The role of exosomal circular RNA ZNF292 in intermittent hypoxia-induced AC16 cardiomyocytes injury.

BACKGROUND: Exosomes are involved in cell-to-cell communication in numerous diseases including cardiovascular diseases, neurological diseases. Little attention has been dedicated to exosomal circular RNAs in obstructive sleep apnea (OSA)-related cardiovascular diseases. The aim of this study was to explore the role of exosomal circular RNA ZNF292 (circZNF292) on AC16 cells exposure to intermittent hypoxia (IH). METHODS: Exosome release inhibitor GW4869 was used to examine the effect of exosomes on IH-induced AC16 cells apoptosis. The expression of exosomal circZNF292 was detected by qRT-PCR in AC16 cells exposure to IH, and a luciferase reporter assay was conducted to confirm the connection between circZNF292 and miR-146a-5p. Exosomal circZNF292 was stably transfected with short hairpin RNAs (shRNAs) against circZNF292 and co-cultured with AC16 cells. The expression of miR-146a-5p and apoptosis-related protein was then measured to evaluate the effect of exosomal circZNF292. RESULTS: We found that IH contributed to the AC16 cells apoptosis, and the administration of GW4869 increased the apoptosis of cardiomyocytes when exposed to IH. The expression of exosomal circZNF292 decreased and miR-146a-5p increased significantly in AC16 cells exposed to IH compared to normoxic conditions. Bioinformatics analysis predicted a circZNF292/miR-146a-5p axis in IH-induced cardiomyocytes apoptosis. The dual-luciferase reporter system validated the direct interaction of circZNF292 and miR-146a-5p. Knockdown of circZNF292 increased the expressions of miR-146a-5p and accelerated the AC16 cardiomyocytes apoptosis. CONCLUSIONS: The findings of this study suggested a novel mechanism by which exosomes transmit intrinsic regulatory signals to the myocardium through the exosomal circZNF292/miR-146a-5p axis. This finding highlights the potential of targeting this pathway as a therapeutic approach for treating cardiovascular diseases associated with OSA.

Retracted: Bcl-2 19-kDa Interacting Protein 3 (BNIP3)-Mediated Mitophagy Attenuates Intermittent Hypoxia-Induced Human Renal Tubular Epithelial Cell Injury.

This publication has been retracted by the Editor due to non-original content and deficiencies in the conduct of the study. Reference: Xiao-Bin Zhang, Gong-Ping Chen, Mao-Hong Huang, Xiang-Xing Chen, Feng-Fu Zhan, Xiu-Zhen He, Ling Cai, Hui-Qing Zeng Med. Bcl-2 19-kDa Interacting Protein 3 (BNIP3)-Mediated Mitophagy Attenuates Intermittent Hypoxia-Induced Human Renal Tubular Epithelial Cell Injury. Med Sci Monit, 2022; 28: e936760. DOI: 10.12659/MSM.936760.

Relationship between severity of obstructive sleep apnea and benign prostatic hyperplasia.

PURPOSE: The cause of benign prostatic hyperplasia (BPH) is controversial, local hypoxia and inflammation being the main two possibilities proposed. The aim of this study was to evaluate the relationship between obstructive sleep apnea (OSA) and BPH. METHODS: The study cohort comprised men from January 2016 to December 2020 in our Sleep Center. These patients were classified into four groups (no, mild, moderate, severe OSA) by apnea-hypopnea indexes (AHI). Logistic regression was used to identify independent risk factors for BPH, after which participants were stratified into younger (age ≤ 40 years) and older groups (age > 40 years) for further analysis. RESULTS: The study cohort comprised 467 patients including 135 younger subjects and 332 older subjects. The prevalence of BPH in the above listed AHI categories was 37.5%, 55.0%, 62.9%, and 52.3%, respectively (p = 0.075). Logistic regression analysis of all patients identified age as a risk factor for BPH (p < 0.001). Stratified analysis according to AHI category found a prevalence of BPH of 0.0%, 13.0%, 33.3%, and 43.9%, respectively, in younger group (p = 0.006), and 52.2%, 71.9%, 71.1%, and 56.3%, respectively, in older group (p = 0.038). Logistic regression analysis found age and AHI were independent risk factors for BPH in younger group (both p < 0.05), whereas only age was identified as a risk factor for BPH in older group (p < 0.001). CONCLUSIONS: Age is an independent risk factor for BPH in men with OSA. AHI is also an independent risk factor for BPH in younger men, suggesting that OSA may affect development of BPH in younger men.

Nrf2 plays protective role during intermittent hypoxia-induced ferroptosis in rat liver (BRL-3A) cells.

PURPOSE: Ferroptosis is reported to be involved in the chronic intermittent hypoxia (CIH)-related liver damage in vivo. Nuclear factor E2-related factor 2 (Nrf2) has an essential role in the regulation of ferroptosis. This study tested the hypothesis that intermittent hypoxia (IH) could lead to hepatocyte ferroptosis in vitro and the function of Nrf2 in IH-induced hepatocyte ferroptosis. METHODS: BRL-3A cells (rat liver cells) were exposed to normoxia or IH. The protocol of IH consisted of 32 cycles of 60-min hypoxic exposure with 30-min reoxygenation phase (nadir of 1% oxygen to peak of 20% oxygen). Ferroptosis was evaluated by cell viability, iron concentration, lipid reactive oxygen species (ROS), protein content of ferritin heavy chain (FTH1), and glutathione peroxidase 4 (GPX4). Both ferrostatin-1 (a ferroptosis inhibitor) and Nrf2 interfering RNA were applied to treat BRL-3A cells, respectively. RESULTS: IH exposure induced ferroptosis in BRL-3A cells with decreased cell viability and increased total iron content and lipid ROS levels. The protein contents of GPX4 and FTH1 in IH group were markedly lower than that in normoxic control. Ferroptosis inhibitor ferrostatin-1 alleviated IH-induced ferroptosis in BRL-3A cells. IH treatment enhanced expression of Nrf2, and Nrf2 knockdown augmented IH-induced ferroptosis in BRL-3A cells. CONCLUSIONS: The results revealed that Nrf2 played a protective role during IH-induced ferroptosis in BRL-3A cells. The finding provides a therapeutic target for obstructive sleep apnea-related liver injury.

The association between obstructive sleep apnea and lung nodule, carcinoembryonic antigen.

PURPOSE: The association between obstructive sleep apnea (OSA) and cancer risks gaining more and more attention. Data on the association between OSA and lung cancer risk are limited. This study is to investigate whether a link exists between low-dose computed tomography (LDCT) scanning of the chest findings, carcinoembryonic antigen (CEA) and OSA in patients suspected of OSA. METHODS: The cross-sectional study included patients aged 18 years or older who underwent continuous nocturnal polysomnography at our sleep center between February 2019 and November 2020. All subjects underwent chest LDCT and CEA. Patients with an apnea-hypopnea index (AHI) of ≥ 15/h were classified as clinically significant OSA group, whereas patients with an AHI < 15/h were classified as control group. RESULTS: A total of 277 patients were enrolled in the study. 176 patients were categorized into the OSA group, while 101 patients were categorized into the control group. There is no relationship between any OSA-related parameter and presence of lung nodule or presence of ≥ 6 mm lung nodule in the binary logistic regression analysis. OSA group demonstrated a significant higher value of CEA than control group. Stepwise multiple linear regression analysis showed that lowest O2 saturation (ß = - 0.256, p < 0.001), smoking status (ß = 0.156, p = 0.007) and age (ß = 0.153, p = 0.008) were independent predictors of elevated CEA. CONCLUSIONS: OSA was independently related to the elevated of serum CEA level, but not with presence of pulmonary nodule or ≥ 6 mm pulmonary nodule in LDCT. Further well-designed longitudinal studies with pathology available are needed to identify the association between OSA and risk of lung cancer.

Bcl-2 19-kDa Interacting Protein 3 (BNIP3)-Mediated Mitophagy Attenuates Intermittent Hypoxia-Induced Human Renal Tubular Epithelial Cell Injury.

BACKGROUND As a novel pathophysiological characteristic of obstructive sleep apnea, intermittent hypoxia (IH) contributes to human renal tubular epithelial cells impairment. The underlying pathological mechanisms remain unrevealed. The present study aimed to evaluate the influence of Bcl-2 19-kDa interacting protein 3 (BNIP3)-mediated mitophagy on IH-induced renal tubular epithelial cell impairment. MATERIAL AND METHODS Human kidney proximal tubular (HK-2) cells were exposed to IH condition. IH cycles were as follows: 21% oxygen for 25 min, 21% descended to 1% for 35 min, 1% oxygen sustaining for 35 min, and 1% ascended to 21% for 25 min. The IH exposure lasted 24 h with 12 cycles of hypoxia and re-oxygenation. Both the siBNIP3 and BNIP3 vector were transfected to cells. Cell viability and apoptosis, mitochondrial morphology and function, and mitophagy were detected by cell counting kit-8, flow cytometry and TUNEL staining, transmission electron microscopy, western blotting, and immunofluorescence, respectively. RESULTS In the IH-induced HK-2 cells, inhibition of BNIP3 further aggravated mitochondrial structure damage, and decreased mitophagy level, leading to increased cell apoptosis and decreased cell viability. While overexpression of BNIP3 enhanced mitophagy, which protected mitochondrial structure, it can decrease cell death in HK-2 cells exposed to IH. CONCLUSIONS The present study showed that BNIP3-mediated mitophagy plays a protective role against IH-induced renal tubular epithelial cell impairment.

Assessment of bone mineral density and bone metabolism in young men with obstructive sleep apnea: a cross-sectional study.

BACKGROUND: Hypoxia in obstructive sleep apnea (OSA) patients during sleep may have an effect on bone metabolism. Few data regarding evaluation of bone metabolism in young individuals diagnosed with OSA. In this study, we aim to identify the association between bone mineral density and OSA in young men (≤ 40 years old of age). METHODS: Consecutive male subjects who underwent polysomnography were enrolled. Serum calcium, 25-hydroxyvitamin-D3, ß-isomerized form C-terminal telopeptide of type I collagen, osteocalcin and procollagen type 1 N-propeptide were measured in all participants, and bone mineral density (BMD) at lumbar spine (L1-L4), femoral neck and hip total were determined by dual energy X-ray absorption (DXA). RESULTS: The population consisted of 85 subjects (mean age 35.53 years). The BMD at lumbar spine (L1-L4) in moderate OSA patients was higher than control and severe OSA group significantly (p = 0.036). After adjustment for confounding factors, stepwise multiple linear regression analyses showed LaSO2 (ß = 0.340, p = 0.008) as an independent explanatory variable for Lumbar L1-L4 BMD, LaSO2 (ß = 0.304, p = 0.037), BMI (ß = 0.393, p = 0.008) for femur neck BMD and BMI (ß = 0.720, p = 0.002) for hip total BMD. CONCLUSIONS: Our finding indicated that there was a relationship between OSA and bone metabolism in younger men, and moderate OSA-related hypoxia positively related with BMD. This study also showed that different degrees of recurrent hypoxia had different effects on bone metabolism, a finding that required further investigation.

Predictive value of the neutrophil to lymphocyte ratio for disease deterioration and serious adverse outcomes in patients with COVID-19: a prospective cohort study.

BACKGROUND: Early identification of patients who are at high risk of poor clinical outcomes is of great importance in saving the lives of patients with novel coronavirus disease 2019 (COVID-19) in the context of limited medical resources. OBJECTIVE: To evaluate the value of the neutrophil to lymphocyte ratio (NLR), calculated at hospital admission and in isolation, for the prediction of the subsequent presence of disease progression and serious clinical outcomes (e.g., shock, death). METHODS: We designed a prospective cohort study of 352 hospitalized patients with COVID-19 between January 9 and February 26, 2020, in Yichang City, Hubei Province. Patients with an NLR equal to or higher than the cutoff value derived from the receiver operating characteristic curve method were classified as the exposed group. The primary outcome was disease deterioration, defined as an increase of the clinical disease severity classification during hospitalization (e.g., moderate to severe/critical; severe to critical). The secondary outcomes were shock and death during the treatment. RESULTS: During the follow-up period, 51 (14.5%) patients' conditions deteriorated, 15 patients (4.3%) had complicated septic shock, and 15 patients (4.3%) died. The NLR was higher in patients with deterioration than in those without deterioration (median: 5.33 vs. 2.14, P < 0.001), and higher in patients with serious clinical outcomes than in those without serious clinical outcomes (shock vs. no shock: 6.19 vs. 2.25, P < 0.001; death vs. survival: 7.19 vs. 2.25, P < 0.001). The NLR measured at hospital admission had high value in predicting subsequent disease deterioration, shock and death (all the areas under the curve > 0.80). The sensitivity of an NLR ≥ 2.6937 for predicting subsequent disease deterioration, shock and death was 82.0% (95% confidence interval, 69.0 to 91.0), 93.3% (68.0 to 100), and 92.9% (66.0 to 100), and the corresponding negative predictive values were 95.7% (93.0 to 99.2), 99.5% (98.6 to 100) and 99.5% (98.6 to 100), respectively. CONCLUSIONS: The NLR measured at admission and in isolation can be used to effectively predict the subsequent presence of disease deterioration and serious clinical outcomes in patients with COVID-19.

Relationship between serum adiponectin and bone mineral density in male patients with obstructive sleep apnea syndrome.

PURPOSE: Obstructive sleep apnea syndrome (OSAS) is reported to have an association with bone mineral density (BMD). However, the underlying mechanism is far from clear. The aim of this study was to investigate the relationship between OSAS, bone turnover markers, and BMD and to evaluate the effect of adiponectin on BMD in patients with OSAS. METHODS: Seventy-one male patients with OSAS and 13 male control subjects were enrolled in this study. Serum adiponectin, calcium, phosphorus, 25-hydroxyvitamin-D3, ß-isomerized form C-terminal telopeptide of type I collagen, osteocalcin, and procollagen type 1 N-propeptide were measured in all subjects, and BMD was evaluated by dual-energy X-ray absorptiometry (DEXA) in the lumbar spine (L1-L4), the femoral neck, and the hip total. RESULTS: No statistically significant differences were found between the studied groups in terms of demographic data and bone turnover markers. Serum adiponectin significantly decreased with the aggravation of OSAS. Compared with subjects without OSAS, those with OSAS had a higher hip total BMD and t scores (p = 0.027 and p = 0.028). The significant negative association was found between serum adiponectin levels and hip total BMD. After adjusting for confounders, adiponectin as well as oxygen desaturation index (ODI) significantly predicted the hip total BMD (ß = -0.232, p = 0.005 and ß = 0.226, p = 0.037). CONCLUSIONS: In male subjects, the presence of obstructive sleep apnea syndrome is associated with higher bone mineral density of the hip. These findings suggest that serum adiponectin may be an underlying mediator for BMD in OSAS.

The effect of CPAP treatment on venous lactate and arterial blood gas among obstructive sleep apnea syndrome patients.

PURPOSE: The aim of this observational study was to investigate the influence of continuous positive airway pressure (CPAP) on arterial blood gas and venous lactate, markers of tissue hypoxia, among obstructive sleep apnea syndrome (OSAS) patients, and determine the risk factor of serum lactate and hydrogen ion concentration (PH) in OSAS patients. MATERIALS AND METHODS: One-hundred and nine patients with newly diagnosed OSAS were enrolled in the study. All individuals were treated with CPAP for one night. Venous lactate and arterial blood gas were gathered from all subjects in the morning at the end of polysomnography and the next morning after CPAP treatment. RESULTS: Of the 109 selected subjects, the average lactate level was 2.23 ± 0.59 mmol/L, and the mean PH, PaO2, and PaCO2 were 7.380 ± 0.23, 88.14 ± 17.83 mmHg, and 38.70 ± 4.28 mmHg, respectively. Compared to baseline, lactic acid significantly decreased (2.10 ± 0.50 mmol/L, p = 0.03), while PH increased (7.388 ± 0.27, p < 0.05) after CPAP treatment. In addition, neck circumference and the polysomnographic parameters, including apnea-hypopnea index, oxygen desaturation index (ODI), mean oxygen saturation (SpO2), and the percentage of sleep time with SpO2 <90 % (TS90 %), positively correlated with lactate, while age correlated negatively with lactate (all p < 0.05). Significantly positive associations were found between age, neck circumference, and PH; furthermore, a negative correlation was found between ODI and PH. Finally, after adjusting for confounding factors, TS90 % was the major contributing predictor for elevated lactate (p < 0.05), and age was a predictor for an increase in PH (p < 0.05). CONCLUSIONS: The results indicated that CPAP treatment could reduce serum lactate and increase PH in OSAS patients and might alleviate acid-base balance disorders in OSAS. Furthermore, TS90 % was a risk factor for elevated lactate, and age was independently associated with PH.

Applicability of visceral adiposity index in predicting metabolic syndrome in adults with obstructive sleep apnea: a cross-sectional study.

BACKGROUND: Obstructive sleep apnea (OSA) is severely affected by visceral adiposity (VA) that correlates to another disorder-metabolic syndrome (MetS). However, little is known concerning the relation of visceral adiposity index (VAI)-a novel and simple indicator of VA, with OSA and MetS. The objective of the study was to analyze the association of VAI with both disorders and applicability to identify OSA patients at risk of MetS. METHODS: Consecutive individuals undergoing polysomnography and biochemical tests were enrolled, and differences in all subjects grouped by apnea-hypopnea index (AHI) were analyzed. Spearman correlation was performed for assessing the relationship between VAI, OSA-related indices and metabolic score-total number of the positive diagnostic criteria of MetS. Receiver operating characteristic (ROC) curve was conducted to obtain a cut-off value of VAI for predicting incident MetS by sex. Then, the risk of MetS in OSA patients according to the cut-offs was attained by logistic regression. RESULTS: A total of 411 individuals were enrolled. Of whom, 361 subjects were diagnosed OSA (mild in 67 patients, moderate in 89 and severe in 205, respectively). A significant increasing trend based on AHI was observed in the variables of blood pressure, triglycerides, fasting glucose, incident MetS, metabolic score and VAI (all p < 0.05). Irrespective of gender, VAI was all significantly correlated with PSG characteristics as AHI, mean nocturnal oxygen saturation, the lowest oxygen saturation, metabolic score(all p < 0.05). A VAI of 2.282, 2.105, 2.511 (for all subjects, males and females, separately) were calculated to determine the occurrence of MetS. According to the cut-offs, OSA patients tended to suffer from greater risk in MetS (odds ratio [OR] = 10.237, p = 0.000; OR = 13.556, p = 0.000; OR = 21.458, p = 0.000). CONCLUSIONS: The present study suggested that VAI was significantly associated with MetS and OSA. As a simple and alternative approach obtained in everyday practice, it may offer a powerful tool to identify patients with OSA at risk of MetS.

Association between nocturnal hypoxia and liver injury in the setting of nonalcoholic fatty liver disease.

PURPOSE: Obstructive sleep apnea (OSA) is suggested as a potential risk factor of nonalcoholic fatty liver disease (NAFLD). However, the underlying mechanism is still far from clear. The aim of this observational study was to investigate the influence of OSA-related hypoxia on severity of liver injury in patients with NAFLD. METHODS: Consecutive patients with ultrasound-diagnosed NAFLD who underwent standard polysomnography were enrolled. Fasting blood samples were obtained from all patients for biological profile measurements, and demographic data were collected. Subjects were divided into control, moderate, and severe groups. RESULTS: A total of 85 subjects with 73 males and 12 females were included (mean age, 44.67 ± 1.28 years; mean body mass index, 27.28 ± 0.33 kg/m(2)). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), ALT/AST, gamma glutamyltransferase, total cholesterol, low density lipoprotein-cholesterol, fasting glucose, and high-sensitivity C-reactive protein significantly increased with the aggravation of OSA. In multivariate analysis, oxygen desaturation index was the major contributing factor for elevated ALT (ß = 0.435, p = 0.000), average O2 saturation was the major independent predictor of elevated AST (ß = -0.269, p = 0.020). CONCLUSIONS: OSA-related hypoxia was independently associated with the biochemical evidence of liver injury in the presence of NAFLD.

TST, as a polysomnographic variable, is superior to the apnea hypopnea index for evaluating intermittent hypoxia in severe obstructive sleep apnea.

The polysomnography (PSG) index of the apnea hypopnea index (AHI) is considered the 'gold standard' for stratifying the severity of obstructive sleep apnea (OSA). However, AHI cannot reflect the true characteristic of chronic intermittent hypoxia (CIH), which may trigger systemic inflammation in some OSA patients. High-sensitivity C-reactive protein (hsCRP) is considered a biomarker of systemic inflammation in OSA patients. The aim of the present study was to evaluate the relationship between PSG variables and hsCRP in men with severe OSA. Men with severe OSA (AHI ≥ 30 events/h) diagnosed by PSG were enrolled. AHI and body mass index were matched between a high hsCRP group (hsCRP ≥ 3.0 mg/L) and a low hsCRP group. A blood sample was taken for serum hsCRP analysis. Multiple regression analysis was performed to assess independent predictors of high hsCRP. One hundred and fifty-two subjects were enrolled in the study (76 in each group). Mean serum hsCRP was 3.76 ± 2.13 mg/L. The mean percentage of total sleep time spent with SaO2 <90% (TST) in the high hsCRP group was significantly higher than in the low hsCRP group (20.99 ± 18.52 vs. 5.84 ± 7.30, p < 0.001). Multivariate analysis showed that TST was the strongest predictor, contributing to 27.7% of hsCRP variability (ß = 0.496, p < 0.01). TST may be superior to AHI for evaluating CIH among OSA patients. The severity of OSA should be stratified by a combination of AHI and other hypoxia variables.

Bronchoalveolar lavage fluid galactomannan detection for diagnosis of invasive pulmonary aspergillosis in chronic obstructive pulmonary disease.

Invasive pulmonary aspergillosis (IPA) is difficult to diagnose in chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate whether detection of galactomannan (GM) in bronchoalveolar lavage fluid (BALF) might be a useful means of making the diagnosis. Patients with COPD and new pulmonary infiltrates were enrolled. BALF was collected for culture and detection of GM. Venous blood was also sampled for GM detection. Biopsy samples were obtained whenever possible. Eleven cases of IPA were diagnosed (three proven and eight probable); 80 controls without IPA diagnosed were recruited. At a GM cut-off of 0.5, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for diagnosing IPA were 90.9, 66.3, 27.0 and 98.1% in serum, and 90.9, 62.5, 25.0 and 98.0% in BALF, respectively. At a cut-off of 1.0, the specificity, PPV and NPV in BALF increased to 95.0, 71.4 and 98.7%; the sensitivity remained 90.9%. The sensitivity in serum was substantially lower than BALF (45.5% versus 90.9%). Receiver operating characteristic curve analysis identified an optimal BALF GM cut-off value of 1.25, with a sensitivity of 90.9% and a specificity of 96.3% for diagnosing IPA. At a relatively high cut-off value, BALF GM detection is a useful tool for the diagnosis of IPA in COPD. Besides piperacillin-tazobactam and amoxicillin-clavulanate, many other factors may also cause false-positive of GM detection in patients without IPA. Further work is needed to identify factors that might lead to false-positive or false-negative results.

Elevated serum cystatin C in severe OSA younger men without complications.

PURPOSE: Serum cystatin C is a promising new biomarker of glomerular filtration rate and cardiovascular events, but few studies focused on serum cystatin C levels in obstructive sleep apnea (OSA) patients. The aim of our study was to evaluate the association between serum cystatin C and OSA in younger men (≤40 years old of age) without complications. METHODS: We prospectively recruited consecutive participants without comorbidities who underwent polysomnography. Fasting blood samples were obtained from all subjects for biological profile measurements. Statistical analysis was used to evaluate the relationship between serum cystatin C and other parameters. RESULTS: The population consisted of 98 subjects (mean age = 32.5 years, mean body mass index = 27.93 kg/m(2)) that were divided according to polysomnographic finding into control group (n = 23), mild (n = 15), moderate (n = 24), and severe (n = 36) OSA group. Compared with the control group, patients with severe OSA were significantly heavier (body mass index, 29.69 ± 3.81 vs. 26.42 ± 3.10) and presented significantly higher levels of high sensitive C-reactive protein (hsCRP) (1.10 ± 0.28 vs. 0.88 ± 0.20 mg/l) and serum cystatin C (0.87 ± 0.12 vs. 0.74 ± 0.10 mg/l) (p < 0.05 for all comparisons). Cystatin C was correlated with Apnea Hypopnea Index (AHI), Oxygen Desaturation Index, hsCRP, creatinine, and estimated glomerular filtration rate (r = 0.319, 0.279, 0.321, 0.233, -0.241, p = 0.001, 0.005, 0.001, 0.021, 0.017, respectively). After adjustment for confounding factors, AHI was significantly and positively associated with serum cystatin C levels (ß = 0.284, p = 0.007). CONCLUSIONS: Our finding indicated that serum cystatin C was associated with the severity of OSA in younger men. Further study is needed to find out whether OSA patients with increased serum cystatin C levels are prone to subclinical cardiovascular and renal diseases.

Expression alteration of serum exosomal circular RNAs in obstructive sleep apnea patients with acute myocardial infarction.

PURPOSE: Circular RNAs (circRNAs) are recently identified as a class of non-coding RNAs that participate in the incidence of acute myocardial infarction (AMI). However, circRNAs expression pattern in obstructive sleep apnea (OSA) with AMI remains unknown. The aim was to investigate circRNAs expression alteration in serum exosomes derived from OSA patients with AMI. METHODS: The serum exosomal circRNAs profile of three healthy subjects, three OSA without AMI and three OSA with AMI were analyzed using high-throughput sequencing. Bioinformatic analyses were carried out to assess potential core circRNAs and functional analyses were conducted to study biological functions. RESULTS: Compared to healthy subjects, there were 5225 upregulated and 5798 downregulated circRNAs in exosomes from OSA with AMI patients. And our study also identified 5210 upregulated and 5813 downregulated circRNAs in OSA with AMI patients compared to OSA without AMI. The differential expression of 2 circRNAs (hsa_circRNA_101147, hsa_circRNA_101561) between healthy subjects and OSA without AMI, and 4 circRNAs (hsa_circRNA_101328, hsa_circRNA_104172, hsa_circRNA_104640, hsa_circRNA_104642) between healthy subjects and OSA with AMI were confirmed by qRT-PCR. In addition, we demonstrated that miR-29a-3p targeted hsa_circRNA_104642 directly. CONCLUSIONS: This study demonstrated that there were a number of dysregulated circRNAs in exosomes from OSA with AMI patients, which might be effectively served as a promising diagnostic biomarker and therapeutic targets.

Obstructive sleep apnea syndrome is associated with some components of metabolic syndrome in nonobese adults.

PURPOSE: The relationship between obstructive sleep apnea (OSA) syndrome and metabolic syndrome is far from conclusion for obesity as a confounding factor. The aim of the present study was to investigate the association between OSA and some components of metabolic abnormality in nonobese patients. METHODS: We consecutively recruited nonobese subjects who underwent polysomnography and analyzed some components of metabolic abnormality in subjects with and without OSA. Multiple linear regression was used to evaluate the independent risk factor of some components of metabolic abnormality. RESULTS: A total of 154 subjects were enrolled and were divided to control group (45 subjects) and OSA group (113 subjects). Body mass index was no different between groups. Systolic blood pressure, triglycerides, and insulin concentration were significantly higher among OSA group compared with control group (p = 0.000, 0.043, and 0.006, respectively), and the prevalences of dyslipidemia, hypertension, and at least two of the metabolic abnormalities were significantly greater in OSA group (p = 0.003, 0.031, and 0.000, respectively). After adjusting for confounding factors, lowest O(2) saturation was the major contributing factor for elevated systolic blood pressure (p = 0.001), and independent associations were found between apnea-hypopnea index and the following parameters of metabolic abnormality: triglycerides and homeostasis model assessment of insulin resistance (all p = 0.000). CONCLUSIONS: Our finding was consistent with previous studies that OSA was independently associated with dyslipidemia, hypertension, and at least two of metabolic abnormalities in nonobese patients.

[Effects of long term nasal continuous positive airway pressure on the blood pressure of patients with obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To analyze the effects of long term nasal continuous positive airway pressure on the blood pressure of patients with OSAHS. METHODS: From April 1997 to October 2008, 2898 patients from the First Affiliated Hospital of Fujian Medical University who complained snore during sleeping were studied. Nine hundred eighty cases were diagnosed as OSAHS with hypertension, and these patients were randomly divided into 2 groups: one group was treated with antihypertensive drugs and nasal continuous positive airway pressure (nCPAP), while the other group only received antihypertensive drugs. The polysomnography (PSG) was recorded during sleeping and the blood pressure was remeasured after 6 months or more. All patients were followed up for 5 years to observe the long-term effects of nCPAP or drugs. RESULTS: Systolic and diastolic blood pressure in the nCPAP group significantly decreased after 6 months [(125 ± 16) mm Hg (1 mm Hg = 0.133 kPa) vs (136 ± 19) mm Hg, (83 ± 10) mm Hg vs (95 ± 15) mm Hg, P < 0.05], and the decreasing extent of blood pressure in nCPAP group was more notable than antihypertensive drug group [decreasing extent of systolic blood pressure:(10 ± 11) mm Hg vs (4 ± 11) mm Hg; decreasing extent of diastolic blood pressure: (11 ± 7) mm Hg vs (6 ± 7) mm Hg; P < 0.05]. The total effective rate in nCPAP group was significantly higher than that in antihypertensive drug group (90% vs 38%, P < 0.01). One hundred and eighty three cases in nCPAP group and 157 cases in antihypertensive drug group completed the 5-year follow-up and the blood pressure was controlled within the normal range. Some patients could gradually reduce or stop the use of antihypertensive drugs and the blood pressure didn't appear to rebound. The number of antihypertensive drugs in the nCPAP group was significantly fewer as compared to the antihypertensive drugs group after 2, 3, 4 and 5 years' follow-up. CONCLUSIONS: nCPAP is a safe and effective treatment for high blood pressure in patients with OSAHS.

Expression profiling and functional analysis of circular RNAs in vitro model of intermittent hypoxia-induced liver injury.

Intermittent hypoxia (IH) is a prominent feature of obstructive sleep apnea (OSA) which is increasingly recognized as a key risk factor for liver injury. Circular RNAs (circRNAs) has been suggested to act as a regulator of multiple biological processes. However, there is no study evaluating circRNAs alterations and potential role of circRNAs in OSA-related liver injury. The present study aimed to investigate circRNA expression profiles in vitro model of IH-induced liver injury, as well as potential functional characterization of the differentially expressed circRNAs (DE circRNAs). BRL-3A cells were exposed to IH or normoxia. Cell apoptosis and cell viability were evaluated using flow cytometry and cell counting kit-8, respectively. The expression profile of circRNAs was depicted by circRNA sequencing. The selected circRNAs were verified by quantitative real-time PCR (qRT-PCR). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) analyses were employed to predict DE circRNAs functions. The circRNA-miRNA-mRNA regulatory network was constructed. IH treatment caused cell injury in BRL-3A cells. 98 circRNAs were identified as being dysregulated in IH-treated BRL-3A cells. Among them, 58 were up-regulated and 40 were down-regulated. Go and KEGG analyses suggested that the DE circRNAs were predominantly enriched in the biological process such as positive regulation of NF-kappaB transcription factor activity and pathways such as circadian entrainment, Wnt signaling pathway, MAPK signaling pathway, and protein export. 3 up-regulated circRNAs and 3 down-regulated circRNAs with high number of back-splicing sites were chosen for qRT-PCR validation and were consistent with the sequencing data. CircRNA1056 and circRNA805 were predicted to interact with microRNAs that might thereby regulate downstream genes. The study characterized a profile of dysregulated circRNAs in IH-induced BRL-3A cell injury. DE circRNAs may play vital roles in the pathophysiology of IH-induced liver injury. Our findings provide preliminary support for further research in mechanisms and a new theory for the pathogenesis of OSA-related liver injury.

Risk Factors and Prognosis in Patients with COVID-19 and Liver Injury: A Retrospective Analysis.

PURPOSE: COVID-19 is a new infectious disease with global spread. The aim of the present study was to explore possible risk factors and evaluate prognosis in COVID-19 with liver injury. METHODS: A retrospective study was conducted on 356 COVID-19 patients in the Third People's Hospital of Yichang, Hubei, China. Clinical characteristics and laboratory tests between patients with and without liver injury were compared, while risk factors of COVID-19-related liver injury were analyzed. Univariate and multivariate Cox regression analyses were conducted to identify risk factors of in-hospital death. RESULTS: Of the patients with liver injury, severe and critical types of COVID-19 comprised 12.43% and 14.69%, respectively, higher than in patients without liver injury (both P<0.05). CRP and male sex were independent risk factors for for patients with liver injury, while decreased lymphocyte count (HR 0.024, 95% CI 0.001-0.821) and elevated monocytes (HR 1.951, 95% CI 1.040-3.662) and CRP (HR 1.028, 95% CI 1.010-1.045) were independent risk factors of prognosis of death in COVID-19 patients with liver injury. CONCLUSION: Liver injury is a common complication in severe COVID-19 patients. Male sex and elevated CRP were independent risk factors in COVID-19 complicated by liver damage. Liver damage with increased CRP and monocyte count and decreased lymphocyte count may imply a poor prognosis.