Xiaojun Zhan

A review of EPAP nasal device therapy for obstructive sleep apnea syndrome

BackgroundExpiratory positive airway pressure (EPAP) nasal devices provide a new therapeutic option for obstructive sleep apnea (OSA).MethodsHere, we review the literature about treatment of OSA with EPAP, which has been shown to reduce the apnea/hypopnea index (AHI) and daytime sleepiness.ResultsPatients generally prefer EPAP to continuous positive airway pressure (CPAP), and there are no serious adverse effects from its use. Although CPAP more effectively improves sleep apnea, a recent study showed similar outcomes in symptom improvement using EPAP. Patients with mild to moderate OSA who do not tolerate CPAP are appropriate candidates for EPAP. However, there are few well-designed clinical trials that evaluate efficacy.ConclusionsMore studies are needed to assess the efficacy of and compliance with EPAP nasal devices, to define which patients will benefit from EPAP therapy, and to compare EPAP to other alternative OSA therapies.

Does Airway Surgery Lower Serum Lipid Levels in Obstructive Sleep Apnea Patients? A Retrospective Case Review

Background Obstructive sleep apnea (OSA) is tightly linked to increased cardiovascular disease. Surgery is an important method to treat OSA, but its effect on serum lipid levels in OSA patients is unknown. We aimed to evaluate the effect of upper airway surgery on lipid profiles. Material/Methods We performed a retrospective review of 113 adult patients with OSA who underwent surgery (nasal or uvulopalatopharyngoplasty [UPPP]) at a major, urban, academic hospital in Beijing from 2012 to 2013 who had preoperative and postoperative serum lipid profiles. Results Serum TC (4.86±0.74 to 4.69±0.71) and LP(a) (median 18.50 to 10.90) all decreased significantly post-operatively (P<0.01, 0.01, respectively), with no changes in serum HDL, LDL, or TG (P>0.05, all). For UPPP patients (n=51), serum TC, HDL and LP(a) improved (P=0.01, 0.01,<0.01, respectively). For nasal patients (n=62), only the serum LP(a) decreased (P<0.01). In patients with normal serum lipids at baseline, only serum LP(a) decreased (P<0.01). In contrast, in patients with isolated hypertriglyceridemia, the serum HDL, TG and LP(a) showed significant improvements (P=0.02, 0.03, <0.01, respectively). In patients with isolated hypercholesterolemia, the serum LP(a) decreased significantly (P=0.01), with a similar trend for serum TC (P=0.06). In patients with mixed hyperlipidemia, the serum TC and LDL also decreased (P=0.02, 0.03, respectively). Conclusions Surgery may improve blood lipid levels in patients with OSA, especially in patients with preoperative dyslipidemia, potentially yielding a major benefit in metabolism and cardiovascular sequelae. Prospective studies should examine this potential metabolic effect of airway surgery for OSA.

Mean apnea–hypopnea duration (but not apnea–hypopnea index) is associated with worse hypertension in patients with obstructive sleep apnea

AbstractTo determine which polysomnography parameters are associated with severity of hypertension.This retrospective study collected data on all patients admitted to our urban, academic center in Beijing with hypertension who had undergone polysomnograms (PSG) and were diagnosed with obstructive sleep apnea (OSA) (apnea–hyponea index [AHI] ≥5/hour). We then compared polysomnographic parameters (AHI, oxygen desaturation index [ODI], lowest oxygen saturation [LOS], and mean apnea–hypopnea duration [MAD]) by hypertension severity in this cohort.There were 596 subjects who met entry criteria. Age, sex distribution, body mass index (BMI), history of current smoking and alcohol were similar among groups. Subjects with longer MAD suffered from more severe hypertension (P = 0.011). There were no relationship between AHI, ODI, and LOS and hypertension in our cohort. There were no significant differences in age, sex, BMI, history of current smoking and alcohol use between hypertension groups. MAD had a small but significant independent association (odds ratio [OR] = 1.072, 95% confidence interval [CI] 1.019–1.128, P = 0.007) with moderate to severe hypertension, using logistic regression analysis that accounted for age, sex, BMI, history of current smoking and alcohol, AHI, and LOS.Chinese inpatients with longer MAD by PSG face higher odds of moderate to severe hypertension. The mechanism of these effects may be due to aggravated nocturnal hypoxaemia and hypercapnia, as well as disturbed sleep architecture. These results suggest that additional information available in the polysomnogram, such as MAD, should be considered when evaluating OSA patients.

Can upper airway surgery for OSA protect against cardiovascular sequelae via effects on coagulation

Abstract Conclusion: Upper airway surgery is associated with salutary effects on the blood coagulation characteristics of OSA patients, a benefit that may be protective against cardiac and cerebrovascular morbidity and mortality. Objective: Increased blood coagulation is an important factor linking OSA and cardiovascular complications. Surgery is an important method to treat OSA, but the effect of surgery on blood coagulation in OSA patients is unknown. Methods: the authors performed a prospective clinical trial of adult OSA patients who underwent surgery from 2012–2014. Pre-operative and post-operative blood coagulation parameters and polysomnography (PSG) results were compared. Result: There were 61 subjects. The total rate of success in curing OSA was 11.5%. The rate of response after surgery was 40.8%. Overall, the Apnea-Hypopnea Index (AHI) improved after surgery (from 39.8 3 ± 24.49 to 25.9 7 ± 18.53, p < 0.01). After surgery, serum platelet counts (PLT) decreased (from 242.5 ± 52.6 to 230.9 ± 40.7, p=0.01), and Fibrinogen (FIB) levels declined (from 262.5 ± 52.5 to 247.3 ± 44.4, p = 0.02). Other blood coagulation parameters also improved: prothrombin time (PT) (from 10.6 2 ± 0.62 to 10.8 6 ± 0.70, p=0.01), activated partial thromboplastin time (APTT) (from 26.9 8 ± 4.94 to 27.7 8 ± 3.02, p = 0.06), and Thrombin time (TT) (from 19.5 3 ± 0.84 to 20.1 1 ± 1.31, p < 0.01).

ESM-1 promotes adhesion between monocytes and endothelial cells under intermittent hypoxia: sun et al.

Intermittent hypoxia (IH), the key property of obstructive sleep apnea (OSA), is closely associated with endothelial dysfunction. Endothelial‐cell‐specific molecule‐1 (ESM‐1, Endocan) is a novel, reported molecule linked to endothelial dysfunction. The aim of this study is to evaluate the effect of IH on ESM‐1 expression and the role of ESM‐1 in endothelial dysfunction. We found that serum concentration of ESM‐1, inter‐cellular adhesion molecule‐1 (ICAM‐1), and vascular cell adhesion molecule‐1 (VCAM‐1) is significantly higher in patients with OSA than healthy volunteers (p < 0.01). The expression of ESM‐1, hypoxia‐inducible factor‐1 alpha (HIF‐1α), and vascular endothelial growth factor (VEGF) was significantly increased in human umbilical vein endothelial cells (HUVECs) by treated IH in a time‐dependent manner. HIF‐1α short hairpin RNA and vascular endothelial growth factor receptor (VEGFR) inhibitor inhibited the expression of ESM‐1 in HUVECs. ICAM‐1 and VCAM‐1 expressions were significantly enhanced under IH status, accompanied by increased monocyte–endothelial cell adhesion rate ( p < 0.001). Accordingly, ESM‐1 silencing decreased the expression of ICAM‐1 and VCAM‐1 in HUVECs, whereas ESM‐1 treatment significantly enhanced ICAM‐1 expression accompanied by increasing adhesion ability. ESM‐1 is significantly upregulated by the HIF‐1α/VEGF pathway under IH in endothelial cells, playing a critical role in enhancing adhesion between monocytes and endothelial cells, which might be a potential target for IH‐induced endothelial dysfunction.