23.8/h) and were more hypersomnolent and depressed, and had poorer QOL than 38 age- and gender-matched controls. RESULTS: Before treatment most QOL domains in the SF-36 were significantly associated with patients' SDS scores. With nasal CPAP, ESS and SDS scores were respectively decreased from 9.7+/-4.5 to 4.0+/-2.4 (p<0.0001) and from 49.2+/-10.4 to 45.1+/-9.6 (p<0.0005). Total SF-36 score and scores for seven of eight domains were increased significantly with treatment. Thus, nasal CPAP lessens EDS and depression, and improves QOL, in patients with severe OSAS. Further, magnitudes of changes in total SF-36 scores and in five of eight domains correlated significantly with magnitude of change in SDS score upon nasal CPAP treatment. No relationship was evident between treatment-associated score changes in SF-36 domains and ESS score change. CONCLUSION: Although patients with severe OSAS have poorer QOL than control subjects, nasal CPAP appears to improve QOL by alleviating depression.

Excessive daytime sleepiness among the Japanese general population.

BACKGROUND: Excessive daytime sleepiness is one of the principal symptoms of sleep disturbances, and is often associated with serious consequences including traffic and industrial accidents, decreased productivity, and interpersonal problems. However, there are few epidemiologic studies on excessive daytime sleepiness in a large scale sample targeting Japanese general population. METHODS: The survey was performed using a self-administered questionnaire in June 2000, targeting a population randomly selected from among 300 communities throughout Japan. This questionnaire included information about sleep habits and sleep problems. Excessive daytime sleepiness measured according to a question "Do you fall asleep when you must not sleep (for example when you are driving a car)?" RESULTS: A total of 28,714 subjects completed the questionnaire. The prevalence of excessive daytime sleepiness was 2.5% (male=2.8% and female=2.2%). Backward elimination analysis showed that the following were associated with excessive daytime sleepiness: male sex, young age, short sleep duration, subjective insufficient sleep, loss of deep sleep, disagreeable sensations in the legs, interruption of sleep by snoring or dyspnea, and feeling psychological stress. Interruption of sleep by snoring or dyspnea was the strongest associated factor (adjusted odds ratio=2.46, 95% confidence interval=1.76-3.43) of excessive daytime sleepiness. CONCLUSIONS: These results suggest that excessive daytime sleepiness in Japanese is associated with several sleep problems. These findings may be useful in attempts to prevent excessive daytime sleepiness in the general population of Japan.

[Bronchoesophageal fistula in a patient with untreated malignant lymphoma].

Bronchoesophageal fistulae associated with lymphomas are generally associated with chemo-radiotherapy. We report here an unusual case of lymphoma with a therapy-unrelated bronchoesophageal fistula. Previously, only 10 similar cases have been reported. A 70-year-old male was diagnosed as having gastric diffuse large B-cell lymphoma in May 1998. In January 1999, he noted a cough after eating and drinking. Because of the presence of a febrile temperature, productive cough and dyspnea, he was referred to our hospital and diagnosed as having aspiration pneumonia. Antibiotics did not improve his symptoms. When tracheal intubation was performed with bronchoscopy, a bronchoesophageal fistula was revealed. Malignant lymphoma cells were found around the fistula in the biopsy specimen. The patient died of pneumonia after treatment with airway stenting and chemotherapy. Induction of necrosis by chemotherapy or low blood flow with stenting and dopamine probably caused enlargement of the fistula.