The role of long-term continuous positive airway pressure in the progression of obstructive sleep apnoea: A longitudinal cohort study.

Recent evidence suggests that short-term obstructive sleep apnea (OSA) treatment could affect OSA pathogenesis such as ventilatory control. The aim of our present study was to identify the impact of long-term treatment on the change in pathogenesis and natural progression of OSA. In a longitudinal analysis of a non-obese cohort study, patients with OSA treated with either continuous positive airway pressure (CPAP) or an oral appliance (OA), interrupted their treatment for 1 week and underwent a polysomnography (PSG) off treatment that was compared with their initial PSG taken 5 years before treatment initiation. In all, 154 consecutive patients with OSA who were treated by CPAP using an auto-titrating continuous positive airway pressure device (CPAP-APAP) (n = 112), or by OA (n = 27) or were untreated (n = 15), PSG was performed twice with a median (range) follow-up of 93 (60-176) months. Multivariate logistic regression showed that reduction of body mass index (BMI) and good treatment adherence to be significant predictors of favourable OSA progression, as represented by an improved or unchanged apnea-hypopnea index (AHI) (odds ratios were 5.14 and 2.89, respectively). Amongst the patients with an unchanged BMI and good CPAP-APAP adherence (n = 55), the improvement in AHI was significantly associated with the decrease in supine non-rapid eye movement-AHI and mixed apnoea index/apnoea index, which are generally recognised to be determinants of ventilator instability. These findings suggest that not only weight but also treatment adherence are determinants in the natural progression of OSA severity.

Obstructive sleep apnea phenotypes in men based on characteristics of respiratory events during polysomnography.

PURPOSE: The upper airway (UA) anatomical collapsibility, UA muscle responsiveness, breathing control, and/or arousability are important contributing factors for obstructive sleep apnea (OSA). Differences in clinical manifestations of OSA are believed to reflect interactions among these factors. We aimed to classify OSA patients into subgroups based on polysomnographic (PSG) variables using cluster analysis and assess each subgroup's characteristics. METHODS: Men with moderate or severe OSA and without any concomitant heart or psychosomatic disease were recruited. A hierarchical cluster analysis was performed using variables including fraction of apnea, respiratory event duration, minimum oxygen saturation, arousal rate before termination, and frequency of respiratory events in the supine position. The impact of sleep stages or body position on PSG variables was also evaluated in each cluster. RESULTS: A total of 210 men (mean age, 50.0 years, mean body mass index, 27.4 kg/m2) were studied. The three subgroups that emerged from the analysis were defined as follows: cluster 1 (high fraction of apnea and severe desaturation (20%)), cluster 2 (high fraction of apnea and long event duration (31%)), and cluster 3 (low fraction of apnea (49%)). There were differences in the body mass index and apnea type between the three clusters. Sleep stages and/or body position affected PSG variables in each cluster. CONCLUSIONS: Patients with OSA could be divided into three distinct subgroups based on PSG variables. This clustering may be used for assessing the pathophysiology of OSA to tailor individual treatment other than continuous positive airway pressure therapy.

The melatonin receptor agonist is effective for free-running type circadian rhythm sleep disorder: case report on two sighted patients.

Along with urbanization of the living environment, the number of patients with circadian rhythm sleep disorder (CRSD) has been increasing. There are several treatment candidates for CRSD, such as light therapy, drugs (melatonin and vitamin B12), and sleep hygiene education. However, successful treatment method has not been established. In free-running type (FRT) CRSD, the endogenous circadian rhythm cannot be entrained to the 24-h light-dark cycle, resulting in free running on a cycle 0.5-2.5 h longer than the 24-h period. This condition is relatively common in blind individuals and is unusual in sighted individuals. Here we report two sighted patients with FRT, successfully treated with a melatonin receptor agonist, ramelteon. Patient 1 (36-year-old female) had suffered from FRT for nearly 4 months after resigning her job. She was given sleep hygiene education together with ramelteon at first and the free-running cycle stopped after treatment day 15. Triazolam was added from the day 25 to promote earlier sleep onset. And the sleep-wake schedule was normalized by the day 34. Patient 2 (33-year-old male) had suffered from FRT for nearly 8 months after starting to take a leave of absence from his job. He was given sleep hygiene education and was treated with ramelteon and methylcobalamin. His sleep-wake schedule was normalized from the first treatment day. By the combined treatment with ramelteon, both patients have maintained favorable sleep-wake schedules. The agonist action of ramelteon at the melatonin 2 receptor may have primarily contributed to the cessation of the free-running cycle in these patients.

Reliability and validity of the Japanese version of the Ullanlinna Narcolepsy Scale and Swiss Narcolepsy Scale for screening Japanese individuals with narcolepsy type 1.

OBJECTIVE: To validate the Japanese versions of the Ullanlinna Narcolepsy Scale (J-UNS) and Swiss Narcolepsy Scale (J-SNS) for screening narcolepsy in the Japanese population and to discuss strategies for their use in hypersomniac individuals. METHODS: We selected 451 outpatients with excessive daytime sleepiness (EDS) already diagnosed according to the International Classification of Sleep Disorders third edition. They responded to both scales twice at 1-month intervals. After eliminating individuals who met the exclusion criteria, validity and reliability analyses were performed on 408 and 381 participants, respectively. RESULTS: Patients with narcolepsy type 1 (NT1) displayed higher J-UNS and lower J-SNS scores than those with NT2 and other sleep disorders. The intraclass correlation coefficients and weighted κ coefficient for scale scores in the total participants and patients with NT1 were ≥0.70 and ≥ 0.40, respectively, indicating high reliability. Furthermore, both the sensitivity and specificity of these scales upon using the original cut-off scores (14 for UNS and 0 for SNS) for detecting NT1 were 0.70 or ≥0.70, suggesting high validity. Additionally, the receiver operating characteristic curve analysis revealed that the best cut-off score did not change for the J-SNS but that for the J-UNS, it increased to 18. In our study, the scale's sensitivity and specificity changed from 96% to 82% and 58%-78%, respectively. CONCLUSIONS: Both scales revealed satisfactory screening abilities for NT1 in the Japanese population. However, it may be better to use J-UNS cut-off scores of 18 for a population with EDS.

Radiofrequency catheter ablation of persistent atrial fibrillation decreases a sleep-disordered breathing parameter during a short follow-up period.

BACKGROUND: Obstructive sleep apnea (OSA) is often associated with atrial fibrillation (AF), but the impact of radiofrequency catheter ablation (RFCA) for AF on sleep apnea syndrome is unknown. METHODS AND RESULTS: A total of 25 patients (3 women; 61 ± 6 years) with sleep apnea syndrome who underwent RFCA for drug-refractory, persistent AF were studied. Polysomnography was also performed 1 day before and 1 week after RFCA in all patients. The total number of central or OSA or hypopnea events was analyzed and compared. Among the 25 patients who all predominantly had obstructive apnea, the apnea-hypopnea index (AHI; median, 21, interquartile range [IQR]: 11-38 to median 15, IQR: 7-23; P=0.002) and obstructive type of apnea (median 10, IQR: 6-19 to median 7, IQR: 2-14; P=0.003) decreased after RFCA. In patients in whom sinus rhythm was restored and maintained after RFCA, the AHI decreased after RFCA (median 22, IQR: 15-38 to median 15, IQR: 7-23; P<0.01), but it did not in those who had AF recurrence (median 10, IQR: 9-11 to median 11, IQR: 10-16; P<0.05). There was a significant correlation between the outcome of RFCA and % change in the AHI (rs=0.569, P=0.003). CONCLUSIONS: In patients with sleep apnea syndrome and AF, restoring sinus rhythm by RFCA was significantly associated with a decrease in AHI (Clinical Trial Registration: Trial number, UMIN000005538).

Fraction of apnea is associated with the required continuous positive airway pressure level and reflects upper airway collapsibility in patients with obstructive sleep apnea.

STUDY OBJECTIVES: We aimed to determine whether the fraction of apnea (Fapnea) could be used as an alternative index to reflect upper airway collapsibility. METHODS: We retrospectively recruited 161 patients (16 women, mean age 47.8 years, body mass index [BMI] 28.0 kg/m2, and apnea-hypopnea index 46.4 events/h) with moderate to severe obstructive sleep apnea who had undergone nasal continuous positive airway pressure (CPAP) titration. Fapnea is defined as the percentage of apneic events relative to the total number of apneic and hypopneic events during sleep in a supine position on diagnostic polysomnography. We randomly split the data (70/30) into the development and validation datasets. In the development dataset, we conducted a multiple regression analysis to assess the association of variables, including age, sex, BMI, supine rapid eye movement (REM) sleep apnea-hypopnea index, and apnea with a CPAP level during supine REM sleep (REM_CPAP). Moreover, we developed an equation for predicting the CPAP level. Thereafter, we evaluated the correlation between the actual CPAP level and the value calculated using the model. RESULTS: BMI and Fapnea were the only significant factors that predicted the REM_CPAP level (adjusted r = .60, P < .001) in the development dataset. The validation data revealed a significant correlation between the actual and predicted CPAP levels (r = .69, P < .0001). We observed similar associations during supine non-REM sleep. CONCLUSIONS: Fapnea could significantly predict the CPAP levels during both REM and non-REM sleep, which likely reflects the upper airway collapsibility, independent of the BMI. CITATION: Nakayama H, Takei Y, Kobayashi M, Yanagihara M, Inoue Y. Fraction of apnea is associated with the required continuous positive airway pressure level and reflects upper airway collapsibility in patients with obstructive sleep apnea. J Clin Sleep Med. 2022;18(5):1243-1249.

[Rifabutin-associated hypopyon uveitis in patient with acquired immunodeficiency syndrome].

BACKGROUND: Rifabutin-associated uveitis has been recognized and established overseas, but there have been no reports of its occurance in Japan. We report a case of rifabutin-induced hypopyon uveitis in a patient with acquired immunodeficiency syndrome (AIDS). CASE: A 45-year-old Filipino man with AIDS and pulmonary tuberculosis was on highly active antiretroviral therapy (HAART; lopinavir/ritonavir, zidovudine/lamivudine) and anti-tuberculosis therapy (isoniazid, rifabutin). At 11 weeks after starting rifabutin administration, unilateral acute uveitis with hypopyon developed, which progressed to bilateral uveitis by the following day. Funduscopic examination revealed no vitreo-retinal abnormalities. The uveitis resolved after discontinuation of the rifabutin and initiating topical corticosteroids and mydriatic therapy. No recurrence of the uveitis was noted during a 5-month follow-up period. CONCLUSION: Rifabutin-associated uveitis with hypopyon should be considered as one possible causes of uveitis.

Concomitant obstructive sleep apnea increases the recurrence of atrial fibrillation following radiofrequency catheter ablation of atrial fibrillation: clinical impact of continuous positive airway pressure therapy.

BACKGROUND: Recent studies have suggested an emerging link between obstructive sleep apnea (OSA) and atrial fibrillation (AF). Patients with OSA are less likely to remain in sinus rhythm after radiofrequency catheter ablation of AF. OBJECTIVE: To evaluate the efficacy of appropriate treatment with continuous positive airway pressure (CPAP) on recurrences of AF after ablation. METHODS: This study prospectively included 153 patients (128 men; 60 ± 9 years) who underwent extensive encircling pulmonary vein isolation for drug refractory AF. The standard overnight polysomnographic evaluation was performed 1 week after ablation, and the total duration and the number of central or obstructive sleep apnea or hypopnea episodes were examined. RESULTS: Of 153 patients, 116 patients were identified as having OSA. Data regarding the use of CPAP and recurrences of AF were obtained in 82 patients. The remaining 34 patients with OSA were defined as the no-CPAP group. Polysomnography revealed no sleep-disordered breathing in 37 patients. During a mean follow-up period of 18.8 ± 10.3 months, 51 (33%) patients experienced AF recurrences after ablation. A Cox regression analysis revealed that the left atrial volume (hazard ratio [HR] 1.11; 95% confidence interval [CI] 1.01-1.23; P<.05), concomitant OSA (HR 2.61; 95% CI 1.12-6.09; P<.05), and usage of CPAP therapy (HR 0.41; 95% CI 0.22-0.76; P<.01) were associated with AF recurrences during the follow-up period. CONCLUSIONS: Patients with untreated OSA have a higher recurrence of AF after ablation. Appropriate treatment with CPAP in patients with OSA is associated with a lower recurrence of AF.