Sleep Apnea Syndromes: Yamaguchi Y

Nakamura H, Kanemura T, Kaneshima H, Yamaguchi Y. · Medical Corporation Jin-aikai, Urasoe Sogo Hospital, Sleep Respiratory Center. · Nippon Rinsho. · Pubmed #10944944 No free full text.

Abstract: Sleep medicine in Japan evolved gradually, beginning with sleep research being conducted in the late 1960's exclusively on the university basis. Japan Sleep Society was founded in 1977 mainly by psychiatrists. Recently public awareness regarding sleep related breathing disorders has been raised as a result of a media campaign in Japan. However, the medical service system is unable to appropriately meet the needs of caring for sleep-disordered patients due to insufficient reimbursement and the lack of well-trained technical personnel. So far only several sleep centers existed in Japan. To make sleep be included in the mainstream of the health care system, the educational system and throughout society, many tasks remains to be done by healthcare professionals and government.

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.

Imagawa S, Yamaguchi Y, Ogawa K, Obara N, Suzuki N, Yamamoto M, Nagasawa T. · Division of Hematology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan. · Respiration. · Pubmed #14872107 links to  free full text

Abstract: BACKGROUND: In previous studies, significantly elevated levels of vascular endothelial growth factor (VEGF) have been reported in patients with severe obstructive sleep apnea-hypopnea syndrome (OSAHS). On the other hand, plasma tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) have been significantly higher in mild sleep apneics than in normal controls. However, this study included a small number of patients and milder cases of OSAHS. OBJECTIVES AND METHODS: To assess the involvement of IL-6 and TNF-alpha in VEGF increases in patients with severe OSAHS, serum levels of IL-6 and TNF-alpha were determined in patients with severe OSAHS (n=110) and compared to those of controls (n=45) using an enzyme-linked immunosorbent assay. RESULTS: No significant increase in IL-6 or TNF-alpha was detected in the present study cohort. However, the body mass index was significantly correlated with the severity of the apnea-hypopnea index. CONCLUSIONS: These data suggest that the elevation in VEGF is not directly related to IL-6 or TNF-alpha levels. However, the question of whether VEGF is the cause or the result of OSAHS remains to be determined. Further studies are needed to clarify the role of IL-6 and TNF-alpha in the pathogenesis of OSAHS, in which obesity should be entered as an independent factor.

Imagawa S, Yamaguchi Y, Higuchi M, Neichi T, Hasegawa Y, Mukai HY, Suzuki N, Yamamoto M, Nagasawa T. · Division of Hematology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan. · Blood. · Pubmed #11493479 links to  free full text

Abstract: To better understand how humans adapt to hypoxia, the levels of hemoglobin (Hb), serum erythropoietin (Epo), and vascular endothelial growth factor (VEGF) were measured in 106 patients with severe obstructive sleep apnea-hypopnea syndrome. The results indicated that temporal hypoxic stimulation increases Hb. Furthermore, a minor increase in Epo and a substantial increase in VEGF were found. The induction in patients with severe sleep apnea was greater than that reported in other types of hypoxia. (Blood. 2001;98:1255-1257)

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.

This publication has no abstract.

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

This publication has no abstract.

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.

This publication has no abstract.

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

This publication has no abstract.

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

This publication has no abstract.

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.