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The Laryngoscope Aug 2017A systematic review and meta-analysis of the literature was undertaken, examining the association between tobacco smoking and olfactory function in humans, utilizing... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES/HYPOTHESIS
A systematic review and meta-analysis of the literature was undertaken, examining the association between tobacco smoking and olfactory function in humans, utilizing PubMed and Web of Science (1970-2015) as data sources.
STUDY DESIGN
Systematic literature review and meta-analysis.
METHODS
This database review of studies of smoking and olfaction, with a focus on identifying high-quality studies (based on modified versions of the Newcastle-Ottawa Scale), used validated olfactory tests among the generally healthy population.
RESULTS
We identified 11 studies meeting inclusion criteria. Of 10 cross-sectional studies, two were excluded from meta-analysis because the cohorts they studied were included in another article in the review. In meta-analysis, current smokers had substantially higher odds of olfactory dysfunction compared to never smokers (odds ratio [OR] = 1.59, 95% confidence interval [CI] = 1.37-1.85). In contrast, former smokers were found to have no difference in risk of impaired olfaction compared to never smokers (OR = 1.05, 95% CI = 0.91-1.21). The single longitudinal study reviewed found a trend toward increased risk of olfactory decline over time in ever smokers; this trend was stronger in current as compared to former smokers.
CONCLUSIONS
Current smoking, but not former smoking, is associated with significantly increased risk of olfactory dysfunction, suggesting that the effects of smoking on olfaction may be reversible. Future studies that prospectively evaluate the impact of smoking cessation on improvement in olfactory function are warranted.
LEVEL OF EVIDENCE
N/A. Laryngoscope, 127:1753-1761, 2017.
Topics: Humans; Olfaction Disorders; Smoking
PubMed: 28561327
DOI: 10.1002/lary.26558 -
Current Opinion in Infectious Diseases Oct 2022Although acute COVID-19 has been milder in children and young people compared with adults, there is a concern that they may suffer persistent symptoms. There is a need... (Meta-Analysis)
Meta-Analysis
PURPOSE OF REVIEW
Although acute COVID-19 has been milder in children and young people compared with adults, there is a concern that they may suffer persistent symptoms. There is a need to define the clinical phenotype, determine those most at risk, the natural course of the condition and evaluate preventive and therapeutic strategies for both mental health and physical symptoms.
RECENT FINDINGS
More recent studies with control groups reported a lower prevalence of persistent symptoms in children and young people exposed to SARS-CoV-2. A systematic review and meta-analysis found that the frequency of the majority of reported persistent symptoms is similar in SARS-CoV-2 positive cases and controls. Children and young people infected with SARS-COV-2 had small but significant increases in persisting cognitive difficulties, headache and loss of smell. Factors associated with persisting, impairing symptoms include increased number of symptoms at the time of testing, female sex, older age, worse self-rated physical and mental health, and feelings of loneliness preinfection.
SUMMARY
This review highlights the importance of a control group in studies following SARS-CoV-2 infection, the need for case definitions and research to understand the outcomes of long COVID in children and young people.
Topics: COVID-19; Female; Humans; Mental Health; SARS-CoV-2; Post-Acute COVID-19 Syndrome
PubMed: 36098262
DOI: 10.1097/QCO.0000000000000854 -
Attention Deficit and Hyperactivity... Mar 2018A large body of research demonstrated that individuals with attention deficit hyperactivity disorder (ADHD) suffer from various neuropsychological deficits. In contrast,... (Review)
Review
A large body of research demonstrated that individuals with attention deficit hyperactivity disorder (ADHD) suffer from various neuropsychological deficits. In contrast, less is known and only divergent evidence exists on perceptual functions of individuals with ADHD. This is problematic as neuropsychological and perceptual functions are closely interrelated and are often difficult to disentangle in behavioral assessments. This study presents the conduct and results of a systematic literature review on perceptual functions in children and adults with ADHD. This review considers studies using psychophysical methods (objective measurements) and self- and informant reports (subjective measurements). Results indicate that individuals with ADHD have altered perceptual functions in various domains as compared to typically developing individuals. Increased perceptual functions in individuals with ADHD were found with regard to olfactory detection thresholds, whereas reduced perceptual functions were evident for aspects of visual and speech perception. Moreover, individuals with ADHD were found to experience discomfort to sensory stimuli at a lower level than typically developing individuals. Alterations of perceptual functions in individuals with ADHD were shown to be moderated by various factors, such as pharmacological treatment, cognitive functions, and symptom severity. We conclude by giving implications for daily life functioning and clinical practice.
Topics: Attention Deficit Disorder with Hyperactivity; Cognition; Humans; Perceptual Disorders
PubMed: 28401487
DOI: 10.1007/s12402-017-0230-0 -
International Journal of Infectious... Apr 2022Chemosensory disorders associated with COVID-19 have been widely discussed during the pandemic. We performed a meta-analysis to assess the risk factors for olfactory and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Chemosensory disorders associated with COVID-19 have been widely discussed during the pandemic. We performed a meta-analysis to assess the risk factors for olfactory and gustatory dysfunction in patients with COVID-19.
METHODS
Three databases (PubMed, Embase, and Cochrane Library) were searched for studies published between December 1, 2019, and August 31, 2021. We selected random-effects model or fixed-effects model to pool data based on heterogeneity. The results were reported as odds ratios (ORs) or standardized mean differences (SMDs) and the corresponding 95% confidence intervals (CIs). Heterogeneity was reported as I.
RESULTS
Twenty-six studies with a total of 13,813 patients were included. The pooled data indicated that sex (OR 1.47; 95% CI 0.93-2.31), age (SMD -5.80; 95% CI -13.35 to 1.75), smoking (OR 2.04; 95% CI 0.72-5.79), and comorbidity (OR 1.21; 95% CI 0.58-2.53) of patients with COVID-19 had no effect on gustatory dysfunction. Olfactory dysfunction was more likely to occur in older patients with COVID-19 (SMD, -5.22; 95% CI, -8.28 to -2.16). Patients with COVID-19 with nasal congestion (OR 3.41; 95% CI 2.30-5.06) and rhinorrhea (OR 2.35; 95% CI 1.60-3.45) were more prone to olfactory dysfunction.
CONCLUSION
These findings emphasize that older patients with COVID-19 are more likely to experience olfactory dysfunction. Symptoms of nasal congestion and rhinorrhea may affect the recognition of olfactory dysfunction.
Topics: Aged; COVID-19; Humans; Olfaction Disorders; Prevalence; SARS-CoV-2; Taste Disorders
PubMed: 35134561
DOI: 10.1016/j.ijid.2022.02.004 -
European Review For Medical and... Jun 2022The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, a viral outbreak that started in December 2019, eventually lead to a worldwide...
OBJECTIVE
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, a viral outbreak that started in December 2019, eventually lead to a worldwide pandemic. COVID-19 usually presents with flu-like symptoms, such as headaches, dry cough, fever, fatigue, myalgia, shortness of breath, diarrhea and loss of smell or taste. However, it can also have major effects on the cardiovascular system. Based on the available relevant literature, we aimed to elaborate the possible mechanisms influencing cardiovascular damage, myocardial injury and thromboembolic disease process in particular.
MATERIALS AND METHODS
After considering our inclusion and exclusion criteria, the systematic review included 8 studies in total.
RESULTS
In general, underlying cardiovascular diseases were associated with poorer clinical outcomes. This may be due to immunological dysregulation. The disease outcomes were also positively correlated with the severity of the disease, especially with myocardial injury. Thus, cardiac biomarkers, such as Troponin T, CK-MB and myoglobin could be utilized in prediction algorithms for deciphering the clinical outcome in COVID-19 patients.
CONCLUSIONS
Venous thromboembolisms were commonly encountered complications despite the administration of thromboprophylaxis, and they mostly presented as pulmonary embolisms, warranting the need for relevant investigations in hemodynamically unstable patients. However, more studies need to be conducted to better understand the mechanisms at play and the ensuing complications, to better treat COVID-19 patients.
Topics: Anticoagulants; COVID-19; Humans; SARS-CoV-2; Troponin T; Venous Thromboembolism
PubMed: 35776052
DOI: 10.26355/eurrev_202206_29090 -
International Forum of Allergy &... Nov 2023Many studies have identified a higher degree of Olfactory Dysfunction (OD) in Black patients compared to White patients. This study aims to analyze olfactory outcomes... (Review)
Review
BACKGROUND
Many studies have identified a higher degree of Olfactory Dysfunction (OD) in Black patients compared to White patients. This study aims to analyze olfactory outcomes in different races.
METHODS
The PubMed, Scopus, and CINAHL databases were searched from inception to September 5, 2022, for English-language articles documenting self-reported and psychophysical OD stratified by race. A meta-analysis of proportions, comparison of weighted proportions, and comparison of means were performed in MedCalc 20.218. In the quantitative analysis, 79,297 patients were included, comprising 79.3% Whites, 16.1% Blacks, and 4.6% Hispanics.
RESULTS
A total of 14 studies were meta-analyzed. The prevalence of self-reported OD in Hispanic, White, and Black patients was 19.5% (95% CI, 16.6% to 22.6%), 17.2% (95% CI, 10.5% to 25.0%), and 13.9% (95% CI, 9.3% to 19.2%), respectively (p < 0.0007). The prevalence of psychophysical OD in Black, White, and Hispanic patients was 30.3% (95% CI, 24.2% to 36.9%), 24.2% (95% CI, 20.1% to 28.5%), and 18.4% (95% CI, 16.3% to 20.7%), respectively (p < 0.0001). Blacks reported a greater extent of unrecognized OD compared to Whites, with a difference of 16.5% (95% CI, 15.0% to 17.9%) versus 5.8% (95% CI, 3.4% to 8.0%), respectively (p < 0.0001). Hispanic rates of self-reported OD and psychophysical OD were not statistically different.
CONCLUSIONS
Our findings suggest that Blacks have the highest rate of psychophysical OD and are more likely to underreport their awareness compared to Whites.
PubMed: 37183309
DOI: 10.1002/alr.23184 -
The Laryngoscope Feb 2017Many studies have reported that olfactory dysfunction frequently occurs in chronic rhinosinusitis (CRS) populations; however, the prevalence and degree of olfactory loss... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Many studies have reported that olfactory dysfunction frequently occurs in chronic rhinosinusitis (CRS) populations; however, the prevalence and degree of olfactory loss has not been systematically studied. The aims of this study were to use combined data to report the prevalence of olfactory dysfunction and to calculate weighted averages of olfactory test scores in CRS patients.
DATA SOURCES
A search was conducted in PubMed and Scopus, following the methods of Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines.
REVIEW METHODS
Studies reporting the prevalence of olfactory dysfunction using objective measures or olfactory test scores using validated scales were included.
RESULTS
A total of 47 articles were included in a systematic review and 35 in the pooled data analysis. The prevalence of olfactory dysfunction in chronic rhinosinusitis was found to be 30.0% using the Brief Smell Identification Test, 67.0% using the 40-item Smell Identification Test, and 78.2% using the total Sniffin' Sticks score. Weighted averages ± standard deviation of olfactory test scores were 25.96 ± 7.11 using the 40-item Smell Identification Test, 8.60 ± 2.81 using the Brief Smell Identification Test, 21.96 ± 8.88 using total Sniffin' Sticks score, 5.65 ± 1.51 using Sniffin' Sticks-Threshold, 9.21 ± 4.63 using Sniffin' Sticks-Discrimination, 9.47 ± 3.92 using Sniffin' Sticks-Identification, and 8.90 ± 5.14 using the Questionnaire for Olfactory Disorders-Negative Statements.
CONCLUSIONS
In CRS populations, a significant percentage of patients experience olfactory dysfunction, and mean olfactory scores are within the dysosmic range. Laryngoscope, 2016 127:309-320, 2017.
Topics: Chronic Disease; Comorbidity; Cross-Sectional Studies; Humans; Olfaction Disorders; Rhinitis; Sinusitis
PubMed: 27873345
DOI: 10.1002/lary.26316 -
Biological Reviews of the Cambridge... Jun 2022Smell is a sensory modality that is rarely considered in birds, but evidence is mounting that olfaction is an important aspect of avian behaviour and ecology. The...
Smell is a sensory modality that is rarely considered in birds, but evidence is mounting that olfaction is an important aspect of avian behaviour and ecology. The uropygial gland produces an odoriferous secretion (preen oil) that can differ seasonally and between the sexes. These differences are hypothesized to function in olfactory camouflage, i.e. minimizing detection by nest predators (olfactory crypsis hypothesis), and/or intraspecific olfactory communication, particularly during breeding (sex semiochemical hypothesis). However, evidence for seasonal and sex differences in preen oil is mixed, with some studies finding differences and others not, and direct evidence for the putative function(s) of seasonal variation and sex differences in preen oil remains limited. We conducted a systematic review of the evidence for such changes in preen oil chemical composition, finding seasonal differences in 95% of species (57/60 species in 35 studies) and sex differences in 47% of species (28/59 species in 46 studies). We then conducted phylogenetic comparative analyses using data from 59 bird species to evaluate evidence for both the olfactory crypsis and sex semiochemical hypotheses. Seasonal differences were more likely in the incubating than non-incubating sex in ground-nesting species, but were equally likely regardless of incubation strategy in non-ground-nesting species. This result supports the olfactory crypsis hypothesis, if ground nesters are more vulnerable to olfactorily searching predators than non-ground nesters. Sex differences were more likely in species with uniparental than biparental incubation and during breeding than non-breeding, consistent with both the olfactory crypsis and sex semiochemical hypotheses. At present, the data do not allow us to disentangle these two hypotheses, but we provide recommendations that will enable researchers to do so.
Topics: Animals; Birds; Communication; Pheromones; Phylogeny; Plant Breeding; Smell
PubMed: 35128775
DOI: 10.1111/brv.12837 -
Frontiers in Psychiatry 2017Research has demonstrated a reduction in olfactory functioning in patients with schizophrenia. This research has led to examination of olfactory functioning in other... (Review)
Review
BACKGROUND
Research has demonstrated a reduction in olfactory functioning in patients with schizophrenia. This research has led to examination of olfactory functioning in other mental disorders, such as depression. There is a great deal of variation in the results generated from such research, and it remains unclear as to how olfactory functioning is associated with or impacted by depression.
METHOD
The current review examined the literature in accordance with PRISMA guidelines in order to generate a better understanding of this relationship and to identify if and what aspects of olfactory processing are altered. Through examination of the available literature from the databases PubMed, Ovid Medline, CINAL, and PsychINFO, 15 manuscripts were selected to determine if there was a difference in olfactory processing-specifically central and peripheral processing-between depressed individuals and non-depressed controls.
RESULTS
The comparison of the 15 studies showed that the majority of studies (9/15, 60%) found a difference in overall olfactory functioning between depressed individuals and non-depressed controls ( < 0.05).
LIMITATIONS
There is still a lack of definitive conclusions due to variation of which olfactory process was altered.
CONCLUSION
Given the differences in the methodology and design of these studies, a possible solution that could eliminate the lack of clarity and reduce variation would be to adhere to a single, thorough methodology that examines and separates central and peripheral olfactory processing. Future research employing a uniform and validated methodology could provide more definitive conclusions as to how and if olfactory functioning is related depression.
PubMed: 29033860
DOI: 10.3389/fpsyt.2017.00190 -
Otolaryngology--head and Neck Surgery :... Dec 2023Olfactory disorders are well-studied in the adult population, however, there is a paucity of literature characterizing olfactory dysfunction in pediatric patients. The... (Review)
Review
OBJECTIVE
Olfactory disorders are well-studied in the adult population, however, there is a paucity of literature characterizing olfactory dysfunction in pediatric patients. The purpose of this scoping review was to identify known causes of olfactory loss in pediatric populations, clarify the extent of use and validity of smell tests, and summarize current therapies for olfactory loss.
DATA SOURCES
PubMed, Ovid MEDLINE, and Web of Science.
REVIEW METHODS
Databases were systematically searched in September 2020. Two independent reviewers conducted the title and abstract screen, followed by review of full-texts for inclusion based on preset inclusion and exclusion criteria. Extracted data included study type, age/age-range of participants, gender, radiological evidence of olfactory dysfunction, types and results of smell tests used, etiology of olfactory loss, and therapies employed for olfactory loss.
RESULTS
A total of 103 articles (n = 1654) were eligible for final data extraction. The University of Pennsylvania Smell Identification Test was used most frequently for smell testing (21% of studies). In total, 45 causes of olfactory dysfunction have been elucidated by this study: 22 congenital and 23 acquired. Few therapies were described, and all were specific to the etiology of olfactory loss.
CONCLUSION
Olfactory dysfunction has a wide range of etiologies in the pediatric population, and clinicians should have a diagnostic algorithm for how to identify a cause should they encounter it in practice. If no etiology can be identified, education around safety should be provided to both the patient and their caregivers.
Topics: Adult; Humans; Child; Smell; Olfaction Disorders; Anosmia
PubMed: 37449420
DOI: 10.1002/ohn.415