Macular choroidal thickness measurements in patients with obstructive sleep apnea syndrome.

PURPOSE: The purpose of this study is to assess macular choroidal thickness measurements in patients with different severities of obstructive sleep apnea syndrome (OSAS) versus normal controls by using enhanced depth imaging optical coherence tomography (EDI-OCT). DESIGN: This paper is a descriptive study. MATERIALS AND METHODS: In this prospective study, the macular area of 74 patients with OSAS and 33 controls were evaluated. All subjects underwent complete ophthalmic examination and macular choroidal thickness (CT) measurements by enhanced depth imaging method of the Spectralis optical coherence tomography system. Choroidal thickness (CT) was measured at the fovea and at 1,000-µm intervals from the foveal center in both temporal and nasal directions by two masked observers. RESULTS: The mean age was not significantly different between patients with OSAS and controls. Patients were grouped as mild (n = 15), moderate (n = 28), and severe (n = 31) according to apnea-hypopnea index (AHI) scores. The mean subfoveal choroidal thickness (SFCT) was 338.0 ± 85.2 µm in the control group versus 351.3 ± 90, 307.8 ± 65.5, and 325.4 ± 110.2 µm in mild, moderate, and severe groups, respectively (p = 0.416). There was no significant correlation between the severity of OSAS and choroidal thickness. CONCLUSIONS: The patients with OSAS seem to protect the choroidal thickness despite hypoxia. The role of OSAS in the pathophysiology of choroidal blood flow and choroidal structure needs further investigation.

The relationship between high-sensitivity C-reactive protein levels and the severity of obstructive sleep apnea.

BACKGROUND AND OBJECTIVE: There is an increased risk of cardiovascular and cerebrovascular events in patients with obstructive sleep apnea (OSA). High-sensitivity C-reactive protein (hs-CRP) is a marker that predicts atherosclerotic complications. However, there are contradictory results about the correlation between serum hs-CRP levels and OSA severity. The purpose of this work was to evaluate the relationship between hs-CRP levels and the severity of OSA in newly diagnosed OSA patients. METHODS: The study group was composed of 76 patients with clinical suspicion of OSA. Subjects with body mass indexes (BMI) ≥30 kg/m(2) were classified as obese. Full-night polysomnography (PSG) was performed on all patients. Patients with an apnea-hypopnea index (AHI) ≥5 were considered to have OSA, and patients with an AHI <5 were accepted as the control group. Blood samples were taken from all patients to analyze serum hs-CRP levels the morning after PSG. RESULTS: The serum hs-CRP levels were significantly higher in the OSA group (4.03 ± 3.58 mg/L) than in the control group (2.41 ± 1.95 mg/L) (p = 0.013). This high level was positively correlated with BMI (r = 0.376, p = 0.001) and with AHI (r = 0.280, p = 0.014). In multiple regression analysis, elevated hs-CRP levels were associated with AHI (F = 3.293, p = 0.033), which was independent of obesity. CONCLUSIONS: Patients with OSA have elevated serum levels of hs-CRP, a marker for inflammation and an independent risk predictor for cardiovascular morbidity. The severity of OSA is responsible for the elevation of hs-CRP.

Role of nitric oxide synthase gene intron 4 and exon 7 polymorphisms in obstructive sleep apnea syndrome.

The objective of our study was to assess the association of eNOS4 and eNOS296 polymorphisms of endothelial nitric oxide synthase (eNOS) gene with obstructive sleep apnea syndrome (OSAS). Forty-eight patients with OSAS and 181 healthy volunteers were included in the study. Genotype analyses were performed for eNOS intron 4 VNTR and exon 7, Glu298Asp (G --> T) polymorphisms. There was no significant difference between the patients and controls regarding eNOS4 polymorphism (P > 0.05). There was a significant difference between the patients and controls regarding eNOS296 polymorphism. Glu/Asp variant was more frequent whereas Glu/Glu variant was less frequent in the patients compared to controls (P < 0.001). There was no relationship between eNOS4 and eNOS296 polymorphisms and polysomnography parameters, apnea-hypopnea index, age, gender, body weight and height, body mass index, hypertension, coronary artery disease, arrhythmia, diabetes mellitus, hypercholesterolemia and smoking (P > 0.05). The eNOS4 polymorphism of NOS gene is not associated with OSAS. However, eNOS296 polymorphism of NOS gene is associated with occurrence of OSAS, but not with severity of OSAS.

Extensive Exposure to Tear Gases in Ankara.

OBJECTIVES: The most common chemical substances used as mass control agents are chloroacetophenone, chlorobenzylidene malononitrile, and oleoresin capsicum. These agents not only have local and rapid effects but also have systemic and long-term effects. The aim of the present study was to discuss the patterns of tear gas exposure and to investigate its effects on respiratory functions. MATERIALS AND METHODS: A face-to-face survey was conducted in 86 individuals who had been exposed to tear gas indoor and outdoor during the public protests in June 2013. RESULTS: The most frequently reported respiratory complaints included cough, dyspnea, phlegm, and chest pain. Spirometry measurements including forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were also performed. Indoor exposers have lower mean % predicted FVC and FEV1 values than outdoor exposers. All complaints and signs were more common in indoor exposure to tear gas than in outdoor exposure. CONCLUSION: Safety of the chemicals used as mass control agents during protests is doubtful as these agents are associated with several health risks.

Comparison of serum adiponectin and tumor necrosis factor-alpha levels between patients with and without obstructive sleep apnea syndrome.

BACKGROUND: The obstructive sleep apnea syndrome (OSAS) is closely associated with cardiovascular and metabolic disorders. OBJECTIVES: The aim of this study was to evaluate the influence of OSAS on plasma adiponectin levels independent of obesity in our study group. We also investigated the association between plasma adiponectin, plasma tumor necrosis factor-alpha (TNF-alpha), obesity, cardiovascular disease (CVD) and OSAS. METHODS: The patients were classified into controls or OSAS patients according to the apnea-hypopnea index (AHI): patients with an AHI <5 constituted the control group (n = 32) and patients with an AHI > or =5 constituted the OSAS group (n = 106). Plasma TNF-alpha and adiponectin levels were measured in both groups. RESULTS: Plasma adiponectin levels were negatively correlated with AHI, body mass index (BMI) and SpO(2) <90% and positively correlated with minimum oxygen saturation. The plasma levels of TNF-alpha were positively correlated with SpO(2) <90%, BMI and fasting plasma glucose levels. In addition, there was a significant negative correlation between plasma TNF-alpha and adiponectin levels in theOSAS group. Compared with thenon-obese OSAS group, subjects with obesity and OSAS had lower adiponectin levels and SpO(2) <90%, and higher TNF-alpha levels. Obese OSAS patients had higher rates of CVD with lower plasma adiponectin levels when compared with obese control subjects. CONCLUSION: Serum adiponectin is significantly lower in patients with OSAS and it is independent of obesity. This might explain the high incidence of CVD and metabolic syndrome in patients with OSAS.

Vascular endothelial growth factor and carotid intima-media thickness in patients with Behçet's disease.

There is morphologic evidence of subclinical atherosclerosis in Behçet's disease (BD) patients obtained by high-resolution B-mode ultrasonography (US). Vascular endothelial growth factor (VEGF) is a potent angiogenetic factor and a marker for endothelial dysfunction. VEGF could contribute to the pathological events in BD. VEGF could also be an important factor in the progression of atherosclerosis. In this study, we investigated whether there is correlation between intima-media thickness (IMT) of the carotid arteries and serum VEGF levels in BD patients and healthy controls. Twenty-one patients with BD (male/female: 15/6, mean age: 35.8 +/- 8.6 years) were individually matched to control subjects on the basis of age (within 3 years) and sex. Carotid IMT of the subjects was measured by high-resolution B-mode US. Mean IMT values of common carotid arteries were 0.86 +/- 0.18 mm for patients with BD, and 0.57 +/- 0.14 mm for healthy controls (p < 0.001). Mean VEGF levels were 130.41 +/- 58.28 pg/ml for patients with BD and 82.69 +/- 25.03 pg/ml for healthy controls (p < 0.001). There was no correlation between VEGF levels in the control group and in the BD group, but there was a significant correlation between VEGF levels and mean carotid IMT in the whole group (r = 0.317, p < 0.05). In conclusion, elevation of VEGF appears as a feature of the inflammatory reaction during the course of BD, not a direct determinant of subclinical atherosclerosis. On the other hand, the significant correlation between carotid IMT and serum VEGF levels in the whole group suggests that association between VEGF levels and carotid IMT warrants further investigation with larger sample sizes.

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.

Insulin receptor substrate gene polymorphism is associated with obstructive sleep apnea syndrome in men.

OBJECTIVE: The objective of this study was to assess significance of insulin receptor substrate (IRS) -1 gene polymorphism (Gly972Arg) at codon 972 in obstructive sleep apnea syndrome (OSAS). METHODS: Using the polymerase chain reaction technique, the codon 972 polymorphism of the IRS-1 gene was analyzed in the DNA obtained from leukocytes of 50 patients and 143 healthy controls. RESULTS: An overall comparison between the genotypes and allele frequencies of the patients and controls did not reveal any statistically significant difference between the patients and controls (P > .05). Gender-specific comparisons were not significantly different except for a significant difference between the genotypes and allele frequencies of the male patients and male controls (P < .05). The heterozygous, Gly/Arg variant of the IRS-1 gene was overrepresented and the homozygous, Gly/Gly variant was less frequent in male patients compared with male controls. In the patients with OSAS, there was no correlation between the genotypes and polysomnography parameters on correlation analyses (P > .05). There was no relationship between the genotypes and diabetes mellitus (P > .05). Body mass indices and polysomnography parameters of the patients with and without diabetes mellitus were not significantly different (P > .05). CONCLUSION: The polymorphism of the IRS-1 gene at codon 972, especially Gly/Arg variant, or the presence of the allele for Arg appears to be associated with occurrence of OSAS in male patients, whereas this polymorphism is not related to severity of OSAS.

Effect of nasal continuous positive airway pressure in uncontrolled nocturnal asthmatic patients with obstructive sleep apnea syndrome.

The mechanisms of nocturnal asthma are intimately related to circadian rhythms, which influence inflammatory cells and mediators, hormone levels and cholinergic tone. Nocturnal airway narrowing in asthma is sometimes associated with sleep disorders, such as obstructive sleep apnea syndrome (OSAS). The aims of this study were to evaluate the association of nocturnal asthma and OSAS, and investigate the influence of continuous positive airway pressure (CPAP) therapy to improve nighttime symptoms in asthmatic patients with OSAS. Forty-three asthmatic patients who had nocturnal symptoms in spite of the optimal medical treatment according to the Global Initiative for Asthma guidelines and associated with snoring were studied. Pulmonary function tests (PFTs), asthma nighttime symptom scores, and polysomnography were performed on all patients. We treated the patients with an apnea-hypopnea index (AHI) 15 (moderate-severe OSAS) (n=16) with CPAP during 2 months. After 2 months, PFT, asthma nighttime symptom scores were reperformed. There was no significant difference in PFT values before and after CPAP treatment in OSAS patients. Asthma nighttime symptom scores were improved significantly (P<0.05) after CPAP treatment. In conclusion, in some patients with nocturnal asthma, OSAS may be responsible disease for nocturnal symptoms. In this condition, CPAP improves nocturnal symptoms without amelioration in PFT abnormalities.

Association of serotonin transporter gene polymorphism with obstructive sleep apnea syndrome.

BACKGROUND AND OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) is a common condition characterized by repetitive pharyngeal collapse during sleep and daytime sleepiness. There is genetic predisposition to sleep disorders. Serotonin is involved in the regulation of sleep. The synaptic 5-hydroxytryptamine (HT) is inactivated by presynaptic reuptake, which is mediated by the serotonin transporter. Blockage of the serotonin transporter leads to increased extracellular 5-HT. Polymorphism of the serotonin transporter gene (STG) leads to alterations in serotonin level and may be important in OSAS. In this study, we aimed to assess the role of STG polymorphism in OSAS. METHODS: Twenty-seven OSAS patients and 162 healthy volunteers were involved in the study. STG polymorphism was investigated using leukocytes obtained from peripheral blood. RESULTS: There was no difference between the genotypes and allele frequencies of the patients and controls regarding VNTR and HTTLPR polymorphisms (P > .05). The VNTR and HTTLPR variants and the frequencies of 12/12, 12/10, L, and S alleles were not significantly different between male and female control subjects (P > .05). The 12/12 and SS genotypes were over-represented in the female patients, whereas 12/10 and LL genotypes were over-represented in the male patients (P < .05). The genotypes 12 to 12 were over-represented in the male controls, whereas the genotypes 12 to 10 and L/S were over-represented in the male patients (P < .05). The alleles 10 and L were more frequent in the male patients than male controls (P < .05). The genotypes of female patients and female controls were not significantly different (P > .05). The allele 10 and L were less frequent in the female patients than female controls with Fisher's exact testing (P < .05). There was no relation between genotypes and clinical data of the patients (P > .05). CONCLUSION: STG polymorphism appears to be associated with the occurrence of OSAS, especially in male patients. Absence of association of between genetic variants and polysomnography findings may suggest that some mechanisms other than STG polymorphism are involved in OSAS pathophysiology. Our results need confirmation in a larger group of patients with OSAS.

[Central sleep apnea syndrome]. / Santral uyku apne sendromu.

Central sleep apnea syndrome (CSAS) is a disorder characterized by repeated apneic events during sleep with no associated ventilatory effort. CSAS is classified as either hypercapnic or non-hypercapnic. In the hypercapnic form of CSAS, increases in PaCO(2) generally result from reductions in ventilation or outright apneas due to an underlying depression of respiratory drive. Hypercapnic CSAS is common in central hypoventilation syndromes which may be primary (idiopathic) or secondary to other disorders that cause damage to the respiratory center. Non-hypercapnic CSAS is not associated with either a primary reduction in respiratory drive or respiratory muscle weakness. Non-hypercapnic CSAS can be a primary disorder or can occur secondary to high altitude, other medical illnesses such as congestive heart failure and central nervous system disease.

Consequences of hypoxia-reoxygenation phenomena in patients with obstructive sleep apnea syndrome.

BACKGROUND AND OBJECTIVES: Obstructive sleep apnea syndrome (OSAS) is a common disorder characterized by numerous episodes of absence of respiratory flow during sleep, which can be followed by a decrease in SaO2, which is rapidly normalized when ventilation resumes. We hypothesize that this hypoxia-reoxygenation phenomena may affect the generation of vascular endothelial growth factor (VEGF), erythropoietin (EPO), endothelin-1 (ENDO-1), and inducible nitric oxide synthase (iNOS). DESIGN AND SETTING: Prospective, patients referred to sleep disorders center. PATIENTS AND METHODS: The presence and severity of OSAS were determined using the standard overnight polysomnography. Diagnosis of OSAS was made when the apnea-hypopnea index (AHI) was ≥15, independent of the appearance of symptoms. Serum levels of VEGF, EPO, ENDO-1, and nitrite-nitrate were measured after overnight fasting in 69 patients with OSAS and in 17 healthy control subjects. Serum levels of VEGF and nitrite-nitrate were measured again after 12 weeks of treatment with continuous positive airway pressure (CPAP) in OSAS patients. RESULTS: Serum VEGF levels were found to be significantly higher and nitrite-nitrate levels were found to be significantly lower in OSAS patients than in controls (P=.003, .008, respectively), but no differences in EPO and ENDO-1 levels were found between the groups. We demonstrated that in OSAS patients, the serum VEGF levels were decreased and nitrate levels were increased after 12 weeks of CPAP treatment (P=.001, .002, respectively). CONCLUSION: According to our data, it is likely that hypoxia-reoxygenation phenomena affect the VEGF and nitrite-nitrate levels, which may be pathogenic factors in generating cardiovascular complications in OSAS.

Obstructive sleep apnea in ischemic stroke patients.

OBJECTIVE: To investigate the prevalence of obstructive sleep apnea in patients with ischemic stroke and to evaluate the effectiveness of nasal continuous positive airway pressure treatment. METHODS: Overnight polysomnography was performed by a computerized system in 19 subjects with ischemic stroke. Patients with an apnea-hypopnea index > or = 5 were considered to have obstructive sleep apnea. The appropriate level of continuous positive airway pressure for each patient was determined during an all-night continuous positive airway pressure determination study. Attended continuous positive airway pressure titration was performed with a continuous positive airway pressure auto-titrating device. RESULTS: Obstructive sleep apnea prevalence among patients with ischemic stroke was 73.7%. The minimum SaO(2) was significantly lower, and the percent of total sleep time in the wake stage and stage 1 sleep was significantly longer in patients with obstructive sleep apnea. In two patients with severe obstructive sleep apnea, we observed a decrease in the apnea-hypopnea index, an increase in mean wake time, mean SaO(2), and minimum SaO(2), and alterations in sleep structures with continuous positive airway pressure treatment. CONCLUSION: As the diagnosis and treatment of obstructive sleep apnea is of particular importance in secondary stroke prevention, we suggest that the clinical assessment of obstructive sleep apnea be part of the evaluation of stroke patients in rehabilitation units, and early treatment should be started.

Comparison of right ventricular functions by tissue Doppler imaging in patients with obstructive sleep apnea syndrome with or without hypertension.

OBJECTIVE: To evaluate the right ventricular function in patients with obstructive sleep apnea syndrome (OSAS) independent from systemic hypertension (HT) and to determine the association between OSAS severity and right ventricular dysfunction. METHODS: The study population included 77 consecutive subjects; 20 of these patients had OSAS, 20 of them had HT, but did not have OSAS, 16 patients, who constituted the study group, had both disorders, and 21 subjects without any of these two disorders represented the control group. Right ventricular function was assessed by echocardiography: standard two-dimensional, M-Mode, and conventional Doppler as well as tissue Doppler imaging. None of the patients had a previous history of cardiac disease. The diagnosis of OSAS was based on an apnea- hipopnea index of 5 or higher in polysomnography. RESULTS: Tricuspid inflow velocities and tissue Doppler derived tricuspid annular diastolic velocities were significantly different in the patient groups (OSAS, HT, OSAS + HT) compared to the control group. Tricuspid annular plane systolic excursion (TAPSE) (18.3 +/- 3.2, 18.4 +/- 2.5, 20.1 +/- 2.1, and 20.7 +/- 2.5 mm, respectively, P = 0.024) and peak systolic myocardial velocity at tricuspid lateral annulus (S-vel) (12.2 +/- 1.5, 10.9 +/- 0.9, 11.2 +/- 1.1, and 13.1 +/- 2.1 cm/s, respectively, P < 0.001) were significantly lower in patient groups compared to those of the study group. Tissue Doppler derived myocardial performance index (MPI) of the right ventricle was significantly impaired in the patient groups compared to the control group (0.34 +/- 0.06, 0.44 +/- 0.06, 0.45 +/- 0.07, and 0.41 +/- 0.06, respectively, P < 0.001). With regard to these right ventricular functional parameters, there was no significant difference between OSAS and the other patient groups (HT and OSAS + HT). There were significant correlations both between OSAS severity and the right ventricular functions, and between diastolic and systolic parameters of the right ventricle (r = -0.45, P < 0.05). CONCLUSION: Both right ventricular systolic and diastolic functions are impaired in patients having OSAS with or without HT. Right ventricular MPI was found to be the parameter most closely related with OSAS severity and the right ventricular subclinical dysfunction.

Elevated C-reactive protein levels and increased cardiovascular risk in patients with obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular morbidity and mortality. Inflammatory processes associated with OSAS may contribute to cardiovascular morbidity in these patients. C-reactive protein (CRP) is an important serum marker of inflammation. We tested the hypothesis that patients with OSAS have increased plasma CRP. After 173 male subjects underwent polysomnography, 94 were considered to have OSAS (apnea-hypopnea index (AHI) > 5), 38 cardiovascular disease (CVD), and 56 without CVD. Seventy-nine subjects were considered not to have OSAS (AHI < 5) and from among these 57 patients without CVD were enrolled as control subjects. Serum CRP levels were significantly elevated in the OSAS + CVD group compared to the two other groups (P < 0.05). When we evaluated the association between the serum CRP level and severity of OSAS, CRP levels were positively correlated with AHI in OSAS patients (r = 0.61, P < 0.001) OSAS, as a marker of inflammation and cardiovascular risk, is associated with elevated levels of CRP. According to these results, the link between cardiovascular morbidity and OSAS may be explained by the coexistence of other cardiovascular risk factors such as circulating CRP levels.

Relationship between sleep complaints and proinflammatory cytokines in haemodialysis patients.

BACKGROUND: Sleep complaints are common in end-stage renal disease. We aimed to investigate the relationship between sleep-related complaints and inflammatory cytokines in haemodialysis (HD) patients, and also the effects of HD on sleep patterns and cytokine levels. METHODS: Predialysis serum interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) levels in nine patients with sleep complaints were compared with those of nine patients without sleep complaints and nine healthy controls. Patients with sleep complaints underwent polysomnography the night after HD and the following night. RESULTS: Patients with sleep complaints had significantly higher predialysis IL-1beta levels compared with those without and healthy controls (P=0.004 and P=0.000, respectively). They also had higher predialysis IL-6 and TNF-alpha levels than those without sleep complaints; however, the difference was not significant. Patients without sleep complaints had higher mean IL-6 and TNF-alpha and similar mean IL-1beta levels compared with healthy controls (P=0.001, P=0.024, P=0.26, respectively). Obstructive sleep apnoea syndrome (OSAS) was found in six out of nine (66%) patients with sleep complaints. Sleep architecture and cytokine levels did not differ between the two nights. The mean serum IL-1beta, IL-6 and TNF-alpha levels did not differ in the pre- and post-polysomnographic samples. There was no correlation between IL-1beta, IL-6 or TNF-alpha levels and the apnoea-hypopnoea index. CONCLUSIONS: Proinflammatory cytokines, IL-1beta in particular, might be associated with sleep complaints in HD patients. OSAS is not uncommon in HD patients with sleep-related complaints and sleep architecture does not appear to be effected by the HD procedure itself.

Apnea-hypopnea indexes calculated using different hypopnea definitions and their relation to major symptoms.

A major problem in the discussion of sleep-disordered breathing is caused by the use of different criteria to define its terms. Hypopnea is a good example of this: there is no consensus about its definition yet. In our study, the diagnosis value of apnea-hypopnea indexes (AHIs) determined by different hypopnea definitions was evaluated. The 90 patients who had an AHI > 5, scored according to the hypopnea definition of the American Academy of Sleep Medicine (AASM), participated in our study. The records of these patients were scored three times more according to different hypopnea definitions (hypopnea-arousal, hypopnea-desaturation, hypopnea-effort). AHI (AASM), AHI (arousal), AHI (desat), and AHI (effort) were determined via new scorings. Patients' daytime sleepiness was evaluated by the Epworth Sleepiness Scale (> 10). When all of three major symptoms (snoring, observed apnea, and daytime sleepiness) were found in a patient's history, the term "clinical OSAS" was applied. The Epworth value correlated with all of the indexes. In the scope of both the determination of daytime sleepiness and the verification of "clinical OSAS" diagnosis, the value AHI (AASM) = 5 had the highest sensitivity (100%) and specificity (94%).

The relationship between serum cytokine levels with obesity and obstructive sleep apnea syndrome.

Inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) may have a direct effect on glucose and lipid metabolism. On the other hand, it is known that IL-6 and TNF-alpha are important pro-inflammatory cytokines in the pathogenesis of atherosclerosis. The goal of present study was to test whether sleep apnea contributes to the previously reported increases of IL-6 and TNF-alpha independent of obesity. Forty-three obese (body mass index, BMI>27 kg/m2) men with newly diagnosed obstructive sleep apnea syndrome (OSAS) (apnea-hypopnea index, AHI> or =5) and age- and BMI-matched 22 obese nonapneic male controls (AHI<5) were enrolled in this study. To confirm the diagnosis, all patients underwent standard polysomnography in the sleep disorders center. Serum samples were taken at 08:00 h in the morning after overnight fasting. Serum IL-6 and TNF-alpha levels were found significantly higher in OSAS patients than in controls (p=0.002, p=0.03). Serum IL-6 and TNF-alpha levels were significantly correlated with AHI in OSAS patients (r=0.03, p=0.046 and r=0.36, p=0.016). There was no significant correlation between serum IL-6, TNF-alpha levels and AHI in controls. Serum IL-6 and TNF-alpha levels were not correlated with BMI both in OSAS patients and controls. In conclusion, circulating IL-6 and TNF-alpha levels in patients with OSAS, as independent of BMI are significantly higher than levels in controls and there is a positive relationship between previously mentioned cytokines' levels and the severity of OSAS. According to these results, the link between cardiovascular morbidity and OSAS may be explained by the coexistence of other cardiovascular risk factors such as circulating IL-6 and TNF-alpha levels.

Obstructive sleep apnea in ischemic stroke patients

OBJECTIVE: To investigate the prevalence of obstructive sleep apnea in patients with ischemic stroke and to evaluate the effectiveness of nasal continuous positive airway pressure treatment. METHODS: Overnight polysomnography was performed by a computerized system in 19 subjects with ischemic stroke. Patients with an apnea-hypopnea index > 5 were considered to have obstructive sleep apnea. The appropriate level of continuous positive airway pressure for each patient was determined during an all-night continuous positive airway pressure determination study. Attended continuous positive airway pressure titration was performed with a continuous positive airway pressure auto-titrating device. RESULTS: Obstructive sleep apnea prevalence among patients with ischemic stroke was 73.7 percent. The minimum SaO2 was significantly lower, and the percent of total sleep time in the wake stage and stage 1 sleep was significantly longer in patients with obstructive sleep apnea. In two patients with severe obstructive sleep apnea, we observed a decrease in the apnea-hypopnea index, an increase in mean wake time, mean SaO2, and minimum SaO2, and alterations in sleep structures with continuous positive airway pressure treatment. CONCLUSION: As the diagnosis and treatment of obstructive sleep apnea is of particular importance in secondary stroke prevention, we suggest that the clinical assessment of obstructive sleep apnea be part of the evaluation of stroke patients in rehabilitation units, and early treatment should be started.