Increased Apnea-hypopnea Index Research Articles

Occurrence of sleep related breathing disorders in Egyptian patients with tachyarrhythmia without heart failure

Obstructive sleep apnea hypopnea syndrome (OSAHS) has been implicated in the pathogenesis of many cardiovascular diseases. Over the last decade, the association between OSAHS and cardiac rhythm disorders has garnered the attention of cardiologists and researchers from different clinical subspecialties. Aim of the workThe aim of the study was to assess the occurrence of OSAHS in Egyptian patients with tachyarrhythmia, and to describe characteristics of patients with concomitant OSAHS and tachyarrhythmia. MethodsWe enrolled 32 patients with tachyarrhythmia. In addition to standard examination, investigations and echocardiography to exclude possible causes for arrhythmia all patients underwent an over-night sleep study (level III) to diagnose OSAHS. Manual scoring was performed by two specialists according to criteria established by the American Academy of Sleep Medicine 2012. We considered AHI of 15/h as a cutoff point for diagnosing OSAHS. ResultsOf the 32 patients: seventeen had rapid atrial fibrillation (AF), eight had premature ventricular contractions, five had persistent sinus tachycardia and three had paroxysmal supraventricular tachycardia. OSAHS was present in 27 patients (84.4%), three patients of them had obesity hypoventilation also. Dividing OSAHS patients according to the disease severity showed that moderate OSAHS in 29.6% patients, and severe OSAHS in 70.4% patients. Studying characteristics of patients with OSAHS revealed that the mean±SD of neck circumference (NC) was 39.9±2.47cm, BMI was 36.3±9.17kg/m2, Waist/hip ratio was 0.91±0.08, Epworth Sleepiness Scale (ESS) was 10.85±4.5, Mallampati score (MS) was 2.11±0.84, clinical apnea score was 2.8±1.5, and STOP BANG score was 4.03±1.99. Apnea hypopnea index (AHI) was 49.3±33.2, oxygen desaturation index [3%] (ODI) was 39.9±31, mean O2 saturation was 93.6±8.84 and minimal O2 saturation was 7.9±14.49. Nocturnal bradytachyarrhythmia was found in most of patients, the minimal pulse rate during sleep ranges from 22 to 82/min while the maximal pulse rate ranges from 77 to 254/min. Both AHI and ODI were found to be significantly directly correlated with each of BMI, NC, waist/hip ratio, clinical apnea score, STOP BANG score, ESS, MS and mean pulse rate. Linear regression analysis of potential predictors of increased apnea hypopnea index revealed that triglyceride level is the highest predictor followed by NC then BMI. ConclusionsOSAHS is highly prevalent in patients with tachyarrhythmia. High triglyceride, NC and BMI are the most predictors of presence of OSAHS. AF is the most common form of the arrhythmia in patients with OSAHS. Clinical implicationsOSAHS should be considered as part of the workup of patients with tachyarrhythmia. Both clinical apnea score and STOP BANG are good screening questionnaire to choose patients who need sleep study.

Breathing and Snoring Sound Characteristics during Sleep in Adults.

Sound level meter is the gold standard approach for snoring evaluation. Using this approach, it was established that snoring intensity (in dB) is higher for men and is associated with increased apnea-hypopnea index (AHI). In this study, we performed a systematic analysis of breathing and snoring sound characteristics using an algorithm designed to detect and analyze breathing and snoring sounds. The effect of sex, sleep stages, and AHI on snoring characteristics was explored. We consecutively recruited 121 subjects referred for diagnosis of obstructive sleep apnea. A whole night audio signal was recorded using noncontact ambient microphone during polysomnography. A large number (> 290,000) of breathing and snoring (> 50 dB) events were analyzed. Breathing sound events were detected using a signal-processing algorithm that discriminates between breathing and nonbreathing (noise events) sounds. Snoring index (events/h, SI) was 23% higher for men (p = 0.04), and in both sexes SI gradually declined by 50% across sleep time (p < 0.01) independent of AHI. SI was higher in slow wave sleep (p < 0.03) compared to S2 and rapid eye movement sleep; men have higher SI in all sleep stages than women (p < 0.05). Snoring intensity was similar in both genders in all sleep stages and independent of AHI. For both sexes, no correlation was found between AHI and snoring intensity (r = 0.1, p = 0.291). This audio analysis approach enables systematic detection and analysis of breathing and snoring sounds from a full night recording. Snoring intensity is similar in both sexes and was not affected by AHI.

Effect of Yokukansan, a Traditional Herbal Prescription, on Sle ep Disturbances in Patients with Alzheimer's Disease

Objective: Evidence of the effects of Yokukansan (YKS), a traditional herbal medicine, on behavioral and psychological symptoms of dementia (BPSD) has accumulated. As well as BPSD, patients with Alzheimer’s disease (AD) demonstrate poorer sleep quality. Specific sleep disorders such as sleep-disordered breathing and periodic limb movement disorder (PLMD) can be prevalent in the elderly. PLMs are generally considered to produce sleep fragmentation by provoking arousals. This study aimed to examine whether YKS alters polysomnography variables in patients with AD. Methods: Seven patients (3 men and 4 women) with probable AD according to the standard criteria were investigated. Participants were treated with YKS for 4 weeks. The Neuropsychiatric Inventory for the assessment of BPSD, the Mini-Mental State Examination (MMSE) for cognitive function, polysomnography for evaluation of sleep structure and Pittsburgh Sleep Quality Index (PSQI) for subjective sleep quality, and Epworth Sleepiness Scale (ESS) were carried out at baseline and at the end of the treatment. The local institutional review boards approved this study. All patients gave written consent according to institutional guidelines and the tenets of the Declaration of Helsinki. Results: Treatment with YKS resulted in a decreased NPI score, a prolonged total sleep time, a shortened sleep latency, an increased sleep efficiency, and decreased periodic limb movement during sleep. YKS also improved subjective evaluations with PSQI and ESS. Conclusions: YKS was effective for BPSD and sleep disturbances in patients with AD. YKS did not induce daytime somnolence, extrapyramidal signs, or an increased apnea-hypopnea index.

Apnea–hypopnea and desaturations in heart failure with reduced ejection fraction: Are we aiming at the right target?

BackgroundSleep disordered breathing (SDB) is common in patients with heart failure with reduced ejection fraction (HFrEF). An increased apnea–hypopnea index (AHI) is associated with poor outcomes. We examined whether an analysis of nocturnal desaturations (NDs) can improve the risk stratification. MethodsThree-hundred seventy-six consecutive patients with stable chronic HFrEF and LVEF ≤45% were prospectively screened using polygraphy. Sleep apnea (SA) was defined as an AHI ≥15. The mean age was 59±13years, the mean LVEF was 30±6%, and the median AHI was 18 [IQR: 9.33). The composite end-point of death, heart transplantation or LV assistance occurred in 98 patients (26%) within 3years. Minimal oxygen saturation (MOS) during sleep, the number of desaturations <90%/h and the time spent with oxygen saturation <90% were significantly associated with adverse events (adjusted HR 1.25 [1.03–1.52], 1.25 [1.03–1.53], and 1.28 [1.04–1.59]), whereas the AHI was not (1.10 [0.86–1.39]). The best MOS cut-off value for poor outcomes was ≤88%. The patients with an MOS ≤88% had a significantly higher event rate (31.9%) than those with an MOS >88% (15.6%; p<0.01). The risk assessment using an MOS of ≤88% in addition to established prognostic markers yielded a net reclassification index (NRI) of nearly 6% and was particularly useful in the subgroup of patients with events (NRI: 8.4%). ConclusionsIn HFrEF patients, ND ≤88% appears to be predictive of adverse events, independent of the presence of SA. This suggests that the risk assessment in HFrEF should also include ND in top of AHI.

The sleep characteristics in symptomatic patients with Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) causes serious health consequences that include impairment of the respiratory system and sleep. The aim of our study is to investigate the sleep architecture and respiratory profile during sleep of symptomatic patients with DMD without ventilatory support. We evaluated polysomnography (PSG) of boys with DMD (n = 44) and a control group (n = 79) with sleep complaints that was matched in age but without neuromuscular disease. DMD patients presented sleep impairments when compared with the control group in terms of decreased sleep efficiency (72.4 ± 1.9 vs 80.3 ± 1.4%, P = 0.002) and increased apnea-hypopnea index (AHI) during nonrapid eye movement (NREM) sleep (1.6 ± 0.3 vs 0.3 ± 0.2/h, P = 0.003). The main changes were observed during rapid eye movement (REM) sleep: an increase in REM sleep latency (202.2 ± 11.8 vs 152.3 ± 8.6min, P < 0.001), a reduced percentage of REM sleep (13.1 ± 0.9 vs 17.9 ± 0.7%, P = 0.001), and exacerbation of AHI (8.7 ± 1.5 vs 1.0 ± 1.1 events/h, P = 0.001). There was an increase in the total number of apneas, especially obstructive apneas (6.8 ± 1.9 vs 0.8 ± 1.3, P = 0.013). The sleep and respiratory profile during sleep of patients with DMD are compromised. The results suggest that these changes reflect the muscle weakness inherent in DMD and are demonstrated mainly during REM sleep. Thus, the use of PSG is important to identify sleep-disordered breathing at an early stage, before deciding when to introduce noninvasive respiratory support for prevention of respiratory complications.

A systematic review of the association between obstructive sleep apnea and ventricular arrhythmias.

Obstructive sleep apnea (OSA) is an independent risk factor for sudden cardiac death. The aim of this review was to study the relationship between OSA and ventricular arrhythmias. PubMed, Medline, and Cochrane databases were searched with MESH headings to find studies linking OSA and ventricular arrhythmias including ventricular ectopy, ventricular tachycardia (VT), and ventricular fibrillation (VF). Studies were graded by a scoring system, and an attempt was made to pool data. There were no matched cohort or case control studies to study the association between OSA and ventricular arrhythmias. Given data heterogeneity, pooling and meta-analysis of data were not possible. An attempt was made to judge the quality of evidence and present a systematic review. Patients with OSA were noted to have higher odds of ventricular ectopy, and were at a higher risk for ventricular arrhythmias. Associations included higher QTc dispersion and HR variability. We did not, however, find any clear evidence for a direct correlation between increased apnea hypopnea index and increased VT or VF. Pooling and meta-analysis of studies linking OSA and ventricular arrhythmias were not possible due to heterogeneity of data. In a systemic review of studies, patients with OSA were noted to have higher odds of ventricular ectopy and arrhythmias. A single study showed that CPAP may help lower arrhythmogenicity; however, it was unclear if CPAP lowered the risk of VT. Further research should focus on studying the association of OSA and causes of sudden cardiac death, including ventricular arrhythmias.

Patients with Pediatric Obstructive Sleep Apnea Show Altered T‐Cell Populations with a Dominant TH17 Profile

To characterize the immunologic changes of the tonsil as they correlate with increasing apnea-hypopnea index (AHI) in children. Prospective immunologic analysis. Tertiary care pediatric otolaryngology practice. Tonsils were collected from 24 children with obstructive sleep apnea, all of whom had undergone polysomnography at an accredited sleep center using scoring determined by the American Academy of Sleep Medicine 2007 scoring manual. Patients were excluded if they had been diagnosed with craniofacial abnormalities, neuromuscular disorders, or immunodeficiency. Single-cell suspensions were isolated from tonsils of 13 individuals and stained with fluor-conjugated antibodies and analyzed using fluorescence-activated cell sorting. Single-cell suspensions from tonsils of 11 additional individuals were incubated 21 hours and subjected to multiplexed enzyme-linked immunosorbent assay cytokine analysis. In patients with an AHI >5 events/h, there was a statistically significant increase in the fraction of CD4(+) CD45RO(+) T cells (P < .01), and the percentage of CD8(+) FoxP3(+) T cells (TcREG) showed a statistically significant decrease (P < .005). Cytokine analysis revealed high levels of interleukin (IL)-17A, IL-1b, IL-10, and IL-12p70 production. Cytokine profiles revealed a conspicuous absence of IL-4 and IL-2. Our results indicate the tonsils of patients with obstructive sleep apnea have an ongoing inflammatory response characterized by increased effector CD4 T cells and decreased FoxP3 CD8 T cells. The TH17 skewing suggests that local immune activation may be either autoimmune or due to an extracellular pathogen.

Serotonin transporter polymorphism is associated with increased apnea-hypopnea index in older adults.

A functional polymorphism of the serotonin transporter gene (5-HTTLPR) has previously been related to upper airway pathology, but its contribution to obstructive sleep apnea (OSA), a highly prevalent sleep disorder in older adults, remains unclear. We aimed to investigate the relationship between apnea-hypopnea index (AHI) and genetic variations in the promoter region of the 5-HTTLPR in older adults. DNA samples from 94 community-dwelling older adults (57% female, mean age 72 ± 8) were genotyped for the 5-HTTLPR polymorphism. All participants were assessed in their homes with full ambulatory polysomnography in order to determine AHI and related parameters such as hypoxia, sleep fragmentation, and self-reported daytime sleepiness. The 5-HTT l allele was significantly associated with AHI (p = 0.019), with l allele carriers displaying a higher AHI than s allele homozygotes. A single allele change in 5-HTTLPR genotype from s to l resulted in an increase of AHI by 4.46 per hour of sleep (95% CI, 0.75-8.17). The l allele was also associated with increased time during sleep spent at oxygen saturation levels below 90% (p = 0.014). The observed significant association between the 5-HTTLPR l allele and severity of OSA in older adults suggests that the l allele may be important to consider when assessing for OSA in this age group. This association may also explain some of the observed variability among serotonergic pharmacological treatment studies for OSA, and 5-HTT genotype status may have to be taken into account in future therapeutic trials involving serotonergic agents.

Association of Obstructive Sleep Apnea With Risk of Serious Cardiovascular Events

The relationship between obstructive sleep apnea (OSA) and cardiovascular events remains unclear. We conducted a systematic review to determine the incident risk of cardiovascular events among patients with OSA. We searched MEDLINE and EMBASE in January 2011 for prospective studies that followed up patients with OSA for incident ischemic heart disease, stroke, and cardiovascular mortality. Outcomes data were pooled using random effects meta-analysis and heterogeneity assessed with the I(2) statistic. Regression analysis was performed to evaluate the effects of different gradations of OSA severity based on apnea-hypopnea index. We identified 9 relevant studies from 1731 citations. OSA was associated with incident stroke in a meta-analysis of 5 studies (8435 participants), odds ratio (OR) 2.24; 95% confidence interval (CI), 1.57-3.19; I(2)=7%. A significant association was seen in studies that were predominantly on men; OR, 2.87; 95% CI, 1.91-4.31, whereas data on women were sparse. In the overall analysis of 6 studies (8785 participants), OSA was nonsignificantly associated with ischemic heart disease (OR, 1.56; 95% CI, 0.83-2.91), with significant findings in the 5 studies that recruited mainly men (OR, 1.92; 95% CI, 1.06-3.48). Substantial heterogeneity was noted (I(2)=74%). OSA was linked to cardiovascular death in 2 studies involving 2446 participants (OR, 2.09; 95% CI, 1.20-3.65, I(2)=0%). Regression analysis showed greater likelihood of stroke or cardiovascular events with increasing apnea-hypopnea index values. OSA appears to be associated with stroke, but the relationship with ischemic heart disease and cardiovascular mortality needs further research.

Prevalence of Comorbid Obstructive Sleep Apnea and Metabolic Syndrome: Syndrome Z and Maxillofacial Surgery Implications

To determine the prevalence of the recently identified syndrome Z (SZ), which is the co-occurrence of obstructive sleep apnea (OSA; hypoxia, systemic and pulmonary hypertension, nocturnal arrhythmias) and metabolic syndrome (MetS; increased abdominal girth, hypertriglyceridemia, decreased high-density lipoprotein, hypertension, increased fasting glucose), which places the surgical patient at heightened risk of perioperative complications (myocardial infarction, stroke, pneumonia, wound infection). Electronic medical records of 296 male veterans were assessed for the presence of SZ using the American Academy of Sleep Medicine definition of OSA and a modified Adult Treatment Panel III definition of MetS, where obesity was defined by a body mass index of at least 30 kg/m(2) rather than by waist circumference. SZ was diagnosed in 59% of patients. These individuals commonly exhibited severe OSA and least commonly mild OSA. The more severe the OSA, the more likely (60%) that patients manifested moderate (4 risk markers) or severe (5 risk markers) MetS. Furthermore, with increasing apnea-hypopnea index values, the more severe were the MetS elements. The results of this study demonstrate the high prevalence rate of MetS in patients with OSA seeking treatment. Given the risk of perioperative complications, it is suggested that all patients scheduled for maxillofacial surgical procedures to treat OSA be evaluated for SZ.

Successful termination of recurrent ventricular arrhythmias by adaptive servo-ventilation in a patient with heart failure

A 60-year-old woman who underwent operation due to severe aortic stenosis with left ventricular dysfunction had frequent nonsustained ventricular tachycardia (NSVT) at night. She had an increased apnea-hypopnea index and a reduction in minimum O2 saturation during sleep, which was closely associated with the frequency of NSVT. Adaptive servo-ventilation (ASV) therapy improved sleep disorder breathing (SDB) and also reduced ventricular arrhythmias. These effects were associated with the attenuation of the sympathetic nerve activities by the analysis of heart rate variability. ASV is expected to be effective in the treatment of ventricular tachyarrhythmias in patients with heart failure and SDB.

The Nightmares of Sleep Apnea: Nightmare Frequency Declines with Increasing Apnea Hypopnea Index

To clarify the association of reported nightmare recall with polysomnographically defined obstructive sleep apnea (OSA) in a sleep laboratory population. This study included 393 individuals undergoing clinical polysomnography including a general intake questionnaire with questions on dream and nightmare recall frequency. Mean age was 50.5 and a range of 13 to 82 years, with 33% of the sample female and 67% male. Reported dream and nightmare recall were classified as infrequent when reported at less than once a month, or frequent when reported at a frequency greater than once per week. Mean Apnea-hypopnea Index AHI was 34.9 (std. 32.0) indicating a high frequency of severe (AHI > 30) OSA in this clinical study population. Both AHI and Apnea Index (AI) were significantly higher (p = 0.000) for the grouping reporting infrequent nightmare recall. As the AHI score increased, the percent of participants with frequent nightmare recall decreased linearly. Patients with higher AHI report a lower nightmare frequency, indicating that significant OSA suppresses the cognitive experience of nightmare recall. Depressed nightmare recall may occur secondary to the REMS suppression know to occur in patients with significant OSA.

Blood pressure increase detected by ambulatory monitoring correlates with hypoxemia reflecting sleep apnea severity

Abstract Ambulatory blood pressure monitoring and parallel polysomnographic study were performed in 116 adult males divided into 6 groups. Thirty blood-pressure (BP) and polysomnographic variables were measured to test their usefulness for screening for both arterial hypertension and sleep apnea-hypopnea syndrome (SAHS). The development of severe breathing disorders and hypoxemia during sleep was attributed to SAHS, when compared with measurements in healthy controls and in patients with arterial hypertension. Such disorders manifested as an increased apnea-hypopnea index, apnea index, duration of arterial oxygen saturation of less than 85%, and decrease of average arterial oxygen saturation that correlated with nocturnal average diastolic BP (p=0.0049, p=0.0027, p=0.049 and p=0.0457, respectively). These respiratory disorders resulted in various nocturnal, rather than diurnal, and diastolic and systolic BP variables. The acute antihypertensive effect of continuous positive airway pressure therapy for SAHS significantly reduced the episodes of apnea and hypopnea and the secondary component of hypertension caused by excessive sympathetic stimulation. For the SAHS-induced, dose-dependent component of hypertension that responded to continuous positive airway pressure, the following variables, in decreasing significance, were useful: nocturnal average systolic and diastolic BP and 24-hour average systolic and diastolic BP, as well as percent time elevation and mean blood pressure load. The monitoring of these variables could contribute to early diagnostic and prognostic stratification of complications and adequate therapy of the secondary component of hypertension caused by SAHS.

Impaired Pulmonary Diffusing Capacity and Hypoxia in Heart Failure Correlates With Central Sleep Apnea Severity*

Heart failure (HF) is often associated with interstitial pulmonary edema and structural changes, resulting in thickening of the alveolar-capillary membrane and reductions in diffusing capacity of the lung for carbon monoxide (Dlco). Reduced Dlco reflects an impaired efficiency of gas exchange, which may increase plant gain, influence ventilatory control stability, and result in central sleep apnea (CSA). In this study, we test the hypothesis that reductions in Dlco would be associated with increased apnea-hypopnea index (AHI) in patients with CSA. Overnight polysomnography, pulmonary function tests, and arterial blood gas analyses were performed in 45 patients with chronic, stable HF. Univariate and multivariate regression analyses were performed in those patients with predominant CSA to test which variables were associated with AHI. Patients had a mean (+/-SD) age of 52.7+/-8.9 years, a mean left ventricular ejection fraction of 26.5+/-9.9%, and a mean AHI of 22.0+/-17.4 events per hour. In CSA patients, Dlco and Pao2 both correlated with total AHI (r=-0.43, p=0.046 and r=-0.53, p=0.011, respectively) and with supine AHI (r=-0.56, p=0.009 and r=-0.60, p=0.004, respectively). In a forward stepwise estimation model, Dlco, Pao2, and body mass index were independent predictors of total AHI, explaining 51% of variability, as was supine AHI, explaining 64% of variability. Dlco and Pao2 accounted for 37% of the variability in total AHI and 49% of the variability in supine AHI. In patients with HF and CSA, reductions in Dlco and Pao2 are independently associated with respiratory disturbance during sleep. The increase in ventilatory instability may be due to plant gain effects.

Relationship between atherosclerosis and the sleep apnea syndrome: An intravascular ultrasound study

Background Sleep apnea hypopnea syndrome (SAHS) is a predictive factor of cardiovascular disease. We hypothesized that SAHS could influence coronary atherosclerosis plaque volume as assessed by 3-dimensional intravascular ultrasound (3D-IVUS). Methods Participating patients were identified from 2 studies assessing the progression of atherosclerosis in stable coronary artery disease using coronary 3D-IVUS. Results Nineteen patients, aged 61 ± 8 years, with a body mass index of 29 ± 5 kg/m 2 were studied. Increased apnea–hypopnea index (AHI) ≥ 15 was found in 12/19 patients (63%). Patients with AHI ≥ 15 had larger coronary atherosclerotic plaque volume than patients with AHI < 15 (238 ± 69 mm 3 vs 169 ± 64 mm 3, p = 0.047) and the difference was even larger in patients with obstructive apnea/hypopnea episodes compared to patients without (243 ± 70 mm 3 vs 170 ± 59 mm 3, p = 0.03). There was a significant positive correlation between obstructive AHI and coronary atherosclerotic plaque volume ( r = 0.6, p = 0.01). A significant positive correlation was also demonstrated between respiratory arousal index and coronary atherosclerotic plaque volume ( r = 0.6, p = 0.02) and between total arousal index and coronary atherosclerotic plaque volume ( r = 0.5, p = 0.03). Conclusion In patients with stable coronary artery disease, there was a significant relationship between the frequency of obstructive sleep apnea/hypopnea episodes and sleep fragmentation and the importance of coronary atherosclerotic plaque volume. 3D-IVUS is well suited to correlate coronary atherosclerosis and sleep breathing disorders at early stages.

Prevalence of Sleep Disordered Breathing in Congestive Heart Failure

Background: Sleep Disordered Breathing (SDB) is very common in patients with congestive heart failure (CHF), with some studies reporting an incidence of 50%. Increased sympathetic activity, caused by frequent arousals (increased Apnea-Hypopnea Index [AHI]) during the night has been implicated as a contributing factor in a four-fold increase in mortality for CHF patients. Many patients are undiagnosed for SDB due to lack of awareness of the disorder and access to an easy, reliable screening test. The purpose of this study is to evaluate the prevalence of SDB in patients with CHF in the inpatient and outpatient settings using the ApneaLink (AL) (ResMed Corp, San Diego, CA) screening device. Methods: We have enrolled 34 patients with CHF from the VA San Diego Healthcare System. Eligible patients are those with diagnosis of CHF, treatment naïve for SDB, and symptomatic for obstructive sleep apnea (OSA) per SDB questionnaire. The mean age was 65 years, and the mean BMI was 32 kg/m2. SDB was defined using an AHI result of ≥ 5 events/hour. The prevalence of OSA was derived from the single page synopsis report generated by the AL device. Determination for the presence of Cheyne-Stokes respiration (CSR) was performed by evaluation of the flow signal data. Results: The overall prevalence of OSA in this population is 68% (23/34 subjects). CSR was detected in 35% (12/34 subjects). For the 27 subjects that have completed the study in the outpatient setting, the prevalence of OSA and CSR are 74% and 30%, respectively. In the inpatient setting, 7 patients with an admission diagnosis of CHF have completed the study with a prevalence of 43% and 57% for OSA and CSR, respectively. The mean AHI was 20 ± 20.3 events/hour. The prevalence of SDB for various age groups and BMI was not statistically significant. Conclusions: SDB appears to be relatively common in the CHF population, regardless of age or BMI. Preliminary results provide supportive evidence for the clinical need to identify, diagnose and treat the CHF patient with SDB. The AL is a relatively simple test to administer to patients and easy to use by patients in the home setting. A larger sample size of hospital patients using the device is required to evaluate utility in the inpatient setting.

Determinants of the apnea index in a sleep center population

We hypothesized that the increased apnea-hypopnea index (AHI) in men compared to women was secondary to an increased proportion of apneas in men as measured by the ratio of the apnea index to the apnea-hypopnea index (AI/AHI ratio), and that the influence of gender was independent of other demographic factors such as body mass index (BMI) and neck circumference (NC). Database analysis of 501 patients (218 men and 283 women) who underwent polysomnography between August 2001 and June 2003 and who were found to have an AHI of at least five events per hour was performed. Respiratory parameters were compared between genders. To correct for differences in demographic parameters, correlations were made between AHI and the AI/AHI ratio and age, BMI, NC, and the percentage time spent in the supine position (%TST-supine) followed by a regression analysis to determine which factors independently predicted these parameters. AHI [women, 26.8 (interquartile range 13.9, 57.0) events per hour vs men, 58.9 (interquartile range 27.7, 105.7) events per hour, p<0.001] and AI/AHI ratio [women, 0.58 (0.36, 0.80) vs men, 0.80 (0.51, 0.95), p<0.001) were higher in men compared to women. The independent predictors of the AHI were male gender, BMI, NC, and the %TST-supine. Independent predictors of the AI/AHI ratio were male gender, BMI, NC, and the percentage of time spent in the supine position. The increased AHI in men is secondary to an increased proportion of apneas in men compared to women and is independent of other potential determinants such as age, BMI, and NC.

Decrease in sE-selectin after pituitary surgery in patients with acromegaly.

Adhesion of circulating leukocytes to endothelial cells is one of the initial events in the development of atherosclerosis (1). This process is mediated by cellular adhesion molecules such as sE-selectin, a specific product of endothelial cells. Circulating concentrations of soluble cell adhesion molecules may serve as surrogate markers for endothelial damage and early atherosclerosis (2)(3)(4). Increased serum concentrations of sE-selectin have been described in patients with insulin resistance (5)(6), diabetes mellitus (2)(7), hypertension(8), and sleep apnea syndrome (SAS) (9). In patients with acromegaly, impaired glucose tolerance, arterial hypertension, and SAS are frequent findings, and macrovascular disease is a common complication (10). The aim of this study was to measure sE-selectin in patients with acromegaly before and after pituitary surgery and to analyze whether sE-selectin concentrations are related to disease activity, insulin resistance, hypertension, or SAS in this particular group of patients. All consecutive patients with newly diagnosed acromegaly who had been referred to the Division of Endocrinology and Diabetes at the University Hospital in Zurich between November 1999 and December 2002 were included. Serum sE-selectin concentrations were measured at diagnosis of acromegaly and 2–4 months after pituitary surgery. The Ethics Committee of the University Hospital of Zurich was contacted and decided that formal approval to measure sE-selectin was not necessary. Oral informed consent to determine additional laboratory values was obtained from all patients. A diagnosis of SAS was established by the simultaneous presence of two criteria: subjective hypersomnolence, defined as >10 points on the Epworth sleepiness scale, and an increased apnea–hypopnea index, defined as more than five apnea or hypopnea episodes per hour of sleep during an overnight sleep …

Population-Based Study of Sleep-Disordered Breathing as a Risk Factor for Hypertension

Clinical observations have linked sleep-disordered breathing, a condition of repeated apneas and hypopneas during sleep, with hypertension but evidence for an independent association has been lacking. Understanding this relationship is important because the prevalence of sleep-disordered breathing is high in adults. To test the hypothesis that sleep-disordered breathing is related to elevated blood pressure independent of confounding factors. The sample included 1060 employed women and men aged 30 through 60 years who had completed an overnight protocol as part of the Wisconsin Sleep Cohort Study. In-laboratory polysomnography was used to determine sleep-disordered breathing status, quantified as the number of apneas and hypopneas per hour of sleep (apnea-hypopnea index). Blood pressure was measured on the night polysomnography was performed. Blood pressure increased linearly with increasing apnea-hypopnea index (P = .003 for systolic, P = .01 for diastolic, adjusted for confounding factors). The magnitude of the linear association increased with decreasing obesity. At a body mass index (weight in kilograms divided by the square of the height in meters) of 30 kg/m2, an apnea-hypopnea index of 15 (vs 0) was associated with blood pressure increases of 3.6 mm Hg for systolic (95% confidence interval, 1.3-6.0) and 1.8 mm Hg for diastolic (95% confidence interval, 0.3-3.3). The odds ratio for hypertension associated with an apnea-hypopnea index of 15 (vs 0) was 1.8 (95% confidence interval, 1.3-2.4). There is a dose-response relationship between sleep-disordered breathing and blood pressure, independent of known confounding factors. If causal, the high prevalence of sleep-disordered breathing could account for hypertension in a substantial number of adults in the United States.