Low serum copeptin levels in patients with obstructive sleep apnea

Nocturia and obstructive sleep apnoea

Nocturia, the need to urinate at night, is a common symptom in patients with obstructive sleep apnoea (OSA). Continuous positive airway pressure treatment can reduce nocturia in some patients, but the underlying mechanisms are complex and not fully understood. OSA affects the autonomic nervous system, oxidative stress and endothelial damage. Furthermore, the commonly held theory attributing polyuria to a false signal of cardiac overload and response natriuresis has limitations. A comprehensive approach to the management of nocturia in OSA, considering factors such as comorbidities, medication use, alcohol consumption and lifestyle, is needed. Effective management of nocturia in OSA requires a multidisciplinary approach, and urologists should be aware of the potential effect of OSA on physiology and refer patients for further testing at a sleep centre. In addition to continuous positive airway pressure, other interventions such as oral appliances and surgical obstruction treatment could be beneficial for some patients. Overall, understanding the complex interplay between OSA and nocturia is crucial for optimizing patient outcomes.

Arginine vasopressin potentiates inspiratory bursting in hypoglossal motoneurons of neonatal mice

Vasopressin (AVP) acts as a neurotransmitter and its activity can potentiate respiratory activity. Hypoglossal (XII) motoneurons that innervate the tongue express V1a vasopressin receptors, which are excitatory. Therefore, we hypothesized that V1a receptor activation at XII motoneurons would potentiate inspiratory bursting. We developed this study to determine whether AVP can potentiate inspiratory bursting in rhythmic medullary slice preparations in neonatal (postnatal, P0-5) mice. Bath or local application of AVP potentiated inspiratory bursting compared to baseline XII inspiratory burst amplitude. Antagonizing V1a receptors revealed significant attenuation of the AVP-mediated potentiation of inspiratory bursting, while antagonism of oxytocin receptors (at which AVP has similar binding affinity) revealed a trend to attenuate AVP-mediated potentiation of inspiratory bursting. Finally, we discovered that the AVP-mediated potentiation of inspiratory bursting increases significantly with postnatal maturation from P0-5. Overall, these data support that AVP potentiates inspiratory bursting directly at XII motoneurons.

Review novel insights into the diagnostic and prognostic function of copeptin in daily clinical practice

As is shown in previous reports, arginine vasopressin (AVP), as one of the most important hormones within circulation in human beings, is of great clinically significance given that it could maintain the body fluid balance and vascular tone. However, the laboratory measurements AVP in daily clinical practice are shown to be difficult and with low accuracy. Concerning on this notion, it is unpractical to use the serum levels of AVP in diagnosing multiple diseases. On the other hand, another key serum biomarker, copeptin, is confirmed as the C-terminal of the AVP precursor which could be released in equal amounts with AVP, resultantly making it as a sensitive marker of arginine vasopressin release. Notably, emerging recent evidence has demonstrated the critical function of copeptin as a clinical indicator, especially in the diagnosis and prognosis of several diseases in diverse organs, such as cardiovascular disease, kidney disease, and pulmonary disease. In addition, copeptin was recently verified to play an important role in diagnosing multiple acute diseases when combined it with other gold standard serum biomarkers, indicating that copeptin could be recognized as a vital disease marker. Herein, in the current review, the functions of copeptin as a new predictive diagnostic and prognostic biomarker of various diseases, according to the most recent studies, are well summarized. Furthermore, the importance of using copeptin as a serum biomarker in diverse medical departments and the impact of this on improving healthcare service is also summarized in the current review.

A meta-analysis and trial sequential analysis of serum copeptin level in adult patients with Obstructive Sleep Apnoea Syndrome

OBJECTIVE

Copeptin can act as a stable biomarker in inflammation and stress response that obstructive sleep apnoea syndrome (OSAS), can induce oxidative stress and consequently promotes systemic inflammation. The purpose of the study is to appraise serum copeptin level in adult patients with OSAS compared to the controls.

MATERIAL AND METHODS

Electronic search was done in the databases of PubMed/Medline, Web of Science, Scopus, and Cochrane Library until June 2021, without any restrictions. For comparison of the serum copeptin level between groups, the mean difference (MD) and 95% confidence interval (CI) were calculated by the Review Manager 5.3 software. Trial sequential analysis (TSA) was used by applying TSA software.

RESULTS

Among the databases, five articles (involving 495 OSAS patients and 135 controls) were included. To report the serum copeptin level in OSAS patients compared to controls, the pooled OR became 12.21pg/mL (95%CI: 2.31 to 22.11; P=0.02) and also the pooled OR for comparison of serum copeptin level in severe versus moderate/mild OSAS patients was 5.96pg/mL (95%CI: 1.46 to 10.47; P=0.009). The results of TSA illustrated that the Z-curve has not crossed the monitoring boundary curves and did not reach the required information size.

CONCLUSIONS

The main findings recommended that copeptin had a significantly higher serum level in OSAS patients compared to controls, as well as a significantly higher level in severe patients compared to mild/moderate OSAS patients for the serum level of copeptin.

Plasma copeptin levels in patients with restless legs syndrome

OBJECTIVES

Copeptin, the C-terminal fragment of antidiuretic hormone, is a new biomarker that has been found to be elevated in several disorders and could be related with prognosis. This study aimed to compare plasma copeptin levels in patients with restless legs syndrome (RLS) with healthy individuals and to investigate whether plasma copeptin levels were associated with the severity of disease.

MATERIAL AND METHODS

41 patients with primary RLS, who were followed in Bakirkoy Psychiatry and Neurology Research and Training Hospital and 41 age- and sex-matched healthy individuals were included into the study. RLS patients were divided into subgroups as mild-moderate, severe, and very severe according to the severity of symptoms. Sleep quality and excessive daytime sleepiness were determined according to Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale, respectively, and sleep quality scores were analyzed statistically among the groups divided according to disease severity. Copeptin levels in all the patients were compared to the controls. RLS subgroups were compared with each other to evaluate association between copeptin levels and disease severity.

RESULTS

Plasma copeptin levels in RLS patients were significantly higher than controls (P < .001). However, there was no association between copeptin levels and disease severity. Excessive daytime sleepiness was found as 14.63% and low sleep quality as 68.29% in patients.

CONCLUSIONS

Hypothalamic-pituitary-adrenal axis activation and sympathetic hyperactivity in RLS might be responsible for increased Antidiuretic hormone (ADH) and copeptin release. We think that copeptin might have a potential role in the pathogenesis of RLS and be a biomarker for this disease.

Does severe obstructive sleep apnea syndrome alter retrobulbar blood flow? A color Doppler ultrasound study

PURPOSE

To evaluate extraocular orbital vessels with color Doppler ultrasound (CDU) and investigate the effects of severe obstructive sleep apnea (OSA) on retrobulbar blood flow.

METHODS

Between February 2014 and September 2015, 30 patients with severe OSA (apnea-hypopnea index (AHI) > 30) and 28 controls were prospectively included in this study. Intraocular pressure (IOP) was measured with a Goldmann applanation tonometer, and CDU was used to evaluate the retrobulbar vessels.

RESULTS

The mean AHI score for the OSA group was 63.2 ± 21.5 per hour. The IOP values were significantly higher in the severe OSA group (p < 0.05). The central retinal artery peak systolic velocity (PSV) (p < 0.05) and end-diastolic velocity (EDV) (p < 0.02), and the ophthalmic artery (OA) PSV and EDV, were found to be significantly lower in the OSA group (p < 0.05).

CONCLUSION

Severe OSA causes an increase in IOP and a decrease in flow velocity in the retrobulbar circulation.

Sleep and Nocturia in Older Adults

Older adults frequently experience nocturia and sleep disturbance concurrently, and problems with sleep resulting from nocturia are a major factor accompanying the bother associated with nocturia. A multicomponent treatment strategy is usually warranted. Initial treatment includes lifestyle modification and behavioral treatment with consideration of pelvic floor muscle exercise-based therapy. Early evidence suggests that behavioral treatment results in similar nocturia reductions compared with the most frequently used drug therapies. Providers should consider formal sleep evaluation if initial treatment strategies for nocturia do not result in significant improvement, because specific sleep disorders may predispose to nocturia.

Copeptin: a new predictor for severe obstructive sleep apnea

INTRODUCTION

Copeptin which is the C-terminal fragment of antidiuretic hormone (ADH), is a biomarker that has been reported to be increased in various cardiovascular disorders, cerebrovascular diseases and associated with prognosis. Patients with obstructive sleep apnea syndrome (OSAS) have a tendency to develop coronary and cerebral atherosclerotic diseases.

OBJECTIVES

The aim of the present study was to study copeptin levels in patients with obstructive sleep apnea and in a control group in order to determine whether copeptin could be used as a biomarker predicting the severity of OSAS and possible complications in this group.

METHODS

A total of 116 patients with OSAS, diagnosed by polysomnography, and 27 controls were included in the study. Blood samples were collected after overnight fasting, and copeptin levels were measured with enzyme-linked immunosorbent assay.

RESULTS

Copeptin levels were significantly higher in the OSAS group compared to control group (2,156±502; 1,845±500 pg/mL, respectively, P=0.004). Mean copeptin level of the patients having apnea-hypopnea index (AHI) ≥30 was significantly higher than that of the patients having AHI <30 (2,392±415; 2,017±500 pg/mL, respectively, P<0.001). A multivariate regression analysis showed that copeptin level, (hazard ratio: 1.58; 95% confidence interval: 1.09-2.30) was a predictor of severe OSAS (P=0.016). Copeptin levels showed significant positive correlation with AHI (r=0.32; P<0.001), desaturation index (r=0.23; P=0.012), arousal index (r=0.24; P=0.010) and CRP (r=0.26; P=0.011) respectively.

CONCLUSION

Copeptin levels are high in OSAS patients and copeptin is a potential marker for identifying patients with a high risk of early cardiovascular complications of OSAS. Copeptin has modest sensitivity (84%) for discriminating severe OSAS patients who are candidates for severe cardiovascular complications.

Can we use serum copeptin levels as a biomarker in obstructive sleep apnea syndrome?

OBJECTIVE

The aim of this study was to compare serum copeptin levels in patients with obstructive sleep apnea syndrome (OSA) and simple snorers without sleep apnea; and to investigate relationships between copeptin levels and polysomnographic parameters.

METHODS

Serum copeptin levels were determined using enzyme-linked immunosorbent assay in 47 patients with OSA and 12 patients without OSA (control group). Full-night polysomnography was performed in each patient. Patients with OSA were divided into three groups according to their Apnea Hypopnea Index (AHI) scores: mild OSA (5 < AHI < 15), moderate OSA (15 < AHI < 30), and severe OSA (AHI > 30).

RESULTS

A total of 59 patients were included in the study. There were 23 female (39.0%) and 36 male (61.0%) subjects. The range of ages of study subjects was between 27 and 63 (mean 44.75 ± 9.64) years. According to the AHI values, patients were classified into four groups: simple snoring (n = 13), mild OSA (n = 10), moderate OSA (n = 15), and severe OSA (n = 21). Statistically significant differences between AHI groups in terms of age, Epworth score, and neck circumference. According to multiple comparison results for age, the difference between simple snoring and moderate OSA was statistically significant. According to multiple comparison results for Epworth score, the difference between simple snoring and severe OSA was statistically significant. According to multiple comparison results for neck circumference, a similar result was found like Epworth Sleepiness Scale score. The difference between AHI groups by gender was tested by a Pearson χ(2) test and was found to be statistically significant. There was no statistically significant difference among AHI groups in terms of copeptin. There was a statistically significant correlation of copeptin with AHI during rapid eye movement (REM) sleep; however, the correlation coefficient was not sufficiently large.

CONCLUSIONS

Increased serum copeptin concentration may reflect a response to stress in some diseases. This is well documented especially in cardiovascular diseases; however, we could not find any difference in OSA groups in terms of copeptin levels.

Diagnostic capability of biological markers in assessment of obstructive sleep apnea: a systematic review and meta-analysis

OBJECTIVE

The purpose of this systematic review is to evaluate the diagnostic value of biological markers (exhaled breath condensate, blood, salivary and urinary) in the diagnosis of OSA in comparison to the gold standard of nocturnal PSG.

METHODS

Studies that differentiated OSA from controls based on PSG results, without age restriction, were eligible for inclusion. The sample of selected studies could include studies in obese patients and with known cardiac disease. A detailed individual search strategy for each of the following bibliographic databases was developed: Cochrane, EMBASE, MEDLINE, PubMed, and LILACS. The references cited in these articles were also crosschecked and a partial grey literature search was undertaken using Google Scholar. The methodology of selected studies was evaluated using the 14-item Quality Assessment Tool for Diagnostic Accuracy Studies.

RESULTS

After a two-step selection process, nine articles were identified and subjected to qualitative and quantitative analyses. Among them, only one study conducted in children and one in adults found biomarkers that exhibit sufficiently satisfactory diagnostic accuracy that enables application as a diagnostic method for OSA.

CONCLUSION

Kallikrein-1, uromodulin, urocotin-3, and orosomucoid-1 when combined have enough accuracy to be an OSA diagnostic test in children. IL-6 and IL-10 plasma levels have potential to be good biomarkers in identifying or excluding the presence of OSA in adults.

Copeptin: a new predictor for severe obstructive sleep apnea

INTRODUCTION

Copeptin which is the C-terminal fragment of antidiuretic hormone (ADH), is a biomarker that has been reported to be increased in various cardiovascular disorders, cerebrovascular diseases and associated with prognosis. Patients with obstructive sleep apnea syndrome (OSAS) have a tendency to develop coronary and cerebral atherosclerotic diseases.

OBJECTIVES

The aim of the present study was to study copeptin levels in patients with obstructive sleep apnea and in a control group in order to determine whether copeptin could be used as a biomarker predicting the severity of OSAS and possible complications in this group.

METHODS

A total of 116 patients with OSAS, diagnosed by polysomnography, and 27 controls were included in the study. Blood samples were collected after overnight fasting, and copeptin levels were measured with enzyme-linked immunosorbent assay.

RESULTS

Copeptin levels were significantly higher in the OSAS group compared to control group (2,156±502; 1,845±500 pg/mL, respectively, P=0.004). Mean copeptin level of the patients having apnea-hypopnea index (AHI) ≥30 was significantly higher than that of the patients having AHI <30 (2,392±415; 2,017±500 pg/mL, respectively, P<0.001). A multivariate regression analysis showed that copeptin level, (hazard ratio: 1.58; 95% confidence interval: 1.09-2.30) was a predictor of severe OSAS (P=0.016). Copeptin levels showed significant positive correlation with AHI (r=0.32; P<0.001), desaturation index (r=0.23; P=0.012), arousal index (r=0.24; P=0.010) and CRP (r=0.26; P=0.011) respectively.

CONCLUSION

Copeptin levels are high in OSAS patients and copeptin is a potential marker for identifying patients with a high risk of early cardiovascular complications of OSAS. Copeptin has modest sensitivity (84%) for discriminating severe OSAS patients who are candidates for severe cardiovascular complications.

Biomarkers associated with obstructive sleep apnea: A scoping review

The overall validity of biomarkers in the diagnosis of obstructive sleep apnea (OSA) remains unclear. We conducted a scoping review to provide assessments of biomarkers characteristics in the context of obstructive sleep apnea (OSA) and to identify gaps in the literature. A scoping review of studies in humans without age restriction that evaluated the potential diagnostic value of biological markers (blood, exhaled breath condensate, salivary, and urinary) in the OSA diagnosis was undertaken. Retained articles were those focused on the identification of biomarkers in subjects with OSA, the latter being confirmed with a full overnight or home-based polysomnography (PSG). Search strategies for six different databases were developed. The methodology of selected studies was classified using an adaptation of the evidence quality criteria from the American Academy of Pediatrics. Additionally the biomarkers were classified according to their potential clinical application. We identified 572 relevant studies, of which 117 met the inclusion criteria. Eighty-two studies were conducted in adults, 34 studies involved children, and one study had a sample composed of both adults and children. Most of the studies evaluated blood biomarkers. Potential diagnostic biomarkers were found in nine pediatric studies and in 58 adults studies. Only nine studies reported sensitivity and specificity, which varied substantially from 43% to 100%, and from 45% to 100%, respectively. Studies in adults have focused on the investigation of IL-6, TNF-α and hsCRP. There was no specific biomarker that was tested by a majority of authors in pediatric studies, and combinatorial urine biomarker approaches have shown preliminary promising results. In adults IL-6 and IL-10 seem to have a favorable potential to become a good biomarker to identify OSA.

Advanced oxidation protein products and ischaemia-modified albumin in obstructive sleep apnea

BACKGROUND

Several studies have shown that obstructive sleep apnea increases incidence of cardiovascular morbidity and mortality. The high systemic oxidative stress in obstructive sleep apnea has been considered as a major pathogenic mechanism leading to cardiovascular disease. Oxidative stress-related lipid and DNA oxidation in obstructive sleep apnea have been reported in the previous studies. In contrast, there is limited and contradictory information regarding protein oxidation in obstructive sleep apnea patients such as ischaemia-modified albumin and advanced oxidation protein products. Therefore, we aimed to investigate plasma ischaemia-modified albumin and advanced oxidation protein products and their correlation with total oxidative status and total antioxidative capacity in the obstructive sleep apnea patients.

METHODS

Plasma ischaemia-modified albumin, advanced oxidation protein products, total oxidative status and total antioxidative capacity were measured in 25 healthy volunteers and 59 obstructive sleep apnea patients diagnosed with polysomnography.

RESULTS

Plasma total antioxidative capacity was significantly lower (P = 0·012) and total oxidative status was significantly higher (P < 0·001) in the patients compared to the controls demonstrating increased oxidative stress in the patients. Plasma advanced oxidation protein products were significantly higher in the patients than the controls (P = 0·024). Plasma ischaemia-modified albumin levels were not statistically different between the obstructive sleep apnea patients and controls (P = 0·74).

CONCLUSIONS

We conclude that high systemic oxidative stress in obstructive sleep apnea is reflected by increased advanced oxidation protein products without causing an increase in ischaemia-modified albumin.

Optic disc and retinal nerve fiber layer parameters as indicators of neurodegenerative brain changes in patients with obstructive sleep apnea syndrome

PURPOSE

Retina is a unique part of the central nervous system (CNS) for visualizing the processes of axonal and neuronal degeneration. Optical coherence tomography (OCT) allows direct visualization and measurement of retinal nerve fiber layer (RNFL) thickness, macular volume, and optic disc (OD) parameters. One of the disorders associated with atrophy in different brain regions is obstructive sleep apnea syndrome (OSAS). In the present study, we aimed to determine OD and RNFL changes measured by OCT for investigating the progress of neurodegeneration development in OSAS, excluding all the other conditions that can directly affect RNFL thickness and optic nerve parameters.

METHODS

Both eyes of 101 patients with OSAS and 20 controls were investigated by OCT. Full-night polysomnography (PSG) and ophthalmologic examination including automated visual field (VF) examination and OCT were performed in all of the patients.

RESULTS

According to the OSAS grading, patients were grouped as mild (n=15), moderate (n=27), and severe (n=59). We found significant decrease in RNFL thickness only in the patients with severe OSAS compared with the other groups and decreased macular ganglion cell thickness in the severe OSAS group compared with the control group. VF parameters were significantly worsened in all the OSAS subgroups compared to the control group. We found different data such as normal or increased optic nerve parameters as result of subtle OD edema, which may mask possible peripapillar axonal loss.

CONCLUSIONS

We think that evaluation of neurodegeneration in OSAS is not always possible by examining OD and RNFL because there are difficulties due to the confounding issues of cerebral atrophy and OD edema.