Severity Of Sleep-disordered Breathing Research Articles

The Influence of Sleep Disordered Breathing on Weight Loss in a National Weight Management Program.

To investigate the influence of sleep disordered breathing (SDB) on weight loss in overweight/obese veterans enrolled in MOVE!, a nationally implemented behavioral weight management program delivered by the National Veterans Health Administration health system. This observational study evaluated weight loss by SDB status in overweight/obese veterans enrolled in MOVE! from May 2008-February 2012 who had at least two MOVE! visits, baseline weight, and at least one follow-up weight (n = 84,770). SDB was defined by International Classification of Diseases, Ninth Revision, Clinical Modification codes. Primary outcome was weight change (lb) from MOVE! enrollment to 6- and 12-mo assessments. Weight change over time was modeled with repeated-measures analyses. SDB was diagnosed in one-third of the cohort (n = 28,269). At baseline, veterans with SDB weighed 29 [48] lb more than those without SDB (P < 0.001). On average, veterans attended eight MOVE! visits. Weight loss patterns over time were statistically different between veterans with and without SDB (P < 0.001); veterans with SDB lost less weight (-2.5 [0.1] lb) compared to those without SDB (-3.3 [0.1] lb; P = 0.001) at 6 months. At 12 mo, veterans with SDB continued to lose weight whereas veterans without SDB started to re-gain weight. Veterans with sleep disordered breathing (SDB) had significantly less weight loss over time than veterans without SDB. SDB should be considered in the development and implementation of weight loss programs due to its high prevalence and negative effect on health.

Sleep-disordered Breathing and the Menopausal Transition Among Participants in the Sleep in Midlife Women Study

ABSTRACT Objective Menopause is widely believed to be an established cause of sleep disorders, but evidence for this theory is inconclusive. Attributing any sleep problem to normal processes of menopause may lead to underdiagnosis of treatable sleep disorders in midlife women. This study uses detailed longitudinal data on sleep and menopausal health from participants in the Sleep in Midlife Women Study to investigate whether risk and severity of sleep-disordered breathing increase with progression through menopause, accounting for changes in age and body habitus. Methods A total of 219 women aged 38 to 62 years were recruited from participants in the Wisconsin Sleep Cohort Study. Menopause status was determined from daily diaries in which participants reported menstrual flow, hot flashes, and use of hormonal medications. Each participant underwent in-home polysomnography studies every 6 months, to measure the apneahypopnea index (AHI) (N = 1,667 studies). Linear models with empirical standard errors were fit for logarithm of AHI on menopause status and years in menopause, adjusting for age, body mass index, waist girth, and neck girth. Results Compared with women in premenopause, AHI was 21% higher among participants in perimenopause (95% CI, −4 to 54), 31% higher among participants in postmenopause (95% CI, 2-68), and 41% higher among participants whose menopausal stage could not be distinguished between peri- and postmenopause (95% CI, 8-82). Among women who had begun perimenopause, each additional year in menopause was associated with 4% greater AHI (95% CI, 2-6). Conclusions Progression through menopause is associated with greater sleep-disordered breathing severity. This association is independent of aging and changes in body habitus.

Immediate postarousal sleep dynamics: an important determinant of sleep stability in obstructive sleep apnea.

Arousability from sleep is increasingly recognized as an important determinant of the clinical spectrum of sleep disordered breathing (SDB). Patients with SDB display a wide range of arousability. The reason for these differences is not known. We hypothesized that differences in the speed with which sleep deepens following arousals/awakenings (postarousal sleep dynamics) is a major determinant of these differences in arousability in patients with SDB. We analyzed 40 preexisting clinical polysomnography records from patients with a range of SDB severity (apnea-hypopnea index 5-135/h). Sleep depth was determined every 3 s using the odds ratio product (ORP) method, a continuous index of sleep depth (0 = deep sleep, 2.5 = full wakefulness) that correlates strongly (r = 0.98) with arousability (Younes M, Ostrowski M, Soiferman M, Younes H, Younes M, Raneri J, and Hanly P. Sleep 38: 641-654, 2015). Time course of ORP was determined from end of arousal until the next arousal. All arousals were analyzed (142 ± 65/polysomnogram). ORP increased from 0.58 ± 0.32 during sleep to 1.67 ± 0.35 during arousals. ORP immediately (first 9 s) following arousals/awakenings (ORP-9) ranged from 0.21(very deep sleep) to 1.71 (highly arousable state) in different patients. In patients with high ORP-9, sleep deepened slowly (over minutes) beyond 9 s but only if no arousals/awakenings recurred. ORP-9 correlated strongly with average non-rapid eye movement sleep depth (r = 0.87, P < 2E-13), the arousal/awakening index (r = 0.68, P < 5E-6), and with the apnea-hypopnea index (r = 0.60, P < 0.001). ORP-9 was consistent within each patient and did not change on continuous positive airway pressure despite marked improvement in sleep architecture. We conclude that postarousal sleep dynamics are highly variable among patients with sleep-disordered breathing and largely determine average sleep depth and continuity.

The efficacy of the OSA-18 as a waiting list triage tool for OSA in children.

Sleep disordered breathing (SDB) is common in children, resulting in extensive waiting lists for specialist clinics. There is an urgent need for a valid method of triaging patients and the OSA-18, a disease-specific tool, is an attractive candidate for this role. We aimed to examine the OSA-18 as a measurement tool in detail and to determine whether the score or aspects of it could be used as a screening tool for SDB in children. Retrospective analysis of 582 children (6months to 16.4years)-216 underwent overnight PSG and 366 overnight oximetry. Confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) were conducted. Receiver operating characteristic curve analysis assessed the diagnostic accuracy of the factors for the presence of OSA. Rasch analysis was used to assess the structure of the items (1-18) and categories of response (Likert scale). The CFA with a forced five-factor structure, revealed three factors with Eigenvalues >1, and explained 73.7% of the variance. EFA resulted in a two-factor structure, explaining 60.3% of the variance. Assessment of sensitivity and specificity showed a high false-positive rate, irrespective of the factor structure tested. Rasch analysis showed poor discrimination between adjacent categories on the Likert scale. This study confirmed that the predictive value of the OSA-18 for SDB severity is weak. Some questions perform better than others statistically, and the seven categories of response introduce significant statistical noise, raising the possibility that modification of the OSA-18 may improve its performance in the prediction of OSA severity.

Hippocampus volume and subjective sleepiness in older people with sleep-disordered breathing: a preliminary report.

Sleep-disordered breathing (SDB) is associated with excessive daytime sleepiness (EDS) and explained by sleep fragmentation and hypoxaemia, both contributing to brain morphology abnormalities. Recent data on middle-aged SDB patients suggest a link between hippocampus volume (HV) and EDS. We tested this hypothesis in a group of SDB older subjects. A total of 232 healthy participants aged 75 ± 0.9 years were examined. Subjective EDS was assessed by the Epworth Sleep Questionnaire (ESS), with a mean score of 5.6 ± 3.5. Volumetric segmentation of the right (RHV) and left HV (LHV) were measured using FreeSurfer software. All subjects underwent extensive cognitive testing to exclude neurological disease, as well as ambulatory polygraphy to assess SDB status. Sleepy subjects showed a lower HV. In a correlation analysis, RHV (r = -0.162, P = 0.01) and LHV (r = -170, P = 0.05) were correlated negatively with ESS and not associated with respiratory data. Multiple regression analysis did not reveal any effect of age, gender, SDB severity and hypoxia. ESS was the only factor possibly explaining the lower RHV (P = -0.03) and LHV (P = -0.04). In older people with SDB, the subjective EDS was associated with lower HV. This morphological finding should be considered on the pathogenesis of sleepiness in SDB patients. NCT 00759304 and NCT 00766584.

Sleep disordered breathing in pregnancy.

Key pointsSleep disordered breathing (SDB) is common and the severity increases as pregnancy progresses.Frequent snoring, older age and high pre-pregnancy body mass index (>25 kg⋅m−2) could be reliable indicators for SDB in early pregnancy.SDB screening tools, including questionnaires, used in the nonpregnant population have poor predictive ability in pregnancy.Accumulating evidence suggests that SDB during pregnancy may be associated with increased risk of adverse pregnancy outcomes, including gestational diabetes and pre-eclampsia. However, the results should be interpreted cautiously because several studies failed to adjust for potential maternal confounders and have other study limitations.There are no pregnancy-specific practice guidelines for SDB treatment. Many clinicians and practices follow recommendations for the treatment in the general population. Women with pre-existing SDB might need to be reassessed, particularly after the sixth month of pregnancy, because symptoms can worsen with nasal congestion and weight gain.Educational aimsTo highlight the prevalence and severity of sleep disordered breathing (SDB) in the pregnant population.To inform readers about risk factors for SDB in pregnancy.To explore the impact of SDB on adverse maternal and fetal outcomes, and biological pathways for associated adverse maternal and fetal outcomes.To introduce current management options for SDB in pregnancy, including medical and behavioural approaches.Sleep disordered breathing (SDB) is very common during pregnancy, and is most likely explained by hormonal, physiological and physical changes. Maternal obesity, one of the major risk factors for SDB, together with physiological changes in pregnancy may predispose women to develop SDB. SDB has been associated with poor maternal and fetal outcomes. Thus, early identification, diagnosis and treatment of SDB are important in pregnancy. This article reviews the pregnancy-related changes affecting the severity of SDB, the epidemiology and the risk factors of SDB in pregnancy, the association of SDB with adverse pregnancy outcomes, and screening and management options specific for this population.

The association between sleep-disordered breathing and aortic stiffness in a community cohort

ObjectiveSleep-disordered breathing is associated with hypertension and cardiovascular disease. Increased aortic stiffness is one possible linking mechanism. We evaluated the association between sleep-disordered breathing and aortic stiffness in a community-based sample. MethodsOur community-based cross-sectional observational study included 381 participants from the Framingham Heart Study (55% women, mean age 58.0 S.D. = 9.4 years, 51% ethnic minorities). Polysomnographically derived apnea–hypopnea index and CT90% (cumulative % sleep time with oxyhemoglobin saturation <90%) quantified sleep-disordered breathing severity. Carotid-femoral pulse wave velocity, the gold-standard measure of aortic stiffness, was calculated using arterial applanation tonometry-derived waveforms and body surface measured transit distance. We assessed associations between sleep-disordered breathing and carotid-femoral pulse wave velocity using multivariable regression. We adjusted for age, sex, race, body mass index, diabetes, alcohol consumption, hormone replacement therapy, cholesterol/high-density lipoprotein, lipid-lowering therapy, anti-hypertensive medication, smoking, hypertension, and prevalent cardiovascular disease. ResultsAfter multivariable adjustment, carotid-femoral pulse wave velocity was associated with both apnea–hypopnea index (β = 0.03, 95% CI: 0.002–0.07, p = 0.04) and CT90% (β = 0.05, 95% CI: 0.005–0.1, p = 0.03). The adjusted mean carotid-femoral pulse wave velocity was 9.43 (95% CI: 9.12–9.74), 9.76 (95% CI: 9.25–10.26), and 10.15 (95% CI: 9.37–10.92) m/s, respectively, in subjects with apnea–hypopnea index <5, 5–14.9, and ≥15 events/h. ConclusionsIn a community-based sample of middle aged and older men and women, sleep-disordered breathing was associated with increased carotid-femoral pulse wave velocity, a strong predictor of cardiovascular risk.

Abstract 18672: Association Between Sleep Disordered Breathing and Electrocardiographic Markers of Atrial Abnormalities: The MESA Study

Introduction: Abnormal P wave terminal force in V1 (PTFV1), an electrocardiographic marker of left atrial abnormalities, has been linked to increased risk of atrial fibrillation (AF). Examining the association between sleep disordered breathing (SDB) and PTFV1 might shed light on the potential mechanisms by which SDB increases risk of AF. Methods: A total of 1546 participants (mean age 67.2 (± 8.8) years, 53.4 % women and 63.3 % non-Whites) from the Multi-Ethnic Study of Atherosclerosis (MESA) Exam 5 Sleep ancillary were included in this analysis. PTFV1 was measured from resting standard digital ECG tracings that were automatically processed centrally. Linear and logistic regression analyses were used to examine the cross-sectional associations between measures of SDB (apnea hypopnea index [AHI], obstructive AHI [OAHI] and % time spent with oxygen saturation &lt;90% [% SpO2 90]) and PTFV1. Results: There was a trend of higher PFTV1 values across quartiles of AHI, OAHI and % SpO2 90 (p for trend &lt;0.01 for each). In multivariable linear regression models, the upper quartile of AHI and OAHI measures were associated with higher values of PTFV1 compared with the lower quartile (Table). A 1-SD increase of AHI and OAHI were associated with increased levels of PTFV1 (Table). When PTFV1 was considered as a binary variable (using the cut point of 4000 μV.ms to define abnormality) in logistic regression analysis, AHI and OAHI were also associated with abnormal PTFV1. Conclusion: Severity of SDB, as measured by AHI is associated with subclinical left atrial disease, as measured by PTFV1. This could partially explain the reported association between SDB and AF.

Obstructive sleep disordered breathing in 2- to 18-year-old children: diagnosis and management.

This document summarises the conclusions of a European Respiratory Society Task Force on the diagnosis and management of obstructive sleep disordered breathing (SDB) in childhood and refers to children aged 2-18 years. Prospective cohort studies describing the natural history of SDB or randomised, double-blind, placebo-controlled trials regarding its management are scarce. Selected evidence (362 articles) can be consolidated into seven management steps. SDB is suspected when symptoms or abnormalities related to upper airway obstruction are present (step 1). Central nervous or cardiovascular system morbidity, growth failure or enuresis and predictors of SDB persistence in the long-term are recognised (steps 2 and 3), and SDB severity is determined objectively preferably using polysomnography (step 4). Children with an apnoea-hypopnoea index (AHI) >5 episodes·h(-1), those with an AHI of 1-5 episodes·h(-1) and the presence of morbidity or factors predicting SDB persistence, and children with complex conditions (e.g. Down syndrome and Prader-Willi syndrome) all appear to benefit from treatment (step 5). Treatment interventions are usually implemented in a stepwise fashion addressing all abnormalities that predispose to SDB (step 6) with re-evaluation after each intervention to detect residual disease and to determine the need for additional treatment (step 7).

It's not just obstructive sleep apnea

A 61-year-old man with a diagnosis of blastic plasmacytoid dendritic cell neoplasm of the skin presented to our institution for induction chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone. His wife reported snoring for many years, with suddenworsening in the past threemonths and associatedwith witnessed apneas in the past month. Sleep medicine service was consulted because of an abnormal overnight oximetry study that showed severe oscillatory desaturations suggesting severe sleep-disordered breathing (Fig. 1). Physical examination was unremarkable. There was no significant weight change in the preceding year. His medications remained unchanged. As the signs and symptoms were very suspicious for an otorhinolaryngology process, the patient underwent a computerized tomography (CT) scan (Fig. 2A) and positron emission tomography (PET) scan with 2-deoxy-2[fluorine-18]fluoroD-glucose integrated with CT (18F-FDG PET/CT) of the head and neck (Fig. 2B). The scans demonstrated multiple lymph nodes and enlarged palatine tonsils withmarked upper airway narrowing thought to be secondary to metastasis from his blastic plasmacytoid dendritic cell neoplasm of the skin. He was treated with continuous positive airway pressure (CPAP), and a repeat overnight oximetry showed resolution of his sleep-disordered breathing (Fig. 3). The patient will return to have further workup for his sleepdisordered breathing after completing his chemotherapy treatment. 2. Image analysis

Association between Glucose Metabolism and Sleep-disordered Breathing during REM Sleep

Sleep-disordered breathing (SDB) has been associated with impaired glucose metabolism. It is possible that the association between SDB and glucose metabolism is distinct for non-REM versus REM sleep because of differences in sleep-state-dependent sympathetic activation and/or degree of hypoxemia. To characterize the association between REM-related SDB, glucose intolerance, and insulin resistance in a community-based sample. A cross-sectional analysis that included 3,310 participants from the Sleep Heart Health Study was undertaken (53% female; mean age, 66.1 yr). Full montage home-polysomnography and fasting glucose were available on all participants. SDB severity during REM and non-REM sleep was quantified using the apnea-hypopnea index in REM (AHIREM) and non-REM sleep (AHINREM), respectively. Fasting and 2-hour post-challenge glucose levels were assessed during a glucose tolerance test (n = 2,264). The homeostatic model assessment index for insulin resistance (HOMA-IR) was calculated (n = 1,543). Linear regression was used to assess the associations of AHIREM and AHINREM with fasting and post-prandial glucose levels and HOMA-IR. AHIREM and AHINREM were associated with fasting glycemia, post-prandial glucose levels, and HOMA-IR in models that adjusted for age, sex, race, and site. However, with additional adjustment for body mass index, waist circumference, and sleep duration, AHIREM was only associated with HOMA-IR (β = 0.04; 95% CI, 0.1-0.07; P = 0.01), whereas AHINREM was only associated with fasting (β = 0.93; 95% CI, 0.14-1.72; P = 0.02) and post-prandial glucose levels (β = 3.0; 95% CI, 0.5-5.5; P = 0.02). AHIREM is associated with insulin resistance but not with fasting glycemia or glucose intolerance.

Diagnosis of Pediatric Obstructive Sleep Apnea Syndrome in Settings With Limited Resources.

Although polysomnographic (PSG) testing is the gold standard for the diagnosis of obstructive sleep apnea syndrome (OSAS) in children, the number of pediatric sleep laboratories is limited. Developing new screening methods for identifying OSAS may reduce the need for PSG testing. To evaluate the combined use of the sleep clinical record (SCR) and nocturnal oximetry testing for predicting PSG results in children with clinically suspected OSAS. Prospective study over 10 months. A cohort of 268 consecutive children (mean [SD], age 6 [3] years) referred for clinically suspected OSAS was studied at a pediatric sleep center at a university hospital. Children with disorders other than adenotonsillar hypertrophy or obesity were excluded. Mild OSAS (obstructive apnea-hypopnea index [AHI], 1-5 episodes/h) and moderate-to-severe OSAS (AHI, >5 episodes/h) were the main outcome measures. Sleep clinical record scores greater than or equal to6.5 were considered positive, as were McGill oximetry scores (MOS) greater than 1, and these positive scores were the main explanatory variables in our study. Each participant was evaluated by the SCR, followed by pulse oximetry test the first night and PSG test in the sleep laboratory the second night. Of the total participants, 236 (88.1%) were diagnosed with OSAS, 236 (88.1%) had a positive SCR score, and 50 (18.7%) had a positive MOS. Participants with positive SCR scores had significantly increased risk of an AHI greater than or equal to 1 (adjusted odds ratio [AOR], 9.3; 95% CI, 3.7-23.2; P < .001). Children with an MOS greater than 1 were significantly more likely to have an AHI greater than 5 episodes/h than children with an MOS equal to 1 (AOR, 26.5; 95% CI, 7.8-89.2; P < .001). A positive SCR score had satisfactory sensitivity (91.9%) and positive predictive value (91.9%) but limited specificity (40.6%) and negative predictive value (40.6%) for OSAS. An MOS greater than 1 had excellent specificity (97.4%) and positive predictive value (94%) but low sensitivity (39.2%) and fair negative predictive value (60.8%) for moderate-to-severe OSAS among children with a positive SCR score. The combination of SCR scores and MOS correctly predicted primary snoring, mild OSAS, or moderate-to-severe OSAS in 154 of 268 (57.4%) participants. The combined use of the SCR score and nocturnal oximetry results has moderate success in predicting sleep-disordered breathing severity when PSG testing is not an option.

Relationship between sleep-disordered breathing and metabolic syndrome after adjustment with cardiovascular risk factors

AimsIt is important to identify the risk factors for metabolic syndrome (MetS) in order to prevent the development of cardio-/cerebrovascular diseases. The authors estimated the risk factors for the development of MetS with special emphasis on the severity of sleep-disordered breathing (SDB). MethodsWe conducted as a cross-sectional study in subjects undergoing intensive health examination (581 men aged 33–84 years). Diagnosis of MetS was based on the criteria of the National Cholesterol Education Program Expert Panel. ResultsThe prevalence of MetS in subjects with severe SDB, which was defined as an apnea–hypopnea index (AHI) of 30 or higher, was 40.7%, which was significantly higher than that in the subjects without severe SDB (29.3%). The odds ratio (OR) (95% confidence interval [CI]) of the logarithmic-transformed AHI for MetS was 1.6 (1.1–2.4) after adjustments for age, serum uric acid, logarithmic-transformed serum C-reactive protein, smoking history, exercise history and alcohol history. When the subjects were categorized by the severity of SDB, the OR (95% CI) of severe SDB, which was the only category that showed significant association, was 2.2 (1.2–4.0). ConclusionA significant association was observed between severe SDB and the presence of MetS in the subjects (all male) of this study.

Long-Term Improvements in Sleep and Respiratory Parameters in Preschool Children Following Treatment of Sleep Disordered Breathing.

Sleep disordered breathing (SDB) in preschool-aged children is common, but long-term outcomes have not been investigated. We aimed to compare sleep and respiratory parameters in preschool children to examine the effects of treatment or non-treatment after 3 years. Children (3-5 years) diagnosed with SDB (n = 45) and non-snoring controls (n = 30) returned for repeat overnight polysomnography (39% of original cohort), 3 years following baseline polysomnography. Children with SDB were grouped according to whether they had received treatment or not. SDB resolution was defined as an obstructive apnea hypopnea index (OAHI) ≤ 1 event/h, no snoring detected on polysomnography and habitual snoring not indicated by parents on questionnaire. Fifty-one percent (n = 23) of the children with SDB were treated. Overall, SDB resolved in 49% (n = 22), either spontaneously (n = 8) or with treatment (n = 14). SDB remained unresolved in 39% (n = 9) of those treated and 64% (n = 14) of the children who were untreated. Two of the non-snoring controls developed SDB at follow-up. The treated group had significantly lower OAHI (p < 0.01), respiratory disturbance index (p < 0.001), total arousal and respiratory arousal indices (p < 0.01 for both) at follow-up compared with baseline. There were no differences between studies for the untreated group. Although treatment resulted in an improvement in indices related to SDB severity, 39% had SDB 3 years following diagnosis. These findings highlight that parents should be made aware of the possibility that SDB may persist or recur several years after treatment. This is relevant regardless of the severity of SDB at baseline and the treatment given.

Longitudinal Impact of Resolution of Snoring in Young Children on Psychosocial Functioning

To determine whether sustained resolution of sleep disordered breathing (SDB) in young children, either because of treatment or spontaneous recovery, predicted long-term improvements in quality of life, family functioning, and parental stress. Children diagnosed with primary snoring (n = 16), mild obstructive sleep apnea (OSA, n = 11), moderate-severe (MS) OSA (n = 8), and healthy nonsnoring controls (n = 25) at ages 3-5 years underwent repeat polysomnography at 6-8 years. Parents completed quality of life and parental stress questionnaires at both time points. Resolution of SDB was determined as obstructive apnea hypopnea index (OAHI) ≤1 event/hour, or absence of snoring during polysomnography or on parent report. Linear mixed-model analyses determined the effects of resolution on psychosocial morbidity. OAHI was used to determine the predictive value of changes in SDB severity on psychosocial outcomes. Fifty percent of primary snoring, 45% mild OSA, and 63% MS OSA resolved, of which 67% received treatment. Children originally diagnosed with SDB continued to show significant psychosocial impairments compared with nonsnoring controls, irrespective of resolution. A reduction in OAHI predicted improvements in physical symptoms, school functioning, family worry and family relationships, and stress related to a difficult child. Treatment was more likely to result in resolution of SDB if original symptoms were MS. Children originally diagnosed with SDB, irrespective of resolution, continued to experience psychosocial dysfunction suggesting additional interventions are required.

PREVALENCE AND CORRELATES OF SLEEP-DISORDERED BREATHING IN CONGENITAL HEART DISEASE

The prevalence of sleep-disordered breathing (SDB) is approximately 10% in the general population and is increased in those with comorbidities such as ischemic heart disease and stroke. The increased survival of patients with congenital heart disease (CHD) into adulthood elevates the risk of both ischemic heart disease and non-cardiovascular diseases. The aim of our study was to assess the prevalence and correlates of SDB in the CHD population at the Toronto Congenital Cardiac Centre for Adults (TCCCA). This was a retrospective cross-sectional study of active CHD patients assessed for SDB via polysomnography between 1998 and 2014 from the TCCCA. Subjects were stratified into those with (apnea-hypopnea index (AHI) ≥ 5/hr) and without SDB (AHI < 5/hr. SDB was classified as per standard criteria. Of the 7167 active patients in TCCCA database, there were 156 with confirmed CHD who had assessment for SDB within the study period. Of these subjects, 63% were males and 37% females with a mean age of 37.9 ± 14.5 years. SDB was present in 131 (83.9%) subjects. Of those in whom full polysomnography data was available (n = 69), 7.7% had no SDB, 8.2% mild, 9.8% moderate, and 12.6% severe SDB. Those with SDB were significantly older (41 vs 33 years, p = 0.029), and had a higher BMI (31.4 vs. 25.4kg/m2, p = 0.01) than those without SDB. A history of congestive heart failure was significantly associated (p=0.021) with SDB. Two percent of patients with CHD had screening performed for SDB. In those screened for SDB there was a very high prevalence. This suggests that many patients remain undiagnosed and that screening is imperative in this population. In keeping with studies in the general population, increased age and BMI were associated with SDB.

Increase in the Oxidized Low-density Lipoprotein Level by Sleep-Disordered Breathing and Correlation with Obesity in Patients with Heart Failure

Sleep disordered breathing (SDB) is associated with increased mortality in heart failure (HF), but the underlying mechanism is not fully elucidated. Oxidative stress plays an essential role in the pathogenesis of HF. We investigated the association of SDB with oxidative stress in HF patients. Overnight polygraphy was performed in 71 patients with HF (ischemic cardiomyopathy n=17, dilated cardiomyopathy n=41, others n=13). Based on the presence of severe SDB, these patients were divided into two groups: Group A (apnea hypopnea index [AHI]≧ 30/h, n=17) and Group B (AHI<30/h, n=54). We measured plasma levels of malondialdehyde-modified low-density lipoprotein (MDA-LDL), one of the representative oxidized LDL. MDA-LDL levels were higher in Group A than Group B (136±56vs.102±34 U/L; p>0.05). Plasma levels of BNP, troponin T and CRP, and FABP were not different between two groups. Plasma MDA-LDL level were higher in patients with obese (BMI>25) than those without (141±51vs.101±36 U/L; p>0.005), but not associated with other cardiovascular risk factors, etiology of HF, cardiovascular medications, and other biomarkers. Multiple regression analysis showed that the most important determinants of log MDA-LDL level was obesity (β=0.39, p<0.005). SDB is associated with enhanced oxidative status, but obesity is the most important determinants of oxidative stress in HF. Weight reduction might be an important strategy to control oxidative stress in HF with SDB.

Ubiquity of Undiagnosed Sleep Disordered Breathing in Community-Dwelling Older Male Veterans

To determine the point prevalence of sleep disordered breathing (SDB) in a community-based sample of older male veterans and to determine if common markers of SDB apply to this population. Two hundred fourteen older male Veterans (age 55-89 years) were recruited for a study on post-traumatic stress disorder and cognitive decline. Questionnaires concerning anthropomorphic and psychological variables were obtained, as was an overnight polysomnographic examination of sleep. Only 13% of the participants lacked clinically meaningful SDB, whereas 33% had moderate SDB and 54% had severe SDB. Being overweight, self-reported snoring, and excessive daytime sleepiness all had good sensitivity (0.86-0.92) but very poor specificity (0.10-0.28) for the prediction of SDB. Undiagnosed SDB was more than threefold higher than expected in these community-dwelling older veterans. Traditional markers of SDB were not specific for predicting clinically relevant SDB.

Echocardiographic Findings in Healthy Elderly People with Unrecognized Sleep Disordered Breathing.

Sleep disordered breathing (SDB) is associated with cardiovascular disease such as hypertension and left ventricular hypertrophy in middle-aged patients; however, this association is not well described in the elderly. The aim of this study was to evaluate the impact of unrecognized SDB on cardiac function and remodeling in a population-based sample of healthy elderly without cardiac disease. A total of 405 healthy elderly (age ≥ 65 years) were examined by echocardiography and respiratory polygraphy. According to the apnea-hypopnea index (AHI), subjects were stratified in four categories: snorers (AHI < 5), mild (AHI: 5-15), moderate (AHI: 15-30), and severe (AHI > 30) cases. Comparative analysis between snorers and SDB cases revealed that left atrial (LA) diameter and surface increased according to SDB severity (p < 0.05) without differences in LA mass index. In subjects with an AHI > 30, an increase was found for LV end-diastolic and end-systolic dimension (p < 0.001), as well as for LV mass (p < 0.03) and LV index (p < 0.05). The current study showed a weak but significant correlation between altered LA and LV measurements versus AHI and hypoxemia indices (p < 0.001). In the regression analysis, AHI and hypoxemia had a minimal effect, body mass index and male gender being the most significant predictors. In a population of healthy elderly with SDB, slight changes in left atrial and ventricular measurements occur in severe cases (AHI > 30). Irrespective of the lack of a strong association between SDB and cardiac dysfunction, the presence of slight cardiac pathology in severe SDB cases might be considered. NCT 00759304 and NCT 00766584.

Poligrafía en niños con enfermedad neuromuscular

Introduction: A high prevalence of sleep-disordered breathing (SDB) has been reported in neuromuscular disease (NMD) patients. Our aim was to describe the results of sleep studies performed by overnight polygraphy in pediatric ward of a public hospital from Concepcion, Chile. Additionally, we purposed to define its utility in the treatment of children with NMD. Methods: Records of NMD patients admitted at G. Grant Benavente Hospital, from 2011 to 2015 were considered. The therapeutic approaches were classified as: non invasive ventilation, surgical treatment and follow up. Results: From 36 patients initially admitted in the study 5 were excluded. Patients median age was 10 years-old (range: 0.3-19), 74% (n = 23) were males. Diagnosis were: Duchenne muscular dystrophy in 12 patients (39%), Myelomeningocele in 6 (19%), Hypotonic syndrome in 5 (16%), Miopathy in 3 (10%), Spinal muscular atrohpy in 3 (10%) and other NMD in 2 patients (6%). Median of polygraphy valid time was 7.3 h (range:4.3-10.5). Median of mean values of O2 saturation was 97% (range: 91-99%) and median of minimum O2 saturation was 90% (51-95%). Six polygraphies (19%) were normal and 25 (81%) showed some degree of SDB. From this group 60% had a mild, 28% (n = 7) had a moderate and 12% (n = 3) presented a severe SDB. Fifteen patients (65%) were under non invasive ventilation, nine (29%) of them received medical treatment and two of them (6%) surgical treatment. There was no difference between the magnitude of SDB and therapeutic approach. Moreover, no association between the severity of SDB and therapeutic approach was found. Conclusion: Polygraphy allows objective diagnosis of SDB in children with NMD and is a suitable tool to define therapeutic conducts.