Mild Obstructive Sleep Apnea Group Research Articles

Dynamic changes in nocturnal blood glucose levels are associated with sleep-related features in patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) has a bidirectional relationship with insulin resistance conditions; however, the mechanism remains unclear. This study aimed to compare dynamic nocturnal glucose changes among patients with OSA of varying levels of severity and evaluate temporal changes associated with the cardinal features of OSA (sympathetic hyperactivation, intermittent hypoxemia, and sleep fragmentation) in nondiabetic subjects. Nocturnal glucose was measured with a continuous glucose monitoring device every 5 min during polysomnography (PSG). The OSA features were evaluated using heart rate variability (HRV), minimum saturation, and electroencephalography. Eleven subjects with moderate to severe OSA and 12 subjects with no or mild OSA were evaluated. Those with moderate to severe OSA showed an increasing trend in blood glucose levels after sleep onset, whereas those without or with mild OSA showed a decreasing trend (F = 8.933, p < 0.001). Delta band power also showed different trends during sleep between the two groups (F = 2.991, p = 0.009), and minimum saturation remained lower in the moderate to severe OSA group than in the no or mild OSA group. High degrees of coupling between nocturnal glucose levels and each OSA feature were observed. Altered trends in nocturnal glucose in moderate to severe OSA may reflect glucose intolerance and result in metabolic consequences. Managing the features of sleep-related OSA may have implications for metabolic management in the future.

The role of antioxidant vitamins and selenium in patients with obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a disorder characterized by recurrent episodes of obstruction ofthe upper respiratory tract during sleepoften accompanied by oxygen desaturations. Antioxidant defense mechanisms are important to prevent OSA-associated diseases and decrease mortality. We aimed to determine the levels ofselenium and vitamins A, C, and E in patients withOSA butwithout any comorbidities and compare the results with a control group, theorizing that the findings may be helpful to understand the antioxidant mechanisms in the pathogenesis ofOSA and associated diseases. We designed a case-control study with 146 subjects. Subjects were categorized into four groups by apnea-hypopneaindex (AHI) scores: control (n = 32; AHI < 5), mild OSA (n = 32; 5 ≤ AHI < 15), moderate OSA (n = 34; 15 ≤ AHI < 30), and severe OSA (n = 48; AHI ≥ 30) groups. Serum levels of selenium were measured by atomic absorption spectrometer. Vitamin A, C, and E levels were measured by high-performance liquid chromatography and ultraviolet (HPLC-UV) detector. After adjusting for age, BMI, and gender, serum selenium and vitamin A levels were found to behigher in patients withOSA compared with controls (ANCOVA, p < 0.008, and p = 0.014 respectively), and levels of these markers increased with the severity of the disease. AHI was positively correlated with selenium (r = 0.289; p < 0.001), and vitamin A levels (r = 0.276; p < 0.001). These results demonstrated that antioxidant response with increased vitamin A, and selenium concentrations, may be important defense mechanisms in patients withOSA patientswho do not have other comorbidities. Antioxidant nutrients or supplements may be implemented as a complementary treatment of OSA to support antioxidant defense.

The coexistence of obstructive sleep apnea in patients with slow coronary flow: a cross-sectional study

BACKGROUND: Interestingly, obstructive sleep apnea (OSA) and coronary slow-flow (CSF) have similar pathogenic mechanisms, including increased sympathetic activity and endothelial dysfunction. However, the association between OSA and CSF is not known well. If undiagnosed, OSA is a cause of increased cardiovascular morbidity and mortality. We investigated the presence of OSA in the patients diagnosed CSF after coronary angiography. METHODS: The prospective cross-sectional study included 4515 patients admitted angiography laboratory from February 2018 to March December 2019. After coronary angiography of 4515 patients, 336 patients were diagnosed as slow coronary flow. These patients were examined by pulmonology and sleep specialist. Of the 336 patients, 276 patients were found high risk in terms of OSA by using Berlin questionnaire (BQ). Only 75 of 276 patients underwent polysomnography (PSG) testing. Control group patients (n=40) had normal coronary artery and no OSA. RESULTS: Of 4515 patients, 336 (7.4%) met the criteria for CSF. After BQ, 276 of 336 patients had high-score BQ (82.1%). The study group consisted of 276 patients (188 males, 88 females). The mean ages of the study group were 48.48 ±7.61 years. Body mass index (BMI) according to WHO criteria was 33.02±2.18 kg/m2. When 75 patients underwent PSG were divided on two groups as mild OSA and moderate/severe OSA according to respiratory disturbance index (RDI). We found a significant positive correlation between mean corrected TIMI Frame Count (CTFC) and RDI. While CTFC-Lad in mild OSA group was 32.73, CTFC-Lad in moderate/severe OSA group was 35.04 (p=0.022). While CTFC-Cx in mild OSA group was 31.67, CTFC-Cx in moderate/severe OSA group was 35.26 (p=0.001). While CTFC-Rca in mild OSA group was 32.57, CTFC-Rca in moderate/severe OSA group was 36.33 (p<0.001). CONCLUSION: This study revealed the coexistence between CSF and OSA. Moreover, we demonstrated a significant relationship between mean CTFC and RDI. To determine the clinical association of OSA and CSF may be help to understand pathophysiology of CSF.

Relationship between sleep architecture and severity of obstructive sleep apnea

To investigate the effect of obstructive sleep apnea (OSA) on different sleep stages, and the relationship between N3 stage of non-rapid eye movement sleep and respiratory abnormal events. A total of 188 adult patients who underwent overnight polysomnography(PSG)monitoring in Sir Run Run shaw Hospital of Zhejiang University from June 24th to December 26th 2019 were enrolled in the study. OSA patients were classified into 3 groups (mild, moderate and severe) according to the apnea-hypopnea index (AHI). PSG data, AHI and the lowest SPO2 in each stage of sleep were compared among three groups. There was no significant difference in total sleep time and sleep efficiency among patients with different severity of OSA (all P>0.05). The proportion of N3 stage in moderate and severe OSA groups were significantly smaller than that in mild OSA group (all P<0.05). The proportion of N3 stage in severe OSA group was also smaller than that in moderate OSA group (P<0.05). In addition, severe OSA group had a longer latency of N3 stage than mild and moderate OSA groups (all P<0.05). The latency of N3 stage in moderate OSA group was longer than that in mild OSA group (P<0.05). The AHI in N3 stage was markedly lower than that in other sleep stages (all P<0.01), regardless of the severity of OSA. Supine AHI in N3 stage in mild and moderate groups was significantly lower than that in N1, N2 and rapid eye movement (REM) stages (all P<0.01). Supine AHI in N3 stage in severe group was also lower than that in N2 and REM stages (P<0.05 or P<0.01). The lowest SPO2 in N3 stage was significantly higher than that in N1, N2 and REM stages (P<0.05 or P<0.01), regardless of the severity of OSA. s The proportion of N3 stage is lower in OSA patients, and N3 stage has less sleep respiratory events than non-N3 stages. The results suggest that the increased N3 stage proportion may indicate less severity of OSA.

Reduction of postural nasal resistance following oropharyngeal surgery in patients with moderate-severe obstructive sleep apnea.

Patients with obstructive sleep apnea (OSA) have elevated nasopharyngeal resistances due to increased turbulent airflow. The study aims to investigate the effect of oropharyngeal surgery on nasal resistance in patients with various severity levels of OSA. Patients with greater or equal to 5 events hourly on the apnea-hypopnea index (AHI) were enrolled. Patients with retropalatal obstruction underwent uvulopalatopharyngoplasty, while patients with concurrent retrolingual obstruction under- went uvulopalatopharyngoplasty (UPPP) plus tongue base suspension. Before surgery and after surgery, subjective outcomes were assessed using a visual analog scale (VAS), and objective outcomes were assessed using overnight polysomnography and rhinomanometry. The limitation of the study was that UPPP instead of expansion sphincter pharyngoplasty was performed in this study. Sixty-two patients were enrolled, while 30 patients were diagnosed as mild OSA (group Mild) and 32 patients were mo- derate-severe OSA (group MS). The preoperative VAS of nasal obstruction in recumbency during sleep was significantly reduced after surgery in group MS. However, no significant differences between preoperative and postoperative VAS were found in group Mild. The postoperative anterior and posterior total nasal resistances (TNR) in sitting and supine positions were not significantly different from those before surgery in group. In contrast, the postoperative posterior TNR in supine position was 0.292±0.301(Pa/ cm3/s), compared with 0.425±0.343(Pa/cm3/s) preoperatively. Oropharyngeal surgery improves nasal obstruction during sleep and lowers the supine TNR measured in poste- rior rhinomanometry in patients with moderate-severe OSA. Oropharyngeal surgery is a possible treatment for postural nasal obstruction in patients with moderate-severe OSA.

Severe obstructive sleep apnea is associated with coronary microvascular dysfunction and obstruction in patients with ST-elevation myocardial infarction.

Coronary microvascular dysfunction and obstruction (CMVO) is a strong predictor of a poor prognosis in patients with ST-segment elevation myocardial infarction (STEMI). Although research has suggested that obstructive sleep apnea (OSA) exacerbates CMVO after primary percutaneous coronary intervention, data supporting a correlation between OSA and CMVO are limited. This study was performed to investigate whether OSA is associated with CMVO, detected as microvascular obstruction on cardiovascular magnetic resonance images, in patients with STEMI. Patients (N = 249) with a first STEMI underwent primary percutaneous coronary intervention. CMVO was evaluated on cardiovascular magnetic resonance images based on the presence of microvascular obstruction. OSA was classified into four levels of severity based on the respiratory event index (REI): absent (REI of <5), mild (REI of ≥5 to <15), moderate (REI of ≥15 to <30) and severe (REI of ≥30). The REI was significantly higher in the presence of microvascular obstruction (n = 139) than in its absence (n = 110) (REI of 12.8 vs. 10.7, respectively; p = 0.023). Microvascular obstruction was observed in 42%, 58%, 57% and 70% of patients in the absent, mild, moderate and severe OSA groups, respectively. Multiple logistic regression analysis showed that severe OSA was associated with increased odds of microvascular obstruction (odds ratio (OR), 5.10; 95% confidence interval (CI),1.61-16.2; p = 0.006). Mild and moderate OSA were also associated with increased odds of microvascular obstruction (mild OSA: OR, 2.88; 95% CI, 1.19-7.00; p = 0.019 and moderate OSA: OR, 3.79; 95% CI, 1.43-10.1; p = 0.008). Severe OSA was associated with CMVO after primary percutaneous coronary intervention in patients with STEMI.

The value of improved Mallampati grading combined with NoSAS in OSA screening

Objective:To evaluate the value of improved Mallampati grading combined with NoSAS questionnaire in screening for obstructive sleep apnea （OSA）. Method:A total of 344 patients admitted to our hospital for sleep disorders were studied. All patients were measured for their height, weight, neck circumference and other parameters. NoSAS scores, improved Mallampati grading and polysomnography （PSG） were performed in these patients. According to AHI in PSG monitoring results, patients were divided into non-osa group （AHI<5） 93 cases and OSA group 251 cases. The OSA group were divided into mild （AHI 5-15）, moderate（AHI 16-30） and severe OSA group（AHI>30） according to the PSG result. The ROC curve was plotted to evaluate the screening value of NoSAS and improved Mallampati grading combined with NoSAS for OSA. Result:With the NoSAS score of 8 or 9 as cutoffs for analysis, the sensitivity for OSA was 0.733 and 0.701; the specificity for OSA was 0.538 and 0.624, respectively. The sensitivity and specificity of NoSAS combined with improved Mallampati grading for screening OSA were 0.813 and 0.710, respectively. Conclusion:As a new screening tool, NoSAS questionnaire is simple and convenient, and has certain screening value to OSA. The improved Mallampati grading combined with NoSAS questionnaire can obviously improve the screening sensitivity and specificity of Osa, and has higher application value.

Is Vimentin the Cause or Effect of Obstructive Sleep Apnea Development?

In obstructive sleep apnea (OSA), hypoxia secondary to apnea and hypopnea and the resulting systemic inflammatory response are the main causes of comorbidities. The aim of this study was to investigate the relationship between OSA and vimentin, which plays an important role in the activation of cells that synthesize inflammatory cytokines. The study included 150 OSA patients (50 mild, 50 moderate, and 50 severe OSA) and 50 patients without OSA as a control group. Plasma vimentin levels were measured from peripheral blood samples using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The OSA patients in our study had significantly higher body mass index, apnea-hypopnea index (AHI), triglyceride level, mean oxygen desaturation, and plasma vimentin levels compared to the healthy control group (p = 0.007, 0.001, 0004, 0.001, and 0.001, respectively). Plasma vimentin level was significantly higher in the moderate and severe OSA groups compared to the control and mild OSA groups (p = 0.001 for all). There was no difference between severe and moderate OSA. There were significant correlations between plasma vimentin levels and OSA patients' AHI and mean oxygen desaturation (r = 0.46, p = 0.001; r = 0.214, p = 0.005). In this study, we observed significant positive correlations between plasma vimentin level and OSA severity, weight, AHI, and mean oxygen desaturation. Vimentin may have utility as a biomarker in the follow-up and treatment of OSA.

Severe obstructive sleep apnea is associated with circulating microRNAs related to heart failure, myocardial ischemia, and cancer proliferation.

Obstructive sleep apnea (OSA) is associated with multiple comorbid conditions including cardiovascular diseases and cancer. There is a growing interest in exploring biomarkers to understand the related mechanisms and improve the risk stratification of OSA. Circulating microRNAs (miRNAs) are single noncoding strands of nearly 22 nucleotides that posttranscriptionally regulate target gene expression. Our aim was to identify miRNA profiles associated with OSA. We studied 48 male subjects, mostly Caucasian (63%) and overweight, divided by polysomnography into the no OSA control group (n = 6), mild OSA group (n = 12), moderate OSA group (n = 15), and severe OSA group (n = 15). The study groups were matched for age, body mass index (BMI), and body fat composition. miRNA profiles were measured from peripheral whole blood using two steps: (1) microarray analysis comprising more than 2500 miRNAs in a subsample of 12 subjects (three from each group); and (2) validation phase using real-time quantitative polymerase chain reaction (RTqPCR). The microarray assessment identified 21 differentially expressed miRNAs among the groups. The RT-qPCR assessment showed that miR-1254 and miR-320e presented a gradual increase in expression parallel to OSA severity. Linear regression analysis showed that severe OSA was independently associated with miR-1254 (ß = 68.4; EP = 29.8; p = 0.02) and miR-320e (ß = 76.1; EP = 31.3; p = 0.02). Severe OSA is independently associated with miRNAs that are involved in heart failure (miR-1254), myocardial ischemia/reperfusion (miR-320e), and cell proliferation in some cancer types (miR-1254 and miR-320e). Future investigations addressing whether these miRs may provide prognostic information in OSA are needed.

Association of the serum irisin level with obstructive sleep apnea: a body mass index- and physical activity-matched study.

Obesity is strongly correlated with the pathogenesis of obstructive sleep apnea (OSA); myokines may play important roles in this condition. We performed a body mass index- (BMI) and physical activity- (PA) matched study to explore the relationship between the irisin level and OSA. Ninety-six consecutive participants were recruited. After matching in terms of BMI and PA, 28 OSA patients and 28 healthy controls were finally included. Whole-night laboratory-based polysomnography was used to identify OSA. The Recent Physical Activity Questionnaire and Epworth Sleepiness Scale Questionnaire were employed to assess PA over the past 4 weeks, and daytime sleepiness. We measured serum irisin, fasting blood glucose, and insulin levels in blood samples. The serum irisin concentrations differed significantly between the control, mild OSA, moderate OSA, and severe OSA groups (p < 0.001) and correlated significantly with the apnea/hypopnea index (AHI) (r = -0.787, p < 0.001). All of age, BMI, neck, waist and hip circumferences, fasting blood glucose level, and the Epworth Sleepiness Scale and PA scores were associated with irisin levels (p < 0.05). After adjustment for these factors, the serum irisin level was independently correlated with the AHI (r = -0.428, p = 0.002). On forward logistic regression analysis, the association remained significant in the final multiple regression model (β = -0.107, p < 0.001). The serum irisin concentration was significantly correlated with OSA severity, independently of BMI and PA. Further studies are needed to determine the molecular mechanisms in play.

High-resolution Peripheral Quantitative Computed Tomography for the Assessment of Bone Strength and Structure in Obstructive Sleep Apnea Patients

Objective To evaluate the bone strength and structure of patients with obstructive sleep apnea(OSA)by the high-resolution peripheral quantitative computed tomography(HR-pQCT)and to explore the relationship between OSA and osteoporosis. Methods Male patients who visited the Sleep Respiratory Center of our hospital from August 2017 to January 2019 were consecutively recruited.Clinical data including the results of Epworth sleep scale(ESS)scoring and overnight polysomnography were collected.HR-pQCT was used to compare the differences in bone geometry,density,and microstructure between OSA patients and non-OSA people;also,the radius and tibia on the non-dominant side were measured to explore the relationship between OSA and osteoporosis. Results A total of 83 subjects were enrolled in the study.The number of patients in the mild,moderate,and severe OSA groups and non-OSA group were 21,18,34,and 10,respectively.There was no significant difference in age,blood pressure,ESS score,sleep stage,and sleep efficiency among these four groups(P>0.05).Body mass index(BMI)and neck circumference were significantly different among these groups(F=4.234,P=0.008;F=3.100,P=0.031).There was no significant difference in the radius indicators(P>0.05).For tibia,there were significant differences among the four groups in the cortical area(Ct.Ar)(F=3.937,P=0.011).There were also significant differences in the bone microstructural indicators including trabecular thickness(Tb.Th)and cortical thickness(Ct.Th)(F=6.247,P=0.001;F=3.746,P=0.014),which were significantly lower in the three OSA groups than in the control group.Pairwise comparisons showed that the Ct.Ar in the severe OSA group was significantly higher than that in the mild OSA group(P=0.019)and Tb.Th in the control group was significantly higher than those in the mild and moderate OSA groups(P=0.006,P=0.001).Correlation analysis showed that,within a certain range,total volumetric bone mineral density(Tt.vBMD)and Tb.Th of radius and tibia were negatively correlated with age(r=-0.312,P=0.004;r=-0.328,P=0.002;r=-0.265,P=0.015;r=-0.280,P=0.010)and positively correlated with BMI(r=0.240,P=0.029;r=0.369,P=0.004;r=0.299,P=0.006;r=0.416,P=0.010).Stepwise multiple regression analysis showed that Tb.Th of radius and tibia were mostly correlated with BMI(β=0.262,P=0.008,R 2=0.243,F=6.270,P=0.000;β=0.494,P=0.000,R 2=0.186,F=7.243,P=0.000)and age(β=-0.216,P=0.030,R 2=0.243,F=6.270,P=0.000;β=-0.306,P=0.003,R 2=0.186,F=7.243,P=0.000).Tt.vBMD of radius had a certain correlation with sleep efficiency and with the decreasing nocturnal mean oxygen saturation caused by OSA(β=0.312,P=0.002, β=-0.249,P=0.012,R 2=0.327,F=7.482,P=0.000). Conclusions In non-elderly male populations,OSA mainly causes a decrease in Tb.Th and Ct.Th of the tibia.The changes in bone strength and structure are mainly related with age and body size and also have certain correlations with sleep efficiency and with the decreasing nocturnal mean oxygen saturation caused by OSA.

The correlation studies between ambulatory blood pressure and OSA in non-hypertensive patients

Objective:To discuss the changes and rules of nighttime blood pressure in obstructive sleep apnea(OSA) patients without hypertension.Method:Eighty-nine non-hypertensive patients whose office blood pressure was lower than 130/85 mmHg and diagnose with OSA by PSG in sleep monitoring room were choose as the research group.Forty non-hypertensive and polyp of vocal cord or vocal nodules patients whose office blood pressure was lower than 130/85 mmHg and diagnose with non-OSA by PSG were choose as matched group.All the patients were in treatment in our hospital from December 2017 to June 2018. All the patients got PSG,and the same time got the ambulatory blood pressure monitoring based on pulse transit time all night.Compared the mean value of systolic blood pressure,the mean value of diastolic blood pressure.Higher than 12 mmHg blood pressure rise index,the mean rise in blood pressure. The highest increase in blood pressure, maximum systolic pressure between the study group and the marched group all night.Result:The difference of all the test index between the study group and the marched group was significant(P<0.05).In OSA patients.The difference of all the test index between the severe OSA group and the mild OSA group or the moderate OSA group was significant(P<0.05).In severe OSA group.The difference between the fluctuation of blood pressure caused by respiratory events and spontaneous blood pressure fluctuation was significant(P=0.004).The difference of the mean value of diastolic blood pressure(P=0.032) blood pressure rise index(P=0.037) the mean rise in blood pressure(P=0.045) between age 55 or older patients and under 55years old patients.Conclusion:Ambulatory blood pressure monitoring synchronizatied in PSG contribute to the early diagnosis and prevention of hypertension in OSA patients.

Effect of moderate or severe obstructive sleep apnea on cardiac structure and function in patients with acute coronary syndrome

Objective: To investigate the effect of obstructive sleep apnea (OSA) on cardiac structure and function in patients with acute coronary syndrome (ACS). Methods: A total of 767 patients with ACS consecutively hospitalized at the Emergency & Critical Care Center of Beijing Anzhen Hospital from June 2015 to May 2017 were enrolled in this study. There were 637 males and 130 females. Patients who met the inclusion criteria according to the sleep apnea hypopnea index (AHI) were examined with portable sleep respiration monitoring. Patients were divided into moderate or severe OSA group (AHI≥15,n=389) and non or mild OSA group (AHI<15, n=78). The general information and echocar diographic results were analyzed. The data fitted normal distribution were compared between the groups with independent sample t test. Results: The body mass index [(27.8±3.6) vs (25.8±3.4) kg/m(2), t=-7.854, P<0.01], neck circumference [(41.1±4.2) vs (39.3±3.2) cm, t=-6.717, P<0.01] and waist-to-hip ratio (0.99±0.54 vs 0.97±0.53, t=-4.735, P<0.01) at admission were significantly higher in moderate or severe OSA group than those in non or mild OSA group. The left ventricular end-diastolic diameter, inter-ventricular septum thickness, left atrial diameter,right atrial diameter were all significantly higher, and the E/A peak ratio was remarkably lower in the moderate or severe OSA group (t=-2.130, 0.278, -3.045, -2.241, 2.260, all P<0.05). Conclusion: Moderate or severe OSA may aggravate cardiac remodeling and diastolic function in ACS patients.

Preliminary study on the relationship between OSA and renal function

Objective:To explore the relationship between obstructive sleep apnea(OSA) and renal function. Method:We collected the clinical data of 487 patients who underwent sleep monitoring in our hospital from January 2013 to December 2017 and excluded history of chronic heart disease, acute and chronic glomerulonephritis, and pyelonephritis. Among the 487 patients, 54 were in nonOSA control group and 433 were in OSA group, including 64 patients with mild OSA, 77 patients with moderate OSA, 108 patients with severe OSA, and 188 patients with extremly severe OSA. The eGFR was calculated using an equation combined serum creatinine and cystatin C. Then propensity score matching(PSM) was used to reduce differences in confounders among groups. The differences of creatinine, cystatin and eGFR between the control group and different degrees of OSA were compared, and the relationship between OSA severity and renal dysfunction was analyzed.Result:There was no statistically significant difference in creatinine between the OSA group and the control group. Serum cystatin C levels in the moderate OSA group and the extremly severe OSA group were higher compared with the control group(0.90±0.18)mg/L, (0.82±0.21) mg/L,P=0.026;(0.92±0.22) mg/L,(0.82±0.21) mg/L,P=0.006,there was no statistically significant difference in cystatin C level of mild OSA group or severe OSA group compared with the control group.The eGFR levels in the moderate OSA group and extremly severe OSA group were lower than that in the control group, 100.64±16.09, 108.57±19.31,P=0.012; 102.03±18.39, 108.57±19.31, P=0.024.After matching with the PSM, the serum cystatin C levels in the moderate OSA group and in the extremely severe OSA group were higher compared with the control group, (0.91±0.19) mg/L,P=0.028;(0.91±0.23) mg/L,P=0.031;(0.82±0.21) mg/L, but only in moderate OSA group, eGFR was lower than the control group,100.86±17.31,108.57±19.31,P<0.05. Conclusion: The renal function of OSA patients has different degrees of impairment. Renal function impairment and the severity of OSA do not show a single linear relationship.

The Association of Salivary Biomarkers With the Severity of Obstructive Sleep Apnea and Concomitant Hypertension

BackgroundWe aimed to assess the association between salivary alpha-amylase and salivary cortisol, and obstructive sleep apnea (OSA) severity. MethodsFifty-eight adults with suspected OSA were divided into the following 4 groups based on the apnea hypopnea index (AHI): control (AHI <5 events/hour), mild OSA (5 events/hour < AHI ≤15 events/hour), moderate OSA (15 events/hour < AHI ≤30 events/hour) and severe OSA (AHI >30 events/hour) groups. Salivary samples were collected after overnight polysomnography. Correlations between the salivary biomarkers and polysomnography parameters were analyzed. ResultsSalivary alpha-amylase levels of the moderate and severe OSA groups were significantly higher than those of the control and mild OSA groups, and no association was found between salivary cortisol and OSA severity. The salivary alpha-amylase levels were positively correlated with the AHI (r = 0.538; P < 0.01) and microarousal index (r = 0.541, P < 0.01), and negatively correlated with the lowest pulse oxygen saturation (r = −0.375, P < 0.01). Salivary cortisol levels were significantly higher in patients with hypertension than in those without hypertension (10.01 ± 2.77 ng/mL vs. 5.52 ± 1.90 ng/mL, P < 0.05), and the salivary alpha-amylase levels were highest in the OSA concomitant hypertension group (32.81 ± 11.85 U/mL). Areas under the receiver operator characteristic analysis revealed that the cutoff values of salivary alpha-amylase for identifying moderate-severe OSA and OSA concomitant hypertension were 17.64 U/mL (sensitivity 85%, specificity 91%) and 25.35 U/mL (sensitivity 70%, specificity 94%), respectively. ConclusionsSalivary alpha-amylase is positively associated with the severity of OSA and OSA concomitant hypertension.

Assessment of Neurocognitive Impairment in Obstructive Sleep Apnea

Sleep apnea is usually reported in south Indian population. The indications of obstructive sleep apnea (OSA) comprise of breathing difficulties particularly owing to obstruction in the upper airway tract. The present study investigated the effect of the syndrome, the patients documented with OSA, by categorizing the patients into mild, moderate and severe OSA groups depending on apnea-hyponea index (AHI), derived from sleep study (polysomnographic findings). The comparative evaluation of various outcomes considered in this study included healthy individuals (control group, AHI 30). Investigations were conducted on the subjects which evaluated baseline characteristics, polysomnographic data and neuro-cognitive performances by Mini-Mental State Examination (MMSE). The results revealed significantly higher body mass index (BMI), snoring and decresed sleep efficiency in patients with sleep apnea syndrome when compared with control group. OSA patients further exhibited compromised neuro-cognitive. The intensity of the impairments and difficulties increased with upsurge in severity of the syndrome among all patients. The findings of this work strongly indicated that impaired executive functioning; neuro-cognitive abnormalities exit in a heightened state among OSA patients, than in the normal healthy individuals, the control group. These findings in aggregate would help clinicians in diagnosis and in understanding the disease prognosis.

Quantitative analysis of carotid arterial calcification using airway CT in obstructive sleep apnea

ObjectiveTo evaluate the relationship between obstructive sleep apnea (OSA) severity and carotid arterial calcification by quantitative analysis using airway computed tomography (CT). MethodsThis study included a total of 180 consecutive OSA patients aged 45–80years underwent polysomnography and airway CT between March 2014 and October 2016. The subjects were divided into three groups based on the results of the respiratory disturbance index (RDI): mild (RDI 5–14, n=29), moderate (RDI 15–29, n=50), and severe (RDI≥30, n=101). The extent of carotid arterial calcification on each airway CT scan was quantified according to the modified Agatston scoring method. Differences among the three groups in clinical characteristics including age, gender, body mass index (BMI), comorbid disease, blood pressure, total cholesterol, and carotid arterial calcification score (CarACS) were analyzed. ResultsThe severe OSA group showed significantly stronger predominance for male and smoker, higher prevalence of diabetes, and larger BMI than those of mild and moderate OSA groups. The mean CarACS was significantly different among the three groups (mild RDI: 4.3±13.4, moderate RDI: 7.4±28.8, severe RDI: 48.6±121.6, P=0.011). Univariate linear regression showed that RDI, age, hypertension, male sex and diabetes significantly influenced on the CarACS. In a multivariate linear regression model, the CarACS was related to age, male sex, and diabetes. ConclusionsThe patients with severe OSA showed larger CarACS and a higher prevalence of atherosclerotic risk factors. The CarACS was correlated with severity of OSA, which might be more dependent on the conventional risk factors of atherosclerosis.

The association between glycometabolism and nonalcoholic fatty liver disease in patients with obstructive sleep apnea

PurposeGrowing evidence has revealed that nonalcoholic fatty liver disease (NAFLD) is associated with type 2 diabetes. This study aimed to assess the association between glycometabolism and NAFLD in patients with obstructive sleep apnea (OSA).MethodsPatients with suspected OSA were enrolled consecutively and then underwent polysomnography, liver ultrasound, and biochemical measurements. Logistic regressions were used to identify factors associated with NAFLD.ResultsIn total, 415 patients were included. The prevalence of NAFLD in the non-OSA, mild OSA, moderate OSA, and severe OSA groups was 37.21%, 69.09%, 68.34%, and 78.08%, respectively. Stepwise logistic regression suggested that percentage of total sleep time spent with oxygen saturation of < 90% (TS90), lowest oxygen saturation (LaSO2), and homeostatic model assessment of insulin resistance (HOMA-IR) were independently associated with NAFLD in all subjects, after adjusting for confounders (odds ratio [OR] = 1.037, p = 0.014; OR = 1.056, p = 0.004; OR = 0.732, p = 0.009; respectively). TS90, LaSO2, and HOMA-IR were also independent predictors for NAFLD in patients with mild and moderate OSA, whereas TS90, LaSO2, and ODI were independent predictors for NAFLD in patients with severe OSA.ConclusionsThere is a relationship between OSA and NAFLD, and the combination of disordered glycometabolism and intermittent hypoxia may act as a “two hit” mechanism to promote the development of NAFLD. Furthermore, intermittent hypoxia alone was an independent predictor for NAFLD in severe OSA patients.

The Presence of Conjunctivochalasis in Obstructive Sleep Apnea Patients.

The aim of our study was to detect the presence of conjunctivochalasis (CCh) in obstructive sleep apnea (OSA) patients. We included 54 subjects (41 OSA patients and 14 control subjects) in the study. All the patients were assessed regarding the presence and stage of CCh. The patients were grouped according to their apnea-hypopnea index as determined during nocturnal polysomnography in our laboratory as mild (12 patients), moderate (16 patients), and severe (13 patients) OSA. The CCh rate was 87.8% in the OSA group and 57.1% in the control group (P=0.022). Mean CCh stage was 1.58±1.24, 2.38±0.88, and 2.15±0.98 in the mild, moderate, and severe OSA groups, respectively, and 0.71±0.72 in the control group (P=0.0001). The moderate and severe OSA groups were associated with higher rates and more advanced stages of CCh. We believe that detailed conjunctival assessment is necessary for patients with complaints such as burning, stinging, and foreign body sensation, which we frequently confront in daily practice. In particular, young patients diagnosed with CCh must be carefully assessed regarding sleep apnea. In light of the above findings, we suggest that patients with ocular surface symptoms that are not relieved by topical medical treatment should be assessed for CCh and OSA. Longitudinal studies monitoring the response of CCh to OSA treatment are needed to clarify the relationship between CCh and OSA.

Relations Between Hyoid-Related Cephalometric Measurements and Severity of Obstructive Sleep Apnea.

To evaluate the relationship between the hyoid-related cephalometric measurements and the apnea-hypopnea index (AHI) in patients diagnosed with obstructive sleep apnea (OSA). A total of 56 subjects were evaluated by lateral cephalometric radiography and polysomnography (PSG). The OSA diagnosis was made according to the patients' AHI. Included were 13 primary snoring, 16 mild OSA, 10 moderate OSA, and 17 severe OSA. C3-hyoid distance and mentum-hyoid distance were measured on lateral cephalogram. Cephalometric measurements and PSG parameters were compared among the different OSA groups. The distance between the mentum and hyoid was significantly longer in the severe OSA group than in the primary snoring, mild OSA, and moderate OSA groups (P = 0.029). There was a significant positive correlation between the AHI value and the distance of the mentum hyoid (r = 0.368, P = 0.005). The C3-hyoid distance among the groups was not statistically significant different (P = 0.889). The mentum-hyoid distance of patients with severe OSA was longer compared to the other OSA groups. These patients might have more benefit from the surgeries that have an impact on the position of the hyoid bone compared to other patients with OSA.