Serum homocysteine levels and cardiovascular morbidity in obstructive sleep apnea syndrome

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular morbidity and mortality. Elevated levels of serum homocysteine are also associated with cardiovascular morbidity and mortality. We aimed to investigate serum homocysteine levels and conventional cardiovascular risk factors (cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides) in OSAS patients with and without cardiovascular diseases (CVD). METHODS AND RESULTS: Levels of homocysteine, cholesterol, LDL, HDL and triglycerides were measured in 114 obese, male participants after overnight fasting. The presence of OSAS was determined by standard overnight polysomnography. The cases included OSAS patients (apnea-hypopnea index: AHI5) with CVD (OSAS+CVD group) (n:25) and without CVD (OSAS-CVD group) (n:47). Control group was patients without OSAS (AHI<5) with CVD (CVD group) (n:42). The serum homocysteine levels were significant.     

Altered blood rheology in obstructive sleep apnea as a mediator of cardiovascular risk

BACKGROUND: Cardiovascular complications are common in patients with obstructive sleep apnea (OSA). Blood rheology is a major determent of coagulation and an established risk factor for cardiovascular events. Since nocturnal hypoxemia could influence parameters of blood rheology, we hypothesized that OSA alters blood rheology independent of other cardiovascular risk factors. METHODS: One hundred and ten consecutive patients admitted to the sleep laboratory were included. The association of plasma fibrinogen and viscosity (as parameters of blood rheology) with OSA was evaluated. RESULTS: One hundred and ten patients aged 61.4+/-10.1 years (body mass index 28.4+/-4.1 kg/m2) were included. OSA was confirmed in 63 patients (57.2%) with an apnea-hypopnea index (AHI) of 28.7+/-14.9 events/hour. Patients with OSA showed higher levels of plasma viscosity (1.36+/-0.09 vs. 1.31+/-0.08 mPas, p=0.005). Nevertheless, hypertensive apneics have even higher levels of plasma viscosity than nonapneics (1.38+/-0.091 vs. 1.32+/-0.028 mPas, p=0.018). Similar results were found in patients with coronary artery disease, where OSA was associated with elevated plasma viscosity (1.36+/-0.076 vs. 1.31+/-0.081 mPas, p=0.007). Plasma fibrinogen was correlated with nocturnal minimal oxygen saturation (r=-0275, p=0.0036) and AHI (r=0.297, p=0.001). OSA was associated with higher plasma fibrinogen (353+/-83 vs. 317+/-62 mg/dl, p=0.015). These differences persist with control for cardiovascular risk factors. CONCLUSIONS: Patients with OSA have elevated morning fibrinogen levels and a higher plasma viscosity, which correlate positively with indices of sleep apnea severity. These changes in blood rheology are independent of cardiovascular risk factors, and therefore, might be specific mechanisms of OSA. This supports the pathophysiological concept that sleep apnea is a cardiovascular risk factor.     

Aortic pressure augmentation as a marker of cardiovascular risk in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is associated with increases in cardiovascular morbidity and mortality. Vascular changes in individuals with OSAS have not been fully elucidated, however. The possible impact of OSAS on the extent of aortic pressure augmentation (AG), an indicator of cardiovascular risk, was investigated. Forty-five consecutive male patients aged 35 to 78 years (56.0+/-9.6 years) who were referred to the sleep clinic of Nagoya University Hospital for screening and treatment of OSAS and 71 age-matched healthy men were enrolled in the study. AG was derived from the pressure waveform measured at the radial artery by applanation tonometry. The number of apnea and hypopnea episodes per hour (apnea-hypopnea index [AHI]) was determined by standard polysomnography. AG was significantly greater in OSAS patients than in controls (9.0+/-4.1 vs. 6.4+/-3.4 mmHg, p<0.001), and it was significantly reduced in 19 OSAS patients treated with continuous positive airway pressure. AG was also significantly correlated with the AHI (r=0.562, p<0.001) and age (r=0.356, p=0.016) but not with the serum concentrations of low and high density lipoprotein-cholesterol, triglyceride, or glycosylated hemoglobin. Stepwise multiple regression analysis revealed that the AHI was the most significant contributing factor to the increased AG in OSAS patients (beta=0.109, r=0.530, p<0.001). OSAS may thus have an adverse effect on vascular function that can be ameliorated by appropriate treatment.     

Cardiovascular morbidity in obstructive sleep apnea

The repetitive respiratory events that characterize obstructive sleep apnea (OSA) are each followed by abrupt increases in heart rate and in pulmonary and systemic artery pressure and by sudden decreases in right and left ventricular stroke volume. The changes in systemic pressure may be profound, with patients who are normotensive while awake having systolic pressures approaching 300 mm Hg after apnea termination. Because of these dramatic hemodynamic oscillations during sleep, many clinicians and investigators have postulated a connection between sleep-disordered breathing and cardiovascular morbidity and even mortality. This review critically examines the evidence for such a causal relationship. We begin, however, by reviewing the normal hemodynamic changes that occur during sleep. We then describe the acute hemodynamic events associated with OSA. Finally, we summarize the evidence for and against a causal connection between sleep apnea and cardiovascular morbidity.     

Plasma homocysteine levels in obstructive sleep apnea: association with cardiovascular morbidity

OBJECTIVES: Obstructive sleep apnea (OSA) is associated with cardiovascular morbidity and mortality. Plasma levels of homocysteine are also associated with cardiovascular morbidity and mortality. We therefore investigated homocysteine and conventional cardiovascular risk factors in OSA patients with and without cardiovascular morbidity in comparison with normal control subjects and ischemic heart disease (IHD) patients without OSA. SETTING: Technion Sleep Medicine Center, Haifa, Israel. METHODS AND PARTICIPANTS: Levels of homocysteine, cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, creatinine, vitamins B(12) and B(6), and folic acid were determined in 345 participants after overnight fasting. These included OSA patients with IHD (n = 49), with hypertension (n = 61), or without any cardiovascular disease (n = 127). Two control groups were employed: IHD patients without or with low likelihood for sleep apnea (n = 35), and healthy control subjects (n = 73). RESULTS: After adjustment for age, body mass index, creatinine, and existence of diabetes mellitus, OSA patients with IHD had significantly higher homocysteine levels (14.6 +/- 6.77 micromol/L) than all other groups including the IHD-only patients. Hypertensive OSA patients had comparable homocysteine levels to IHD patients (11.80 +/- 5.28 micromol/L and 11.92 +/- 5.7 micromol/L, respectively), while patients with OSA only had comparable levels to normal control subjects (9.85 +/- 2.99 micromol/L and 9.78 +/- 3.49 micromol/L, respectively). No differences in conventional cardiovascular risk factors or in vitamin levels were found between groups. CONCLUSIONS: Patients with the combination of IHD and OSA have elevated homocysteine levels. We hypothesize that these results may be explained by endothelial dysfunction combined with excess free-radical formation in OSA patients.     

The behavioral morbidity of obstructive sleep apnea

The behavioral morbidity associated with obstructive sleep apnea (OSA) includes symptoms of excessive daytime sleepiness (EDS), neurocognitive deficits, psychological problems, and possibly an increased chance of accidents. EDS is among the most frequently reported symptoms in patients diagnosed with OSA. The available data suggest that the primary cause of EDS is sleep fragmentation. The subjective measures of sleepiness include the sleep wake activity inventory and the epworth sleepiness scale. Sleepiness can also be evaluated objectively in the sleep laboratory using the multiple sleep latency test or the maintenance of wakefulness test. The neurocognitive manifestations of OSA include impairments in vigilance, concentration, memory, and executive function. There is no agreed on consensus as to how to best quantify neurocognitive deficits in this population. Symptoms consistent with depression or personality changes have also been described, but are likely to be correlates of EDS and/or the chronicity of the disorder. Manifestations of the behavioral morbidity of OSA are reversible, but dependent on the degree of normalization in sleep-disordered breathing and the individual's sleep habits.     

阻塞性睡眠呼吸暂停低通气综合征对心脏的影响

目的:探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)对心血管事件的影响。方法:对237例OSAHS患者与228例健康者的心率变异性(HRV)、24h动态心电图及超声心动图进行对比分析。结果:对照组与OSAHS组间比较,HRV各指标差异有统计学意义(P<0.01);室性期前收缩、房室传导阻滞、窦性停搏发生次数差异有统计学意义(P<0.01);左室质量及质量指数差异有统计学意义(P<0.01)。结论:OSAHS可引起严重的HRV、心律失常及左室质量增加。     

阻塞型睡眠呼吸暂停低通气综合征与心血管疾病的关系

目的探讨阻塞型睡眠呼吸暂停低通气综合征（OSAHS）与心血管疾病的关系。方法对265例鼾症患者与20例健康自愿者进行多导睡眠呼吸监测。根据睡眠呼吸暂停低通气指数（AH I）和夜间血氧饱和度（SaO2）分为5组:正常对照组、单纯性鼾症组、轻、中和重度OSAHS组,并分析并发冠心病、高血压患者的心电和血压变化。结果①OSAHS组188例,并发心血管疾病106例（56%）,其中高血压病61例（32%）,冠心病45例（24%）。单纯鼾症组77例并发心血管疾病12例（16%）,高血压病7例（9%）,冠心病5例（6%）,OSAHS组并发心血管疾病发生率显著高于单纯鼾症组（P<0.05）。②OSAHS组晨间收缩压、舒张压均高于单纯鼾症组与正常对照组（P<0.05）。③OSAHS组夜间窦性心动过缓、室性早搏、室性心动过速、室上性心动过速发生率均显著高于单纯性鼾症组和正常对照组（P<0.05）。结论OSAHS与心血管疾病的发生密切相关,随着其程度的加重对患者血压变化及心律失常有显著影响。     

阻塞性睡眠呼吸暂停综合征合并心血管疾病的血清预测指标

阻塞性睡眠呼吸暂停综合征(OSAS)以慢性间歇低氧为基础,通过多种发病机制导致心血管疾病(CVD)的发生。OSAS合并CVD已经成为威胁人类健康的重大疾病,引起了社会的广泛关注。既往研究主要集中在两者的病理生理机制上,而对血清学预测指标的研究较少。血脂指标简便易测、反应灵敏;脂肪因子指标可能是新的治疗靶点;蛋白质指标对调节糖脂代谢、早期诊断高血压以及心肌缺血起重要作用,本文将从上述3个方面进行重点阐述,以期为临床提供新的诊疗思路。     

Analysis of pattern visual evoked potential in obstructive sleep apnea syndrome

<正>Objective To objectively evaluate visual function using pattern visual evoked potential(PVEP)and its related factors in patients with obstructive sleep apnea syndrome(OSAS)without any ocular symptoms.Methods Eighty-three newly diagnosed OSAS and 18 normal subjects were enrolled in the study.The OSAS patients were     

Severe obstructive sleep apnea syndrome in a toddler

We report the case of a 3-year-old boy who had experienced intense snoring, frequent awakenings, intense respiratory effort during sleep, and delayed growth starting at the age of 15 months. He underwent adenoidectomy at 18 months. Symptoms initially improved but reappeared 3 months after surgery. He underwent a second adenoidectomy, this time with tonsillectomy, but there was no significant clinical improvement. Polysomnography revealed severe sleep apnea-hypopnea with an apnea-hypopnea index of 45. Continuous positive airway pressure improved sleep quality, although some symptoms, mainly snoring, persisted. A third adenoidectomy was necessary to normalize his breathing pattern during sleep.     

睡眠呼吸暂停低通气综合征问卷对阻塞性睡眠呼吸暂停综合征诊断价值

目的 评价阻塞性睡眠呼吸暂停低通气综合征(OSAHS)的流行病学调查表筛查价值.方法 疑似OSAHS的987例患者为研究对象,按照中华医学会呼吸病学分会睡眠学组睡眠呼吸暂停低通气综合征流行病学调查表进行问卷并行多导睡眠监测.将此问卷表进行量化评分,用克隆巴赫信度系数(α系数)进行信度计算,将各相关因素做方差分析及x2检验,筛选出有统计学意义的因素最后做Logistic回归分析.以鼾声中度以上的打鼾及体质量指数≥25 kg/m2为高危,反之为低危,进行敏感性,特异性,假阳性,假阴性,阳性似然比,阴性似然比,阳性预测值等.结果 疑似OSAHS患者987例,其中男800例(81.05％),女187例(18.95％),年龄18～80岁,平均(47±12)岁,平均体质量指数(29±5) kg/m2.＞60岁者156例(15.81％),≤60岁者831例(84.19％).克隆巴赫信度系数(Cronbach'salpha)是0.803,假阳性者20,假阴性者142,真阳性者742,真阴性者83,问卷的敏感性是83.94％,特异性是80.58％,假阳性率19.42％,假阴性率16.06％,阳性似然比4.32,阴性似然比0.20,阳性预测值0.97,阴性预测值0.37,正确率83.59％.结论 该睡眠调查表对OSAHS筛查具有一定意义,可用于临床OSAHS的初筛,尤其适合在社区和基层医院中推广使用.     

阻塞性睡眠呼吸暂停综合征与心血管病关系的随访研究

目的调查随访阻塞性睡眠呼吸暂停综合征（OSAS）与心血管病（CVD）的关系。方法自1989年1aY]起入组1868例,其中OSAS患者598例,无OSAS1270例作为对照组,对入组人群每年进行一次体检,以发生CVD为随访终点,如未发生CvD则随访至2009年结束。结果随访期间,OSAS组发生CVD者占83．9％（502／598例）,对照组发生CVD者占28．6％（363／1270例）,两组CVD发生率存在显著统计学差异（P〈0．01）。随访期间死亡率为43．7％（817／1868例）,其中OSAS组死亡率66．2％（396／598例）,对照组死亡率为33．1％（421／1270例）,两组死亡率存在显著统计学差异（P〈0．01）。结论与一般健康人群相比,OSAS患者发生CVD的比例和死亡率均较高。     

Serum cardiovascular risk factors in obstructive sleep apnea

BACKGROUND: Obstructive sleep apnea (OSA) patients have increased cardiovascular morbidity and mortality. The cardiovascular markers associated with OSA are currently not defined. OBJECTIVES: The aims of this study were to determine whether OSA is associated with serum cardiac risk markers and to investigate the relationship between them. METHODS: Sixty-two male patients were classified into two groups with respect to apnea-hypopnea index (AHI): group 1, sleep apnea (n = 30), with AHI > 5; and group 2 (n = 32), with AHI < 5. We compared cardiovascular risk factors in both groups with control subjects (n = 30) without OSA (AHI < 1). Serum cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A-I, apolipoprotein B, lipoprotein (a), C-reactive protein (CRP), and homocysteine were measured. Statistical significance was assessed with analysis of variance at p < 0.05. In correlation analysis, Pearson correlation was used. RESULTS: There was no significant difference between group 1 and group 2 in total cholesterol, LDL-C, HDL-C, triglyceride, apolipoprotein A-I, apolipoprotein B, and lipoprotein (a). All of the M-mode echocardiographic parameters were in the normal reference range. Serum homocysteine and CRP levels were significantly increased in group 1 compared to group 2 (p < 0.05). Serum CRP values were increased in both group 1 and group 2 when compared with control subjects (p < 0.05). Serum homocysteine values were higher in group 1 than in control subjects (p < 0.05). CONCLUSIONS: Our results show that OSA syndrome is associated not only with slight hyperhomocysteinemia but also with increased CRP concentrations. Increased plasma concentrations of homocysteine and CRP can be useful in clinical practice to be predictor of long-term prognosis for cardiovascular disease and the treatment of OSA.     

The effects of obstructive sleep apnea hypopnea syndrome on cardiovascular system]

Obstructive sleep apnea hypopnea syndrome (OSAHS) is characterized by repetitive upper airway obstruction during sleep and it is commonly seen in the adult population, 4% in the men, 2% in the women. The most common nocturnal symptom is snoring while the most common daytime symptom is excessive daytime sleepiness. The gold standard in the diagnosis is polysomnography. Nasal continuous positive airway pressure is the most efficient therapy in the treatment and prevention of the disease. The OSAHS may cause cardiovascular complications in long-term, including systemic hypertension, pulmonary hypertension, congestive heart failure, arrhythmias, stroke and myocardial infarction. All these complications increase the morbidity and mortality of OSAHS. In this paper, effects of OSAHS on cardiovascular system were reviewed.     

老年心血管疾病患者阻塞性睡眠呼吸暂停综合征的评价

目的 评价老年心血管疾病患者阻塞性睡眠呼吸暂停综合征(OSAS)的患病情况和特点,为临床决策提供参考. 方法 采用便携式睡眠监测仪对入住在老年心内科的患者,进行睡眠呼吸监测,了解其阻塞性睡眠呼吸暂停(OSA)的患病情况. 结果 共监测了317例老年心血管疾病患者的夜间睡眠呼吸紊乱情况,得出符合OSA[睡眠呼吸紊乱指数(AHI)≥5]的有281例,占88.6%;符合阻塞性睡眠呼吸暂停综合征(OSAS)[AHI≥5,Epworth量表(ESS)≥9分]的有47例,占14.8%.多元回归分析结果 提示,以OSA严重程度作为因变量,对它影响有显著性意义的是最低血氧饱和度和血氧饱和度下降指数(简称氧减指数),而年龄、习惯性打鼾、嗜睡评分、体质指数(BMI)、血氧饱和度平均值和低于90%的时间对其影响无显著性意义. 结论 老年心血管疾病患者中OSAS具有高的患病率,而且无白天嗜睡症状的OSA的老年人患病率更高.对睡眠呼吸暂停严重程度的独立预测因子是最低血氧饱和度氧减指数,而老年人的年龄、BMI、是否经常打鼾、是否白天嗜睡与OSA的严重程度关系不密切.     

Elevated morbidity and health care use in children with obstructive sleep apnea syndrome.

RATIONALE: Health care use, a reliable measure of morbidity, is noticeably higher 1 yr before obstructive sleep apnea syndrome (OSAS) diagnosis in preschool children. It is not clear at what age OSAS-related morbidity becomes expressed. OBJECTIVE: To explore morbidity and health care use among children with OSAS starting from first year of life. METHODS: Case-control study, starting from the first year of life to date of OSAS diagnosis, among 156 patients (age range, 3-5 yr) and their pair-matched healthy control subjects, by age, sex, primary care physician, and geographic location. MEASUREMENTS: Patients with OSAS underwent nocturnal polysomnography studies. Medical records during hospital visits were reviewed for diagnosis. Variables of health care use were obtained from computerized databases of Clalit Health Care Services, the largest health maintenance organization in Israel. MAIN RESULTS: From the first year of life to date of OSAS diagnosis, children with OSAS had 40% more (p = 0.048) hospital visits, 20% more repeated (two or more) visits (p < 0.0001), and higher consumption of antiinfective and respiratory system drugs (p < 0.0001). Referrals of children with OSAS to otolaryngology surgeons and pediatric pulmonologists were higher from Year 1 (p < 0.0001) to date of OSAS diagnosis, especially in Year 4 (odds ratio, 9.4; 95% confidence interval, 4.2-21.1). The 215% elevation (p < 0.0001) in health care use of the OSAS group was due mainly to higher occurrence of respiratory tract morbidity (p < 0.0001). CONCLUSIONS: Practitioners should be aware that starting in Year 1 until date of diagnosis, children with OSAS have higher health care use, mostly related to respiratory diseases.