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The Cochrane Database of Systematic... Sep 2019Topical cyclosporine A (also known as ciclosporin A) (CsA) is an anti-inflammatory that has been widely used to treat inflammatory ocular surface diseases. Two CsA...
BACKGROUND
Topical cyclosporine A (also known as ciclosporin A) (CsA) is an anti-inflammatory that has been widely used to treat inflammatory ocular surface diseases. Two CsA eyedrops have been approved by US Food and Drug Administration for managing dry eye: Restasis (CsA 0.05%, Allergan Inc, Irvine, CA, USA), approved in 2002, and Cequa (CsA 0.09%, Sun Pharma, Cranbury, NJ, USA), approved in 2018. Numerous clinical trials have been performed to assess the effectiveness and safety of CsA for dry eye; however, there is no universal consensus with regard to its effect.
OBJECTIVES
To assess the effectiveness and safety of topical CsA in the treatment of dry eye.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 2); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 16 February 2018.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) of people with dry eye regardless of age, sex, severity, etiology, or classification of dry eye. We included RCTs in which different concentrations of topical CsA were compared with one another or with artificial tears, placebo, or vehicle. We also included RCTs in which CsA in combination with artificial tears was compared to artificial tears alone.
DATA COLLECTION AND ANALYSIS
We followed the standard Cochrane methodology and assessed the certainty of the evidence using GRADE.
MAIN RESULTS
We included 30 RCTs (4009 participants) with follow-up periods ranging from 6 weeks to 12 months. We studied dry eye of various severity and underlying causes. The interventions investigated also varied across RCTs: CsA versus artificial tears; CsA with artificial tears versus artificial tears alone; and in some studies, more than one concentration of CsA. Artificial tears were used as adjunctive to study medication in all but five trials. Almost all trials had deficiencies in the reporting of results (e.g. reporting P values or direction only), precluding the calculation of between-group estimates of effect or meta-analysis.Eighteen trials compared topical CsA 0.05% plus artificial tears versus vehicle plus artificial tears or artificial tears alone. One trial reported subjective symptoms of dry eye at 6 months and the results were in favor of CsA (mean difference (MD) -4.80, 95% confidence interval (CI) -6.41 to -3.19; low-certainty evidence). Two trials reported MD in ocular surface dye staining at 6 months, but the results were inconsistent in these two trials (MD -0.35, 95% CI -0.69 to -0.01 in one and MD 0.58, 95% CI 0.06 to 1.10 in the other; low-certainty evidence). Four trials reported MD in Schirmer test scores at 6 months and the estimates ranged from -4.05 (95% CI -6.67 to -1.73) to 3.26 (95% CI -1.52 to 5.00) (low-certainty evidence). Three trials reported risk ratio (RR) of improved Schirmer test scores at 6 months; estimates ranged from 0.98 (95% CI 0.83 to 1.17) to 3.50 (95% CI 2.09 to 5.85) (low-certainty evidence). Four trials reported MD in tear film stability measured by tear break-up time at 6 months and the estimates ranged from -1.98 (95% CI -3.59 to -0.37) to 1.90 (95% CI 1.44 to 2.36) (low-certainty evidence). Three trials reported RR of improved tear break-up time at 6 months and the estimates ranged from 0.90 (95% CI 0.77 to 1.04) to 4.00 (95% CI 2.25 to 7.12) (low-certainty evidence). Three trials reported frequency of artificial tear usage at 6 months without providing any estimates of effect; the direction of effect seem to be in favor of CsA (low-certainty evidence). Because of incomplete reporting of the results data or considerable statistical heterogeneity, we were only able to perform a meta-analysis on mean conjunctival goblet cell density. Mean conjunctival goblet cell density in the CsA treated group may be greater than that in the control group at the end of follow-up at four and 12 months (MD 22.5 cells per unit, 95% CI 16.3 to 28.8; low-certainty evidence). All but two trials reported adverse events that included burning and stinging. Participants treated with CsA may be more likely to have treatment-related adverse events than those who treated with vehicle (RR 1.33, 95% CI 1.00 to 1.78; low-certainty evidence).Other comparisons evaluated were CsA 0.05% plus artificial tears versus higher concentrations of CsA plus artificial tears (4 trials); CsA 0.05% versus placebo or vehicle (4 trials); CsA 0.1% plus artificial tears versus placebo or vehicle plus artificial tears (2 trials);CsA 0.1% cationic emulsion plus artificial tears versus vehicle plus artificial tears (2 trials); CsA 1% plus artificial tears versus placebo plus artificial tears (3 trials); and CsA 2% plus artificial tears versus placebo plus artificial tears (3 trials). Almost all of these trials reported P value or direction of effect only (mostly in favor of CsA), precluding calculation of between-group effect estimates or meta-analyses.
AUTHORS' CONCLUSIONS
Despite the widespread use of topical CsA to treat dry eye, we found that evidence on the effect of CsA on ocular discomfort and ocular surface and tear film parameters such as corneal fluorescein staining, Schirmer's test, and TBUT is inconsistent and sometimes may not be different from vehicle or artificial tears for the time periods reported in the trials. There may be an increase in non-serious, treatment-related adverse effects (particularly burning) in the CsA group. Topical CsA may increase the number of conjunctival goblet cells. However, current evidence does not support that improvements in conjunctival mucus production (through increased conjunctival goblet cells) translate to improved symptoms or ocular surface and tear film parameters. All published trials were short term and did not assess whether CsA has longer-term disease-modifying effects. Well-planned, long-term, large clinical trials are needed to better assess CsA on long-term dry eye-modifying effects. A core outcome set, which ideally includes both biomarkers and patient-reported outcomes in the field of dry eye, is needed.
Topics: Cyclosporine; Dry Eye Syndromes; Humans; Lubricant Eye Drops; Randomized Controlled Trials as Topic
PubMed: 31517988
DOI: 10.1002/14651858.CD010051.pub2 -
The Cochrane Database of Systematic... Jan 2019Cystic fibrosis is a life-limiting genetic condition in which thick mucus builds up in the lungs, leading to infections, inflammation, and eventually, deterioration in...
BACKGROUND
Cystic fibrosis is a life-limiting genetic condition in which thick mucus builds up in the lungs, leading to infections, inflammation, and eventually, deterioration in lung function. To clear their lungs of mucus, people with cystic fibrosis perform airway clearance techniques daily. There are various airway clearance techniques, which differ in terms of the need for assistance or equipment, and cost.
OBJECTIVES
To summarise the evidence from Cochrane Reviews on the effectiveness and safety of various airway clearance techniques in people with cystic fibrosis.
METHODS
For this overview, we included Cochrane Reviews of randomised or quasi-randomised controlled trials (including cross-over trials) that evaluated an airway clearance technique (conventional chest physiotherapy, positive expiratory pressure (PEP) therapy, high-pressure PEP therapy, active cycle of breathing techniques, autogenic drainage, airway oscillating devices, external high frequency chest compression devices and exercise) in people with cystic fibrosis.We searched the Cochrane Database of Systematic Reviews on 29 November 2018.Two review authors independently evaluated reviews for eligibility. One review author extracted data from included reviews and a second author checked the data for accuracy. Two review authors independently graded the quality of reviews using the ROBIS tool. We used the GRADE approach for assessing the overall strength of the evidence for each primary outcome (forced expiratory volume in one second (FEV), individual preference and quality of life).
MAIN RESULTS
We included six Cochrane Reviews, one of which compared any type of chest physiotherapy with no chest physiotherapy or coughing alone and the remaining five reviews included head-to-head comparisons of different airway clearance techniques. All the reviews were considered to have a low risk of bias. However, the individual trials included in the reviews often did not report sufficient information to adequately assess risk of bias. Many trials did not sufficiently report on outcome measures and had a high risk of reporting bias.We are unable to draw definitive conclusions for comparisons of airway clearance techniques in terms of FEV, except for reporting no difference between PEP therapy and oscillating devices after six months of treatment, mean difference -1.43% predicted (95% confidence interval -5.72 to 2.87); the quality of the body of evidence was graded as moderate. The quality of the body of evidence comparing different airway clearance techniques for other outcomes was either low or very low.
AUTHORS' CONCLUSIONS
There is little evidence to support the use of one airway clearance technique over another. People with cystic fibrosis should choose the airway clearance technique that best meets their needs, after considering comfort, convenience, flexibility, practicality, cost, or some other factor. More long-term, high-quality randomised controlled trials comparing airway clearance techniques among people with cystic fibrosis are needed.
Topics: Chest Wall Oscillation; Cystic Fibrosis; Drainage; Humans; Positive-Pressure Respiration; Respiratory Therapy; Systematic Reviews as Topic
PubMed: 30676656
DOI: 10.1002/14651858.CD011231.pub2 -
Cureus Oct 2023Muco-obstructive lung disease is a new classification under the diseases of respiratory tract. A lot of discussion is still going on regarding this new group of... (Review)
Review
Muco-obstructive lung disease is a new classification under the diseases of respiratory tract. A lot of discussion is still going on regarding this new group of diseases. It is characterised by obstruction of the respiratory tract with a thick mucin layer. Usually in normal individuals, the mucus is swept out of the respiratory system while coughing in the form of sputum or phlegm, but if the consistency of the mucus is thick, or the amount is heavy or there is a certain defect in the ciliary function of the respiratory tract, the mucus is not cleared and it gets accumulated in the lungs alveoli, therefore blocking it. The mucus trapped in the distal airways cannot be cleared by coughing therefore forming a layer in the alveoli and bronchioles. Long-standing condition causes inflammation and infection. This new group of diseases specifically includes chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), primary ciliary dyskinesia (PCD) and non-cystic fibrosis bronchiectasis (NCFB). Asthma, although an obstructive disease of the lung, is not particularly included under muco-obstructive lung disease. The major symptoms with which these diseases present are sputum production, chronic cough and acute exacerbations of the condition. The mucus adheres to the lung parenchyma causing airway obstruction and hyperinflation. In this article, we will see how muco-obstructive lung diseases affect the normal physiology of the respiratory system and how is it different from other obstructive and restrictive lung diseases. We will individually look into all the four conditions that come under the category of muco-obstructive lung diseases.
PubMed: 37954759
DOI: 10.7759/cureus.46866 -
The Cochrane Database of Systematic... May 2018Acute sinusitis is a common reason for primary care encounters. It causes significant symptoms including facial pain, congested nose, headache, thick nasal mucus, fever,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Acute sinusitis is a common reason for primary care encounters. It causes significant symptoms including facial pain, congested nose, headache, thick nasal mucus, fever, and cough and often results in time off work or school. Sinusitis treatment focuses on eliminating causative factors and controlling the inflammatory and infectious components. The frozen, dried, natural fluid extract of the Cyclamen europaeum plant delivered intranasally is thought to have beneficial effects in relieving congestion by facilitating nasal drainage, and has an anti-inflammatory effect.
OBJECTIVES
To assess the effectiveness of topical intranasal Cyclamen europaeum extract on clinical response in adults and children with acute sinusitis.
SEARCH METHODS
We searched CENTRAL, which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE, Embase, and trials registers (ClinicalTrials.gov; WHO ICTRP) in January 2018. We also searched the reference lists of included studies and review literature for further relevant studies and contacted trial authors for additional information.
SELECTION CRITERIA
Randomised controlled trials comparing Cyclamen europaeum extract administered intranasally to placebo, antibiotics, intranasal corticosteroids, or no treatment in adults or children, or both, with acute sinusitis. Acute sinusitis was defined by clinical diagnosis and confirmed by nasal endoscopy or by radiological evidence.
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted data and assessed trial quality. We used standard methodological procedures expected by Cochrane.
MAIN RESULTS
We included two randomised controlled trials that involved a total of 147 adult outpatients with acute sinusitis confirmed by radiology or nasal endoscopy who were assigned to Cyclamen europaeum nasal spray or placebo study arms for up to 15 days. The risk of selection and detection bias was unclear, as allocation concealment and blinding of outcome assessors were not reported in either study. Attrition was high (60%) in one study, although dropouts were balanced between study arms.Neither study reported our two primary outcomes: proportion of participants whose symptoms resolved or improved at 14 days and 30 days. No serious adverse events or complications related to treatment were reported; however, more mild adverse events such as nasal and throat irritation, mild epistaxis, and sneezing occurred in Cyclamen europaeum group participants (50%) compared to placebo group participants (24%) (risk ratio 2.11, 95% confidence interval 1.35 to 3.29); moderate-quality evidence.
AUTHORS' CONCLUSIONS
The effectiveness of Cyclamen europaeum for people with acute sinusitis is unknown. Although no serious side effects were observed, 50% of participants who received Cyclamen europaeum reported adverse events compared with 24% of those who received placebo.
Topics: Acute Disease; Adult; Anti-Inflammatory Agents; Cyclamen; Humans; Nasal Polyps; Plant Extracts; Randomized Controlled Trials as Topic; Rhinitis; Sinusitis
PubMed: 29750825
DOI: 10.1002/14651858.CD011341.pub2 -
Multidisciplinary Respiratory Medicine 2018Uncertainty exists regarding the physiological basis of physiotherapy strategies to facilitate mucus clearance. The aim of this review was to describe the physiological... (Review)
Review
BACKGROUND
Uncertainty exists regarding the physiological basis of physiotherapy strategies to facilitate mucus clearance. The aim of this review was to describe the physiological factors and intrinsic conditions that facilitate airway mucus transport.
METHOD
A scoping review was performed. A systematic literature search of six databases was executed. Eligibility criteria were applied by two researchers to reach the aim of the review. Papers were identified independently by two reviewers on title, abstract and full-text level. Any discrepancies were discussed with a third reviewer.
RESULTS
The search identified 35 papers published between 1975 and 2015. These differed significantly in terms of outcome measures, measurement techniques and methodologies and included animal studies, laboratory investigations, and the use of small human samples. Nine key factors influencing mucus transport were identified. These include: temperature and humidity, bronchial perfusion, ATP, forced expiratory technique and cough, generation of oscillation, ventilation patterns/airflow, epithelial differences, mucus properties and positioning.
CONCLUSION
This review provides a framework for factors/conditions influencing mucus transport. Existing physiotherapy strategies for augmentation of airway mucus clearance can now be evaluated against the framework and new modalities informed.
PubMed: 29988934
DOI: 10.1186/s40248-018-0127-6 -
Journal of Clinical Medicine Apr 2021Mucins are a family of glycosylated proteins which are the primary constituents of mucus and play a dynamic role in the regulation of the protective mucosal barriers... (Review)
Review
Mucins are a family of glycosylated proteins which are the primary constituents of mucus and play a dynamic role in the regulation of the protective mucosal barriers throughout the human body. Ulcerative colitis (UC) is an Inflammatory Bowel Disease (IBD) characterised by continuous inflammation of the inner layer of the large intestine, and in this systematic review we analyse currently available data to determine whether alterations exist in mucin activity in the colonic mucosa of UC patients. Database searches were conducted to identify studies published between 1990 and 2020 that assess the role of mucins in cohorts of UC patients, where biopsy specimens were resected for analysis and control groups were included for comparison. 5497 articles were initially identified and of these 14 studies were systematically selected for analysis, a further 2 articles were identified through citation chaining. Therefore, 16 studies were critically reviewed. 13 of these studies assessed the role of MUC2 in UC and the majority of articles indicated that alterations in MUC2 structure or synthesis had an impact on the colonic mucosa, although conflicting results were presented regarding MUC2 expression. This review highlights the importance of further research to enhance our understanding of mucin regulation in UC and summarises data that may inform future studies.
PubMed: 33946184
DOI: 10.3390/jcm10091935 -
The Cochrane Database of Systematic... Apr 2023Cystic fibrosis (CF) is an inherited progressive life-limiting disease characterised by the build-up of abnormally thick, sticky mucus affecting mostly the lungs,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Cystic fibrosis (CF) is an inherited progressive life-limiting disease characterised by the build-up of abnormally thick, sticky mucus affecting mostly the lungs, pancreas, and digestive system. Airway clearance techniques (ACTs), traditionally referred to as chest physiotherapy, are recommended as part of a complex treatment programme for people with CF. The aim of an ACTs is to enhance mucociliary clearance and remove viscous secretions from the airways within the lung to prevent distal airway obstruction. This reduces the infective burden and associated inflammatory effects on the airway epithelia. There are a number of recognised ACTs, none of which have shown superiority in improving short-term outcomes related to mucus transport. This systematic review, which has been updated regularly since it was first published in 2000, considers the efficacy of ACTs compared to not performing any ACT in adults and children with CF. It is important to continue to review this evidence, particularly the long-term outcomes, given the recent introduction of highly effective modulator therapies and the improved health outcomes and potential changes to CF management associated with these drugs.
OBJECTIVES
To determine the effectiveness and acceptability of airway clearance techniques compared to no airway clearance techniques or cough alone in people with cystic fibrosis.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings, to 17 October 2022. We searched ongoing trials registers (Clinicaltrials.gov and the WHO International Clinical Trials Registry Platform) to 7 November 2022.
SELECTION CRITERIA
We included randomised or quasi-randomised studies that compared airway clearance techniques (chest physiotherapy) with no airway clearance techniques or spontaneous cough alone in people with CF.
DATA COLLECTION AND ANALYSIS
Both review authors independently assessed study eligibility, extracted data, and assessed the risk of bias of the included studies. We used GRADE methodology to assess the certainty of the evidence.
MAIN RESULTS
We included 11 cross-over studies (153 participants) and one parallel study (41 participants). There were differences between studies in how the interventions were delivered, with several intervention groups combining more than one ACT. One study used autogenic drainage; five used conventional chest physiotherapy; nine used positive expiratory pressure (PEP), with one study varying the water pressure between arms; three studies used oscillating PEP; two used exercise; and two used high-frequency chest wall oscillation (HFCWO). Of the 12 included studies, 10 were single-treatment studies, and two delivered the intervention over two consecutive days (once daily in one study, twice daily in the second). This substantial heterogeneity in the treatment interventions precluded pooling of data for meta-analysis. Blinding of participants, caregivers, and clinicians is impossible in airway clearance studies; we therefore judged all studies at unclear risk of performance bias. Lack of information in eight studies made assessment of risk of bias unclear for most other domains. We rated the certainty of evidence as low or very low due to the short-term cross-over trial design, small numbers of participants, and uncertain risk of bias across most or all domains. Six studies (84 participants) reported no effect on pulmonary function variables following intervention; but one study (14 participants) reported an improvement in pulmonary function following the intervention in some of the treatment groups. Two studies reported lung clearance index: one (41 participants) found a variable response to treatment with HFCWO, whilst another (15 participants) found no effect on lung clearance index with PEP therapy (low-certainty evidence). Five studies (55 participants) reported that ACTs, including coughing, increased radioactive tracer clearance compared to control, while a further study (eight participants) reported no improvement in radioactive tracer clearance when comparing PEP to control, although coughing was discouraged during the PEP intervention. We rated the certainty of evidence on the effect of ACTs on radioactive tracer clearance as very low. Four studies (46 participants) investigated the weight of mucus cleared from the lungs and reported greater secretions during chest physiotherapy compared to a control. One study (18 participants) reported no differences in sputum weight (very low-certainty evidence).
AUTHORS' CONCLUSIONS
The evidence from this review shows that ACTs may have short-term effects on increasing mucus transport in people with CF. All included studies had short-term follow-up; consequently, we were unable to draw any conclusions on the long-term effects of ACTs compared to no ACTs in people with CF. The evidence in this review represents the use of airway clearance techniques in a CF population before widespread use of cystic fibrosis transmembrane conductance regulator (CFTR) modulators. Further research is needed to determine the effectiveness and acceptability of airway clearance in those treated with highly effective CFTR modulators.
Topics: Adult; Child; Humans; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Cough; Radioactive Tracers; Forced Expiratory Volume
PubMed: 37042825
DOI: 10.1002/14651858.CD001401.pub4 -
Cureus Jun 2023The systematic review aims to evaluate the efficacy and safety of endobronchial stent placement for malignant airway obstruction. A comprehensive search was conducted... (Review)
Review
The systematic review aims to evaluate the efficacy and safety of endobronchial stent placement for malignant airway obstruction. A comprehensive search was conducted across multiple databases to identify relevant studies. Cohort studies, randomized controlled trials, and case-control studies examining the outcomes of endobronchial stent placement in patients with malignant airway obstruction were included. Data on pre-treatment evaluation, such as pulmonary function testing, dyspnea severity scoring systems, arterial blood gas parameters, imaging, and degree of obstruction, were also collected. Primary outcomes of interest included post-procedure stenosis, pulmonary function testing evaluation, blood gas parameters, and survival outcomes. Secondary outcomes encompassed improvements in clinical status, dyspnea grade, and procedure-related complications. A total of 27 studies met the inclusion criteria and were included in the systematic review. The included studies demonstrated promising outcomes of endobronchial stent placement in managing malignant airway obstruction. Post-procedure airway diameters, pulmonary function testing, and blood gas parameters improved significantly. Survival outcomes varied among studies. Furthermore, endobronchial stent placement was associated with improvements in clinical status and dyspnea grade. Procedure-related complications ranged from pain, hemoptysis and mucus plugging to stent obstruction, migration and pneumothorax. This systematic review suggests that endobronchial stent placement is an effective and safe intervention for managing malignant airway obstruction. It offers significant improvements in post-procedure stenosis, pulmonary function testing, blood gas parameters, and clinical outcomes. However, further studies with larger sample sizes and standardized reporting are warranted to better evaluate the long-term efficacy and safety of endobronchial stent placement for malignant airway obstruction.
PubMed: 37496555
DOI: 10.7759/cureus.40912 -
Reproduction & Fertility Jan 2022To summarize the currently available phase I and II clinical trials of the effects of nonoxynol-9 (N-9) on human sperm structure and functions. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To summarize the currently available phase I and II clinical trials of the effects of nonoxynol-9 (N-9) on human sperm structure and functions.
METHODS
A systematic review and meta-analysis aiming to evaluate the spermicidal activity of N-9 on motility, was conducted in PubMed, EMBASE, and Cochrane databases by 10 March 2021. The counted numbers of progressive motile (PR) sperm in cervical mucus and the vanguard sperm penetration distances were analyzed. Other effects on sperm structures and physiological activities were reviewed as well.
RESULTS
In the pooled results, percentages or counted numbers of PR sperm decreased after the treatment of N-9. Vanguard sperm penetration distance was shortened in treated groups. N-9 has been confirmed to damage the structures of sperm, as well as other organelles like acrosome and mitochondria. The physiological activities such as generation of reactive oxygen species, superoxide dismutase activity, acrosin activity, and hemizona binding were all inhibited in the reviewed studies.
CONCLUSIONS
N-9 has several impacts on sperm owing to its potency in reducing sperm motility and cervical mucus penetration, as well as other functional competencies.
LAY SUMMARY
Nonoxynol-9 (N-9) has been used worldwide as a spermicide to kill sperm for more than 60 years but can cause side effects including vaginal irritation and can increase the rate of contraceptive failure. A detailed analysis of published literature aiming to evaluate the spermicidal activity of N-9 on sperm was carried out. In the pooled results, N-9 reduced the number of active sperm and the distance they traveled. It also caused damage to the structures of sperm and to the way the sperm acted and interacted with the egg. In conclusion, N-9 impacts on sperm in a number of ways that lead to sperm death and dysfunction.
Topics: Female; Humans; Male; Nonoxynol; Semen; Sperm Motility; Spermatocidal Agents; Spermatozoa
PubMed: 35350652
DOI: 10.1530/RAF-21-0024 -
Laryngoscope Investigative... Apr 2022The aim of this systematic review and meta-analysis was to investigate the association between obstructive sleep apnea (OSA) and erythrocytosis. (Review)
Review
OBJECTIVE
The aim of this systematic review and meta-analysis was to investigate the association between obstructive sleep apnea (OSA) and erythrocytosis.
METHODS
The PubMed, Web of Science, and Cochrane Library databases were searched for articles examining hematocrit values in patients with OSA and control individuals published till September 1, 2021. The pooled standardized mean difference (SMD) with 95% confidence interval (CI) was calculated, and subgroup analyses were performed.
RESULTS
Eleven eligible studies with a total of 4608 patients with OSA were included in this meta-analysis. Pooled outcomes revealed that hematocrit values were significantly higher in patients with OSA than in controls (SMD, 0.19; 95% CI, 0.08-0.29; < .01). When studies were stratified by disease severity, the significant differences in hematocrit values between patients and controls were only observed in the severe OSA group (SMD, 0.34; 95% CI, 0.08-0.59; < .01), but not in the mild and moderate OSA groups. In subgroup analyses according to sex and publication year, significant differences in hematocrit values between patients and controls remained stable in studies with only female patients (SMD, 0.25; 95% CI, 0.12-0.38; < .01) and in studies published after 2012 (SMD, 0.17; 95% CI, 0.06-0.28, < .01).
CONCLUSION
Our meta-analysis revealed that the hematocrit value was significantly increased in patients with OSA, particularly in severe patients, compared with that in controls. However, the elevation was modest, and the hematocrit value is expected to be within the normal range in patients with OSA. These data suggest that OSA leads to slight increases in hematocrit but does not cause clinically significant erythrocytosis.
PubMed: 35434329
DOI: 10.1002/lio2.751