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Sleep terrors are a non-rapid eye movement (NREM) sleep–related parasomnia characterized by abrupt terror with a frightening scream. However, it remains unknown whether sleep terrors occur only from NREM sleep. We evaluated 3 cases of a sleep terrors–like parasomnia that occurred exclusively during arousals from rapid eye movement (REM) sleep. These parasomnia events occurred at REM sleep-wake transitions, manifesting with screaming or crying, similar to sleep terrors, without alertness or clear orientation. The patients were all young-adult females without notable medical conditions. REM sleep behavior disorder and nocturnal frontal lobe epilepsy were not detected based on their video-polysomnographic findings. These 3 cases should be provisionally diagnosed as “Parasomnia, Unspecified” according to the International Classification of Sleep Disorders, third edition; however, the phenomenological diagnosis is proposed to be “Disorders of Arousal from REM Sleep.” Our reported cases indicate that sleep terrors may also arise from REM sleep. CITATION: Futenma K, Inoue Y, Saso A, Takaesu Y, Yamashiro Y, Matsuura M. Three cases of parasomnias similar to sleep terrors occurring during sleep-wake transitions from REM sleep. J Clin Sleep Med. 2022;18(2):669–675.

Rationale: The effects of telemedicine on adherence in patients with obstructive sleep apnea with long-term continuous positive airway pressure (CPAP) use have never been investigated.Objectives: T...

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.

We experienced a case of very early-onset REM sleep behavior disorder (RBD) with ADHD. This case showed typical RBD symptoms with REM sleep without atonia on polysomnography. Methylphenidate, which enhances the dopamine system, attenuated his ADHD symptoms but not RBD symptoms. We speculate that the dysfunction of the laterodorsal tegmental nucleus in the pontine was responsible for the symptoms of RBD and ADHD in this case. Very early-onset RBD is rare, and its profile is not well known. ADHD with dysfunction in the laterodorsal tegmental nucleus may form asubtype of ADHD that is commonly comorbid with very early-onset RBD.

(Pro)renin receptor ((P)RR), a receptor for renin and prorenin, is implicated in the pathophysiology of diabetes mellitus, hypertension and their complications. Soluble (P)RR (s(P)RR) is composed of extracellular domain of (P)RR and thus exists in blood. We have reported that plasma concentrations of s(P)RR were elevated in male patients with obstructive sleep apnea syndrome (OSAS). The aim of the present study was to clarify the difference in plasma s(P)RR concentrations between male and female OSAS patients. Plasma s(P)RR concentrations were studied in 289 subjects (206 males and 83 females) consisting of 259 OSAS patients and 30 non-OSAS control subjects. The 259 OSAS patients were classified into mild (5 ≤ apnea hypopnea index (AHI) < 15 events/h), moderate (15 ≤ AHI < 30), and severe OSAS (AHI ≥ 30). Plasma s(P)RR levels were significantly elevated in all three OSAS groups compared to non-OSAS control subjects (AHI < 5) in the entire cohort and male subjects, whereas in female subjects, the significant elevation was found only in severe OSAS. Plasma s(P)RR levels were significantly correlated with AHI in both sexes, with a higher r value found in male subjects (male r = 0.413, p < 0.0001; female r = 0.263, p < 0.05). Importantly, when OSAS patients (26 males and 15 females) with AHI ≥ 20 underwent continuous positive airway pressure treatment, plasma s(P)RR levels were significantly decreased. In conclusion, plasma s(P)RR levels are elevated in both male and female OSAS patients in parallel with the disease severity.

Plasma concentrations of soluble (pro)renin receptor [s(P)RR], which are elevated in patients with obstructive sleep apnea (OSA), have not been studied in morbid obesity. The aim of this study is to clarify effects of bariatric surgery on plasma s(P)RR concentrations and identify associated factors for their changes in OSA patients with morbid obesity.Twenty-three patients with OSA complicated by morbid obesity (10 men and 13 women; body mass index, 40.7 ± 6.16 kg/mPreoperative plasma s(P)RR concentrations showed significant positive correlations with serum creatinine (P 0.05), arousal index (P 0.01), apnea-hypopnea index (AHI) (P 0.05), apnea index (P 0.005), and desaturation index (P 0.05), and a significant inverse correlation with an estimated glomerular filtration rate (P 0.05). With the improvement of these PSG parameters, plasma s(P)RR concentrations significantly decreased from 15.3 ± 3.6 to 12.5 ± 2.7 ng/mL 4 weeks after surgery, which further decreased to 11.4 ± 2.4 ng/mL 24 weeks after surgery. The association observed before surgery between plasma s(P)RR concentrations and the PSG parameters was not seen after surgery.Bariatric surgery in patients with OSA complicated by morbid obesity decreased plasma s(P)RR concentrations. The most associated factors for their changes were arousal index, AHI, apnea index, and desaturation index.

Background Sleep-disordered breathing (SDB), especially obstructive sleep apnea disorder (OSA), is thought to mainly affect men over the age of 40. Following findings that Asian people are more likely to experience severe OSA, regardless of obesity, we investigated the prevalence of SDB and OSA in a larger sample and in more younger age groups than those described in previous reports. Methods Between 2011 and 2016, 487 medical students (358 males, mean age 24.8 ± 1.9 years; 129 females: mean age 23.8 ± 1.6 years) underwent an out-of-center sleep test using a type-3 portable monitor. The results were analyzed visually. Results The mean ± standard deviation of the respiratory event index (REI: events/hour of monitoring) was 5.4 ± 6.7 (6.7 ± 7.5 in male participants, 2.6 ± 2.1 in female participants). There were 170 participants (36.6%) with an REI ≥ 5, including 158 male participants (46.9%) and 12 female participants (9.1%). SDB or undefined OSA with low REI (15 > REI ≥ 5) was observed in 141 participants (30.4%), defined OSA with moderate REI (30 > REI ≥ 15) in 19 participants (4.1%), and defined OSA with high REI (REI ≥ 30) in 10 participants (2.2%). Among the male students, 129 had low REI (38.3%), 19 had moderate REI (5.6%), and 10 had high REI (3.0%). All female participants with OSA events (9.4%) had a low REI. Conclusions The prevalence of OSA in Japanese young adults, especially males under 30 years old, is similar or even higher than that in older age groups described previously. Thus, an aggressive sleep study for SDB might be necessary for the younger generation in the Asian population.

This double-blind study evaluated the efficacy and safety of modafinil for treating excessive daytime sleepiness in Japanese patients with obstructive sleep apnea syndrome (OSAS).Patients with residual excessive sleepiness (Epworth Sleepiness Scale [ESS] ≥ 11) on optimal nasal continuous positive airway pressure (nCPAP) therapy (apnea-hypopnea index ≤ 10) were randomized to either 200 mg modafinil (n = 52) or placebo (n = 62) once daily for 4 weeks. Outcomes included baseline-week 4 changes in ESS total score, sleep latency on maintenance of wakefulness test (SL-MWT), nocturnal polysomnography, Pittsburgh Sleep Quality Index (PSQI), and safety.All 114 randomized patients completed the study. Mean change in ESS total score (-6.6 vs -2.4, p0.001) and SL-MWT (+2.8 vs -0.4 minutes, p = 0.009) were significantly greater with modafinil than with placebo. ESS total score decreased from11 to11 at the final assessment in 69.2% of modafinil-treated patients and 30.6% of placebo-treated patients (p0.001). Corresponding rates at week 1 were 57.7% and 33.9% (p = 0.014). Changes in nocturnal polysomnography, PSQI, and apnea-hypopnea index from baseline to the final assessment were similar in both groups. Adverse drug reactions occurred in 36.5% and 22.6% of patients in the modafinil and placebo groups, respectively (p = 0.146).Once-daily modafinil was effective and well tolerated for managing residual daytime sleepiness in Japanese OSAS patients with residual excessive daytime sleepiness on optimal nCPAP therapy.

Craniofacial morphological anomalies can be divided into two principal categories: skeletal anomalies and soft tissue anomalies. This study examined the hypothesis that the assessment of indices representing both skeletal and soft tissue can be used to appropriately identify the risk factor of obstructive sleep apnea–hypopnea syndrome (OSAHS). 232 suspected OSAHS male patients were examined with polysomnography and divided into two groups (202 males with OSAHS and 30 male controls without OSAHS). Cephalometric analysis was performed on all patients to evaluate craniofacial morphological anomalies. The measurement sites were as follows: skeletal morphology; soft tissue morphology; mixed morphology including mandibular plane to hyoid bone (MP-H); and jaw soft tissue (JS) ratio; a novel ratio we defined, between the area of jaw and area of tongue with soft palate. JS ratio increased with AHI as well as MP-H. MP-H and JS ratio showed significant but weak correlation with apnea–hypopnea index. JS ratio was significantly associated with an increased risk for severe OSAHS, even after adjusting age and BMI, its odds ratio was the greatest among these variables. These results showed that mixed craniofacial, skeletal and soft tissue morphology are correlated with AHI, and JS ratio may be a useful parameters to explain the characteristics of OSAHS in male patients.

Background Pathological studies of bronchial biopsy specimens have confirmed the apparent thickening of lamina reticularis of the epithelial basement membrane. Corticosteroids have proven to be most effective in modifying airway inflammation. However, there is not much data on the effects of corticosteroid-treatment on the basement membrane. Objective To investigate the effects of inhaled beclomethasone dipropionate (BDP) on the thickness of basement membrane and cellular infiltration into the bronchial mucosa, and the expression of growth factors in patients with asthma. Methods We studied bronchial biopsies from 24 asthmatic patients before and after treatment with inhaled BDP, 400 μg twice a day or placebo, for 6 months in a double-blind manner. Each subject recorded daily asthma symptoms and peak expiratory flow (PEF). Lung function and bronchial responsiveness to methacholine were measured before and after treatment. The thickness of the basement membrane was determined by electron microscopy. Inflammatory cells and the expression of growth factors were examined by immunohistochemistry in endobronchial biopsy specimens. Results After 6 months of treatment, we observed a significant improvement of asthma symptoms (P

We report on a patient with sleep apnea and an unusual familial movement disorder. The movements were present only during wakefulness and nocturnal arousals caused by disordered breathing. A 27-year-old obese man was referred with sleep onset insomnia, symptoms suggesting restless legs syndrome, daytime sleepiness, loud snoring and awakening with choking sensations. He was proven to have obstructive sleep apnea (apnea hypopnea index = 60.6). He also had a daytime movement disorder that was characterized by almost continuous stereotypic tapping of one or both legs. The movements were suppressible and not associated with any unpleasant or abnormal leg sensation. Virtually identical movements were present in three generations of his family. The severity of the movements did not worsen late in the day or with supine posturing. The nocturnal movements, consisting of a visible shaking of one or both legs, occurred only during arousals secondary to the apnea, had a mean duration of 5.7 +/- 3.0 (standard deviation) seconds and could not be defined as periodic limb movements in sleep (PLMS). Successful treatment of apnea by nasal continuous positive airway pressure dramatically reduced the movements during sleep (from 88.2 to 1.9 per hour). The clinical significance and the mechanism of this movement disorder is unknown. We discuss the features inconsistent with restless legs syndrome and consider other possible phenomenology, including akathisia. We conclude that this patient may have a previously unreported familial movement disorder and in addition developed the sleep apnea syndrome related to obesity.

We studied 107 patients with sleep-disordered breathing to confirm the effectiveness of continuous positive airway pressure (CPAP) titration using a split-night protocol. Patients spent two consecutive nights in our laboratory with complete polysomnography. On the first night, we applied a split-night protocol; the first half of the night was used as a baseline (B), and after a diagnosis was made, CPAP was applied during the second half of the night (SN). On the second night (2N), patients spent the entire night on CPAP to confirm the effectiveness of CPAP treatment. The SN and 2N both revealed a significant reduction in arousal index (37.8 +/- 27.9 on B, 13.2 +/- 12.1 on SN, 11.4 +/- 8.0 on 2N, values are mean +/- SD, p0.001), apnea hypopnea index (AHI) (23.6 +/- 26.3/h on B, 3.0 +/- 3.7/h on SN, 2.4 +/- 2.6/h on 2N, p0.001), percent total sleep time below 90% SaO2 (21.0 +/- 27.2% on B, 8.2 +/- 13.8% on SN, 4.9 +/- 10.2% on 2N, p0.001), and percent total sleep time below 80% SaO2 (1.1 +/- 3.8% on B, 0.0 +/- 0.1% on SN, 0.1 +/- 0.5% on 2N, p0.001). There were no significant differences between the SN and the 2N for these measurements. Final CPAP pressure was significantly lower at the end of the SN when compared with the 2N (8.8 +/- 2.7 cm H2O on SN, vs 10.3 +/- 2.8 cm H2O on 2N, p0.001). When patients were divided into three groups (AHI20, n = 69; 20AHI40, n = 18; AHI40, n = 20), the final CPAP pressure was different only in the group with AHI20 (8.1 +/- 2.3 cm H2O on SN, 9.6 +/- 2.3 cm H2O on 2N, p0.001). We conclude that a split-night protocol may be sufficient to determine the effective CPAP pressure, especially in patients with an AHI20.

It has been shown that nasal continuous positive airway pressure (nasal CPAP) significantly reduces nocturnal reflux both in patients with sleep apnea and in patients without sleep apnea but consistent abnormal nocturnal reflux. The mechanism by which CPAP is thought to reduce reflux includes the elevation of the resting lower esophageal sphincter (LES) pressure. In this study, we tested the effect of nasal CPAP in two groups of patients with aperistaltic esophagus but with different resting LES pressure. Seven patients with scleroderma esophagus and six patients treated for achalasia were tested over a 48-h period. On the first night, the patients were untreated; on the second night, both groups received applied nasal CPAP at 8 cm H2O pressure. The percentage of time the pH4.0, the number of reflux events5 min, and the length of the longest reflux event were all significantly reduced in the patients with achalasia (p0.03), but not in the scleroderma group (p0.20). These results suggest that a residual resting LES pressure greater than that demonstrated by patients with scleroderma (10 mm Hg) may be necessary for nasal CPAP to affect nocturnal reflux.

Obstructive sleep apnea (OSA) is a common disorder, and it is likely that there are a large number of undiagnosed patients. Although the primary pathophysiologic events occur during sleep, OSA causes adverse daytime multisystem dysfunction. These sequelae affect the patients' life physically and psychosocially, and in severe cases, they may be life threatening. Treatments can reverse most of these sequelae. This report reviews the effect of treatment on these sequelae. Some of the severe complications may not be reversible. The goal of treatment is to prevent the repetitive upper airway obstructions during sleep, and thus reverse the severe sequelae and restore the patient's quality of life. Although nasal continuous positive airway pressure (nCPAP) is the treatment of choice for OSA, this approach has many problems and is still far from ideal. A large number of patients treated with nCPAP are not compliant and so remain subject to the severe sequelae.

Sleep-disordered breathing is commonly associated with periodic limb movements (PLMS). Nasal continuous positive airway pressure (nCPAP) is the most widely used treatment for sleep-disordered breathing. However, it is not clear whether nCPAP treatment of apnea also has a systematic effect on PLMS. We studied 15 patients with sleep-disordered breathing and PLMS in a split-night protocol in order to confirm the acute effects of nCPAP on PLMS. Although the PLMS index (PLMSI) did not change statistically (baseline, 38.7 +/- 20.5; CPAP, 31.3 +/- 17.0; p = ns), the PLMS-related index (PLMS-ArI) decreased significantly on nCPAP (baseline, 17.8 +/- 10.1; CPAP, 9.2 +/- 5.7; p < 0.05). Whether the reduced PLMS-ArI is sustained with chronic nCPAP is unknown and a matter of future investigation.

Craniofacial morphological anomalies can be divided into two principal categories: skeletal anomalies and soft tissue anomalies. This study examined the hypothesis that the assessment of indices representing both skeletal and soft tissue can be used to appropriately identify the risk factor of obstructive sleep apnea–hypopnea syndrome (OSAHS). 232 suspected OSAHS male patients were examined with polysomnography and divided into two groups (202 males with OSAHS and 30 male controls without OSAHS). Cephalometric analysis was performed on all patients to evaluate craniofacial morphological anomalies. The measurement sites were as follows: skeletal morphology; soft tissue morphology; mixed morphology including mandibular plane to hyoid bone (MP-H); and jaw soft tissue (JS) ratio; a novel ratio we defined, between the area of jaw and area of tongue with soft palate. JS ratio increased with AHI as well as MP-H. MP-H and JS ratio showed significant but weak correlation with apnea–hypopnea index. JS ratio was significantly associated with an increased risk for severe OSAHS, even after adjusting age and BMI, its odds ratio was the greatest among these variables. These results showed that mixed craniofacial, skeletal and soft tissue morphology are correlated with AHI, and JS ratio may be a useful parameters to explain the characteristics of OSAHS in male patients.

Background A lower (more caudal) position of the larynx may result in a longer collapsible segment of the upper airway. One could thus hypothesize that the lower the larynx the greater the risk for obstructive sleep apnea (OSA). To test this hypothesis, we measured the upper airway length to the level of the vocal cord and the horizontal and vertical segments of the supralaryngeal vocal cord tract (SVT) using multislice CT scan in Japanese patients with OSA. Methods We recruited 249 consecutive patients who had polysomnography for suspected OSA (age, 47.8 ± 14.8 years; BMI, 24.8 ± 4.3 kg/m 2 ). Using CT images, we measured airway length (AL), airway length to vocal cord (ALVC), ALVC-AL, horizontal segment of SVT (SVTH), and vertical segment of SVT (SVTV). The ratio SVTR (SVTH to SVTV) was calculated. The correlation between these measurements and age, BMI, and AHI were evaluated. Results Men had a longer ALVC than women. AL, ALVC, and SVTR were significantly correlated with age and AHI in all patients. Logistic regression analysis showed that ALVC > 0.24 (OR, 4.2; CI, 2.3-7.6) and BMI > 25 (OR, 4.8; CI, 2.7-8.5) were significant variables predicting AHI > 30. Even after controlling for BMI, the effect of ALVC was still significant. Conclusions The laryngeal position is lower in men than women. Aging is associated with a lower laryngeal position, and a longer ALVC is independently associated with OSA severity in Japanese patients. We conclude that both laryngeal descent and BMI may be risk factors for OSA.

Background: Because increased sympathetic nervous activity (SNA) in patients with dilated cardiomyopathy (DCM) associated with sleep breathing disorder (SBD) is known to deteriorate the prognosis of cardiac failure, 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was used as the investigative tool in the present study. Methods and Results: The study group comprised 53 patients (47 men, 6 women; mean age 56 ±3 years) with chronic stable DCM. Patients were divided into SBD(+) or SBD(-) group according to 24-h pulse oximetry results. SBD(+) was defined when the 3% oxygen desaturation index was more than 15/h during sleep. In total, 32 patients were SBD(-) and 21 were SBD(+). In both groups, pulse oximetry were performed during sleep and awakening pulse rate, and measurement of the blood levels of catecholamines and B-type natriuretic peptide was performed. MIBG myocardial scintigraphy and echocardiography were performed at the same time. No significant difference was found between the 2 groups in catecholamine levels or left ventricular ejection fraction. However, MIBG had a significantly increased washout rate and a significantly decreased delayed heart to mediastinum ratio in the SBD(+) group compared with the SBD(-) group. Conclusions: SNA is increased in DCM patients when associated with SBD. MIBG myocardial scintigraphy may be a sensitive method of detecting increased SNA. (Circ J 2009; 73: 686 - 690)

Background Obesity and craniofacial abnormalities such as small maxilla and mandible are common features of patients with obstructive sleep apnea (OSA). The authors hypothesized that anatomical imbalance between the upper airway soft-tissue volume and the craniofacial size (rather than each alone) may result in pharyngeal airway obstruction during sleep, and therefore development of OSA. Methods Blind measurements of tongue cross-sectional area and craniofacial dimensions were performed through lateral cephalograms in 50 adult male patients with OSA and 55 adult male non-OSA subjects with various craniofacial dimensions. Results Maxillomandibular dimensions were matched between OSA and non-OSA groups. While the tongue was significantly larger in subjects with larger maxillomandible dimensions, OSA patients had a significantly larger tongue for a given maxillomandible size than non-OSA subjects. The hypothesis was also supported in subgroups matched for both body mass index and maxillomandible dimensions. Conclusions Upper airway anatomical imbalance is involved in the pathogenesis of OSA.

We report a case of sepsis caused by Escherichia coli (E. coli) of serotype O-143. A 78-year-old man developed symptoms of gastroenteritis after ingesting raw meat on noodles. He rapidly developed respiratory failure. Blood culture grew E. coli. The sepsis seemed to have directly spread from a food-borne infection. The development of primary sepsis after ingesting E. coli is very rare. We suspect that bacterial translocation played a major role. Serotype O-143 is recognized in enteroinvasive E. coli (EIEC) as well as in Shigella dysenteriae. The pathogen in the present case is suspected of being EIEC although the isolated E. coli strain was negative for the inv and ipa genes.

The adverse effects of and adherence of a treatment with nasal continuous positive airway pressure (nCPAP) for obstructive sleep apnea and hypopnea syndrome (OSAHS) were examined. The subjects comprised 321 patients with OSAHS. An all-night polysomnography was performed for all subjects. Titration of CPAP was performed manually. Regarding the adverse effects of nCPAP therapy, the subjects most frequently complained of nasal symptoms, air-leaks and any trouble with the mask. Complaints heard less frequently were sleep disturbances, dry pharyngeal and oral cavities, noises, and pronounced pressure sensations due to CPAP. No adverse effects were noted in 13% of the subjects. The adherence was as high as 73.0% in 122 patients in whom time spent for nCPAP treatment could be analyzed. The mean treatment time was 4.7 +/- 1.8 hours. We found no significant correlation between mean treatment time and age, BMI, ESS, CPAP, AHI, Ar-I, ODI, lowest SpO 2, or %TST with SpO 290%. Multivariate analysis revealed no factor significantly correlated with treatment time. These results showed that detailed instructions for the prevention of adverse effects may improve the adherence of CPAP.

The objective of this study was to examine the usefulness of home oximetry for the screening of sleep disorders presenting with excessive daytime sleepiness (EDS). This was accomplished by blinded comparison of diagnosis by oximetry alone versus polysomnographic diagnosis carried out at a sleep disorders center at a tertiary referral hospital. This study included three hundred patients who had been referred because of EDS and suspected sleep apnea. A number of measurements were made. The arterial oxygen saturation (SaO2) data were sampled at 2 Hz and stored digitally during polysomnography (PSG). From the SaO2 data recorded onto paper six scorers calculated the number of desaturations3% per hour (desaturation index: DI) and then made a diagnosis [normal, DI5; mild obstructive sleep apnea (OSA), 5DI20; moderate OSA, 20DI40; severe OSA, DI40]. Upper airway resistance syndrome (UARS) was diagnosed when DI was5 but associated with small fluctuations in SaO2. The diagnosis made by each of six scorers was compared to the clinical diagnosis made independently using PSG. Thirty-one (10.3%) of all the records were rejected by scorers because of inadequate SaO2 signals requiring technologist intervention. Sensitivity of screening for sleep-breathing disorders was 90.0% and specificity was 75.0%. All moderate and severe OSA patients were detected by oximetry. However, among the 66 patients who were classified as normal by oximetry, 1 had mild OSA, 20 had UARS, 9 had periodic limb movements in sleep, 4 had narcolepsy and 2 had a parasomnia. In conclusion, home oximetry may not have sufficient sensitivity and specificity to detect breathing disorders reliably during sleep and is useless for other disorders of sleep.

We studied changes in the peripheral plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in seven patients with congestive heart failure (CHF) during four 1-h protocols during which patients maintained either an upright or a supine posture with or without nasal continuous positive airway pressure therapy (N-CPAP) at a pressure of 10 cm H2O (FIO2 = 0.21). The mean plasma ANP concentration of patients increased significantly from baseline at the end of 1 h of recumbency (65.9 +/- 5.8 to 82.6 +/- 8.3 pg/mL (mean +/- standard error); p0.05). This increase was prevented by concomitant N-CPAP therapy (72.1 +/- 8.0 to 61.0 +/- 8.8 pg/mL; p = NS). The mean level of ANP decreased significantly (71.9 +/- 9.0 to 62.5 +/- 8.0 pg/mL; p0.05) while patients simply maintained an upright posture. A significant reduction was also observed when patients remained upright with accompanying N-CPAP (72.6 +/- 10.9 to 54.6 +/- 4.3 pg/mL; p0.05). There were no significant changes observed in the mean level of BNP for any of the protocols undertaken. We conclude that in patients with chronic CHF, (1) an increase in ANP concentration occurs with recumbency, and this can be prevented by N-CPAP therapy; (2) a decrease in ANP occurs with maintenance of an upright posture, and that this reduction may be augmented by N-CPAP; and (3) no net change in BNP concentration occurs with either posture change or N-CPAP.

We hypothesize that breathing disorder related arousal index (B-ArI) can differentiate sleep breathing disorder from simple snorer when apnea hypopnea index (AHI) is low. We studied 54 patients using polysomnography. Breathing disorder related arousal (B-Ar) was defined as arousal accompanied by apnea, hypopnea, desaturation or snort. Mean AHI was 44.2+/-34.0/h, and B-ArI correlated significantly with AHI, desaturation index, percentage total sleep time with SpO2 below 90%. Breathing disorder related arousal index was greater than AHI when AHI was below 20. In 11/54 patients, AHI was below 10, and B-ArI more than 10. Nasal continuous positive airway pressure was applied to six patients and showed reduced B-ArI. Breathing disorder related arousal index may be one of the useful indices for the diagnosis of sleep breathing disorder when AHI is less than 10.

3-(Succinimidoxy)-l,2-benzoisothiazole-l,1-dioxide was found to be a useful reagent to convert the carboxylic acids to the corresponding N-hydroxysuccinimide esters. Various dipeptides and leucine-enkephalin were prepared using the reagent in good yields.