Obstructive sleep apnea （OSA）,which is the most common sleep-related breathing disorder,is characterized as frequent upper airway collapse and obstruction.It is a treatable disorder but if left untreated is associat...Obstructive sleep apnea （OSA）,which is the most common sleep-related breathing disorder,is characterized as frequent upper airway collapse and obstruction.It is a treatable disorder but if left untreated is associated with complications in several organ systems.The health risk to OSA patients shows a strong association with acute cardiovascular events,and with chronic conditions.To the central nervous system,OSA causes behavioral and neuropsychologic deficits including daytime sleepiness,depression,impaired memory,mood disorders,cognition deficiencies,language comprehension and expression deficiencies,all of which are compatible with impaired hippocampal function.Furthermore,there exists a significant correlation between disease severity and cognitive deficits in OSA.Children with severe OSA have significantly lower intelligence quotient （IQ） and executive control functions compared to normal children matched for age,gender and ethnicity.This corroborates the findings of several pediatric studies of cognition in childhood OSA,where deficits are reported in general intelligence and some measures of executive function.In studies of OSA,it is difficult to differentiate the effects of its two main pathologic traits,intermittent hypoxia （IH） and sleep fragmentation.Many OSA studies,utilize IH as the only exposure factor in OSA studies.These approaches simplify research process and attain most of the academic goals.IH,continuous hypoxia and intermittent continuous hypoxia can all result in decreases in arterial O2.There are striking differences to them in the response of physiological systems.There are multiple studies showing that IH treatment in a rodent model of OSA can impair performance of standard water maze tests associated with deficits in spatial learning and memory which most likely are hippocampal-dependent.Cellular damage to the hippocampal cornuammonis 1 （CA1） region likely contributes to neuropsychological impairment among OSA patients,since neural circuits in the hippocampus are important in learning and memory.In this article,studies of hippocampal impairments from IH are reviewed for elucidating the mechanisms and relationships between hippocampal impairments and IH of OSA.展开更多
Background Sleep disturbance is common in patients with emphysema. This study aimed to develop a novel model of sleep-related hypoxemia （SRH） in emphysema （SRHIE） with rats, and to explore the inflammatory status ...Background Sleep disturbance is common in patients with emphysema. This study aimed to develop a novel model of sleep-related hypoxemia （SRH） in emphysema （SRHIE） with rats, and to explore the inflammatory status of SRHIE in lung, liver, pancreas, carotid artery and whole blood.Methods Seventy-five male Wistar rats were assigned to 5 groups with 15 per group according to the exposure conditions. The protocols varied with the degree of hypoxia exposure and severity of pre-existing emphysema caused by cigarette smoke exposure： （1） SRH control （SRHCtrl） group, sham smoke exposure （smoke exposure, exposed to smoke of 15 cigarettes twice everyday, 16 weeks） and SRH exposure （12.5% O2, 3 hours, SRH exposure, divide total hypoxia time （1.5 hours or 3 hours） into 4 periods evenly （22.5 minutes or 45 minutes） and distribute these hypoxia periods evenly into physiological sleep time of rats identified by electroencephalogram, week 9 to week 16）; （2） Emphysema control （ECtrl） group, smoke exposure and sham SRH exposure （21% O2, 3 hours）; （3） Short SRH in emphysema （SRHShort） group, smoke exposure and short SRH exposure （12.5% O2, 1.5 hours）; （4） Mild SRH in emphysema （SRHMild） group,smoke exposure and mild SRH exposure （15% O2, 3 hours）; （5） Standard SRH in emphysema （SRHStand） group, smoke exposure and SRH exposure （12.5% O2, 3 hours）. ECtrl, SRHShort, SRHMild and SRHStand groups were groups with emphysematous rats. Two days before the end of exposure, 5 rats in each group were randomly selected for arterial blood gas analysis. In the rest 10 rats in each group, we obtained blood samples and bronchoalveolar lavage fluid （BALF）for routine tests. We also obtained tissue blocks of lung, liver, pancreas, and right carotid artery for pathologic scoring and measurements of liver oxidative stress （measuring hepatic oxidative stress enzymes, superoxide dismutase （SOD） activity, catalase （CAT） activity and malondialdehyde （MDA） concentration）.Results Emphysematous groups had higher mean linear intercept （MLI） and mean alveolar number （MAN） values than SRHCtrl group. MLI values in SRHStand group were the highest （ail P 〈0.05）. O2Sat in SRHStand rats when SRH exposure was （83.45±1.76）%. Histological scores of lung, liver, pancreas and right carotid artery were higher in emphysematous groups than SRHCtrl group, and SRHStand group were the highest （all P 〈0.05） （SOD and CAT values were lower and MDA values were higher in groups with emphysema than without and in SRHStand group than in ECtrl group （all P 〈0.05））. MDA values were the highest in SRHStand group （all P 〈0.05）. Total cellular score in BALF and White blood cell （WBC） in whole blood were the highest in SRHStand group （all P 〈0.05）. Lymphocyte ratios were the highest in SRHStand group both in BALF and blood （all P 〈0.05）. Red blood cell （RBC） and hemoglobin in emphysematous groups were higher than that in SRHCtrl group, and SRHStand group were higher than ECtrl group （all P 〈0.05）.Conclusions With a proper novo model of SRHIE with Wistar rats, we have demonstrated SRH may aggravate the degree of emphysematous changes, polycythemia,oxidative stress and systematic inflammation. SRH and emphysema may have a synergistic action in causing systematic damages, and lymphocyte may be playing a central role in this process. Longer duration and more severe extent of SRHIE exposure also seem to result in more serious systematic damages. The mechanisms of all these concerned processes remain to be studied.展开更多
Background Chronic obstructive pulmonary disease （COPD） has a variable natural history and not all individuals follow the same course. This study aimed to identify the prevalence and characteristics of asymptomatic ...Background Chronic obstructive pulmonary disease （COPD） has a variable natural history and not all individuals follow the same course. This study aimed to identify the prevalence and characteristics of asymptomatic COPD patients from a population-based survey in China.Methods A multistage cluster sampling strategy was used in a population from seven different provinces/cities. All residents （over 40 years old） were interviewed with a standardized questionnaire and spirometry.Post-bronchodilator forced expiratory volume in 1 second （FEV1）/forced vital capacity （FVC） of less than 70% was defined as the diagnostic criterion of COPD. All COPD patients screened were divided into symptomatic group and asymptomatic group according to the presence or absence of chronic respiratory symptoms. Socio-demographic,personal and exposure variables were collected and analyzed.Results Among the 1668 patients who were diagnosed with COPD from the 25 627 sampling subjects, 589 （35.3%）were asymptomatic. The age, sex, body mass index （BMI）,rural and urban distributions, smoking habit and education levels were similar in the two groups. A total of 64.7% of the asymptomatic patients had no comorbidities. Cardiovascular diseases and lung cancer were more common among symptomatic COPD patients than asymptomatic group.Asymptomatic COPD group were less likely to present with poor ventilation in the kitchen, a family history of respiratory disease and recurrent childhood cough. Asymptomatic COPD patients had significantly higher FEV1 （73.1% vs. 61.0%）, FVC （91.9% vs. 82.0%）, and a higher ratio of FEV1/FVC （62.9% vs.58.7%） （all P 〈0.001） than symptomatic group. More asymptomatic patients were underdiagnosed （91.9% vs.54.3%, P〈0.001） than symptomatic patients.Conclusions This large population-based survey confirmed a high prevalence of asymptomatic COPD patients in China. More use of spirometry screening test may be important to the early detection of COPD.展开更多
Objective A general review was made of studies involving： （1） the relationship between sleep apnea hypopnea syndrome/sleep apnea style intermittent hypoxia and liver injury and （2） the mechanism that causes the l...Objective A general review was made of studies involving： （1） the relationship between sleep apnea hypopnea syndrome/sleep apnea style intermittent hypoxia and liver injury and （2） the mechanism that causes the liver injury. Data sources The data used in this review were mainly from Medline and PubMed published in English from 1993 to February 2009. The search term was ＂sleep apnea hypopnea syndrome＂. Study selection （1） Clinical and laboratory evidence that sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia leads to liver injury; （2） the mechanism that causes the liver injury. Results The effect of sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia on the liver function is characterized by serum aminotransferase elevation. The liver histological injury includes hepatic steatosis, hepatocyte ballooning, Iobular inflammation, Iobular necrosis, and liver fibrosis. Sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia can cause insulin resistance and oxidative stress. Conclusions Sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia can lead to chronic liver injury, which, in most cases, is shown as nonalcoholic fatty liver disease. Insulin resistance and oxidative stress caused by sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia play an important role in the mechanism of chronic liver disease development.展开更多
Background Epidemiologic studies have shown an independent and definite association between obstructive sleep apnea （OSA） and hypertension. This study aimed to define the association between daytime blood pressure a...Background Epidemiologic studies have shown an independent and definite association between obstructive sleep apnea （OSA） and hypertension. This study aimed to define the association between daytime blood pressure and severity of OSA in Chinese population in mainland of China. Methods Twenty university hospital sleep centers in mainland of China were invited by the Chinese Medical Association （CMA） to participate in this epidemiologic study and 2297 consecutive patients （aged 18-85 years; 1981 males and 316 females） referred to these twenty sleep centers for evaluation of OSA between January 2004 and April 2006 were prospectively enrolled. Nocturnal polysomnography was performed in each patient, and disease severity was assessed based on the apnea-hypopnea index （AHI）. These patients were classfied into four groups： non-apneic control （control, n=257） with AHI 〈5 episodes/hour; mild sleep apnea （mild, n=402） with AHI 〉5 and 〈15 episodes/hour; moderate sleep apnea （moderate, n=460） with AHI 〉15 and 〈30 episodes/hour and severe sleep apnea （severe, n=1178） with AHI 〉30 episodes/hour. Daytime blood pressure measurements were performed under standardized conditions in each patient at 10 a.m. in office on the day of referring to sleep centers for getting average value. All the patients were requested to quit medications related to blood pressure for three days before the day of assessing. Results Both daytime systolic blood pressure and diastolic blood pressure values were significantly related to AHI positively （r = 0.201 and 0.276, respectively; both P values 〈0.001） and to nadir nocturnal oxygen saturation negatively （r = -0.215 and -0.277, respectively; both P values 〈0.001）, which were the parameters of OSA severity. In two special designed mean plots, means of daytime systolic and diastolic blood pressure increased gradually with increasing AHI. Beyond AHI of 61-65, this increasing trend reached a plateau. Conclusions The results showed that OSA severity was associated with daytime blood pressure until AHI of 61-65, providing evidence for early OSA management, especially in OSA patients with concomitant hypertension.展开更多
Background The nocturnal nondipping and elevated morning blood pressure （BP） in patients with obstructive sleep apnea syndrome （OSAS） have not yet been well investigated in Chinese patients. This study aimed to de...Background The nocturnal nondipping and elevated morning blood pressure （BP） in patients with obstructive sleep apnea syndrome （OSAS） have not yet been well investigated in Chinese patients. This study aimed to describe the BP profile, and to elucidate the relationships between daytime BP and nighttime BP, and between evening BP and morning BP in patients with OSAS. Methods Twenty teaching hospital sleep centers in China were organized by the Chinese Medical Association to participate in this study and 2297 patients were recruited between January 2004 and April 2006. BP assessments were made at four time points （daytime, evening, nighttime and morning） and polysomnography （PSG） was performed and subjects were classified into four groups by their apnea-hypopnea index （AHI）： control, n=213 with AHI 〈5; mild, n=420 with AHI -〉5 and 〈15; moderate, n=460 with AHI -〉15 and 〈30; and severe, n=1204 with AHI -〉30. SPSS 11.5 software package was used for statistical analysis and figure drawing. Results All the average daytime, nighttime, evening and morning BPs were positively correlated with AHI and negatively correlated with nadir nocturnal oxygen saturation. The ratios of nighttime/daytime and morning/evening average BP were positively correlated with AHI. The ratio of nighttime/daytime systolic BP became a ＂reversed BP dipping＂ pattern until the classification reached severe, while the ratio of nighttime/daytime diastolic BP became reversed at moderate. Similarly, the ratio of morning/evening diastolic BP becomes reversed even at mild. Conclusions OSAS may result in higher BP levels at all four time points. The ratios of nighttime/daytime and morning/evening BP increase with increased AHI. The increasing of diastolic BP, which is inclined to rise more quickly, is not parallel with increasing systolic BP.展开更多
Hypoxia is encountered under many physiological and .pathophysiological situations. Although bothintermittent hypoxia （IH） and continuous hypoxia （CH） result in decreases in arterial 02, there are striking differe...Hypoxia is encountered under many physiological and .pathophysiological situations. Although bothintermittent hypoxia （IH） and continuous hypoxia （CH） result in decreases in arterial 02, there are striking differences in the response of the physiological systems to CH and IH. Obstructive sleep apnea-hypopnea syndrome （OSAHS）, characterized by frequently recurrent intermittent hypoxia/reoxygenation （IH/ROX） as its obvious pathological trait, is clearly associated with an increased risk of cardiovascular disorders, particularly hypertension,1 and IH/ROX may be the prima pathological basis for OSAHS complicated hypertension.展开更多
Obstructive sleep apnea （OSA）, which is the most common sleep-related breathing disorder and characterized by recurrent collapse of the upper airway, causes repeated arousals from sleep, decreased oxygen saturation ...Obstructive sleep apnea （OSA）, which is the most common sleep-related breathing disorder and characterized by recurrent collapse of the upper airway, causes repeated arousals from sleep, decreased oxygen saturation of the blood, and excessive daytime sleepiness. Patients with OSA are at increased risk of cardiovascular and cerebrovascular disease,展开更多
基金This study was supported by the grants from the National Natural Science Foundation of China （No.30800507,81170071）.
文摘Obstructive sleep apnea （OSA）,which is the most common sleep-related breathing disorder,is characterized as frequent upper airway collapse and obstruction.It is a treatable disorder but if left untreated is associated with complications in several organ systems.The health risk to OSA patients shows a strong association with acute cardiovascular events,and with chronic conditions.To the central nervous system,OSA causes behavioral and neuropsychologic deficits including daytime sleepiness,depression,impaired memory,mood disorders,cognition deficiencies,language comprehension and expression deficiencies,all of which are compatible with impaired hippocampal function.Furthermore,there exists a significant correlation between disease severity and cognitive deficits in OSA.Children with severe OSA have significantly lower intelligence quotient （IQ） and executive control functions compared to normal children matched for age,gender and ethnicity.This corroborates the findings of several pediatric studies of cognition in childhood OSA,where deficits are reported in general intelligence and some measures of executive function.In studies of OSA,it is difficult to differentiate the effects of its two main pathologic traits,intermittent hypoxia （IH） and sleep fragmentation.Many OSA studies,utilize IH as the only exposure factor in OSA studies.These approaches simplify research process and attain most of the academic goals.IH,continuous hypoxia and intermittent continuous hypoxia can all result in decreases in arterial O2.There are striking differences to them in the response of physiological systems.There are multiple studies showing that IH treatment in a rodent model of OSA can impair performance of standard water maze tests associated with deficits in spatial learning and memory which most likely are hippocampal-dependent.Cellular damage to the hippocampal cornuammonis 1 （CA1） region likely contributes to neuropsychological impairment among OSA patients,since neural circuits in the hippocampus are important in learning and memory.In this article,studies of hippocampal impairments from IH are reviewed for elucidating the mechanisms and relationships between hippocampal impairments and IH of OSA.
基金This study was supported by the grants from the National Natural Science Foundation of China （No. 30800507, 30770934）. None of the authors has a financial relationship with a commercial entity that has an interest in the subject of this manuscript.
文摘Background Sleep disturbance is common in patients with emphysema. This study aimed to develop a novel model of sleep-related hypoxemia （SRH） in emphysema （SRHIE） with rats, and to explore the inflammatory status of SRHIE in lung, liver, pancreas, carotid artery and whole blood.Methods Seventy-five male Wistar rats were assigned to 5 groups with 15 per group according to the exposure conditions. The protocols varied with the degree of hypoxia exposure and severity of pre-existing emphysema caused by cigarette smoke exposure： （1） SRH control （SRHCtrl） group, sham smoke exposure （smoke exposure, exposed to smoke of 15 cigarettes twice everyday, 16 weeks） and SRH exposure （12.5% O2, 3 hours, SRH exposure, divide total hypoxia time （1.5 hours or 3 hours） into 4 periods evenly （22.5 minutes or 45 minutes） and distribute these hypoxia periods evenly into physiological sleep time of rats identified by electroencephalogram, week 9 to week 16）; （2） Emphysema control （ECtrl） group, smoke exposure and sham SRH exposure （21% O2, 3 hours）; （3） Short SRH in emphysema （SRHShort） group, smoke exposure and short SRH exposure （12.5% O2, 1.5 hours）; （4） Mild SRH in emphysema （SRHMild） group,smoke exposure and mild SRH exposure （15% O2, 3 hours）; （5） Standard SRH in emphysema （SRHStand） group, smoke exposure and SRH exposure （12.5% O2, 3 hours）. ECtrl, SRHShort, SRHMild and SRHStand groups were groups with emphysematous rats. Two days before the end of exposure, 5 rats in each group were randomly selected for arterial blood gas analysis. In the rest 10 rats in each group, we obtained blood samples and bronchoalveolar lavage fluid （BALF）for routine tests. We also obtained tissue blocks of lung, liver, pancreas, and right carotid artery for pathologic scoring and measurements of liver oxidative stress （measuring hepatic oxidative stress enzymes, superoxide dismutase （SOD） activity, catalase （CAT） activity and malondialdehyde （MDA） concentration）.Results Emphysematous groups had higher mean linear intercept （MLI） and mean alveolar number （MAN） values than SRHCtrl group. MLI values in SRHStand group were the highest （ail P 〈0.05）. O2Sat in SRHStand rats when SRH exposure was （83.45±1.76）%. Histological scores of lung, liver, pancreas and right carotid artery were higher in emphysematous groups than SRHCtrl group, and SRHStand group were the highest （all P 〈0.05） （SOD and CAT values were lower and MDA values were higher in groups with emphysema than without and in SRHStand group than in ECtrl group （all P 〈0.05））. MDA values were the highest in SRHStand group （all P 〈0.05）. Total cellular score in BALF and White blood cell （WBC） in whole blood were the highest in SRHStand group （all P 〈0.05）. Lymphocyte ratios were the highest in SRHStand group both in BALF and blood （all P 〈0.05）. Red blood cell （RBC） and hemoglobin in emphysematous groups were higher than that in SRHCtrl group, and SRHStand group were higher than ECtrl group （all P 〈0.05）.Conclusions With a proper novo model of SRHIE with Wistar rats, we have demonstrated SRH may aggravate the degree of emphysematous changes, polycythemia,oxidative stress and systematic inflammation. SRH and emphysema may have a synergistic action in causing systematic damages, and lymphocyte may be playing a central role in this process. Longer duration and more severe extent of SRHIE exposure also seem to result in more serious systematic damages. The mechanisms of all these concerned processes remain to be studied.
文摘Background Chronic obstructive pulmonary disease （COPD） has a variable natural history and not all individuals follow the same course. This study aimed to identify the prevalence and characteristics of asymptomatic COPD patients from a population-based survey in China.Methods A multistage cluster sampling strategy was used in a population from seven different provinces/cities. All residents （over 40 years old） were interviewed with a standardized questionnaire and spirometry.Post-bronchodilator forced expiratory volume in 1 second （FEV1）/forced vital capacity （FVC） of less than 70% was defined as the diagnostic criterion of COPD. All COPD patients screened were divided into symptomatic group and asymptomatic group according to the presence or absence of chronic respiratory symptoms. Socio-demographic,personal and exposure variables were collected and analyzed.Results Among the 1668 patients who were diagnosed with COPD from the 25 627 sampling subjects, 589 （35.3%）were asymptomatic. The age, sex, body mass index （BMI）,rural and urban distributions, smoking habit and education levels were similar in the two groups. A total of 64.7% of the asymptomatic patients had no comorbidities. Cardiovascular diseases and lung cancer were more common among symptomatic COPD patients than asymptomatic group.Asymptomatic COPD group were less likely to present with poor ventilation in the kitchen, a family history of respiratory disease and recurrent childhood cough. Asymptomatic COPD patients had significantly higher FEV1 （73.1% vs. 61.0%）, FVC （91.9% vs. 82.0%）, and a higher ratio of FEV1/FVC （62.9% vs.58.7%） （all P 〈0.001） than symptomatic group. More asymptomatic patients were underdiagnosed （91.9% vs.54.3%, P〈0.001） than symptomatic patients.Conclusions This large population-based survey confirmed a high prevalence of asymptomatic COPD patients in China. More use of spirometry screening test may be important to the early detection of COPD.
文摘Objective A general review was made of studies involving： （1） the relationship between sleep apnea hypopnea syndrome/sleep apnea style intermittent hypoxia and liver injury and （2） the mechanism that causes the liver injury. Data sources The data used in this review were mainly from Medline and PubMed published in English from 1993 to February 2009. The search term was ＂sleep apnea hypopnea syndrome＂. Study selection （1） Clinical and laboratory evidence that sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia leads to liver injury; （2） the mechanism that causes the liver injury. Results The effect of sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia on the liver function is characterized by serum aminotransferase elevation. The liver histological injury includes hepatic steatosis, hepatocyte ballooning, Iobular inflammation, Iobular necrosis, and liver fibrosis. Sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia can cause insulin resistance and oxidative stress. Conclusions Sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia can lead to chronic liver injury, which, in most cases, is shown as nonalcoholic fatty liver disease. Insulin resistance and oxidative stress caused by sleep apnea hypopnea syndrome and sleep apnea style intermittent hypoxia play an important role in the mechanism of chronic liver disease development.
基金All the coauthors from different centers in the name list have the same contribution to this paper. There is no ordering difference. This study was supported by the grants from National Natural Science Foundation of China （No. 30800507, 30770934）.
文摘Background Epidemiologic studies have shown an independent and definite association between obstructive sleep apnea （OSA） and hypertension. This study aimed to define the association between daytime blood pressure and severity of OSA in Chinese population in mainland of China. Methods Twenty university hospital sleep centers in mainland of China were invited by the Chinese Medical Association （CMA） to participate in this epidemiologic study and 2297 consecutive patients （aged 18-85 years; 1981 males and 316 females） referred to these twenty sleep centers for evaluation of OSA between January 2004 and April 2006 were prospectively enrolled. Nocturnal polysomnography was performed in each patient, and disease severity was assessed based on the apnea-hypopnea index （AHI）. These patients were classfied into four groups： non-apneic control （control, n=257） with AHI 〈5 episodes/hour; mild sleep apnea （mild, n=402） with AHI 〉5 and 〈15 episodes/hour; moderate sleep apnea （moderate, n=460） with AHI 〉15 and 〈30 episodes/hour and severe sleep apnea （severe, n=1178） with AHI 〉30 episodes/hour. Daytime blood pressure measurements were performed under standardized conditions in each patient at 10 a.m. in office on the day of referring to sleep centers for getting average value. All the patients were requested to quit medications related to blood pressure for three days before the day of assessing. Results Both daytime systolic blood pressure and diastolic blood pressure values were significantly related to AHI positively （r = 0.201 and 0.276, respectively; both P values 〈0.001） and to nadir nocturnal oxygen saturation negatively （r = -0.215 and -0.277, respectively; both P values 〈0.001）, which were the parameters of OSA severity. In two special designed mean plots, means of daytime systolic and diastolic blood pressure increased gradually with increasing AHI. Beyond AHI of 61-65, this increasing trend reached a plateau. Conclusions The results showed that OSA severity was associated with daytime blood pressure until AHI of 61-65, providing evidence for early OSA management, especially in OSA patients with concomitant hypertension.
基金This study was supported by the grants from the National Natural Science Foundation of China （No. 30800507, No. 30770934）. All the coauthors from different centers in the name list have made equal contributions to this article. There is no ordering difference. None of the authors has a financial relationship with a commercial entity that has an interest in the subject of this manuscript.
文摘Background The nocturnal nondipping and elevated morning blood pressure （BP） in patients with obstructive sleep apnea syndrome （OSAS） have not yet been well investigated in Chinese patients. This study aimed to describe the BP profile, and to elucidate the relationships between daytime BP and nighttime BP, and between evening BP and morning BP in patients with OSAS. Methods Twenty teaching hospital sleep centers in China were organized by the Chinese Medical Association to participate in this study and 2297 patients were recruited between January 2004 and April 2006. BP assessments were made at four time points （daytime, evening, nighttime and morning） and polysomnography （PSG） was performed and subjects were classified into four groups by their apnea-hypopnea index （AHI）： control, n=213 with AHI 〈5; mild, n=420 with AHI -〉5 and 〈15; moderate, n=460 with AHI -〉15 and 〈30; and severe, n=1204 with AHI -〉30. SPSS 11.5 software package was used for statistical analysis and figure drawing. Results All the average daytime, nighttime, evening and morning BPs were positively correlated with AHI and negatively correlated with nadir nocturnal oxygen saturation. The ratios of nighttime/daytime and morning/evening average BP were positively correlated with AHI. The ratio of nighttime/daytime systolic BP became a ＂reversed BP dipping＂ pattern until the classification reached severe, while the ratio of nighttime/daytime diastolic BP became reversed at moderate. Similarly, the ratio of morning/evening diastolic BP becomes reversed even at mild. Conclusions OSAS may result in higher BP levels at all four time points. The ratios of nighttime/daytime and morning/evening BP increase with increased AHI. The increasing of diastolic BP, which is inclined to rise more quickly, is not parallel with increasing systolic BP.
文摘Hypoxia is encountered under many physiological and .pathophysiological situations. Although bothintermittent hypoxia （IH） and continuous hypoxia （CH） result in decreases in arterial 02, there are striking differences in the response of the physiological systems to CH and IH. Obstructive sleep apnea-hypopnea syndrome （OSAHS）, characterized by frequently recurrent intermittent hypoxia/reoxygenation （IH/ROX） as its obvious pathological trait, is clearly associated with an increased risk of cardiovascular disorders, particularly hypertension,1 and IH/ROX may be the prima pathological basis for OSAHS complicated hypertension.
基金This study was supported by-the grants from National Natural Science Foundation of China （No. 30800507 and No. 30770934）.
文摘Obstructive sleep apnea （OSA）, which is the most common sleep-related breathing disorder and characterized by recurrent collapse of the upper airway, causes repeated arousals from sleep, decreased oxygen saturation of the blood, and excessive daytime sleepiness. Patients with OSA are at increased risk of cardiovascular and cerebrovascular disease,
