Sleep Apnea Syndromes: Yamamoto H

Horie T, Akashiba T, Muto T, Otsuka K, Yoshizawa T, Saito O, Sasaki G, Kurashina K, Ito D, Suzuki R, Minemura H, Yamamoto H, Kosaka N, Akahoshi T, Kawahara S. · No affiliation provided · Masui. · Pubmed #11871103 No free full text.

This publication has no abstract.

Akashiba T, Minemura H, Yamamoto H, Itoh D, Kosaka N, Saitoh O, Horie T. · First Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan. · Respirology. · Pubmed #10339735 No free full text.

Abstract: We investigated the acute effects of nasal continuous positive airway pressure (CPAP) on pulmonary haemodynamics and tissue oxygenation in eight men with obstructive sleep apnoea (OSA) by means of right heart catheterization. They were tested at four dosage levels of nasal CPAP: 0, 5, 10, and 15 cmH2O. Nasal CPAP significantly reduced the cardiac index at the 10 and 15 cmH2O doses. The mean pulmonary artery pressure was significantly elevated with 10 and 15 cmH2O, and pulmonary capillary wedge pressure was significantly increased with 15 cmH2O of nasal CPAP. Pulmonary vascular resistance was significantly increased with 10 cmH2O of nasal CPAP. The 5 cmH2O dose of nasal CPAP did not affect significantly these parameters. Mixed venous oxygen tension was unchanged at any pressure. We conclude that tissue oxygenation was maintained in the OSA patients during administration of nasal CPAP, even though a high CPAP clearly affected pulmonary haemodynamics.

Yamamoto U, Mohri M, Shimada K, Origuchi H, Miyata K, Ito K, Abe K, Yamamoto H. · Department of Cardiology, Kyushu Kosei-Nenkin Hospital, Kitakyushu, Japan. · J Card Fail. · Pubmed #18068615 No free full text.

Abstract: BACKGROUND: Sleep-disordered breathing (SDB) is common in patients with heart failure and carries an independent risk for poor long-term prognosis. We aimed to study the effects of supervised, aerobic exercise training for 6 months on SDB in patients with chronic heart failure. METHODS AND RESULTS: We enrolled 18 patients having both systolic dysfunction (left ventricular ejection fraction <45%) and SDB (apnea-hypopnea index [AHI] >10). The exercise group comprised 10 patients who participated in our cardiac rehabilitation program for 6 months, and the remaining 8 patients served as control. AHI (median [interquartile range]) was unchanged in the control group patients at 6-month intervals (30.4 [19.9-36.3] versus 36.6 [8.6-39.4], NS). In contrast, AHI was significantly decreased in the exercise group from 24.9 [19.2-37.1] to 8.8 [5.3-10.1] (P < .01). In the exercise group, the numbers of central sleep apnea per night was significantly decreased (152 [124-244] versus 50 [24-67], P < .01) after exercise training, but those of obstructive apnea/hypopnea were unchanged (42 [7-94] versus 18 [7-54], NS). In addition, exercise training significantly increased peak oxygen consumption and decreased minute ventilation to carbon dioxide production slope (both P < .01). CONCLUSIONS: Six-month, aerobic exercise training increased exercise capacity and improved central sleep apnea in patients with chronic heart failure from systolic dysfunction.

Yamamoto H, Teramoto S, Yamaguchi Y, Hanaoka Y, Ishii M, Hibi S, Ouchi Y. · Department of Geriatric Medicine, Faculty of Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. · Sleep Med. · Pubmed #17512795 No free full text.

Abstract: BACKGROUND AND PURPOSE: Obstructive sleep apnea syndrome (OSAS) is recognized as one of the risk factors of hypertension and cardiovascular disorders. In the current study, we hypothesized that the hypoxic stress caused by obstructive sleep apnea would increase circulating adrenomedullin (ADM) levels in untreated OSAS patients compared to an age-matched control group. We further hypothesized that oxygen administration treatment may decrease OSAS-induced hypoxic stress and ADM levels. METHODS: We examined short-term and long-term oxygen administration effects on circulating ADM in 48 OSAS patients. RESULTS: The circulating levels of ADM in untreated OSAS patients were significantly greater than those in the controls. We did not observe a significant effect in 2 weeks of oxygen administration on the circulating ADM in the patients, but we observed a significant effect in long-term oxygen administration for more than 3 months on plasma ADM levels. Long-term oxygen therapy decreased both the magnitude of arterial oxygen desaturation and plasma ADM levels in patients but did not decrease blood pressure. CONCLUSIONS: These observations suggest that long-term oxygen therapy could reduce OSAS-induced nocturnal hypoxemia and plasma ADM levels in patients with OSAS.

Nakata S, Noda A, Yanagi E, Suzuki K, Yamamoto H, Nakashima T. · Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya, Japan. · Clin Otolaryngol. · Pubmed #16441801 No free full text.

Abstract: OBJECTIVES: To evaluate the efficacy of simple tonsillectomy to treat obstructive sleep apnoea syndrome (OSAS) in adults. DESIGN: Prospective study. SETTING: Tertiary referral centre. PARTICIPANTS: Thirty patients (28 males) underwent simple tonsillectomy under general anaesthesia. The patients' mean age was 33.2 +/- 6.8 years and body mass index was 30.7 +/- 6.0 kg/m2. Seven patients (23%) were classified with grade 4, 16 patients (53%) with grade 3, and seven patients (23%) with grade 2 according to the tonsil size of Friedman's classification. MAIN OUTCOME MEASURES: The number of apnoea episodes per hour (apnoea index), the number of apnoea and hypopnoea episodes per hour (apnoea-hypopnoea index), lowest nocturnal oxygen saturation and oxygen desaturation time were measured during overnight polysomnography before and after surgery. A successful tonsillectomy was defined as an apnoea-hypopnoea index improvement ratio of > or =50% and an apnoea-hypopnoea index <20 after operation. RESULTS: Apnoea-hypopnoea index decreased from 69.0 +/- 28.4/h to 30.1 +/- 24.0/h (P < 0.0001). Simple tonsillectomy was successful in all six patients with body mass index <25 kg/m2. Concerning success rate of simple tonsillectomy with tonsil, size 2 was lowest (42.9%). Eight of the 13 patients who used continuous positive airway pressure before simple tonsillectomy did not use continuous positive airway pressure after simple tonsillectomy because of a significant reduction of excessive daytime sleepiness. Continuous positive airway pressure decreased significantly after simple tonsillectomy from 13.6 +/- 2.5 cmH2O preoperatively to 10.6 +/- 1.3 cmH2O postoperatively (P < 0.05). CONCLUSIONS: These data suggest that simple tonsillectomy is a beneficial modality to treat OSAS in selected patients (larger tonsil, low body mass index), even in adults.

Teramoto S, Kume H, Yamamoto H, Ishii T, Miyashita A, Matsuse T, Akishita M, Toba K, Ouchi Y. · Department of Geriatric Medicine, The University of Tokyo Hospital, Tokyo. · Intern Med. · Pubmed #12924491 links to  free full text

Abstract: OBJECTIVE: Repeated nocturnal hypoxia is implicated in the pathogenesis of cardiovascular complications in obstructive sleep apnea syndrome (OSAS). We hypothesized that circulating vascular endothelial growth factor (VEGF) levels are affected by nocturnal hypoxemia in patients with OSAS. METHODS: We examined the serum VEGF levels in patients with OSAS and in control subjects. We also tested the effects of oxygen or air administration on the subjects' VEGF levels. PATIENTS AND MATERIALS: Twenty-four OSAS patients (mean age 54.2 +/- 3.6 years) and 24 age-matched control subjects (53.2 +/- 3.6 years). Their serum samples were tested. RESULTS: Serum VEGF levels at 8:00 AM were significantly higher in OSAS patients than in controls (p<0.01). VEGF levels decreased from 515 +/- 31 (pg/ml) to 178 +/- 16 (pg/m) (p<0.01) in OSAS patients whose nocturnal hypoxemia was found to be improved by administration of 2 l/min of oxygen during the night. However, the administration of compressed air affected neither the VEGF level nor nocturnal oxygen desaturation in OSAS patients. CONCLUSION: These results indicate that circulating VEGF levels are elevated in OSAS patients, primarily due to nocturnal hypoxemia.

Ohga E, Tomita T, Wada H, Yamamoto H, Nagase T, Ouchi Y. · Department of Geriatric Medicine, Graduate School of Medicine, University of Tokyo, Japan. · J Appl Physiol. · Pubmed #12391099 links to  free full text

Abstract: Obstructive sleep apnea syndrome (OSAS) is one of the most important risk factors of cardiovascular disorders. In the treatment of OSAS, nasal continuous positive airway pressure (nCPAP) has been widely used and found to be effective. In the present study, we hypothesized that the hypoxic stress caused by obstructive sleep apnea would increase circulating intercellular adhesion molecule-1 (ICAM-1), interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) in untreated OSAS patients compared with an age-matched control group. In addition, we hypothesized that nCPAP may decrease OSAS-induced hypoxic stress and mediators. To examine these hypotheses, we measured circulating ICAM-1 and IL-8 before and after nCPAP therapy in OSAS patients. We observed that nCPAP decreased apnea, desaturation, and the circulating ICAM-1 and IL-8 levels in OSAS patients. The circulating levels of ICAM-1, IL-8, and MCP-1 in untreated OSAS patients were significantly greater than those in the controls. These observations suggest that nCPAP therapy could reduce OSAS-induced hypoxia and generation of inflammatory mediators. Treatment of OSAS using nCPAP can be, therefore, a potential approach to decrease risk of the progression of OSAS-associated disorders.

Ito D, Akashiba T, Yamamoto H, Kosaka N, Horie T. · First Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan. · Respirology. · Pubmed #11422896 No free full text.

Abstract: OBJECTIVE: To clarify that factors besides obesity play an important role in the development of obstructive sleep apnoea syndrome (OSAS) in Japanese patients, we compared craniofacial structures in patients with severe OSAS with those of normal controls. METHODOLOGY: The craniofacial structures of 60 Japanese patients with severe OSAS and 30 normal controls were evaluated using standard cephalometric analysis. Patients were stratified according to body mass index (BMI): non-obese, BMI < 25; moderately obese, BMI = 25-30, severely obese, BMI > 30. RESULTS: The SNA (sella to nasion to subspinale angle) was significantly smaller in the patient groups than in the controls. The SNB (sella to nasion to supramentale angle) and NSBa (cranial base flexure) were significantly smaller in the non-obese and moderately obese patients than in controls. The MP-H (distance from the mandibular plane to the hyoid bone) and the PNS-P (distance from the posterior nasal spine to the tip of the soft palate) were significantly longer in the patient groups than in the controls. The PNS-P was significantly longer in the severely obese patients than in the non-obese patients. CONCLUSIONS: Japanese patients with severe OSAS have enlargement of the soft tissues and palate as well as craniofacial bony structural abnormalities. This is particularly apparent in non-obese patients.

Akashiba T, Kosaka N, Yamamoto H, Ito D, Saito O, Horie T. · First Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan. · Respir Med. · Pubmed #11392581 No free full text.

Abstract: Although nasal continuous positive airway pressure (CPAP) is effective in improving nocturnal obstructive apnoea, daytime sleepiness and well-being in patients with obstructive sleep apnoea syndrome (OSAS), not all patients tolerate this treatment. Since optimal CPAP titration is essential to maintain compliance, it is important to elucidate the factors that help to determine the optimal pressure. However, the determinants of the optimal CPAP level are controversial. The subjects comprised 27 Japanese male patients with OSAS who underwent standard polysomnography (PSG), pulmonary function tests, arterial blood gas analysis, cephalometry and CPAP titration. Twenty normal controls also underwent cephalometric analysis. The apnoea-hypopnoea index (AHI), mean oxygen saturation (mean SaO2) and the lowest SaO2 during sleep were found to be 54.7+/-22.6, 89.0+/-5.6%, and 69.7+/-9.0%, respectively by PSG. The mean optimal CPAP was 9.6+/-1.8 cmH2O. The cephalometric angles (SNA, SNB and NSBa) were similar to those found in the control subjects. but MP-H, and PNS-P were significantly longer than those in the control subjects as shown by cephalometry. The optimal CPAP was correlated with the mean SaO2 (P<0.0001), neck circumference (P<0.05) and three cephalometric variables (NSBa: P<0.01, MP-H: P<0.05, PNS-P: P<0.05). Multiple, step-wise, regression analysis showed that the mean SaO2 and NSBa were independent variables that best predicted the optimal CPAP. These variables accounted for 57.5% of the total variance (R2=0.575, P<0.001). Optimal CPAP was closely correlated with oxygen desaturation during sleep. However, the craniofacial structure had additional effects such as an independent factor in determining the optimal CPAP level.

Suzuki H, Moriguchi K, Matsuura M, Kojima T, Matsuda T, Noda Y, Minemura H, Yamamoto H, Akashiba T, Horie T. · Department of Neuropsychiatry, Nihon University School of Medicine, Tokyo, Japan. · Psychiatry Clin Neurosci. · Pubmed #11186079 No free full text.

Abstract: The two nap sleep test (TNST) was developed and its usefulness for detecting sleepiness in long-distance drivers has been reported. This study's authors attempted to apply the TNST as a clinical test of sleepiness. A normal control group (n = 29), an obstructive sleep apnea syndrome (OSAS) group (n = 9), and another sleep disorder group (n = 6) participated. As a result of polysomnography, the sleep latency and sleep time did not differ among the groups. In contrast, the frequency of micro-arousal and movement arousal was significantly higher in the OSAS group than in the other groups. The TNST is thought to be useful for evaluating disturbance of sleep maintenance.

Yamamoto H, Akashiba T, Kosaka N, Ito D, Horie T. · First Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan. · Respir Med. · Pubmed #10714485 No free full text.

Abstract: To describe the long-term effects of nasal continuous positive airway pressure (CPAP) on the rate of traffic car accidents, excessive daytime sleepiness (EDS) and mood in patients with obstructive sleep apnoea syndrome (OSAS), we investigated the changes of these parameters before and after nasal CPAP treatment using a questionnaire. Seventy-five male patients who were diagnosed with severe OSAS by polysomnography were evaluated for driving competence, by looking at their driving history for 2 yr, for EDS by the Epwarth Sleepiness Scale (ESS) and for mood by the Self-related Depression Scale (SDS), and then underwent nasal CPAP treatment. After 2 yr of treatment, questionnaires inquiring about the patients' use of CPAP, their ESS, SDS and driving history during treatment were sent to the patients. A total of 47 patients (63%) responded to these questionnaires. Forty-six of the 47 responders had continued to use the nasal CPAP and completed the questionnaire. No traffic car accidents were observed among the 39 routine car users during treatment, while 13 of 39 patients (33%) had had car accidents before treatment. Although near-miss accidents had been reported by 32 of 39 patients (82%) before treatment, only four patients reported near-miss accidents during nasal CPAP treatment. The mean score of ESS was significantly (P<0.01) reduced in 46 patients after nasal CPAP. The mean score of SDS was also decreased (P<0.01) after nasal CPAP in 46 patients. Although 26 of 41 patients had been depressive on SDS before treatment, the mood was improved in 13 patients after nasal CPAP. These results suggest that long-term nasal CPAP treatment reduces the rate of traffic car accidents and improves the EDS and the mood in patients with OSAS.

Akashiba T, Minemura H, Yamamoto H, Kosaka N, Saito O, Horie T. · First Department of Internal Medicine, Nihon University School of Medicine, Itabashi, Tokyo, Japan. · Sleep. · Pubmed #10566903 No free full text.

Abstract: To evaluate the circadian pattern of blood pressure (BP) and the effects of nasal continuous positive airway pressure (CPAP) on patients with obstructive sleep apnea (OSA), we examined 24-hour BP in 38 male OSA patients with and without nasal CPAP. We measured the BP at 30-min intervals during daytime (800 to 2200) and nighttime (2200 to 800) hours. A "dipper" was defined as a patient who showed an average reduction of at least 10 mm Hg systolic and 5 mm Hg diastolic between daytime and nighttime values. The subjects were predominantly "non-dipper" (22 of 38 patients, 58%). Daytime hypertension (>160/95 mm Hg) was present in 11 of 38 patients (4 "dippers" and 7 "non-dippers"). After nasal CPAP treatment for 3 days, the average BP decreased significantly during the day and night in all subjects (p<0.05). Fifteen of 22 subjects who were "non-dippers" before treatment reversed to become "dippers." And daytime hypertension was detected in only 5 of these patients during nasal CPAP treatment (4 "dippers" and 1 "non-dipper"). These results showed that the "non-dipper" status was common in patients with OSA, and that nasal CPAP restored the normal circadian "dipper" pattern. We suggest that nasal CPAP may contribute to an improved prognosis in patients with OSA because of a reduction in cardiovascular risk factors in "non-dipper" with severe OSA.

Teramoto S, Yamaguchi Y, Yamamoto H, Hanaoka Y, Ishii M, Shinichiro H, Kume H, Akishita M, Ouchi Y. · No affiliation provided · J Am Geriatr Soc. · Pubmed #18315673 No free full text.

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Teramoto S, Yamaguchi Y, Yamamoto H, Hanaoka Y, Ishii M, Hibi S, Ishii T, Kume H, Ouchi Y. · No affiliation provided · Eur Respir J. · Pubmed #18166604 links to  free full text

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Teramoto S, Yamaguchi Y, Yamamoto H, Hanaoka Y, Ishii M, Hibi S, Kume H, Akishita M, Ouchi Y. · No affiliation provided · J Am Geriatr Soc. · Pubmed #17979911 No free full text.

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Teramoto S, Kume H, Yamaguchi Y, Yamamoto H, Hanaoka Y, Ishii M, Ishii T, Ouchi Y. · No affiliation provided · Eur Respir J. · Pubmed #17197486 links to  free full text

This publication has no abstract.

Teramoto S, Kume H, Yamaguchi Y, Yamamoto H, Ishii M, Ishii T, Ouchi Y. · No affiliation provided · Eur Respir J. · Pubmed #16880376 links to  free full text

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Teramoto S, Yamamoto H, Yamaguchi Y, Namba R, Ouchi Y. · No affiliation provided · Chest. · Pubmed #15764798 links to  free full text

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Teramoto S, Yamamoto H, Ouchi Y. · No affiliation provided · Chest. · Pubmed #15136420 links to  free full text

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Teramoto S, Yamamoto H, Ouchi Y. · No affiliation provided · Chest. · Pubmed #12907575 links to  free full text

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Teramoto S, Yamamoto H, Ouchi Y. · No affiliation provided · Circulation. · Pubmed #12578892 links to  free full text

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Yamamoto H, Teramoto S, Yamaguchi Y, Ouchi Y. · Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. · Hypertens Res. · Pubmed #18250556 No free full text.

Abstract: Obstructive sleep apnea syndrome (OSAS) is recognized as one of the risk factors of hypertension and cardiovascular disorders. In the current study, we hypothesized that the hypoxic stress and oxidative stress caused by obstructive sleep apnea would increase circulating adrenomedullin (ADM) levels in untreated OSAS patients as compared to an age and body mass index (BMI)-matched control group and an age-matched, but normal-BMI control group. We further hypothesized that nasal continuous positive airway pressure (nCPAP) treatment may decrease OSAS-induced hypoxic stress, oxidative stress and ADM levels. To examine these hypotheses, we measured circulating ADM and reactive oxygen species (ROS) from leukocytes before and after nCPAP therapy in OSAS patients. The circulating levels of ADM and amount of ROS in untreated OSAS patients were significantly greater than those in the controls. No differences in ADM levels were found between the increased-BMI controls and normal-BMI controls. We observed that nCPAP treatment decreased sleep apneas, nocturnal oxyhemoglobin desaturation, the circulating ADM, and ROS production by leukocytes in OSAS patients. The ADM levels were associated with the magnitude of oxyhemoglobin desaturation rather than the number of sleep apneas. These observations suggest that nCPAP therapy could reduce OSAS-induced nocturnal hypoxemia, generation of ROS, and ADM in patients with OSAS.