Diagnostic accuracy of the Berlin questionnaire and therapeutic effect of nasal continuous positive airway pressure in OSAHS patients with glucose metabolic dysfunction.

PURPOSE: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with alterations in glucose metabolism. The Berlin questionnaire (BQ) is effective in identifying subjects with high risk of OSAHS. However, its validity in patients with glucose metabolic dysfunction remains unclear. Our study aims to examine the diagnostic efficacy of the BQ in detecting OSAHS in patients with glucose metabolic dysfunction and to explore the effect of nasal CPAP on glucose metabolism. METHODS: Patients with glucose metabolic dysregulation were first asked to complete the BQ and then recruited for polysomnogram (PSG). The diagnostic accuracy of the BQ and the relationships between groups with normal glucose tolerance (NGT), elevated fasting blood glucose (IFG), impaired glucose tolerance (IGT), and diabetes mellitus (DM) were analyzed. Subjects with both OSAHS and glucose dysregulation received CPAP treatment and underwent an oral glucose tolerance test. Changes in apnea-hypopnea indices (AHI) and glycemic parameters were calculated to determine the efficacy of CPAP. RESULTS: Glycosylated hemoglobin and insulin levels were statistically different between the high-risk and low-risk groups according to the BQ. For diagnosis of subjects with OSAHS who also had glucose metabolic dysfunction, the sensitivity and specificity of the BQ using AHI cut-off values at 5 events per hour were 73% and 67%. CPAP therapy effectively reduced the blood glucose, HOMA-IR, and insulin levels. CONCLUSIONS: The BQ can be considered to be an effective and economical screening tool for patieints with OSAHS who also have glucose metabolic dysfunction. Treatment with CPAP may improve glycemic parameters.

Postoperative diastolic perfusion pressure is associated with the development of acute kidney injury in patients after cardiac surgery: a retrospective analysis.

BACKGROUND: We aimed to investigate the relationship between the perioperative hemodynamic parameters and the occurrence of cardiac surgery-associated acute kidney injury. METHODS: A retrospective study was performed in patients who underwent cardiac surgery at a tertiary referral teaching hospital. Acute kidney injury was determined according to the KDIGO criteria. We investigated the association between the perioperative hemodynamic parameters and cardiac surgery-associated acute kidney injury to identify the independent hemodynamic predictors for acute kidney injury. Subgroup analysis was further performed in patients with chronic hypertension. RESULTS: Among 300 patients, 29.3% developed acute kidney injury during postoperative intensive care unit period. Multivariate logistic analysis showed the postoperative nadir diastolic perfusion pressure, but not mean arterial pressure, central venous pressure and mean perfusion pressure, was independently linked to the development of acute kidney injury after cardiac surgery (odds ratio 0.945, P = 0.045). Subgroup analyses in hypertensive subjects (n = 91) showed the postoperative nadir diastolic perfusion pressure and peak central venous pressure were both independently related to the development of acute kidney injury (nadir diastolic perfusion pressure, odds ratio 0.886, P = 0.033; peak central venous pressure, odds ratio 1.328, P = 0.010, respectively). CONCLUSIONS: Postoperative nadir diastolic perfusion pressure was independently associated with the development of cardiac surgery-associated acute kidney injury. Furthermore, central venous pressure should be considered as a potential hemodynamic target for hypertensive patients undergoing cardiac surgery.

Early Postoperative Serum Creatinine Adjusted for Fluid Balance Precisely Predicts Subsequent Acute Kidney Injury After Cardiac Surgery.

OBJECTIVES: Cumulative fluid overload may influence acute kidney injury (AKI) diagnosis due to the dilution effect. The authors hypothesized a small increase of early postoperative serum creatinine (SCr) adjusted for fluid balance might have superior discrimination ability in subsequent AKI prediction. DESIGN: Retrospective analyses. SETTING: A single-center study in a university hospital. PARTICIPANTS: The study comprised 1,016 adult patients who underwent elective isolated or combined valve surgery in 2015. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline characteristics, intraoperative parameters, and intraoperative and postoperative fluid balance were collected through a retrospective chart review. Early postoperative SCr level was drawn within 12 hours of surgical completion and then measured daily. Early relative changes of SCr were categorized as a cutoff value of 10% with or without adjustment for cumulative fluid balance. Kidney Disease: Improving Global Outcomes criteria were used to detect AKI. Logistic analyses were performed to determine risk factors for subsequent AKI with the inclusion of measured or fluid-adjusted early relative changes of SCr, respectively. In this study, 355 patients (34.9%) developed AKI. Multivariate logistic analyses showed age, weight, European System for Cardiac Operative Risk Evaluation II, and cardiopulmonary bypass duration were associated independently with the development of AKI. Model discrimination for AKI prediction was improved significantly when the addition of measured (area under the receiver operating characteristic curve [AUROC] 0.830) and fluid-adjusted early changes of SCr to the basic model (AUROC 0.850). CONCLUSIONS: Early fluid-adjusted relative changes of SCr could improve the predictive ability for subsequent development of AKI in valve surgery patients.

Usefulness of High Estimated Pulmonary Artery Systolic Pressure to Predict Acute Kidney Injury After Cardiac Valve Operations.

High estimated pulmonary artery systolic pressure (ePASP) has been established as a detrimental predictor for adverse outcomes in patients with chronic kidney disease. However, the relation between preoperative high ePASP and the development of cardiac surgery associated acute kidney injury (CSA-AKI) has not been validated. We performed a retrospective cohort study of adult patients who underwent valve surgery in 2015 at Zhongshan Hospital, Fudan University. Right ventricular systolic pressure, a surrogate for pulmonary systolic pressure, was estimated in the study group of 1056 patients by preoperative echocardiography. CSA-AKI was defined based on the Kidney Disease Improving Global Outcomes criteria. The relation between preoperative ePASP and CSA-AKI was demonstrated with the use of multivariate analysis after adjusting for potential risk factors for CSA-AKI. Of these patients, preoperative ePASP was 44.5 ± 14.9 mm Hg. 401 (38%) patients developed CSA-AKI in which 73 patients (6.9%) suffered from severe AKI (stage II and III). Multivariate analysis showed that preoperative ePASP was independently associated with CSA-AKI (odds ratio per 10 mm Hg increment, 1.099; 95% confidence interval, 1.003 to 1.204; p = 0.042). Preoperative ePASP more than 60 mm Hg was found to be linked with the increasing incidence of AKI by 62% and in-hospital mortality by over 300%, but not linked with severe AKI or renal replacement therapy. In conclusion, an increase in preoperative ePASP was independently and significantly associated with the development of CSA-AKI in patients who underwent valve surgery. Such relation between preoperative ePASP and CSA-AKI could provide a novel therapeutic target against prevention of AKI.

NLRP3 inflammasome mediates chronic intermittent hypoxia-induced renal injury implication of the microRNA-155/FOXO3a signaling pathway.

Chronic intermittent hypoxia (CIH), as the foremost pathophysiological change of obstructive sleep apnea (OSA), contributes to continued deterioration in renal function. Nucleotide-binding domain like receptor protein 3 (NLRP3) inflammasome is a multiprotein complex that triggers innate immune responses to infection and cell stress through activation of caspase-1 and maturation of inflammatory pro-interleukin-1ß cytokine. Emerging evidence indicates that inhibition of the NLRP3 inflammasome ameliorates renal injury. Nevertheless, it is uncertain whether NLRP3 inflammasome participates in CIH-induced renal injury. The molecular mechanisms modulating NLRP3 inflammasome activation remain to be elucidated. Compared with wild-type mice, NLRP3 knockout mice dramatically protected them from kidney injury, as indicated by the restoration of creatinine levels, lessened histopathological alterations, and the suppression of macrophages infiltration stained with F4/80. NLRP3 deficiency notably reversed CIH-induced oxidative stress (malondialdehyde and superoxide dismutase), concomitantly with the abrogated apoptosis-related proteins and proinflammatory signaling pathway. Consistently, NLRP3-deficient tubular cells remarkably inhibited reactive oxygen species generation and NLRP3 inflammasome activation. Furthermore, our study revealed that microRNA-155 (miR-155) was augmented in the renal tissue and HK-2 cells exposed to CIH. In addition, we investigated the role of miR-155 in the regulation of NLRP3 inflammasome. Inhibition of miR-155 suppressed the CIH-induced NLRP3 inflammasome activation in renal tubular cells, whereas overexpression of miR-155 promoted oxidation and enhanced NLRP3 pathway. Collectively, we demonstrated that miR-155 might be a positive-regulator of NLRP3 pathway by inhibiting the targeted FOXO3a gene. These results established a link between the miR-155/FOXO3a pathway and the NLRP3 inflammasome, suggesting pharmacological blockage of NLRP3 as a potential therapeutic strategy for OSA-associated chronic kidney disease.

Screening and managing obstructive sleep apnoea in nocturnal heart block patients: an observational study.

BACKGROUND: Nocturnal heart block often occurs in patients with obstructive sleep apnoea (OSA). It is more likely to be undiagnosed in heart block patients who are ignorant of the symptoms of sleep disorder. Berlin Questionnaire (BQ) is a highly reliable way to discover the risk factors of OSA, whereas the validity in sleep-related heart block patients is uncertain. We performed an observational study to address these issues and confirmed the potential protective effect of continuous positive airway pressure (CPAP). METHODS: Patients who were previously diagnosed with nocturnal heart block with R-R pauses exceeding 2 seconds were retrospective screened from the ECG centre of Zhongshan hospital. These recruited participants completed Berlin Questionnaire and underwent polysomnography synchronously with 24-hour Holter monitoring. A cross-sectional analysis was performed to confirm the association between nocturnal arrhythmia and OSA, as well as to assess the diagnostic accuracy of the BQ. Subsequently, subjects diagnosed with OSA (apnoea-hypopnoea index > 5) underwent 3 consecutive days of CPAP therapy. On the third day, patients repeated 24-hour Holter monitoring within the institution of CPAP. RESULTS: The symptoms of disruptive snoring and hypersomnolence in 72 enrolled patients were more related to the occurrence of nocturnal heart block (r = 0.306, 0.226, respectively, p = 0.015, 0.019) than syncope (r = 0.134, p = 0.282) and palpitations (r = 0.106, p = 0.119), which were prominent trait of our study population. The sensitivity, specificity, positive and negative predictive value of the BQ at a cut-off point of 5 of AHI for detecting OSA in heart block patients was 81.0 %, 44.4 %, 91.07 % and 25 %. Nocturnal heart block does not appear to occur exclusively in severe sleep apnoea. The frequent occurrence of arrhythmias in prominent oxygen desaturation supports the correlation between them. CPAP therapy resulted in significant decrease in the average number of episodes of heart block, from 148.58 ± 379.44 to 16.07 ± 58.52 (p < 0.05), same to the change of the longest RR pausing time (from 4.38 ± 2.95 s to 0.57 ± 1.05 s, p = 0.169) in 51 patients. The optimal therapy pressure to make the observed arrhythmia disappeared is 12 cm H2O. CONCLUSION: Concerning high prevalence of OSA in heart block patients, BQ provided an economical and efficient screening method for OSA. For better management, CPAP therapy is feasible to prevent heart blocks avoiding unnecessary concomitant pacemaker implantation.