Respiratory response to proton pump inhibitor treatment in children with obstructive sleep apnea syndrome and gastroesophageal reflux disease

ObjectiveEvaluation of the respiratory response to proton pump inhibitors (PPI) in children with obstructive sleep apnea syndrome (OSAS) and gastroesophageal reflux disease (GERD).MethodsOf 131 children diagnosed with OSAS (Apnea Hypopnea Index, AHI >1/h), 37 children (6.9 years; 28.24%) with GERD symptoms (>3 times/week) were included. Overnight polysomnography with 24 h pH-metry was performed before and after 4–8 weeks of PPI treatment (omeprazole once a day, 1 mg/kg).ResultsOf 37 children, 21 were diagnosed with acid GERD where pre- and post-treatment reflux indexes were 14.09 ± 1.47 vs. 7.73 ± 1.36; (p < 0.001). The number of obstructive apneas and hypopneas decreased after PPI treatment, resulting in an AHI reduction from 13.08 ± 3.11/h to 8.22 ± 2.52/h; (p < 0.01). Respiratory response to PPI ranged from complete resolution of OSA (three children with mild OSA; AHI < 5/h; 10.31 years; 14.29%) to lack of significant AHI change (six children with severe OSA; AHI > 10/h; 3.62 years; 28.57%). Post-treatment AHI was predicted by pre-treatment reflux index (adjusted R² = 0.487; p < 0.001).ConclusionsReduction of obstructive respiratory events following short-term PPI treatment in children with both GERD and OSAS may suggest a causal relationship between apnea and reflux in some children. Questionnaire screening for GERD in children with OSAS may be of benefit.     

Daytime sleepiness and polysomnography in obstructive sleep apnea patients

BackgroundExcessive daytime sleepiness (EDS) is the major complaint in subjects with obstructive sleep apnea syndrome (OSAS). However, EDS is not universally present in all patients with OSAS. The mechanisms explaining why some patients with OSAS complain of EDS whereas others do not are unknown.ObjectiveTo investigate polysomnographic determinants of excessive daytime sleepiness (EDS) in a large multicenter cohort of patients with obstructive sleep apnea (OSAS).MethodsAll consecutive patients with an apnea–hypopnea index greater than 5 h⁻¹ who were evaluated between 2003 and 2005. EDS was assessed using the Epworth Sleepiness Scale (ESS), and patients were considered to have EDS if the ESS was >10.ResultsA total of 1649 patients with EDS ((mean [±SD] Epworth 15 ± 3) and 1233 without EDS (Epworth 7 ± 3) were studied. Patients with EDS were slightly younger than patients without EDS (51 ± 12 vs 54 ± 13 years, p < 0.0001), had longer total sleep time (p < 0.007), shorter sleep latency (p < 0001), greater sleep efficiency (p < 0.0001) and less NREM sleep in stages 1 and 2 (p < 0.007) than those without EDS. Furthermore, patients with EDS had slightly higher AHI (p < 0.005) and arousal index (p < 0.001) and lower nadir oxygen saturation (p < 0.01).ConclusionsPatients with OSAS and EDS are characterized by longer sleep duration and increased slow wave sleep compared to those without EDS. Although patients with EDS showed a mild worsening of respiratory disturbance and sleep fragmentation, these results suggest that sleep apnea and sleep disruption are not the primary determinants of EDS in all of these patients.     

Prevalence and risk factors for obstructive sleep apnea in a multiethnic population of patients presenting for bariatric surgery in Singapore

IntroductionObesity is becoming more prevalent world wide. Bariatric surgery is one treatment option for patients with severe or morbid obesity. There have been few comprehensive studies examining prevalence and risk factors for obstructive sleep apnea (OSA) in the multiracial Singaporean bariatric surgery population.MethodsWe performed full polysomnography on 176 consecutive patients undergoing assessment for bariatric surgery. Questionnaires regarding snoring, the presence of witnessed apneas and the Epworth Sleepiness Scale (ESS) were administered. Anthropometric and demographic measurements include age, sex, race, body mass index (BMI) and neck circumference.ResultsThe prevalence of OSA was 72%, and 49% of the 176 patients had an AHI ? 15. There was a male predominance of OSA (X² = 29.7; p < 0.001). OSA subjects had larger neck circumference (43.9 ± 4.5 vs. 39.4 cm ± 3.3; p < 0.001) and higher BMI (43.1 ± 7.6 vs. 39.1 ± 5.4 kg/m²; p < 0.001). The neck circumference (OR = 1.37; p < 0.001), presence of snoring (OR = 8.25; p < 0.001) and an ESS >10 (OR = 3.24; p = 0.03) were significant independent predictors of an AHI ? 15. A neck circumference of 43 cm had an 80% sensitivity and 83% specificity for predicting an AHI ? 15.ConclusionsOSA is common amongst Singaporeans undergoing evaluation for bariatric surgery, with a high prevalence of moderate and severe disease. An increased neck circumference is a strong independent predictor for an AHI ? 15, with a neck circumference of greater than 43 cm being a sensitive and specific predictor. Race was not found to be a risk factor.     

Nasal continuous positive airway pressure treatment reduces systemic oxidative stress in patients with severe obstructive sleep apnea syndrome

ObjectiveTo evaluate whether nasal continuous positive airway pressure (nCPAP) reduces oxidative stress in patients with severe obstructive sleep apnea (OSA) syndrome.Materials and methodsForty-six patients with severe OSA (AHI ? 30) requiring nasal CPAP treatment and 46 controls (subjects without OSA and with mild OSA as defined by an AHI < 15) were enrolled. Oxidative stress was evaluated in blood samples with a commercially available automated spectrophotometric assay (D-ROMs test, Diacron, Grosseto, Italy). Blood samples were collected the evening before (10:00 p.m.) and the morning after (07:00 a.m.) a diagnostic polysomnography. Patients with severe OSA syndrome were subsequently submitted to a second polysomnography with nasal CPAP titration the following night. Using the same schedule we collected blood samples from the patients the morning after the nCPAP titration and after two months of nCPAP treatment.ResultsPatients with severe OSA presented higher levels of oxidative stress than patients with AHI < 15 in the evening and in the morning (357.57 ± 13.07 UCarr vs. 319.28 ± 12.66 UCarr, p = 0.038, and 371.83 ± 12.83 UCarr vs. 328.09 ± 11.76 UCarr, p = 0.014, respectively). Patients with severe OSA presented a significant reduction the levels of oxidative stress the morning after the nCPAP titration study (371.83 ± 12.83 UCarr vs. 298.21 ± 9.62 UCarr, p = 0.001) and this reduction was further preserved after a period of two months of nCPAP treatment (293.72 ± 6.55 UCarr, p = 0.001 vs. baseline). Statistically significant correlations were observed between levels of oxidative stress and nocturnal polysomnography (NPSG) markers as oxygen desaturation index (ODI), arousal index (AI), lowest oxygen saturation of hemoglobin, and mean oxygen saturation of hemoglobin.ConclusionsPatients with severe OSA syndrome presented increased systemic oxidative stress. A single night of nCPAP treatment significantly reduced the levels of oxidative stress in patients with severe OSA syndrome, and this reduction was maintained at least after two months of nCPAP treatment.     

Association between heart rate recovery and severity of obstructive sleep apnea syndrome

BackgroundObstructive sleep apnea syndrome (OSAS) is associated with autonomic dysfunction and metabolic abnormalities including obesity, dyslipidemia, and insulin resistance. Heart rate recovery at 1 min after exercise termination (HRR-1) is a marker of vagal tone. We hypothesized that patients with more severe OSAS would have a lower HRR-1, either due to the co-existing metabolic abnormalities or OSAS.MethodsSixty-three patients with untreated OSAS (49.2 ± 9.8 years) without glucose- or lipid-lowering or negatively chronotropic drugs underwent cardiopulmonary exercise testing including HRR-1 measurement and assessment of several metabolic parameters. Patients with severe OSAS (apnea–hypopnea index [AHI] > 30 h⁻¹; n = 32) were compared to patients with mild to moderate OSAS (AHI 5–30 h⁻¹; n = 31).ResultsPatients with severe OSAS were more likely to be male (25 vs. 3%; p = 0.01) and to have hypertension (72 vs. 39%; p = 0.01); they also had higher fasting glucose (5.4 ± 0.5 vs. 5.1 ± 0.4 mmol/l; p = 0.016) and C-peptide [905 (651–1353) vs. 749 (597–919) pmol/l; p = 0.028] levels compared to patients with mild to moderate OSAS. The groups did not differ with respect to peak heart rate (p = 0.2) or peak oxygen consumption (p = 0.9), but HRR-1 was significantly lower in patients with severe OSAS compared to patients with mild and moderate OSAS [20 (15–25) vs. 24 (18–34) bpm; p = 0.022]. Higher AHI (p = 0.01) and lower peak heart rate (p = 0.02), but not body mass index or insulin resistance, were independently associated with lower HRR-1.ConclusionsThe severity of OSAS expressed as higher AHI is independently associated with lower HRR-1, a measure of autonomic dysfunction.     

Exhaled breath condensate cytokine level as a diagnostic tool for obstructive sleep apnea syndrome

BackgroundRelationships between exhaled breath condensate (EBC) and serum cytokines and apnea–hypopnea index (AHI) in patients with excessive daytime sleepiness and loud snoring were evaluated for their potential to predict the severity of obstructive sleep apnea syndrome (OSAS).MethodsNon-smoking patients with suspected OSAS who had undergone polysomnography (PSG) were selected until 22 non-OSAS, and 22 mild, 22 moderate and 24 severe OSAS cases based on AHI were achieved. Ten healthy smokers served as a smoker control group. Interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), and 8-isoprostane were measured in EBC and serum on the morning after PSG and related to OSAS severity using linear discriminant analysis (LDA) and logistic regression (LR).ResultsBiomarker levels, in both EBC and serum, differed significantly across the four groups. Classification by LDA using IL-10 in EBC showed the highest agreement with AHI classification (kappa = 0.88). LR distinguished moderate and severe OSAS from mild OSAS and non-OSAS perfectly using IL-6 in EBC and almost perfectly using IL-10 in EBC (area under the ROC curve = 0.997). The levels of biomarkers among smokers overlapped with mild to severe OSAS patients.ConclusionsAmong non-smoker OSAS suspects, EBC IL-6 and IL-10 have potential to predict severity of OSAS.     

Obstructive sleep apnea in narcolepsy

Study objectivesNarcolepsy and obstructive sleep apnea syndrome (OSAS) are two conditions associated with excessive daytime sleepiness (EDS). They may coexist in the same patient but the frequency of this association and its clinical significance is unknown. The presence of obstructive sleep apnea (OSA) in a narcoleptic patient may interfere with the diagnosis of narcolepsy. The aim of the study was to determine the prevalence of OSA in narcolepsy.Design and settingUniversity hospital sleep clinic series of narcoleptic patients diagnosed with nocturnal polysomnography and multiple sleep latency test. Patients were systematically interviewed evaluating narcoleptic and OSAS features and their response to continuous positive airway pressure (CPAP) treatment when applied.PatientsOne hundred and thirty-three patients with narcolepsy.ResultsThirty-three patients (24.8%) had an apnea–hypopnea index greater than 10 with a mean index of 28.5 ± 15.7. Ten of them were initially diagnosed only with OSAS and the diagnosis of narcolepsy was delayed 6.1 ± 7.8 years until being evaluated in our center for residual EDS after CPAP therapy. In the remaining 23 patients, narcolepsy and OSA were diagnosed simultaneously. Cataplexy occurred with similar frequency in both groups. EDS did not improve in 11 of the 14 patients who were treated with CPAP. The presence of OSA was associated with male gender, older age and higher body mass index.ConclusionsOSA occurs frequently in narcolepsy and may delay the diagnosis of narcolepsy by several years and interfere with its proper management. In patients with OSA, cataplexy should be actively looked for to exclude the presence of narcolepsy. Treatment with CPAP does not usually improve EDS in narcoleptics with OSA.     

Comparison of obstructive sleep apnea patients with and without leg edema

BackgroundTo determine the proportion of patients with obstructive sleep apnea (OSA) who have leg edema, and to identify differences between edematous and non-edematous OSA patients.MethodsRetrospective, cross-sectional study of 378 patients with OSA (apnea/hypopnea index [AHI] ⩾15) who had neither heart failure nor chronic lung disease.ResultsThirty-five percent (133/378) of the subjects with OSA had bilateral leg edema. Eighty-one percent (108/133) of the edematous subjects had mild pitting that was 1+. Compared to the non-edematous OSA subjects, the edematous subjects were older (age = 51 ± 13 versus 45 ± 13 years, p = 0.001), more obese (body mass index = 39 ± 9 versus 33 ± 8 kg/m², p = 0.001), had more severe OSA (AHI = 46 ± 71 versus 27 ± 29, p = 0.004), spent a greater proportion of sleep time with an oxygen saturation <90% (20 ± 26 versus 11 ± 18%, p = 0.001), and were more likely to have diabetes mellitus (11% versus 3%, p = 0.001) and hypertension (32% versus 10%, p = 0.001). Age, obesity, hypertension and diabetes mellitus correlated significantly with edema status. After adjusting for these confounding variables, the AHI means remained different between the edema and non-edema groups (41 ± 5 versus 28 ± 3, p = 0.04).ConclusionsApproximately one-third of OSA patients have edema. Edematous OSA patients are older, more obese, more likely to have diabetes mellitus and hypertension, and have more severe OSA than OSA patients who lack edema.     

Severe obstructive sleep apnea impairs left ventricular diastolic function in non-obese men

ObjectiveTo evaluate whether obstructive sleep apnea (OSA) contributes directly to left ventricular (LV) diastolic dysfunction.MethodsSeventy-four non-obese male OSA (apnea hypopnea index (AHI) ⩾ 5/h) patients without cardiac disease, hypertension or diabetes were enrolled. Echocardiography, pulse wave velocity (PWV) measurements and laboratory testing were performed in all patients. LV diastolic function was assessed by the transmitral flow velocity (E/A ratio), and mitral annular velocity (Ea) was derived from tissue Doppler imaging (TDI).ResultsThe E/A ratio and Ea in the severe OSA group (AHI ⩾ 30/h) was significantly lower than those in the mild to moderate OSA group (5 ⩽ AHI < 30/h) (P < 0.0001), whereas the S/D ratio, an indicator of pulmonary vein flow velocity, in the severe OSA group was significantly higher than that in the mild to moderate OSA group (P = 0.04). AHI exhibited a statistically significant inverse correlation with the E/A ratio (r = −0.47, P = 0.0001), but not with relative wall thickness (RWT), LV mass index (LVMI) or PWV. RWT, LVMI and PWV exhibited an inverse correlation with the E/A ratio. Multivariate linear regression analysis revealed that severe OSA was independently associated with the E/A ratio even after adjusting for age, insulin resistance, blood pressure, LV geometry, and PWV (β = −0.23, P = 0.001).ConclusionsThese results indicate that severe OSA itself may contribute directly to LV diastolic dysfunction irrespective of LV geometry, arterial stiffness, obesity and its associated cardiovascular risk factors.     

Effect of added dead space on sleep disordered breathing at high altitude

ObjectiveSleep disordered breathing with central apnea or hypopnea frequently occurs at high altitude and is thought to be caused by a decrease in blood CO₂ level. The aim of this study was to assess the effects of added respiratory dead space on sleep disordered breathing.MethodsFull polysomnographies were performed on 12 unacclimatized swiss mountaineers (11 males, 1 female, mean age 39 ± 12 y.o.) in Leh, Ladakh (3500 m). In random order, half of the night was spent with a 500 ml increase in dead space through a custom designed full face mask and the other half without it.ResultsBaseline data revealed two clearly distinct groups: one with severe sleep disordered breathing (n = 5, AHI > 30) and the other with moderate to no disordered breathing (n = 7, AHI < 30). DS markedly improved breathing in the first group (baseline vs DS): apnea hypopnea index (AHI) 70.3 ± 25.8 vs 29.4 ± 6.9 (p = 0.013), oxygen desaturation index (ODI): 72.9 ± 24.1/h vs 42.5 ± 14.4 (p = 0.031), whereas it had no significant effect in the second group or in the total population. Respiratory events were almost exclusively central apnea or hypopnea. Microarousal index, sleep efficiency, and sleep architecture remained unchanged with DS. A minor increase in mean PtcCO₂ (n = 3) was observed with DS.ConclusionA 500 ml increase in dead space through a fitted mask may improve nocturnal breathing in mountaineers with severe altitude-induced sleep disordered breathing.     

The relation between abnormal behaviors and REM sleep microstructure in patients with REM sleep behavior disorder

ObjectiveTo investigate the temporal relation between rapid eye movement (REM) sleep microstructure (REMs, EMG activity) and motor events in REM sleep behavior disorder (RBD).MethodsPolysomnographic records of eight patients with RBD were analyzed and compared with those of eight sex- and age-matched controls. We examined sleep microstructure for REM sleep with and without REMs and phasic chin EMG activity and their temporal relation to motor events on video.ResultsAll types of motor events were either more frequent in RBD patients than in controls (P ? 0.007) or present solely in RBD patients. In RBD, major motor events were significantly more frequent during REM sleep with REMs than during REM sleep without REMs (violent, 84.0% vs. 16.0%, P < 0.001; complex/scenic behavior, 78.1% vs. 23.2%, P < 0.001; major jerks, 77.5% vs. 20.3%, P < 0.001), whereas minor motor activity was evenly distributed (54.1% vs. 45.9%, P = 0.889). Controls showed predominantly minor motor activity with rare myoclonic body jerks. The distribution of motor events did not differ between REM sleep with and without REMs (40.9% vs. 59.1%, P = 0.262).ConclusionsIn RBD, major motor activity is closely associated with REM sleep with REMs, whereas minor jerks occur throughout REM sleep. This finding further supports the concept of a dual nature of REM sleep with REMs and REM sleep without REMs and implies a potential gate control mechanism of REM sleep with REMs for the manifestation of elaborate or violent behaviors in RBD.     

Reciprocal interactions of obstructive sleep apnea and hypertension associated with ACE I/D polymorphism in males

BackgroundThe angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism gene contributes to the genesis of hypertension (HTN) and may help explain the relationship between obstructive sleep apnea (OSA) and HTN. However, ACE is a pleiotropic gene that has several influences, including skeletal muscle and control of ventilation. We therefore tested the hypothesis that ACE polymorphism influences OSA severity.MethodsMale OSA patients (apnea-hypopnea index [AHI] > 5 events/h) from 2 university sleep centers were evaluated by polysomnography and ACE I/D polymorphism genotyping.ResultsWe studied 266 males with OSA (age = 48 ± 13y, body mass index = 29 ± 5kg/m², AHI = 34 ± 25events/h). HTN was present in 114 patients (43%) who were older (p < 0.01), heavier (p < 0.05) and had more severe OSA (p < 0.01). The I allele was associated with HTN in patients with mild to moderate OSA (p < 0.01), but not in those with severe OSA. ACE I/D polymorphism was not associated with apnea severity among normotensive patients. In contrast, the only variables independently associated with OSA severity among patients with hypertension in multivariate analysis were BMI (OR = 1.12) and II genotype (OR = 0.27).ConclusionsOur results indicate reciprocal interactions between OSA and HTN with ACE I/D polymorphism, suggesting that among hypertensive OSA males, the homozygous ACE I allele protects from severe OSA.     

Beneficial effect of donepezil on obstructive sleep apnea: a double-blind, placebo-controlled clinical trial

Introduction/objectivesPrevious publications have shown beneficial effects of cholinergic medication on obstructive sleep apnea (OSA) in Alzheimer’s disease (AD) patients. We hypothesized that cholinergic medication could also improve OSA in non-AD patients. The present study evaluated the effects of donepezil on OSA in non-AD patients.MethodsA randomized, double-blind, placebo-controlled study was conducted. The final sample consisted of 21 male patients with mild to severe OSA and AHI >10 divided into two groups, a donepezil-treated group (n = 11) and a placebo-treated group (n = 10). The dosage was one tablet/day (5 mg) for the first two weeks and two tablets/day (10 mg) for the last two weeks. Polysomnography and sleepiness evaluations were performed at baseline and after one month of treatment. Groups were compared using two-way ANOVA for repeated measures with treatment–group and treatment–time as the main factors and time–treatment as an interaction effect.ResultsConsidering the effect of the interaction with time–treatment, there was a significant improvement in the obstructive apnea/hypopnea index, desaturation index, percentage of time with O₂ saturation ?3% lower than baseline, lowest oxygen saturation, and the Epworth Sleepiness Scale (ESS) scores with donepezil treatment (p < 0.05). Sleep efficiency significantly decreased (p < 0.01).ConclusionsDonepezil treatment improved obstructive sleep apnea index, oxygen saturation, and sleepiness in parallel with a reduction in sleep efficiency. Our findings support the concept that cholinergic transmission may influence breathing regulation in OSA patients.     

Residual sleep apnea on polysomnography after 3 months of CPAP therapy: Clinical implications,predictors and patterns

ObjectiveWe sought to determine the clinical implications, predictors and patterns of residual sleep apnea on continuous positive airway pressure (CPAP) treatment in patients with moderate-to-severe obstructive sleep apnea (OSA).MethodsWe performed a post hoc secondary analysis of data from a previously reported randomized trial. Sleepy patients with a high risk of moderate-to-severe OSA identified by a diagnostic algorithm were randomly assigned to standard CPAP titration during polysomnography (PSG) or ambulatory titration using auto-CPAP and home sleep testing. We observed them for 3 months and measured apnea–hypopnea index (AHI) on CPAP, Epworth sleepiness scale (ESS), sleep apnea quality of life index (SAQLI), CPAP pressure and objective CPAP compliance.ResultsSixty-one patients were randomized, 30 to the PSG group and 31 to the ambulatory group. Fifteen patients (25%) had residual sleep apnea (AHI >10/h on CPAP) with similar proportions in the PSG (7/30) and ambulatory (8/31) groups. Baseline variables including age, body mass index (BMI), ESS, SAQLI, respiratory disturbance index (RDI) and CPAP pressure did not differ between the groups. Outcomes including compliance were worse in patients with residual sleep apnea. Periodic breathing was prevalent among patients with residual sleep apnea.ConclusionsResidual sleep apnea is common in patients with moderate-to-severe OSA, despite careful CPAP titration, and is associated with worse outcomes.     

Retinal nerve fiber thickness is reduced in sleep apnea syndrome

ObjectiveTo investigate the prevalence of glaucoma, visual field abnormalities, as well as changes in retinal nerve fiber layer in patients with obstructive sleep apnea syndrome (OSAS).MethodsIn this cross-sectional study, 51 patients with OSAS were included. Based on apnea hypopnea index (AHI), there were 26, 6 and 19 cases of severe (AHI ⩾ 30), moderate (15 ⩽ AHI < 30), and mild (5 ⩽ AHI < 15) OSAS, respectively. The control group was matched for age, sex and body mass index. Prevalence of glaucoma and ocular hypertension as well as the following values were assessed and compared between two groups: best-corrected visual acuity, intraocular pressure, central corneal thickness (CCT), cup:disk ratio, mean deviation (MD), pattern standard deviation, and retinal nerve fiber layer (RNFL) parameters using glaucoma diagnosis measurement (GDx).ResultsSeven eyes (6.7%) had intraocular pressure (IOP) > 21 mm Hg; of these, four eyes (3.9%) had glaucoma. No significant difference was detected in CCT between the two groups. IOP was significantly higher in the OSAS group before (p < 0.001) and after (p < 0.001) correcting for CCT. There was a significant difference between groups in MD and most GDx parameters including DISK (temporal–superior–nasal–inferior–temporal) average (p = 0.002), superior average (p = 0.05) and nerve fiber indicator (NFI) (p = 0.03), where those in the patient group showed lower values. There was a significant positive correlation between AHI and both IOP and NFI.ConclusionsOSAS patients had a higher prevalence of glaucoma and ocular hypertension. OSAS patients also had higher IOP, worse visual field indices, and lower RNFL parameters compared with the control group.     

Obstructive sleep apnea has little impact on quality of life in the elderly

Study objectiveTo analyze the impact of the number of respiratory sleep disorders or clinically related conditions (especially excessive daytime sleepiness [EDS]), on health related quality of life (HRQoL) in subjects over 65 years of age, as compared to younger subjects and the general population.MethodsTwo hundred and twelve adult patients with obstructive sleep apnea (OSA, AHI ? 10) divided into two age groups, over 65 (n = 109, mean age 74.6 [6, 8] years, and 65 or under (n = 103, mean age 51.7, [6, 5] years).General, anthropometric and clinical data related to OSA (epworth sleepiness score [ESS]), comorbidities (Charlson comorbidity index [CCI]), HRQoL (SF-36 questionnaire), use of psychotropic medications and habitual polygraphic/polysomnographic parameters were recorded and compared between the two age groups. The HRQoL values in each age group were compared with the values in the general population, adjusted for age and gender.ResultsIn patients 65 and under, both the presence of OSA as well as the presence of EDS (ESS > 11) were associated with an important deterioration in HRQoL as compared to normal reference values. The principal determinants of HRQoL were the presence of EDS (p < 0.04), body mass index (p < 0.03) and the apnea–hypopnea index (AHI) (p < 0.04). Nevertheless, in subjects over 65 years of age, the presence of OSA or EDS had only a slight impact on HRQoL, relative to normal values. In this age group, the principal determinants of HRQoL were the presence of comorbidities (CCI, p < 0.01), age (p < 0.01), oxygen desaturation parameters (p < 0.04) and the use of psychotropic medications (p < 0.04).ConclusionIn elders, the presence of OSA with or without EDS has little impact on HRQoL measures.     

Genetic polymorphisms in endothelin-receptor-subtype-a-gene as susceptibility factor for obstructive sleep apnea syndrome

IntroductionTraits of obstructive sleep apnea syndrome (OSAS) such as impaired ventilatory control, craniofacial abnormalities, and concomitant cardiovascular diseases are associated with modified endothelin-1 gene (EDN-1) or endothelin-receptor-subtype-a (EDNRA) gene. The endothelin system regulates the cardiovascular homeostasis. EDN-1 interacts mainly with EDNRA for signal transduction. In our study we investigate associations of EDNRA-polymorphisms (four frequent polymorphisms with an allele frequency >5%) and OSAS severity.MethodsThree hundred ninety-three patients older than 18 years, of Caucasian origin and with OSAS (AHI > 5/h and daytime sleepiness) were investigated by cardiorespiratory polysomnography. In addition 58 control subjects with healthy sleep were recruited from nearly 300 volunteers. We analysed the EDNRA-polymorphisms E335E, H323H, G-231A and G+70C by polymerase-chain-reaction, restriction-fragment-length-polymorphism and real-time-PCR.ResultsCarrier of the mutant G-231A allele had a significantly lower AHI (p = 0.03, OR 0.53, 95% CI 0.3–0.94) when comparing patients and controls. When comparing OSAS severity groups without controls we could not detect significant correlations for the four investigated EDNRA-polymorphisms. Our data confirm that BMI (p < 0.001) and male gender (p = 0.02) are significantly associated with AHI. The allele frequencies were similar.DiscussionThe genetic investigation of OSA remains important. Our control group was relatively small and we investigated 4 reasonable candidates out of more than 100 EDNRA-polymorphisms. The detected protective effect of the mutant G-231A allele needs further confirmation. Gene based research in OSAS should use genome wide scan and should still consider the endothelin system.     

Prevalence and risk factors of obstructive sleep apnea among middle-aged urban Indians: A community-based study

BackgroundThe epidemiology of obstructive sleep apnea (OSA) and obstructive sleep apnea syndrome (OSAS) is not well studied among Indians. We sought to determine the prevalence and risk factors of OSA in a middle-aged urban Indian population.MethodsWe conducted a two-stage, cross-sectional, community-based study in four different socioeconomic zones of the South Delhi district, India, from April 2005 to June 2007. In stage 1, subjects of either gender aged 30–65 yrs were administered a questionnaire by door-to-door survey using systematic random sampling. Subjects that responded were classified as habitual and non-habitual snorers. In stage 2, all the habitual and 10% of randomly selected non-habitual snorers were invited for overnight polysomnographic study.ResultsOf the 2860 subjects approached, 2505 (88%) completed stage 1. Habitual snoring was present in 452 (18%) subjects. In stage 2, OSA defined as apnea–hypopnea index ?5 was observed in 94 (32.4%) of 290 habitual snorers and 3 (4%) of 75 non-habitual snorers. Estimated population prevalence of OSA and OSAS was 9.3% (95% CI 8.2–10.5%) and 2.8% (2.1–3.4%) respectively. On multivariable analysis, male gender (adjusted odds ratio 3.8 [1.7–4.9]), body-mass index ?25 kg/m² (4.1 [2.0–8.3]), and abdominal obesity (2.2 [1.9–5.3]) were independently associated with the presence of OSA. A linear trend was observed in the prevalence of OSA across the socioeconomic strata.ConclusionsOSA is a significant public health problem in the middle-aged Indian population across the socioeconomic spectrum. OSA is associated with some of the well known risk factors for cardiovascular disease.     

The effect of sildenafil on sleep respiratory parameters and heart rate variability in obstructive sleep apnea

ObjectiveTo evaluate the magnitude of effects of sildenafil on respiratory parameters and heart rate variability (HRV) in slow wave sleep (SWS) and REM sleep of patients with severe obstructive sleep apnea (OSA).MethodsThirteen male patients with untreated severe OSA (aged 43 ± 10 years, body mass index of 26.7 ± 1.9 kg/m²) were studied on two nights, one with sildenafil 50 mg and one with a placebo, in a double-blind, randomized fashion. All-night polysomnography and HRV were simultaneously recorded. Short-term HRV measures were performed in apnea-free intervals. Respiratory parameters were separately assessed in non-REM and REM sleep and compared to total sleep time (TST). Short-term HRV analysis was conducted in samples with regular respiration obtained in SWS and REM sleep.ResultsComparing to placebo, during sildenafil night there was an increase in apnea–hypopnea index (AHI) in TST and also in non-REM and REM sleep. Increase in central AHI occurred in non-REM sleep; increase in obstructive AHI and decrease in oxyhemoglobin saturation occurred in both non-REM and REM sleep. Additionally, an increase in arousal index and in low/high frequency component of HRV ratio (LF/HF) was significant only in REM sleep. Correlation between sleep architecture and respiratory parameters were more frequent in non-REM sleep for placebo and in REM sleep for sildenafil.ConclusionIn severe OSA, the use of sildenafil 50 mg at bedtime plays a detrimental role on respiratory parameters in both non-REM and REM sleep, fragmentation in REM sleep, and a prolonged increase in LH/HF component of HRV after resumption of ventilation.     

Increased risk of psoriasis following obstructive sleep apnea: a longitudinal population-based study

BackgroundThis study aims to investigate the risk of psoriasis or psoriatic arthritis in patients with obstructive sleep apnea (OSA) compared with age- and gender-matched unaffected individuals, using a nationally representative population-based dataset.MethodsWe used data from the Taiwan “Longitudinal Health Insurance Database 2000.” The study consisted of 2258 patients with OSA and 11 255 matched comparison patients as the study cohort. Each selected subject (n = 13 513) in this study was individually traced for a three-year period from their index ambulatory care visits to identify patients who had been diagnosed with psoriasis during the follow-up period. A stratified Cox proportional hazard regression was used to compute the risk of psoriasis between patients with and without OSA.ResultsIt showed that, of 13 513 sampled subjects, 0.27% (n = 36) had psoriasis during the three-year follow-up period; the percentage was 0.49% and 0.22% for sampled subjects with and without OSA, respectively. After adjusting for the patients’ monthly incomes, geographic location, urbanization level, and obesity, the hazard of psoriasis during the three-year follow-up period was 2.30 (95% CI = 1.13–4.69, p = 0.022) times greater for patients with OSA than for comparison patients.ConclusionsOur results suggest that OSA is associated with an increased risk of subsequent psoriasis or psoriatic arthritis.