Lowest Oxyhemoglobin Saturation Research Articles

Tumor-Derived Exosomes Promote Tumor Growth Through Modulating Microvascular Hemodynamics in a Human Ovarian Cancer Xenograft Model.

Abnormal tumor vascular network contributes to aberrant blood perfusion and reduced oxygenation in tumors, which lead to poor efficacy of chemotherapy and radiotherapy. We aimed to explore the effects of the tumor-derived exosomes (TDEs) and C188-9 (a small molecule inhibitor of signal transducer and activator of transcription 3, STAT3) on tumor microvascular hemodynamics and determine which blood flow oscillations for various frequency intervals are responsible for these changes. Microvascular hemodynamics parameters were recorded using a PeriFlux 6000 EPOS system in tumor surface in a nude mouse subcutaneous xenograft model. Oscillations of laser Doppler flowmetry (LDF) signal were investigated by wavelet transform analysis. TDEs facilitated tumor growth at least partially was associated with increasing blood flow in smaller vessels with lower speed and decreasing the blood flow at larger vessels with higher speed. Lower oxyhemoglobin saturation (SO2) on tumor surface was aggravated by TDEs, and C188-9 treatment significantly alleviated this decrease. Wavelet transform spectral analysis revealed that TDEs increased the amplitude of oscillations in four frequency intervals related to endothelial (NO-dependent and -independent), myogenic and neurogenic activities, and C188-9 had no effect on this increase. TDEs facilitated tumor growth partially was associated with increasing blood flow in distributing vessels, reducing blood perfusion in larger vessels, and lowering SO2 on tumor surface. Enhanced vascular smooth muscle, endothelial and neurogenic activities occurred in tumor superficial zone.

The Correlation between the Severity of Obstructive Sleep Apnea and Insulin Resistance in a Japanese Population.

Background: Repetitive episodes of apnea and hypopnea during sleep in patients with obstructive sleep apnea (OSA) are known to increase the risk of atherosclerosis. Underlying obesity and related disorders, such as insulin resistance, are indirectly related to the development of atherosclerosis. In addition, OSA is independently associated with insulin resistance; however, data regarding this relationship are scarce in Japanese populations. Methods: This study aimed to examine the relationship between the severity of OSA and insulin resistance in a Japanese population. We analyzed the data of consecutive patients who were referred for polysomnography under clinical suspicion of developing OSA and who did not have diabetes mellitus or any cardiovascular disease. Multiple regression analyses were performed to determine the relationship between the severity of OSA and insulin resistance. Results: The data from a total of 483 consecutive patients were analyzed. The median apnea-hypopnea index (AHI) was 40.9/h (interquartile range: 26.5, 59.1) and the median homeostasis model assessment for insulin resistance (HOMA-IR) was 2.00 (interquartile range: 1.25, 3.50). Multiple regression analyses revealed that the AHI, the lowest oxyhemoglobin saturation (SO2), and the percentage of time spent on SO2 < 90% were independently correlated with HOMA-IR (an adjusted R-squared value of 0.01278821, p = 0.014; an adjusted R-squared value of -0.01481952, p = 0.009; and an adjusted R-squared value of 0.018456581, p = 0.003, respectively). Conclusions: The severity of OSA is associated with insulin resistance assessed by HOMA-IR in a Japanese population.

Virtual Surgical Planning for Patients with Skeletal-Dental and Obstructive Sleep Apnea Syndrome.

The integration of virtual surgical planning (VSP) for the treatment of skeletal, dental, and facial abnormalities and obstructive sleep apnea (OSA) with maxillofacial surgery has catapulted surgical planning. Although reported for treating skeletal dental abnormalities and dental implant surgery, a paucity of knowledge existed reporting the feasibility and resultant outcome measures when virtual surgical planning was employed for planning maxillary and mandibular surgery for OSA patients. The surgery first approach is at the forefront of advancing maxillofacial surgery. Case series reporting success with the surgery first approach for patients with skeletal-dental and sleep apnea patients have been reported. In sleep apnea patients, clinically significant reductions in AHI (apnea hypopnea index) and improvement of low oxyhemoglobin saturation have been achieved. More so, significant improvement in the posterior airway space at the occlusal and mandibular planes were achieved, while preserving aesthetic norms as measured by tooth to lip measurements. VSP is a feasible tool used for predicting surgical outcome measures in maxillomandibular advancement surgery for patients with skeletal, dental, facial and OSA derangements.

A Machine Learning Model for Predicting Hospitalization in Patients with Respiratory Symptoms during the COVID-19 Pandemic.

A machine learning approach is a useful tool for risk-stratifying patients with respiratory symptoms during the COVID-19 pandemic, as it is still evolving. We aimed to verify the predictive capacity of a gradient boosting decision trees (XGboost) algorithm to select the most important predictors including clinical and demographic parameters in patients who sought medical support due to respiratory signs and symptoms (RAPID RISK COVID-19). A total of 7336 patients were enrolled in the study, including 6596 patients that did not require hospitalization and 740 that required hospitalization. We identified that patients with respiratory signs and symptoms, in particular, lower oxyhemoglobin saturation by pulse oximetry (SpO2) and higher respiratory rate, fever, higher heart rate, and lower levels of blood pressure, associated with age, male sex, and the underlying conditions of diabetes mellitus and hypertension, required hospitalization more often. The predictive model yielded a ROC curve with an area under the curve (AUC) of 0.9181 (95% CI, 0.9001 to 0.9361). In conclusion, our model had a high discriminatory value which enabled the identification of a clinical and demographic profile predictive, preventive, and personalized of COVID-19 severity symptoms.

Central and mixed sleep apnea related to patients treated with maxillomandibular advancement for obstructive sleep apnea: A retrospective cohort study

The aim of this study was to evaluate the clinical efficacy of maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) patients with a percentage of central and mixed apnea index in the total apnea−hypopnea index (CMAI%) ≧25%.Patients treated with MMA for OSA were retrospectively evaluated for baseline and postoperative patient data and polysomnographic results. The pre- and postoperative obstructive, central and mixed apnea parameters were compared.Of the included 78 patients, 21 patients (27%) presented with CMAI% ≧25% (median CMAI%, 49.1%; 35.9–63.8) prior to MMA. In 67% of these cases, MMA resulted in CMAI% <25 (median CMAI%, 6.1%; 2.1–8.9) and significantly improved the apnea−hypopnea index (AHI) (p < 0.001), the lowest oxyhemoglobin saturation (p < 0.001), central and mixed apnea index (p < 0.001), percentage of central and mixed apneas of total AHI (p = 0.004), central apnea index (p < 0.001), and mixed apnea index (p < 0.001). CMAI% ≧25% emerged in 25% of patients after MMA (median CMAI%, 49.1%; 35.9–63.8).Within the undeniable limitations of the study, it seems that the presence of CMAI% ≧25% should not be regarded as a contraindication for MMA in OSA patients.

Comparative Study of Clinical Manifestations and Sleep Structure in Children with Obstructive Sleep Apnea-hypopnea Syndrome with Different BMI

To compare and analyze the clinical manifestations and sleep structure of children with obstructive sleep apnea-hypopneasyndrome (OSAHS) with different body mass index (BMI). 452 children who were diagnosed with OSAHS between December 2016 and February 2021 by the Department of Respiratory Medicine, Children's Hospital of Soochow University were included in the study. All of them did polysomnography (PSG). They were divided, according to their BMI, into the normal BMI group, the overweight group, and the obesity group. Their clinical data and PSG results were collected. 287 boys (63.5%) and 165 girls (36.5%) were enrolled, with their age ranging between 3 and 15, and the median age being 5.5 (4.5, 7.0). Their BMI ranged between 12.09 kg/m 2 and 38.48 kg/m 2, with the median being 16.29 kg/m 2. 275 cases (60.8%) had normal BMI, 76 cases (16.8%) were overweight, and 101 cases (22.3%) were obese. There was no significant difference in the distribution of clinical manifestations and severity of OSAHS among the three groups. The duration and proportion of rapid eye movement (REM) stage sleep in the obese group was lower than that of the overweight and the normal BMI groups ( P<0.05). The lowest oxyhemoglobin saturation (LSaO 2) of children in the overweight group was lower than that of the normal BMI group ( P=0.050). The oxygen desaturation index (ODI) of the obese group was higher than that of the normal BMI and the overweight groups ( P<0.05). Obesity worsens the degree of hypoxia in children with OSAHS and affects their sleep structure.

Acute Effect of Repeated Sprint Exercise With Blood Flow Restriction During Rest Periods on Muscle Oxygenation.

PurposeThis study aimed to examine the effect of applying BFR during rest periods of repeated cycling sprints on muscle oxygenation.MethodsSeven active males performed 5 × 10-s maximal pedaling efforts with 40-s passive rest, with or without BFR application during rest period. BFR was applied for 30 s between sprints (between 5 and 35 s into rest) through a pneumatic pressure cuff inflated at 140 mmHg. Vastus lateralis muscle oxygenation was monitored using near-infrared spectroscopy. In addition, blood lactate concentration and heart rate were also evaluated.ResultsThe BFR trial showed significantly lower oxyhemoglobin (oxy-Hb) and tissue saturation (StO2) levels than the CON trial (P < 0.05). However, power output and blood lactate concentration did not significantly differ between the two trials (P > 0.05).ConclusionApplying BFR during rest periods of repeated cycling sprints decreased muscle oxygenation of active musculature, without interfering with power output during sprints.

Effects of maxillomandibular advancement surgery on a skeletal Class III patient with obstructive sleep apnea: A case report

This case report describes the successful surgical treatment of a patient diagnosed with obstructive sleep apnea (OSA). A 55-year-old Caucasian male patient with a body mass index (BMI) of 25.6 kg/m2 sought treatment with a chief concern of excessive daytime sleepiness and fatigue. An initial polysomnography report showed moderate OSA with an apnea-hypopnea index (AHI) of 21.2 events/h, and Epworth Sleepiness Score (ESS) of 12/24. The patient was initially prescribed with CPAP treatment but was unable to tolerate treatment after a few months. Clinical and radiographic examination revealed a concave facial profile with maxillary retrognathism. Intraoral examination revealed generalized gingival recession, missing upper lateral incisors and lower first premolars, anterior crossbite, and maxillary transverse deficiency with bilateral posterior crossbite. The lateral cephalogram showed a narrow posterior airway space at the level of the base of the tongue. The patient was treated with maxillomandibular advancement (MMA) surgery to improve airway obstruction. Results showed balanced facial esthetic and stable occlusion with a complete resolution of the patient’s OSA and a post-operative improvement of AHI from 21.2 to 0.7 events/h and ESS from 12/24 to 3/24. The lowest oxyhemoglobin saturation during sleep was improved to 97%, and the BMI decreased from 25.6 to 25.2 kg/m2. These results suggest that MMA surgical procedure can be used as a definitive treatment for patients with maxillomandibular deficiency and OSA.

Study on the correlation between OSAS and thoracic deformity in children: A retrospective single-center study in China

ObjectiveTo evaluate the correlation between obstructive sleep apnea syndrome (OSAS) and the development of thoracic deformity in Children. MethodsA retrospective analysis was performed with the medical records of 39 pediatric OSAS patients with thoracic deformity and matching 39 without thoracic deformity as control group between January 2015 and June 2019. The contrast was performed with age, gender, height, weight, body mass index (BMI), apnea/hypopnea index (AHI), the lowest oxyhemoglobin saturation (loSpO2)at night, tonsil and adenoid size, Alkaline phosphatase (ALP)and trace elements and metals between two groups. ResultsBMI, AHI, the lowest SpO2, Phosphorus and Zinc were the risk factors of thoracic deformity. Age, gender, disease history, the size of tonsil and adenoid, ALP and other trace elements were no significant difference occurred between two groups. ConclusionOSAS characterized by apnea and hypoxia which are caused by narrow upper airway may be one cause of thoracic deformity in children. Pediatricians, thoracic and otolaryngologic surgeons should be alert to OSAS when thoracic deformities are diagnosed in children.

Association Between Perfusate Oxygenation and Acute Lung Injury in Tetralogy of Fallot Surgery.

Little is known regarding precise estimates of the association between perfusate oxygenation (PpO2) and acute lung injury (ALI) following tetralogy of Fallot repair. The objective is to investigate PpO2 and the risk of ALI following tetralogy of Fallot repair in pediatric patients. We conducted a nested case-control study within a prospective Chinese TedaICH cohort including 134 ALI patients aged 1 month to 18 years undergoing complete repair of tetralogy of Fallot, and each was matched to two controls. We selected the highest PpO2 during aortic crossclamp as the exposure. Conditional logistic regression was used to quantify the association between PpO2 and overall ALI risk by covariates of interest. We identified and integrated the risk covariates to build ALI nomograms and internally validated the nomograms using bootstrapping. After adjusting for covariates, continuously and categorically higher PpO2 values were associated with ALI risk (all P < 0.05), especially for those with a z-score of pulmonary annulus < -4.0 (P = 0.002), McGoon ratio < 1.5 (P = 0.029), and major aortopulmonary collateral arteries (P = 0.005), despite no statistical heterogeneity (all P interaction >0.05). Younger age, lower oxyhemoglobin saturation, untreated minor aortopulmonary collateral arteries, transannular patch, larger transpulmonary gradient, major transfusion, and longer cardiopulmonary bypass time were independent risk factors for ALI (all P < 0.05). Combining the PpO2 nomogram provided further risk discriminative information on ALI diagnosis compared with the covariate-based nomogram alone in the training cohort (AUC 0.865, 95% CI [0.828-0.903] vs. 0.869 [0.832-0.906], respectively) with no statistical significance (P = 0.445). The findings suggested an association between high PpO2 and ALI risk, and more importance should be attached to independent risk factors for ALI.

Polysomnography Parameters Assessing Gas Exchange Best Predict Postoperative Respiratory Complications Following Adenotonsillectomy in Children With Severe OSA.

Adenotonsillectomy (AT) is the treatment of choice for obstructive sleep apnea (OSA) in children with adenotonsillar hypertrophy. Severe OSA, identified by the apnea-hypopnea index (AHI), is a risk factor for surgical complications and AHI thresholds are used by surgeons to decide elective postoperative hospital admissions. The objective of this study was to identify the prevalence of surgical complications of AT in children with severe OSA and determine their association with specific parameters of polysomnography (PSG). Retrospective evaluation of respiratory and nonrespiratory complications in children undergoing AT for severe OSA was performed. Events were then compared to several individual PSG indices. PSG indices included classic parameters such as AHI, and obstructive apnea indexes (OAI) as well as gas exchange parameters including the oxygen desaturation index (ODI), lowest oxyhemoglobin saturation (lowest SpO₂), peak end-tidal CO₂ (peak ETCO₂), the percentage of the total sleep time (%TST) with ETCO₂ > 50 mmHg (%TST ETCO₂ > 50 mmHg) and oxygen saturation < 90% (%TST O₂ < 90%). A total of 158 children were identified with severe OSA. Major respiratory complications occurred in 21.5% and were only associated with the ODI (P = .014), lowest SpO₂ (P = .001) and %TST O₂ < 90% (P < .001). Minor respiratory complications occurred in 19.6% and these were not associated with any PSG parameters. Major nonrespiratory complications occurred in 4.4% and also were not associated with any PSG parameters; however, minor nonrespiratory complications occurring in 37.3%, and were associated with %TST O₂ < 90% (P < 0.001). PSG measures of gas exchange are strongly associated with postoperative complications of AT and are better suited for postoperative planning than classic indices such as AHI. Molero-Ramirez H, Tamae Kakazu M, Baroody F, Bhattacharjee R. Polysomnography parameters assessing gas exchange best predict postoperative respiratory complications following adenotonsillectomy in children with severe OSA. J Clin Sleep Med. 2019;15(9):1251-1259.

Retinal oximetry and systemic arterial oxygen levels.

Retinal oximetry and systemic arterial oxygen levels.

Impact of pulmonary emphysema on exercise capacity and its physiological determinants in chronic obstructive pulmonary disease

Exercise limitation is common in chronic obstructive pulmonary disease (COPD). We determined the impact of pulmonary emphysema on the physiological response to exercise independent of contemporary measures of COPD severity. Smokers 40–79 years old with COPD underwent computed tomography, pulmonary function tesing, and symptom-limited incremental exercise testing. COPD severity was quantified according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) by spirometry (GOLD 1–4); and symptom burden and exacerbation risk (GOLD A-D). Emphysema severity was quantified as the percent lung volume <−950 Hounsfield units. Regression models adjusted for age, gender, body size, smoking status, airflow limitation, symptom burden and exacerbation risk. Among 67 COPD subjects (age 67 ± 8 years; 75% male; GOLD 1–4: 11%, 43%, 30%, 16%), median percent emphysema was 11%, and peak power output (PPO) was 61 ± 32 W. Higher percent emphysema independently predicted lower PPO (−24 W per 10% increment in emphysema; 95%CI −41 to −7 W). Throughout exercise, higher percent emphysema predicted 1) higher minute ventilation, ventilatory equivalent for CO2, and heart rate; and 2) lower oxy-hemoglobin saturation, and end-tidal PCO2. Independent of contemporary measures of COPD severity, the extent of pulmonary emphysema predicts lower exercise capacity, ventilatory inefficiency, impaired gas-exchange and increased heart rate response to exercise.

A5889 Metabolic Syndrome and Lower Oxyhemoglobin Saturation in Tibet Autonomous Region, China

A5889 Metabolic Syndrome and Lower Oxyhemoglobin Saturation in Tibet Autonomous Region, China

深圳市新生儿先心病出生监测和绿色通道的建立

目的：了解深圳市先心病发病率，初步建立先心病救治绿色通道管理系统。方法：筛查2016年上半年在深圳市部分辖区内妇幼医院连续分娩的新生活产婴儿。如果临床表现和经皮血氧饱和度的测定结果提示有先心病可能者推荐为继续做超声心动图检查。对于重症先心病病例，通过绿色通道转诊至先心病诊疗终端医院进行相应的干预、治疗。结果：三家医院连续分娩14,221名活产新生儿，其中男孩53.2% (7566例)，女孩46.8% (6655例)；足月儿95.8%，早产儿(<孕37周) 4.2%。平均出生体重3310 ± 460 g，超声心动图检查的平均时间为生后47小时(2~97小时)。共诊断先心病患儿138名(男孩41.3%，女孩58.7%)，发病率9.7‰ (138/14221)，其中轻症先心病约占2/3 (92/138)。最常见的先心病为VSD (6.3‰)，其中肌部缺损占将近2/3，其次是ASD (2.3‰)、PDA (0.5‰)。在所有先心病患儿中，61例(44.2%)患儿通过心脏杂音检出，提示新生儿期间许多先心病没有杂音，故不能单独依靠心脏听诊来区分是否存在先心病。有2例重症先心病患儿于新生儿期进行手术矫治。4例于婴儿期行矫治术。结论：本研究初步明确深圳市先心病的发病率为9.7‰，对重症先心病开通了先心病诊疗的绿色通道系统。 Objective: To study the morbidity of congenital heart disease (CHD) in Shenzhen, establish a green channel system of CHD management. Methods: Live birth babies were monitored for CHD screening in 3 women and children hospitals in Shenzhen. Echocardiography was recommended if a baby had suspicious CHD clinical manifestation and/or low oxyhemoglobin saturation. Severe CHD cases were transferred through green channel system to terminal CHD diagnosis and treatment hospital for further management and intervention. Results: Continuous partal 14,221 live babies in the first half year of 2016 were monitored with 7566 male babies and 6655 female babies. CHD diagnoses were established in 138 cases (male 41.3%, female 58.7%). The morbidity of CHD was 9.7‰ (138/14221). Most CHD cases were mild (92/138). The most common CHD was ventricular septal defect (6.3‰), secondly atrial septal defect (2.3‰), the third patent ductus arteriosus (0.5‰). Heart murmurs were found only in 61 babies. That meant many CHD babies had no heart murmurs in the newborn period. So CHD diagnosis in this period didn’t rely on heart murmurs only. Surgical procedure was implemented among two severe babies in the newborn period, 4 cases in infant period. Conclusion: The study preliminarily reveals that the morbidity of CHD in Shenzhen is 9.7‰. The green channel system is helpful to CHD management.

Hyoid myotomy and suspension without simultaneous palate or tongue base surgeryfor obstructive sleep apnea.

ObjectiveDetermine the effects of hyoid myotomy and suspension (HMS) without concurrent palatal or tongue base sleep surgery for obstructive sleep apnea (OSA).MethodPatients with OSA treated with HMS were identified using CPT code (21685) at an academic and private sleep surgery clinic. Those who underwent concurrent palatal or tongue base sleep surgery were excluded. Outcomes included simultaneous procedures, apnea-hypopnea index (AHI), lowest oxyhemoglobin saturation (LSAT), and Epworth Sleepiness Scale (ESS).ResultsNineteen patients with OSA underwent HMS without palatal or tongue base sleep surgery. The average age at surgery was (55.3 ± 13.5) years with a majority of patients being male (71%). Concurrent procedures included the following: torus mandibularis excision (n = 1), endoscopic sinus surgery (n = 4), septoplasty (n = 10), inferior turbinate reduction (n = 12), and nasal valve repair (n = 2). AHI improved significantly from (39.7 ± 21.2) events/h to (22.6 ± 22.7) events/h after HMS (P < 0.01), which represented a 43% reduction. LSAT significantly increased from (82.2% ± 9.9%) to (86.6% ± 6.2%), P < 0.01. There was no improvement in ESS after surgery (8.2 ± 4.4) to (8.3 ± 5.2), P = 0.904. A subset of patients with severe OSA (AHI > 30 events/h) had an improvement in AHI from (49.9 ± 16.6) events/h to (29.1 ± 24.9) events/h, P < 0.01.ConclusionHMS without palatal or tongue base sleep surgery improves OSA severity. It can be considered as a valid option in the treatment of OSA in appropriately-selected patients.

Retinal oximetry measures systemic hypoxia in central nervous system vessels in chronic obstructive pulmonary disease.

BackgroundDetermination of the blood oxyhemoglobin saturation in the retinal vessels of the eye can be achieved through spectrophotometric retinal oximetry which provides access to the state of oxyhemoglobin saturation in the central nervous system circulation. The purpose of this study was to test the capability of the Oxymap T1 oximeter to detect systemic hypoxemia and the effect of supplemental oxygen on retinal vessel oxyhemoglobin saturation.MethodsOxygen saturation of hemoglobin in retinal arterioles and venules was measured in 11 subjects with severe chronic obstructive pulmonary disease (COPD) on long term oxygen therapy. Measurements were made with and without their daily supplemental oxygen. Eleven healthy age and gender matched subjects were measured during ambient air breathing for comparison of oxyhemoglobin saturation in retinal arterioles and venules. Retinal arteriolar oxyhemoglobin saturation in COPD subjects inspiring ambient air was compared with finger pulse oximetry and blood samples from radial artery.ResultsCOPD subjects had significantly lower oxyhemoglobin saturation during ambient air breathing than healthy controls in both retinal arterioles (87.2%±4.9% vs. 93.4%±4.3%, p = 0.02; n = 11) and venules (45.0%±10.3% vs. 55.2%±5.5%, p = 0.01). Administration of their prescribed supplemental oxygen increased oxyhemoglobin saturation in retinal arterioles (87.2%±4.9% to 89.5%±6.0%, p = 0.02) but not in venules (45.0%±10.3% to 46.7%±12.8%, p = 0.3). Retinal oximetry values were slightly lower than radial artery blood values (mean percentage points difference = -5.0±5.4, 95% CI: -15.68 to 5.67) and finger pulse oximetry values (-3.1±5.5, 95% CI: -14.05 to 7.84).ConclusionsThe noninvasive Oxymap T1 retinal oximetry detects hypoxemia in central nervous system vessels in patients with severe COPD compared with healthy controls. The instrument is sensitive to changes in oxygen breathing but displays slightly lower measures than finger pulse oximetry or radial artery measures. With further technological improvement, retinal oximetry may offer noninvasive “on-line” measurement of oxygen levels in central circulation in general anesthesia and critically ill patients.

OS 33-08 OBSTRUCTIVE SLEEP APNEA PROMOTES CARDIOVASCULAR RISK IN HYPERTENSIVE POPULATIONS

Objective: Current study sought to evaluate the effects of obstructive sleep apnea (OSA) plus hypertension (HTN) on prevalent cardiovascular diseases (CVD). Design and Method: This was a cross-sectional study and a total of 1889 subjects were enrolled. The apnea-hypopnea index (AHI) was measured by polysomnography and OSA degree was classified as mild (AHI 5–14.9) and moderate-severe (AHI ≥ 15), and AHI < 5 was considered no-OSA. Mean and lowest oxyhemoglobin saturation (SaO2) was detected by pulse oximetry. Between-group differences were assessed and logistic regression analysis was used to analyze the effects of OSA plus HTN on prevalent CVD which included coronary heart disease, ischemic stroke, aortic dissection and aneurysm. Results: Compared to normotensive subjects, hypertensive subjects were older and had higher body mass index, neck girth, waist-hip ratio, blood pressure, AHI, and low density lipoprotein. Conversely, mean and lowest SaO2 levels were significantly lower. Similar trends were observed in moderate-severe-OSA subjects compared to subjects with mild-OSA or no-OSA. Logistic regression analysis showed that in unadjusted model, compared to subjects with no-OSA and no-HTN (reference group), subjects with either OSA or HTN had higher CVD prevalence, with most prominent in HTN plus moderate-severe-OSA group (OR: 2.638 and 95 % CI: 1.942–3.583). In normotensive subjects, after adjusting for covariates, the effects of OSA (regardless of severity) on CVD were attenuated to nonsignificant. In hypertensive subjects, however, the effects of OSA on CVD remained significant but were reduced, with HTN plus moderate-severe-OSA was attenuated most prominently (OR: 1.836 and 95 % CI: 1.266–2.663). Further adjusting for mean and lowest SaO2, the effects of OSA remained significant and were promoted in subjects with HTN plus mild-OSA and HTN plus no-OSA, but not in subjects with HTN plus moderate-severe OSA. Conclusions: OSA promotes CV risk in hypertensive subjects, which is independent of mean and lowest SaO2.

Association of obstructive sleep apnea plus hypertension and prevalent cardiovascular diseases: A cross-sectional study.

Current study sought to evaluate the associations of obstructive sleep apnea (OSA) plus hypertension (HTN) and prevalent cardiovascular diseases (CVD).This was a cross-sectional study and a total of 1889 subjects were enrolled. The apnea-hypopnea index (AHI) was measured by polysomnography and OSA degree was classified as mild (AHI 5–14.9) and moderate-severe (AHI ≥ 15), and AHI < 5 was considered no-OSA. Mean and lowest oxyhemoglobin saturation (SaO2) was detected by pulse oximetry. Between-group differences were assessed and logistic regression analysis was used to analyze the association of OSA plus HTN and prevalent CVD.Compared to normotensive subjects, hypertensive subjects were older and had higher body mass index (BMI), neck girth, waist–hip ratio, AHI, and low-density lipoprotein cholesterol (LDL-C) level. Conversely, mean and lowest SaO2 levels were significantly lower. Logistic regression analysis showed that in an unadjusted model, compared to subjects with no-OSA and no-HTN (reference group), the association of HTN plus moderate-severe-OSA and prevalent CVD was the most prominent (odds ratio [OR]: 2.638 and 95% confidence interval [CI]: 1.942–3.583). In normotensive subjects, after adjusted for potential covariates, the associations of OSA (regardless of severity) and prevalent CVD were attenuated to nonsignificant. In hypertensive subjects, however, the associations remained significant but were reduced. Further adjusted for mean and lowest SaO2, the associations remained significant in HTN plus no-OSA (OR: 1.808, 95% CI: 1.207–2.707), HTN plus mild-OSA (OR: 2.003, 95% CI: 1.346–2.980), and HTN plus moderate-severe OSA (OR: 1.834, 95% CI: 1.214–2.770) groups.OSA plus HTN is associated with prevalent CVD, and OSA may potentiate the adverse cardiovascular effects on hypertensives patients but not normotensives.

Increased Cardiometabolic Risk and Worsening Hypoxemia at High Altitude.

Miele, Catherine H., Alan R. Schwartz, Robert H. Gilman, Luu Pham, Robert A. Wise, Victor G. Davila-Roman, Jonathan C. Jun, Vsevolod Y. Polotsky, J. Jaime Miranda, Fabiola Leon-Velarde, and William Checkley. Increased cardiometabolic risk and worsening hypoxemia at high altitude. High Alt Med Biol. 17:93-100, 2016.-Metabolic syndrome, insulin resistance, diabetes, and dyslipidemia are associated with an increased risk of cardiovascular disease. While excessive erythrocytosis is associated with cardiovascular complications, it is unclear how worsening hypoxemia of any degree affects cardiometabolic risk factors in high-altitude populations. We studied the relationship between daytime resting oxyhemoglobin saturation and cardiometabolic risk factors in adult participants living in Puno, Peru (3825 m above sea level). We used multivariable logistic regression models to study the relationship between having a lower oxyhemoglobin saturation and markers of cardiometabolic risk. Nine hundred and fifty-four participants (mean age 55 years, 52% male) had information available on pulse oximetry and markers of cardiometabolic risk. Average oxyhemoglobin saturation was 90% (interquartile range 88%-92%) and 43 (4.5%) had excessive erythrocytosis. Older age, decreased height-adjusted lung function, and higher body mass index (BMI) were associated with having an oxyhemoglobin saturation ≤85%. When adjusting for age, sex, socioeconomic status, having excessive erythrocytosis, and site, we found that each 5% decrease in oxyhemoglobin saturation was associated with a higher adjusted odds of metabolic syndrome (OR = 1.35, 95% CI: 1.07-1.72, p < 0.04), insulin resistance as defined by homeostasis model assessment-insulin resistance (HOMA-IR) >2 mass units (OR = 1.29, 95% CI: 1.00-1.67, p < 0.05), hemoglobin A1c ≥6.5% (OR = 1.66, 95% CI: 1.09-2.51, p < 0.04), and high sensitivity C-reactive protein (hs-CRP) ≥3 mg/L (OR = 1.46, 95% CI: 1.09-1.96, p < 0.01). In high-altitude populations in Puno, Peru, a higher BMI and lower pulmonary function were associated with lower resting daytime oxyhemoglobin saturation. Lower resting oxyhemoglobin saturation, in turn, was associated with higher odds of having multiple unfavorable cardiometabolic factors. Worsening hypoxia of any degree in high-altitude dwellers may be an independent risk factor for cardiovascular disease.