Progression of obstructive sleep apnoea syndrome in Japanese patients.

PURPOSE: The aggravation of obstructive sleep apnoea syndrome (OSAS) is reportedly associated with weight gain. The present study investigated the factors associated with worsening of respiratory functional parameters in Japanese OSAS patients who showed no body weight change during the follow-up period. METHODS: A follow-up polysomnography (PSG) was performed in 82 patients with a mean of 7.5 years after the diagnostic PSG, and the apnoea-hypopnoea index (AHI), respiratory event duration, minimum percutaneous oxygen saturation (SpO2), baseline SpO2, and 3 % oxygen desaturation index (ODI) during sleep were compared between the two PSGs. Furthermore, factors associated with worsened AHI, respiratory event duration, and minimum SpO2 were investigated using logistic regression analysis. RESULTS: No significant differences were observed in AHI, baseline SpO2, and 3 % ODI between the two PSGs. However, there was a significantly increased respiratory event duration and decreased minimum SpO2 observed. In addition, 17 patients had a ≥25 % AHI increase, and the age of 40-60 years and initial OSAS severity (mild and moderate) were the significantly associated factors. Age of ≥60 years and a baseline body mass index (BMI) of ≥25 kg/m(2) were significantly associated with prolonged respiratory event duration. The age of 40-60 years was significantly associated with decreased minimum SpO2. CONCLUSIONS: Untreated middle-aged patients may be at a high risk for worsened AHI and SpO2 even without weight gain.

Prevalence and clinical characteristics of children with medical complexity in Tottori Prefecture, Japan: A population-based longitudinal study.

OBJECTIVES: To investigate the prevalence and background of children with medical complexity (CMC) and its secular trend in Japan. METHODS: CMC were defined as patients under the age of 20 years requiring medical care and devices. The patients were enrolled using the national health insurance claims data of three hospitals and two rehabilitation centers in Tottori Prefecture. The study period was divided into three periods: Period 1, 2007-2010; Period 2, 2011-2014; and Period 3, 2015-2018. RESULTS: A total of 378 CMC were enrolled. The prevalence of CMC was 1.88 per 1000 population among subjects aged <20 years in 2018, and it increased by approximately 1.9 times during the study period. The number of CMC who presented with severe motor and intellectual disabilities did not change from Period 1 to Period 3. Meanwhile, the number of CMC who had relatively preserved motor and intellectual abilities increased from 58 to 98. The proportion of CMC who required respiratory management and oxygen therapy increased by 1.3 and 1.8 times, respectively. By contrast, the proportion of CMC who need tube feeding decreased significantly between periods 1 and 3 (P < 0.05). CONCLUSIONS: The prevalence of CMC increased almost twice during the 12-year study period; however, the increase in the number of patients with relatively preserved motor and intellectual abilities was pronounced. This study showed that the need for medical care and devices differed based on the underlying disorders and severity of CMC; therefore, individualized medical, welfare, and administrative services and education about the various types of CMC must be provided.

Experience in using split-day studies for suspected obstructive sleep apnea syndrome.

BACKGROUND: Because in many locations the demand for sleep studies exceeds resources, we evaluated the utility of split-day in-laboratory studies (SDS) in highly selected patients. METHODS: We studied 100 eligible cases: 68 males (age 48.6+/-1.3 [standard error, se] years, body mass index (BMI): 32.6+/-0.8 kg/m(2)) and 32 females (age 50.9+/-2.4 years, BMI: 36.3+/-1.3 kg/m(2)) with severe subjective sleepiness (Epworth sleepiness scale: ESS 16) and suspected obstructive sleep apnea syndrome (OSAS). RESULTS: There were 86 conclusive studies that yielded both a diagnosis and sufficient information for management (86.0%) and 14 inconclusive studies that did not yield sufficient information for management (14.0%). In six cases (6.0%) with an inconclusive study a diagnosis was made, however, no titration data was obtained. Thus a definitive diagnosis was obtained in 92.0% of all cases. Those with inconclusive studies had additional assessment, and eight of them ultimately had a final diagnosis of a sleep breathing disorder (SBD) and six had another sleep disorder: four had narcolepsy, one had a movement disorder, one had sleep deprivation. Thus there were six patients (6.0%) in whom SDS yielded only an SBD diagnosis but there was insufficient data for titration; two patients (2.0%) who ultimately had severe OSAS who were not diagnosed on SDS. CONCLUSIONS: SDS was found to be useful in the evaluation and treatment of highly selected patients with severe daytime sleepiness (ESS 16) and suspected OSAS.

Age-related changes in cerebral lactate metabolism in sleep-disordered breathing.

Thirty-one patients, aged 22-71 years, with nocturnal apneic episodes and/or habitual snoring were studied with magnetic resonance spectroscopy (MRS) and diagnostic polysomnography separately to determine whether accumulation of lactate caused by cerebral hypoxia during sleep is associated with sleep-disordered breathing (SDB), aging and co-morbidities related to SDB. Eight proton magnetic resonance spectra for sleep and two for periods of arousal were obtained from the right centrum semiovale. All patients were evaluated for the presence or absence of co-morbidities including hypertension, cardiac disease, diabetes mellitus, and hyperlipidemia. Significant lactate signals were found in seven patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) during sleep periods, and none during periods of arousal. Aging was significantly related to the presence or absence of significant lactate signals during sleep periods as determined by logistic regression analysis (beta=0.2480; 95% confidence interval, 0.0905-0.5094; P=0.0001). Apnea index (AI), apnea-hypopnea index (AHI), and minimum value of peripheral oxyhemoglobin saturation each significantly interacted with age (P=0.0081, 0.0284, and 0.0302, respectively). Our findings suggest that SDB combined with aging is related to accumulation of lactate during sleep.

Non-linear behaviour of respiratory movement in obstructive sleep apnoea syndrome.

In this study we investigated the non-linear properties of respiratory movement in patients with obstructive sleep apnoea syndrome (OSAS) during sleep without and with nasal continuous positive airway pressure (nCPAP). To calculate the correlation dimension (D2) in respiratory movement we applied an algorithm proposed by Grassberger and Procaccia. Non-linearity in respiratory movement was tested by comparing D2 for the original data with that for surrogate data. Respiratory movement was recorded from 10 patients with OSAS. D2 during both wakefulness with eyes closed and during sleep with nCPAP at 8 cm H2O could be computed in all subjects (2.50 +/- 0.69 and 1.68 +/- 0.17, respectively). On the other hand, D2 during sleep with apnoea could not be computed in patients with severe OSAS. These results indicate the abnormal properties of respiratory movement during apnoeic sleep in severe OSAS. Moreover, respiratory movement with nCPAP was shown to be non-linear deterministic behaviour in respiratory movement during sleep. Analysis of D2 for respiratory movement may be useful in adjusting (titrating) nCPAP and classifying severity in OSAS.

Clinical significance of sleep-related breathing disorder in narcolepsy.

Both the influence of comorbid obstructive sleep apnea-hypopnea syndrome (OSAHS) on daytime sleepiness and its pathological mechanism in 10 narcoleptic patients was studied. Mild elevation of esophageal negative pressure and obstruction in the velopharyngeal area, as observed by upper airway magnetic resonance imaging, during apneic episodes was observed in the subjects. Severity of the disorder was correlated positively with body mass index, and the latencies of the multiple sleep latency tests were not improved with nasal continuous positive airway pressure treatment in subjects. Pathogenesis of OSAHS in narcolepsy was thought to be almost similar to typical OSAHS, and that the disorder seemed to lack a pathological influence on daytime sleepiness.

Endoscopic classification of pharyngeal stenosis pattern in obstructive sleep apnea hypopnea syndrome.

Twenty-one patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) were classified into three categories according to their pharyngeal stenosis patterns during sleep, as determined from endoscopic findings: (i) a falling type (n = 6); (ii) an all-round type (n = 11); and (iii) a bilateral type (n = 4). In all patients with the bilateral type, the palatine tonsils were hypertrophied, and the apnea-hypopnea indexes (AHI) were improved markedly by surgery. Conversely, the AHI of patients with the falling and all-round types were reduced by a smaller percentage. Surgical therapy is only to be recommended to patients with OSAHS whose pharynx is bilaterally stenotic.