Increased Urinary Erythropoietin Excretion in Severe Sleep Apnea-Hipoapnea Syndrome: The Effect of CPAP

Role of HIF-1α in hypercoagulable state of COPD in rats

OBJECTIVE

To explore the role of HIF-1α in hypercoagulable state of COPD induced by lipopolysaccharide plus smoking in rats. It also has to explore the regulatory mechanism of HIF-1α-EPO/EDN-1/VEGF pathway by using its activator and inhibitor.

METHODS

60 Sprague-Dawley rats (SD rats) were randomly divided into healthy control group, COPD hypercoagulable control group, activator group, and inhibitor group with 15 rats in each group. The healthy control group was fed freely. The other groups were given smoke and lipopolysaccharide by tracheal instillation to establish the experimental animal model of COPD hypercoagulability. After successful modeling, each experimental group was given 0.9 % sodium chloride solution and corresponding drugs by intraperitoneal injection for 7 days. Lung function was detected after drug administration. Hematoxylin-eosin staining was used to observe the pathological changes of lung tissue. Enzyme-linked immunosorbent assay was used to detect serum D-D,F (1 + 2),IL-6,TNF-α. The mRNA expressions of HIF-1α, EPO, EDN-1, and VEGF were detected by RT-PCR. Western-Blot and IHC were used to detect the expression of HIF-1α, EPO, EDN-1, and VEGF in lung tissue of rats.

RESULTS

Compared with the healthy control group, rats in COPD hypercoagulable control group had COPD symptoms/signs, decreased lung function, increased the expression of serum D-D and F (1 + 2), increased the expression of inflammatory factors IL-6,TNF-α, and increased the expression of proteins HIF-1α, EPO, EDN-1 and VEGF. Compared with COPD hypercoagulable control group, lung function in activator group and inhibitor group had no obvious changes. The expressions of serum D-D,F (1 + 2),IL-6,TNF-α in activator group have increased noticeably. The expressions of proteins HIF-1α, EPO, EDN-1, and VEGF have further increased. Compared with COPD hypercoagulable control group, the expression of serum D-D, F (1 + 2), HIF-1α, EPO, EDN-1, and VEGF in the inhibitor group decreased.

CONCLUSION

HIF-1α-EPO/EDN-1/VEGF pathway plays an important role in the hypercoagulable state of COPD. HIF-1α inhibitor can improve airway inflammation and reduce hypercoagulability in COPD model rats.

Prevalence of elevated hemoglobin and hematocrit levels in patients with obstructive sleep apnea and the impact of treatment with continuous positive airway pressure: a meta-analysis

OBJECTIVES

Obstructive sleep apnea (OSA) is reported to be a cause of secondary polycythemia. The present study (i) reviewed the literature reporting the prevalence of secondary polycythemia in patients with OSA and (ii) determined the effect of continuous positive airway pressure (CPAP) therapy on hemoglobin and hematocrit levels in patients with OSA.

METHODS

We searched MEDLINE, Embase and Cochrane for studies of adult patients with OSA that reported hemoglobin and/or hematocrit levels. We performed summary estimates of (i) polycythemia prevalence and a subgroup analysis according to OSA severity, and (ii) change in hemoglobin and hematocrit levels following treatment with CPAP.

RESULTS

Synthesis of seven studies including 3,654 patients revealed an overall polycythemia prevalence of 2% (95% CI 1-4%); 2% (95% CI 1-3%) in mild-to moderate and 6 % (95% CI 3-12%) in severe OSA. In the pooled analysis of ten single-arm trials including 434 patients, CPAP treatment reduced hemoglobin by 3.76 g/L (95% CI -4.73 to -2.80 g/L). Similarly, pooled analysis of ten single-arm trials including 356 patients without baseline polycythemia showed that CPAP treatment reduced hematocrit by 1.1% (95% CI -1.4 to -0.9%).

CONCLUSION

Our pooled analysis supports an increased prevalence of secondary polycythemia in OSA. This estimated prevalence is likely underestimated due to the change in the polycythemia diagnostic criteria in 2016. Future randomized controlled trials are needed to evaluate the effect of CPAP in patients with baseline polycythemia.

HIGHLIGHTS

Pooled analysis shows OSA is associated with an increased prevalence of secondary polycythemiaPrevalence of polycythemia is greater in severe OSACPAP treatment for OSA reduces both the hemoglobin and hematocrit.

Sleep Apnea and Serum Serotonin Level Pre- and Post-PAP Therapy: A Preliminary Study

Introduction

The high prevalence of obstructive sleep apnea (OSA), which impairs quality of life for numerous patients and leads to various OSA complications, has contributed to the continued interest in this disorder. The role of serotonin (5-HT) in many physiological processes, studies on its connection with the circadian system, and relationship to changes in sleep architecture are insufficient to assess the interaction of this neurotransmitter with nocturnal hypoxia. The aim of this study was to determine changes in sleep patterns and serum serotonin levels before and after positive airway pressure (PAP) therapy in patients with OSA.

Methods

The study involved 30 OSA patients (27 men and 3 women) who were treated with PAP for 3 months. Polysomnography using the GRASS TELEFACTOR (USA) and blood collection were conducted before and after PAP courses. Determination of serum serotonin was performed by high-performance liquid chromatography (HPLC). PAP therapy was performed using an automatic Prisma 20A (Germany) continuous positive airway pressure (CPAP) device.

Results

The use of PAP for 3 months revealed a significant improvement as measured by sleep data and serotonin levels (before: apnea index [AI] 17.2 eV/h, after: 2.4 eV/h p = 0.001; SpO₂ < 90% − 45.7 min vs. 6.2 min p = 0.001; serotonin 20.3 ng/mL vs. 26.03 ng/mL p = 0.036].

Conclusion

Our results demonstrate an improvement in sleep patterns. There was an increase in serum serotonin levels in OSA patients following PAP therapy, which could be an effect of intermittent hypoxia decline, and could be used as criteria for the effectiveness of PAP and an improvement in sleep quality.

Red cell distribution width: a new tool for the severity prediction of sleep apnoea syndrome in children

Introduction

Red cell distribution width (RDW) is a parameter included in the complete blood count which informs about the size of the circulating red blood cell population and its distribution. In adults, an increase in RDW was shown to be associated both with obstructive sleep apnoea (OSA) and with an increase in cardiovascular mortality. The aim of this study was to determine whether RDW is a potential biomarker for screening children with moderate–severe OSA.

Methods

An observational study in snoring patients was performed. All patients underwent a sleep study and were classified either as simple snorers (apnoea–hypopnoea index (AHI) <1 event·h⁻¹) or as patients with OSA (mild AHI ≥1 to <5 events·h⁻¹; moderate–severe AHI ≥5 events·h⁻¹). Blood analyses (complete blood count and C-reactive protein) were performed for every individual.

Results

A total of 175 individuals were recruited. The mean age was 8.3±3.6 years. Correlation studies between RDW and several sleep-related parameters showed negative significant associations with minimum oxygen saturation, and positive significant associations with oxygen desaturation index (≥3% and ≥4%), AHI and the arousal index. A predictive model for paediatric severe OSA (AHI ≥5 events·h⁻¹) was found based on mean corpuscular haemoglobin concentration (MCHC) <34.9 g·dL⁻¹ and RDW >13.1% values, adjusting for body mass index z-score and age (area under the curve 0.657; p=0.004). In addition, differences were found in eosinophil count and C-reactive protein concentrations among the three subgroups.

Conclusions

In children, RDW stands out as a biomarker associated with the severity of OSA. The use of RDW and MCHC could be a simple but useful tool for the severity prediction of paediatric OSA in snoring patients.

Red cell distribution width and mean corpuscular haemoglobin concentration are blood markers associated with the severity of paediatric OSAhttps://bit.ly/2Asw1xa