Apnea-hypopnea Index In Group Research Articles

Association Between Obstructive Sleep Apnea (OSA) Severity and Optimal Continuous Positive Airway Pressure (CPAP); Do Severe OSA Patients Always Need High CPAP Pressure?

Objective: Obstructive sleep apnea (OSA) is a prevalent sleep disorder associated with an increased risk of cardiovascular disease. Severity of OSA is assessed using the apnea-hypopnea index (AHI), but the optimal continuous positive airway pressure (CPAP) does not always correlate proportionally with AHI. This study aims to identify factors leading to the need for high CPAP pressure despite low AHI or vice versa.Methods: The study includes 91 patients diagnosed with OSA through polysomnography. Participants undergoing CPAP titration were categorized in three groups based on AHI (30/h) and optimal CPAP pressure (10 cm H<sub>2</sub>O); low AHI and high CPAP pressure group (LH group), high AHI and low CPAP pressure group (HL group), direct proportion group (DP group). The Kruskal–Wallis nonparametric statistical test is used to identify significant differences between the three groups.Results: Among the subjects, 78% were male, with no significant age or BMI differences between groups. There were 36 (39.6%) subjects with mild to moderate OSA and 55 (60.4%) subjects with severe OSA. The study revealed that patients requiring high CPAP pressure despite low AHI (LH group) had lower AHI, oxygen desaturation index, and various other parameters compared to other groups as expected. However, certain factors like the percentage of hypopnea in AHI, limb movement (LM) arousal index, and spontaneous arousal index were higher in the LH group.Conclusion: Patients with mild to moderate OSA requiring high CPAP pressure are more likely associated with specific aspects such as hypopnea in AHI, LM arousal, and spontaneous arousal index, presenting unpredictable outcomes.

The importance of systemic immune-inflammation index in obstructive sleep apnea syndrome.

This study aims to explore the importance of systemic immune-inflammation index (SII) in patients diagnosed with obstructive sleep apnea (OSA). In this study planned as a retrospective cohort, the files of the patients who presented with sleep apnea/snoring complaint between 10.01.2017 and 10.01.2021 and underwent polysomnography (PSG) and complete blood count analyses were reviewed. PSG findings (age, sex, body mass index (BMI), apnea-hypopnea index (AHI), mean oxygen saturation) were compared with SII in 194 patients meeting study eligibility criteria. Patients included in this study were divided into 4 groups by AHI value. Statistical difference was detected between the groups in terms of age, sex, body mass index (BMI), and mean oxygen saturation (p < 0.05). There is an approximately 30% positive statistically significant correlation between the severity of OSA and SII (p < 0.001). As for the mean SII values of the AHI groups, it was observed that the more severe AHI is, the higher the mean SII value is. The correlation between SII and the severity of OSA was found to be more significant than the correlation with neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR). There is a significant correlation between SII and the severity of OSA. This correlation is stronger compared to NLR and PLR. SII can be used to demonstrate the chronic systemic inflammation observed in OSA patients, and can be utilized as a simple and inexpensive biomarker as it can be easily calculated from the parameters present in routine blood analyses.

Understanding potential associations between anatomic and other factors in OSA severity.

The aim of this prospective study was to investigate associations between nasal/oropharyngeal structures and a range of factors including age, gender, daytime sleepiness, and body mass index (BMI). Patients with OSA were prospectively selected as research participants in rhinomanometric analysis as well as for otolaryngological evaluation. Participants were grouped as follows according to their apnea/hypopnea index (AHI) scores: no OSA (AHI < 5), mild OSA (5 ≤ AHI ≤ 15), moderate OSA (15 ≤ AHI < 30), and severe OSA (AHI ≥ 30). One-way analysis of variance (ANOVA), Kruskal-Wallis H, and Mann-Whitney U tests were performed to assess OSA severity in terms of the relationships between nasal resistance (NR) and anthropometric indices (body mass index (BMI), Friedman tongue position (FTP)), age, and gender. The study cohort of 177 men and 81 women ranged in age between 21 and 76years, with BMI ranging from 23 to 45. In total, 37 patients were simple snorers (AHI < 5), and 221 patients were diagnosed with OSA. There was no significant difference among the AHI groups in terms of nasal volume (Vol05) (p = 0.952), mean flow (p = 0.778), and mean NR total (p = 0.723). A statistically significant difference was found between the AHI groups in terms of mean BMI and median FTP scores (p < 0.001). This study provides evidence that that the oropharyngeal region (oropharynx, tongue, and vallecula) is a more important determinant of OSA severity than the nasal region.

Correlation of obstructive sleep apnea with components of metabolic syndrome and implications for long-term adverse cardiovascular risk in elderly patients

To investigate the relationship between obstructive sleep apnea (OSA) and components of metabolic syndrome (MetS) in the elderly and the implications for long-term risk for major adverse cardiovascular events (MACE). This multicenter prospective cohort study was conducted among 1157 consecutive patients with OSA [defined as an apnea-hypopnea index (AHI) ≥5 times/h recorded by overnight polysomnography] aged ≥60 years enrolled from January, 2015 to October, 2017. All the patients did not have a history of MACE at baseline and had complete documentations of MetS indicators. The baseline demographic data, clinical characteristics, biochemical markers, and sleep parameters were collected from all the patients, who were divided into 4 groups according to the quartile level of AHI and followed up for a median of 42 months for MACE and its component events (cardiovascular death, myocardial infarction, and hospitalization for unstable angina or heart failure). Multivariate linear regression and Cox proportional risk regression models were used to analyze the correlation of MetS components with major objective predictors of OSA, AHI and LSpO2 and the long- term risk of MACE. AHI and LSpO2 quartiles group showed a positive dose-response relationship with MetS components [fasting blood glucose, waist circumference, systolic blood pressure, and triglycerides] and a negative dose-response relationship with high-density lipoprotein level. MACE occurred in 119 (10.3%) patients with OSA during the follow-up. Multivariate Cox regression analysis showed that a high triglycerides, a high systolic blood pressure, and an increased waist circumference were independent risk factors for MACE and its component events (P < 0.05 or 0.01); a high HDL was a protective factor against MACE and myocardial infarction (P < 0.05 or 0.01) independent of the AHI. MetS components independent of LSpO2 showed no significant correlations with the risk of MACE or its component events. The major diagnostic indexes AHI and LSPO2 in elderly patients with OSA have a dose-response relationship with MetS components, and the interaction between the components of MetS and AHI can increase the risk of MACE and its component events.

Polysomnography and Nocturia Evaluations after Uvulopalatopharyngoplasty for Obstructive Sleep Apnea Syndrome.

A higher incidence rate of nocturia in patients with obstructive sleep apnea (OSA) has been observed. We investigated the differences in clinical examinations between OSA patients with and without nocturia, and further compared those with successful and unsuccessful uvulopalatopharyngoplasty (UPPP). This retrospective study enrolled 103 patients with OSA undergoing UPPP. Patients were diagnosed with OSA by following the 2018 American Academy of Sleep Medicine (AASM) Scoring Manual Version 2.5. Patients were divided into two groups depending on if they urinated more than twice per night. The medical data of body mass index (BMI), nocturia frequency per night, apnea–hypopnea index (AHI), Epworth Sleepiness Scale (ESS), International Prostatic Symptom Score (IPSS), and Overactive Bladder Symptom Score (OABSS) were analyzed before and after uvulopalatopharyngoplasty (UPPP) surgery. All of the measurements were compared between successful and unsuccessful surgery in the non-nocturia or nocturia groups, respectively. Fifty patients (41 males and nine females) without nocturia were assigned to group 1, and 53 patients (43 males and 10 females) with nocturia were assigned to group 2. Nocturia frequency and post-surgery AHI in group 2 were significantly higher than those in group 1 (p < 0.05). Significant decreases in IPSS and OABSS were observed in the successful surgery subgroup of group 2 (p < 0.05). A significant decrease in post-surgery AHI was observed between unsuccessful and successful surgery in patients with nocturia (p < 0.05), but not in the non-nocturia group (p > 0.05). Although AHI had a significant correlation to nocturia frequency in all OSA patients before UPPP, no significant correlation between AHI reduction and nocturia frequency was found. UPPP appeared to be an effective treatment for nocturia associated with OSA. OSA should be taken into consideration for patients who complain of nocturia syndrome. The relationship of AHI reduction and nocturia improvement after OSA treatment with UPPP is still unclear. In addition, it is necessary to establish the existence of nocturia in patients with OSA, as a result of its high prevalence in OSA patients. UPPP could reduce the symptoms of OSA and could also contribute to a reduction of nocturia even in the unsuccessful surgery group.

Long-term obstructive sleep apnea therapy: a 10-year follow-up of mandibular advancement device and continuous positive airway pressure

Obstructive sleep apnea (OSA) is a sleep-related breathing disorder, commonly managed by either continuous positive airway pressure (CPAP) or a mandibular advancement device (MAD). Long-term follow-up and comparison regarding efficacy of these therapies is scarce. In this study the results of treatment, patient adherence, and satisfaction over a 10-year follow-up of these therapies are reported. This is a longitudinal follow-up study taken from a subset of patients initially enrolled in a randomized controlled clinical trial of 103 patients with OSA (51 and 52 patients randomized for MAD and CPAP, respectively). After a 10-year follow-up period, 14 patients using MAD and 17 patients using CPAP could be evaluated for this longitudinal follow-up study. Data were analyzed at baseline, after 3 months and at 1-, 2-, and 10-year follow-up. All 31 patients with OSA underwent polysomnography and self-reported measurements. Polysomnography results showed a favorable outcome of both therapies at 10-year follow-up. At baseline, included patients in both groups did not significantly differ in apnea-hypopnea index (AHI) values. At 10-year follow-up, both the MAD and CPAP groups showed a significant reduction in AHI. At baseline the mean AHI in the MAD group was 31.7 ± 20.6 events/h whereas in the CPAP group it was 49.2 ± 26.1 events/h. At 10-year follow-up the mean AHI in the MAD group was 9.9 ± 10.3 events/h and in the CPAP group it was 3.4 ± 5.4 events/h. Both therapies resulted in a substantial improvement in self-reported neurobehavioral outcomes at 10-year follow-up. Both CPAP and MAD therapy demonstrate good and stable treatment effects after a 10-year follow-up period. Therefore, when indicated, both therapies are appropriate modalities for the long-term management of OSA. Registry: Netherlands Trial Register; Name: Management of the Obstructive Sleep Apnea-Hypopnea Syndrome: Oral Appliance versus Continuous Positive Airway Pressure Therapy; Identifier: NL75; URL: https://www.trialregister.nl/trial/75.

Olfactory Function in Patients With Obstructive Sleep Apnea Using Positive Airway Pressure.

Previous studies reported that positive airway pressure (PAP) treatment may improve olfaction function in patients with obstructive sleep apnea (OSA) through various mechanisms. Olfactory function before and after PAP treatment is understudied regarding patient group at issue. The aim of this study is to investigate the contribution of PAP to olfactory function in patients with OSA. The study was conducted on 26 patients with OSA (10 females and 16 males, mean age 50.1 [9.3] years) who scheduled for PAP treatment. The Connecticut Chemosensory Clinical Research Center odor test was performed before and 4 months after PAP treatment. Patients were grouped (normal, anosmia, mild hyposmia, moderate hyposmia, and severe hyposmia) with respect to olfactory function by measuring odor test parameters, including threshold determination and identification. The odor test average scores of the patients after 4-month PAP treatment compared to pretreatment scores were increased and the difference was statistically significant (P = .002). In the apnea hypopnea index groups, statistically significant difference was found in the threshold and discrimination values regarding before PAP treatment (P = .038, P = .022, respectively). This study revealed that improvement in olfactory thresholds in patients with OSA receiving PAP treatment seems to improve olfactory dysfunction. This provides minimization of OSA consequences, including progressive upper airway inflammation, cognitive impairment, and associated olfactory dysfunction. Resolving the associations between olfactory function and PAP treatment is an important area for future research.

The Influence of Functional Endoscopic Sinus Surgery on Sleep Related Outcomes in Patients with Chronic Rhinosinusitis.

Purpose Chronic rhinosinusitis (CRS) patients often complain of nasal obstruction, which may cause sleep impairment for them. The goal of this study was to investigate the influence of functional endoscopic sinus surgery (FESS) on sleep related outcomes in CRS patients. Materials and Methods CRS patients who received FESS were included in this study. Prior to FESS and 3 months after surgery the patients were asked about the severity of nasal obstruction and completed the 20-item Sinonasal Outcome Test (SNOT-20), along with the Epworth Sleepiness Scale (ESS) questionnaire. Endoscopic examination, acoustic rhinometry, and polysomnography were performed in all patients. They were divided into four groups according to their preoperative apnea hypopnea index (AHI) scores: nonobstructive sleep apnea syndrome (non-OSAS), mild OSAS, moderate OSAS, and severe OSAS. Results A total of 96 subjects completed the study. The scores of the sleep domain of the SNOT-20 and ESS decreased in all of the AHI groups, with the exception of the severe OSAS group, after FESS. A reduction in the AHI of less than 5 was achieved in 9 patients (13.2%) after FESS. Conclusions Our results showed that FESS improved sleep quality in CRS patients, except those with severe OSAS, and a preoperative lower AHI was the only significant predictor of post-FESS OSAS outcome.

한국 성인 남성에서 체질량지수를 이용한 현재의 비만 기준과 중증 수면무호흡과의 상관관계

Background and Objectives: We tried to assess the effect of body mass index (BMI) on obstructive sleep apnea (OSA) in Korean male patients by using portable polysomnography. Materials and Methods: We evaluated 796 patients whose Apnea+hypopnea index (AHI) were over 5 as the result of overnight portable polysomnography from September 2011 to December 2016. The subjects were classified into 2 groups on basis of the AHI severity : A group : 5≤AHI&lt;30 ; B group : 30≤AHI. The subjects were classified into 3 groups on basis of the BMI : X group : BMI&lt;25 ; Y group : 25≤BMI&lt;27.7 ; Z group: 27.7≤BMI. By multiple logistic regression analysis, we studied the relationship of AHI as dependent variable to BMI and age in each group. Results: There was significant correlation between 30≤AHI group and 27.7≤BMI group (odds ratio, 3.443 ; p&lt; 0.01). Conclusions: Weight reduction is more needed in the 27.7≤BMI group due to the risk of 30≤AHI in Korean male OSA patients. (J Clinical Otolaryngol 2018;29:53-56)

Hypoxia and inflammation indicate significant differences in the severity of obstructive sleep apnea within similar apnea-hypopnea index groups.

We determined whether hypoxia parameters are associated with C-reactive protein (CRP), mean platelet volume (MPV), white matter hyperintensity (WMH), and the severity of obstructive sleep apnea (OSA), and also evaluated whether hypoxia parameters, CRP, MPV, and WMH differ in patients with similar apnea-hypopnea index (AHI) scores. A total of 297 patients, who were evaluated using polysomnography, were assessed retrospectively. The measured hypoxia parameters included total sleep time with oxygen saturation <90% (ST90), percentage of cumulative time with oxygen saturation <90% (CT90), and lowest oxygen saturation (min SaO2). The patients were divided into subgroups according to their CT90 values, and patients with different AHI severities were divided into subgroups according to their ST90 and min SaO2 levels. Hypoxia parameters are associated with CRP, MPV, WMH, and the severity of OSA (P<0.05). The hypoxia parameters differed in all subgroup analyses of similar AHI groups (P<0.001), and CRP differed only in severe OSA (P<0.008, P<0.001). In subgroup analyses of similar AHI groups, MPV and WMH were not significantly different (P>0.05). Above the hypoxia threshold (CT90≥10%) of CRP, MPV increased significantly and the presence of WMH increased twofold. These data suggest that increased hypoxia severity may mediate increased inflammation and activation of platelets and contribute to the pathogenesis of WMH in patients with OSA. In addition, patients with severe OSA may show significant variability in inflammation and vascular risk. Further prospective data are needed.

Association Between Sleep-Disordered Breathing and Hypertensive Disorders of Pregnancy and Gestational Diabetes Mellitus.

To estimate whether sleep-disordered breathing during pregnancy is a risk factor for the development of hypertensive disorders of pregnancy and gestational diabetes mellitus (GDM). In this prospective cohort study, nulliparous women underwent in-home sleep-disordered breathing assessments in early (6-15 weeks of gestation) and midpregnancy (22-31 weeks of gestation). Participants and health care providers were blinded to the sleep test results. An apnea-hypopnea index of 5 or greater was used to define sleep-disordered breathing. Exposure-response relationships were examined, grouping participants into four apnea-hypopnea index groups: 0, greater than 0 to less than 5, 5 to less than 15, and 15 or greater. The study was powered to test the primary hypothesis that sleep-disordered breathing occurring in pregnancy is associated with an increased incidence of preeclampsia. Secondary outcomes were rates of hypertensive disorders of pregnancy, defined as preeclampsia and antepartum gestational hypertension, and GDM. Crude and adjusted odds ratios and 95% confidence intervals (CIs) were calculated from univariate and multivariate logistic regression models. Three thousand seven hundred five women were enrolled. Apnea-hypopnea index data were available for 3,132 (84.5%) and 2,474 (66.8%) women in early and midpregnancy, respectively. The corresponding prevalence of sleep-disordered breathing was 3.6% and 8.3%. The prevalence of preeclampsia was 6.0%, hypertensive disorders of pregnancy 13.1%, and GDM 4.1%. In early and midpregnancy the adjusted odds ratios for preeclampsia when sleep-disordered breathing was present were 1.94 (95% CI 1.07-3.51) and 1.95 (95% CI 1.18-3.23), respectively; hypertensive disorders of pregnancy 1.46 (95% CI 0.91-2.32) and 1.73 (95% CI 1.19-2.52); and GDM 3.47 (95% CI 1.95-6.19) and 2.79 (95% CI 1.63-4.77). Increasing exposure-response relationships were observed between apnea-hypopnea index and both hypertensive disorders and GDM. There is an independent association between sleep-disordered breathing and preeclampsia, hypertensive disorders of pregnancy, and GDM.

Effect of Sleep-disordered Breathing Severity on Cognitive Performance Measures in a Large Community Cohort of Young School-aged Children.

Sleep-disordered breathing (SDB) in children is associated with cognitive challenges. However, potential associations between SDB severity and neurocognitive function, as well as the presence of an SDB cutoff, have not been fully explored. To determine whether SDB-associated adverse changes in neurocognitive functioning are severity dependent. A total of 1,010 snoring and nonsnoring children ages 5-7 years were prospectively recruited from public schools and underwent polysomnography and neurocognitive assessments of intellectual, attention, memory, language, and executive function development. The children were subdivided into four severity groups on the basis of apnea-hypopnea index (AHI), followed by comparisons of cognitive function, with a particular focus on standardized subtests of intellectual, language, attention, memory, and executive function. Differential Ability Scales Verbal (P < 0.001) and Nonverbal (P = 0.002) performance, as well as global conceptual ability (IQ) (P < 0.001) scores, differed significantly across the groups, with individuals with higher AHI showing worse performance. Additionally, specific NEPSY (a Developmental Neuropsychological Assessment) subscores focused on attention and executive skills differed across the groups, indicating differences in levels of engagement and problem solving. Children with higher AHI (>5 per hour of total sleep time) were significantly more impaired than all three lower AHI groups, indicating a dose-response impact of SDB. This large community-based sample of children highlights the significant deleterious impact of SDB, particularly in children with moderate to severe obstructive sleep apnea, and also that even snoring alone affects neurocognitive function. By affecting developing capabilities, as illustrated by cognitive measures in a severity-graded manner, SDB could adversely impact children's capacity to attain academic and adaptive goals, ultimately hampering their ability to reach independence. Our findings support the need for increased awareness of SDB, with particular emphasis on children with more severe obstructive sleep apnea.

Heart Rate Variability and Sleep-Related Breathing Disorders in the General Population

Obstructive sleep apnea seems to have an important influence on the autonomic nervous system. In this study, we assessed the relations of sleep apnea-related parameters with 24-hour heart rate variability (HRV) in a large population of young and healthy adults. Participants aged 25 to 41years with a body mass index <35kg/m(2) and without known obstructive sleep apnea were included in a prospective population-based cohort study. HRV was assessed using 24-hour electrocardiographic monitoring. The SD of all normal RR intervals (SDNN) was used as the main HRV variable. Apnea-Hypopnea Index (AHI) and oxygen desaturation index (ODI) were obtained from nighttime pulse oximetry with nasal airflow measurements. We defined sleep-related breathing disorders as an AHI ≥5 or an ODI ≥5. Multivariable regression models were constructed to assess the relation of HRV with either AHI or ODI. Median age of the 1,255 participants was 37years, 47% were men, and 9.6% had an AHI ≥5. Linear inverse associations of SDNN across AHI and ODI groups were found (p for trend= 0.006 and 0.0004, respectively). The β coefficients (95% CI) for the relation between SDNN and elevated AHI were-0.20 (-0.40 to-0.11), p= 0.04 and-0.29 (-0.47 to-0.11), p= 0.002 for elevated ODI. After adjustment for 24-hour heart rate, the same β coefficients (95% CI) were-0.06 (-0.22 to 0.11), p= 0.51 and-0.14 (-0.30 to 0.01), p= 0.07, respectively. In conclusion, even early stages of sleep-related breathing disorders are inversely associated with HRV in young and healthy adults, suggesting that they are tightly linked with autonomic dysfunction. However, HRV and 24-hour heart rate seem to have common information.

C-reactive Protein as a Potential Biomarker of Residual Obstructive Sleep Apnea Following Adenotonsillectomy in Children.

Adenotonsillectomy (AT) is first-line treatment for pediatric obstructive sleep apnea (OSA), with most children having improvements in polysomnography (PSG). However, many children have residual OSA following AT as determined through PSG. Identification of a biomarker of residual disease would be clinically meaningful to detect children at risk. We hypothesize serum high-sensitivity C-reactive protein (hsCRP), an inflammatory biomarker, is predictive of residual OSA following AT. PSG was performed both preoperatively and postoperatively on children undergoing AT for the diagnosis of OSA. HsCRP serum concentrations were determined in all children pre-AT, and in most children post-AT. Resolution of OSA after AT was defined by a post-AT apnea-hypopnea index (AHI) < 1.5/h total sleep time (TST). Residual OSA was defined as a post-AT AHI > 5/h TST, which is considered clinically significant. AT significantly improved the AHI from 15.9 ± 16.4 to 4.1 ± 5.3/h TST in 182 children (P < 0.001). Of 182 children, residual OSA (post-AT AHI > 5) was seen in 46 children (25%). Among children who had hsCRP levels measured pre- and post-AT (n = 155), mean hsCRP levels pre-AT were 0.98 ± 1.91 mg/L and were significantly reduced post-AT (0.63 ± 2.24 mg/dL; P = 0.011). Stratification into post-AT AHI groups corresponding to < 1.5/h TST, 1.5/h TST < AHI < 5/h TST, and AHI > 5/h TST revealed post-AT hsCRP levels of 0.09 ± 0.12, 0.57 ± 2.28, and 1.49 ± 3.34 mg/L with statistical significance emerging comparing residual AHI > 5/h TST compared to post-AT AHI < 1.5/h TST (P = 0.006). Hierarchical multivariate modeling confirmed that pre-AT AHI and post-AT hsCRP levels were most significantly associated with residual OSA. Even though AT improves OSA in most children, residual OSA is frequent. Assessment of post-AT hsCRP levels emerges as a potentially useful biomarker predicting residual OSA.

The platelet-to-lymphocyte ratio reflects the severity of obstructive sleep apnea syndrome and concurrent hypertension

BackgroundChronic intermittent hypoxia, platelet activation and inflammation all play roles in the pathogenesis of obstructive sleep apnea syndrome (OSAS), which may increase the risk of cardiovascular disease (CVD). The aim of this study was to evaluate the relationship of the platelet-to-lymphocyte ratio (PLR) as a new biomarker showing systemic inflammation and platelet distribution width (PDW) as an indicator of platelet activation to the severity of OSAS.MethodsA total of 290 patients suspected with OSAS who underwent a full night of polysomnography were included. The patients were placed into 4 separate groups according to their apnea-hypopnea index (AHI) scores; the control group (AHI <5), mild OSAS group (AHI 5–15), moderate OSAS group (AHI 16–30), and severe OSAS group (AHI >30). CVD risk was defined by the presence of hypertension, diabetes mellitus, current smoking, and dyslipidemia.ResultsHigher AHI groups were significantly correlated with increasing age, body mass index, systolic blood pressure and male sex. PLR and PDW were also significantly associated with AHI (r = 0.417 for PLR and r = 0.227 for PDW, all p-values < 0.001) and the Epworth sleepiness scale (r = 0.160 for PLR and r = 0.189 for PDW, all p-values <0.05). Multivariate regression analysis revealed that AHI ≥9.2 (adjusted odds ratios [OR] 5.03, 95 % confidential interval (CI) = 1.67-15.2, p = 0.004) and PLR ≥159 (adjusted OR 2.81, 95 % CI = 1.34-5.91, p = 0.006) were independently associated with the presence of hypertension.ConclusionPLR and PDW are associated with OSAS severity. PLR may also be useful as a systemic biomarker for the concurrent hypertension in OSAS patients.

Prevalence of Undetected Sleep Apnea in Patients Undergoing Cardiovascular Surgery and Impact on Postoperative Outcomes.

We examined the prevalence of obstructive sleep apnea (OSA) among patients undergoing cardiac surgery and its impact on postoperative outcomes. Subjects were recruited from inpatient cardiovascular surgery units at two tertiary care centers. Crystal Monitor 20-H recorded polysomnograms preoperatively. Regression analyses were performed to explore associations between OSA using different apnea-hypopnea index (AHI) cutoffs and postoperative outcomes adjusting for key covariates. Prevalence of postoperative outcomes was compared among groups defined by AHI and left ventricle ejection fraction (LVEF) median cutoffs. Of 107 participants, the AHI was ≥ 5 in 79 (73.8%), ≥ 10 in 63 (58.9%), ≥ 15 in 51(47.7%), and ≥ 30 in 29 (27.1%). Patients with AHI ≥ 15 had significantly lower LVEF (p < 0.001). Logistic regression analyses with OSA cutoffs as above adjusting for age, gender, race, BMI, and LVEF found no significant increase in odds for any postoperative outcomes. No significant differences were found in %Total sleep time (TST) with SpO2 < 90% between AHI or LVEF groups, or by presence/absence of complications. Patients with any amount of TST with SpO2 < 90% had greater BMI, longer OR tube time, and greater prevalence of prolonged intubation (p = 0.007, 0.035, 0.038, respectively). OSA is highly prevalent in patients undergoing cardiovascular surgery. It could not be shown that OSA was significantly associated with adverse postoperative outcomes, but this may have been due to an insufficient number of subjects. AHI ≥ 15 was associated with lower LVEF. Larger samples are required to explore the impact of OSA on key postoperative outcomes that have clinical and economic importance in the care of cardiovascular surgery populations. A commentary on this article appears in this issue on page 1081.

English

Data from the sleep disorder institute showed that subjects with similar apnea hypopnea index (AHI) but different body mass index (BMI) had no difference in oxygen saturation in rapid eye movement (REM) or non-rapid eye movement (NREM) sleep. Only 6 pairs of subjects were evaluated in the study and they were not age-matched. The objective of this study was to evaluate, in age-matched subjects, if there are any differences in oxygen saturation and duration of apenic spells in subjects with similar AHI but different BMI. Ninety eight (98) subjects paired for AHI within one event/hour and BMI difference of 5 and above were grouped in 9 groups. Subjects belonged mainly to normal, mild and moderate AHI group. Diagnostic nocturnal polysomnography inclusion criteria were normal REM sleep and total sleep time of 5 h. Oxygen saturation was continuously assessed throughout the nocturnal polysomnography (NPSG), and was calibrated for each NPSG study, and was visually identified by sleeping physician and artifacts were eliminated from the analyses. For all age groups, differences between matched pairs on BMI were regressed on the following factors: baseline oxygen saturation, lowest oxygen saturation, average oxygen saturation difference between pairs, apnea maximum and mean durations. Mean BMI differences between age- and AHI-matched pairs were 10.2 ± 5.7 (range 5.0 to 29.0). Stepwise regression indicated that BMI differences between pairs best predicted minimum oxygen saturation (p = 0.008, 1-tail). One-way analysis of variance (ANOVA) showed that age differences contributed to the robust finding regarding how BMI differences predicted lowest oxygen saturation. Using a very conservative Bonferroni correction for multiple comparisons, lowest saturation differed only between lower age groups [group 1 < group 2 (p = 0.3) < group 3 (p = 0.001) and < group 4 (p = 0.02)]. Difference in BMI (when AHI is matched), especially between ages 25 and 44 years old, predicts differences in minimum oxygen saturation. Caution is warranted as severe apneics were not evaluated in small sample sizes in subject older than 40. Key words: Obstructive sleep apnea (OSA), apnea hypopnea index (AHI), body mass index (BMI), nocturnal polysomnography (NPSG), oxygen saturation, sleep disorder.

Can we use serum copeptin levels as a biomarker in obstructive sleep apnea syndrome?

ObjectiveThe aim of this study was to compare serum copeptin levels in patients with obstructive sleep apnea syndrome (OSA) and simple snorers without sleep apnea; and to investigate relationships between copeptin levels and polysomnographic parameters. MethodsSerum copeptin levels were determined using enzyme-linked immunosorbent assay in 47 patients with OSA and 12 patients without OSA (control group). Full-night polysomnography was performed in each patient. Patients with OSA were divided into three groups according to their Apnea Hypopnea Index (AHI) scores: mild OSA (5 < AHI < 15), moderate OSA (15 < AHI < 30), and severe OSA (AHI > 30). ResultsA total of 59 patients were included in the study. There were 23 female (39.0 %) and 36 male (61.0 %) subjects. The range of ages of study subjects was between 27 and 63 (mean 44.75 ± 9.64) years. According to the AHI values, patients were classified into four groups: simple snoring (n = 13), mild OSA (n = 10), moderate OSA (n = 15), and severe OSA (n = 21). Statistically significant differences between AHI groups in terms of age, Epworth score, and neck circumference. According to multiple comparison results for age, the difference between simple snoring and moderate OSA was statistically significant. According to multiple comparison results for Epworth score, the difference between simple snoring and severe OSA was statistically significant. According to multiple comparison results for neck circumference, a similar result was found like Epworth Sleepiness Scale score. The difference between AHI groups by gender was tested by a Pearson χ2 test and was found to be statistically significant. There was no statistically significant difference among AHI groups in terms of copeptin. There was a statistically significant correlation of copeptin with AHI during rapid eye movement (REM) sleep; however, the correlation coefficient was not sufficiently large. ConclusionsIncreased serum copeptin concentration may reflect a response to stress in some diseases. This is well documented especially in cardiovascular diseases; however, we could not find any difference in OSA groups in terms of copeptin levels.

Cardiac autonomic control in the obstructive sleep apnea

IntroductionThe sympathetic activation is considered to be the main mechanism involved in the development of cardiovascular diseases in obstructive sleep apnea (OSA). The heart rate variability (HRV) analysis represents a non-invasive tool allowing the study of the autonomic nervous system. The impairment of HRV parameters in OSA has been documented. However, only a few studies tackled the dynamics of the autonomic nervous system during sleep in patients having OSA.AimsTo analyze the HRV over sleep stages and across sleep periods in order to clarify the impact of OSA on cardiac autonomic modulation. The second objective is to examine the nocturnal HRV of OSA patients to find out which HRV parameter is the best to reflect the symptoms severity.MethodsThe study was retrospective. We have included 30 patients undergoing overnight polysomnography. Subjects were categorized into two groups according to apnea–hypopnea index (AHI): mild-to-moderate OSAS group (AHI: 5–30) and severe OSAS group (AHI>30). The HRV measures for participants with low apnea–hypopnea indices were compared to those of patients with high rates of apnea–hypopnea across the sleep period and sleep stages.ResultsHRV measures during sleep stages for the group with low rates of apnea–hypopnea have indicated a parasympathetic activation during non-rapid eye movement (NREM) sleep. However, no significant difference has been observed in the high AHI group except for the mean of RR intervals (mean RR). The parasympathetic activity tended to increase across the night but without a statistical difference. After control of age and body mass index, the most significant correlation found was for the mean RR (p=0.0001, r=−0.248).ConclusionOSA affects sympathovagal modulation during sleep, and this impact has been correlated to the severity of the disease. The mean RR seemed to be a better index allowing the sympathovagal balance appreciation during the night in OSA.

The importance of laboratory parameters in patients with obstructive sleep apnea syndrome

Platelet activation and inflammation are the related mechanisms of pathogenesis in obstructive sleep apnea syndrome (OSAS). Mean platelet volume (MPV) and platelet distribution width (PDW) are the markers of platelet activation. C-reactive protein (CRP) and red cell distribution width (RDW) in relation to the inflammation in OSAS might be increased. We aimed to investigate the correlation of the MPV, PDW, and RDW levels with the severity of OSAS. We included 98 patients with suspected OSAS, evaluated by polysomnography. According to their apnea-hypopnea index (AHI), patients were divided into group A (n = 20; 20.4%) with AHI below 5/h; group B (n = 15; 15.3%) with AHI 5-14.9/h; group C (n = 26; 26.5%) with AHI 15-29.9/h; and group D (n = 37; 37.8%) with AHI ≥30/h. Hemoglobin, MPV, PDW, and RDW were measured using an automated blood cell counter. BMI and age showed a statistically significant and gradual increase in AHI groups. Hemoglobin, platelet, CRP, MPV, and RDW values did not differ between AHI groups. PDW was significantly higher in group D (mean value 14.4 ± 1.8) than in group A (13.2 ± 0.5) (P < 0.001). Epworth sleepiness scale was significantly higher in group D (9.9 ± 5.5) than in group A (5.6 ± 3.5), B (9.2 ± 3.6) and C (6.6 ± 3.8) (P = 0.005). When the four groups were compared, group D had the lowest minimum SpO2 value [group A (89.4 ± 3.0), B (86.7 ± 4.2), C (81.2 ± 6.4), and D (68.2 ± 13.0)]. There was a statistically significant correlation between AHI and age (r = 0.35, P < 0.001), BMI (r = 0.31, P = 0.003), PDW (r = 0.28, P = 0.006), and Epworth sleepiness scale (r = 0.29, P = 0.007). However, AHI was not correlated with CRP, MPV, and RDW. PDW is higher in severe OSAS and is correlated with different parameters of breathing function during sleep. The severity of OSAS was not correlated with CRP, MPV, and RDW. These findings show an evidence for platelet activation in OSAS and suggest that PDW might be related markers of OSAS severity.