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Asian Pacific Journal of Allergy and... Sep 2020Olfactory and gustatory dysfunctions (OGD) are pathognomonic symptoms in patients with Coronavirus Disease 2019 (COVID-19). This study reviews the associations of OGD... (Meta-Analysis)
Meta-Analysis
Olfactory and gustatory dysfunctions (OGD) are pathognomonic symptoms in patients with Coronavirus Disease 2019 (COVID-19). This study reviews the associations of OGD with COVID-19 which will be useful for early diagnosis and self-isolation. Systematic searches of PubMed, Ovid Medline, Scopus, and EMBASE electronic databases were performed. Studies reporting OGD in COVID-19 patients were included. Data were pooled for meta-analysis. The outcomes were odds ratios (OR) of OGD in COVID-19 patients. Proportions of smell and/or taste dysfunctions in the COVID-19 patients were assessed. Fourteen studies (21,515 participants, age 49.12 years, 26% male) were included. The OR of olfactory and/or gustatory dysfunctions in COVID-19 patients were 11.26 (95% confidence interval (CI) 5.41 to 23.4) when compared with acute respiratory infection (ARI) without detectable virus and 6.46 (95% CI 2.79 to 14.97) in patients with other respiratory viruses. The OR of olfactory dysfunction in COVID-19 patients were 11.67 (95% CI 6.43 to 21.17) when compared with the ARI patients without detectable virus and 4.17 (95% CI 1.34 to 12.98) with other respiratory viruses. The OR of gustatory dysfunction in COVID-19 patients were 12.70 (95% CI 7.9 to 20.44) when compared with the ARI patients without detectable virus and 4.94 (95%CI 1.59 to 15.31) with other respiratory viruses. Fifty percent (95% CI 36.7 to 63.3%) of COVID-19 patients had olfactory and/or gustatory dysfunctions. In summary, there are associations between OGD and COVID-19 patients. Patients presenting with ARI should be assessed for olfactory and gustatory functions.
Topics: Adult; Betacoronavirus; COVID-19; Coronavirus Infections; Female; Host-Pathogen Interactions; Humans; Male; Middle Aged; Olfaction Disorders; Pandemics; Pneumonia, Viral; Prognosis; Risk Factors; SARS-CoV-2; Smell; Taste; Taste Disorders
PubMed: 32563232
DOI: 10.12932/AP-210520-0853 -
PloS One 2023Research on the long-term impact on COVID-19 in children and young people (CYP) has been published at pace. We aimed to update and refine an earlier systematic review... (Meta-Analysis)
Meta-Analysis
Persistent symptoms are associated with long term effects of COVID-19 among children and young people: Results from a systematic review and meta-analysis of controlled studies.
BACKGROUND
Research on the long-term impact on COVID-19 in children and young people (CYP) has been published at pace. We aimed to update and refine an earlier systematic review and meta-analysis to assess the current evidence for Post-COVID-19 Condition in CYP.
METHODS
Studies from the previous systematic review were combined with studies from a systematic search from July 2021 to November 2022 (registration PROSPERO CRD42021233153). Eligible studies included CYP aged ≤19 years with confirmed or probable SARS-CoV-2 infection and symptoms persisting at least 12 weeks.
FINDINGS
55 studies (n = 1,139,299 participants) were included. Over two-hundred symptoms were associated with Post COVID-19 Condition. Gastrointestinal problems, headaches, cough and fever were among the most prevalent symptoms with rates of 50.2%, 35.6%, 34.7% and 25.8% respectively. Twenty-one symptoms from 11 studies were suitable for meta-analysis. There were significantly higher pooled estimates of proportions of symptoms for altered / loss of smell or taste, dyspnoea, fatigue, and myalgia in CYP with confirmed SARS-CoV-2 infection. Heterogeneity was high suggesting substantial variation amongst the included studies.
CONCLUSIONS
Many CYP continue to experience symptoms after SARS-CoV-2 infection. Efforts to aid early identification and intervention of those most in need is warranted and the consequences of COVID-19 for CYP call for long-term follow-up.
Topics: Child; Humans; Adolescent; COVID-19; SARS-CoV-2; Headache; Research Design; Gastrointestinal Diseases; Post-Acute COVID-19 Syndrome
PubMed: 38153928
DOI: 10.1371/journal.pone.0293600 -
Association of Olfactory Impairment With All-Cause Mortality: A Systematic Review and Meta-analysis.JAMA Otolaryngology-- Head & Neck... May 2022Olfactory impairment is highly prevalent and associated with multiple comorbidities, including neurodegenerative, cardiovascular, nutritional, and immune disorders.... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Olfactory impairment is highly prevalent and associated with multiple comorbidities, including neurodegenerative, cardiovascular, nutritional, and immune disorders. However, epidemiologic associations between olfactory impairment and mortality are discordant.
OBJECTIVE
To systematically clarify the epidemiologic associations between olfactory impairment and mortality.
DATA SOURCES
The PubMed, Embase, and Cochrane Library databases were searched from inception to August 13, 2021.
STUDY SELECTION
Two blinded reviewers selected observational studies published as full-length, English-language articles in peer-reviewed journals that reported the presence or severity of chronic olfactory impairment, whether objectively measured or self-reported, in association with any mortality estimate, among adults aged 18 years or older.
DATA EXTRACTION AND SYNTHESIS
Two reviewers independently extracted data, evaluated study bias using the Newcastle-Ottawa Scale, and appraised the quality of the evidence using the Grading of Recommendations Assessment, Development and Evaluation framework, following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines and a PROSPERO-registered protocol. Maximally adjusted estimates were pooled using mixed-effects models, heterogeneity was measured using I2 statistics, sources of heterogeneity were investigated using meta-regression and subgroup meta-analyses, and publication bias was qualitatively and quantitatively assessed.
MAIN OUTCOMES AND MEASURES
Hazard ratios for all-cause mortality.
RESULTS
One retrospective cohort study and 10 prospective cohort studies (with a total of 21 601 participants) from 1088 nonduplicated records were included. Ten studies had a low risk of bias, whereas 1 study had a moderate risk; exclusion of the latter did not alter conclusions. Nine studies were included in the meta-analysis. Olfactory loss was associated with a significantly higher pooled hazard of all-cause mortality (hazard ratio, 1.52; 95% CI, 1.28-1.80; I2 = 82%). Meta-regression sufficiently explained heterogeneity, with longer mean follow-up duration weakening the pooled association, accounting for 91.3% of heterogeneity. Self-reported and objective effect sizes were similar. Associations were robust to trim-and-fill adjustment and the Egger test for publication bias. The overall quality of evidence was moderate.
CONCLUSIONS AND RELEVANCE
The findings of this systematic review and meta-analysis suggest that olfactory impairment is associated with all-cause mortality and may be a marker of general health and biological aging. Further research is required to establish the underlying mechanisms and the scope for interventions.
Topics: Comorbidity; Humans; Olfaction Disorders; Prospective Studies; Retrospective Studies; Risk
PubMed: 35389456
DOI: 10.1001/jamaoto.2022.0263 -
Neuropsychology Review Dec 2023Reports of smell loss following traumatic brain injury (TBI) are a well-documented but understudied phenomenon. Given the broad consequences of olfactory loss, we... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Reports of smell loss following traumatic brain injury (TBI) are a well-documented but understudied phenomenon. Given the broad consequences of olfactory loss, we characterized psychophysical olfactory dysfunction in individuals with moderate to severe TBI using systematic review and meta-analytic methods.
METHODS
Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) protocol, five databases (PubMed, EMBASE, Cochrane Library, Web of Science, Scopus) were reviewed for studies investigating olfactory dysfunction in persons with moderate to severe TBI. Of the 5,223 studies reviewed, 19 met our inclusion criteria for the systematic review and 11 met inclusion criteria for meta-analysis. We calculated effect sizes (Hedges' g) to characterize the degree of olfactory dysfunction between patients with moderate to severe TBI and controls.
RESULTS
A total of 951 moderate-severe TBI patients from 19 studies were included in the systematic review, which largely demonstrated poorer olfactory psychophysical performances in this patient population. Meta-analysis demonstrated a large effect size for olfactory dysfunction in moderate-severe TBI relative to healthy controls (g=-2.43, 95%CI: -3.16 < δ<-1.69). The magnitude of the effect was moderated by age and patient sex, with larger effect sizes associated with older age (following exclusion of a pediatric population) and larger compositions of women in the patient group.
CONCLUSION
Moderate to severe TBI is associated with prominent olfactory dysfunction. Significant research gaps remain regarding the mechanism, recovery and natural history of olfactory dysfunction following moderate to severe TBI, which has significant clinical implications for the identification and treatment for those with post-traumatic olfactory dysfunction.
Topics: Humans; Child; Female; Olfaction Disorders; Brain Injuries, Traumatic; Smell
PubMed: 36070126
DOI: 10.1007/s11065-022-09563-2 -
The Cochrane Database of Systematic... Sep 2022Loss of olfactory function is well recognised as a symptom of COVID-19 infection, and the pandemic has resulted in a large number of individuals with abnormalities in... (Review)
Review
BACKGROUND
Loss of olfactory function is well recognised as a symptom of COVID-19 infection, and the pandemic has resulted in a large number of individuals with abnormalities in their sense of smell. For many, the condition is temporary and resolves within two to four weeks. However, in a significant minority the symptoms persist. At present, it is not known whether early intervention with any form of treatment (such as medication or olfactory training) can promote recovery and prevent persisting olfactory disturbance. This is an update of the 2021 review with four studies added.
OBJECTIVES
1) To evaluate the benefits and harms of any intervention versus no treatment for people with acute olfactory dysfunction due to COVID-19 infection. 2) To keep the evidence up-to-date, using a living systematic review approach. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the latest search was 20 October 2021.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) in people with COVID-19 related olfactory disturbance, which had been present for less than four weeks. We included any intervention compared to no treatment or placebo. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were the presence of normal olfactory function, serious adverse effects and change in sense of smell. Secondary outcomes were the prevalence of parosmia, change in sense of taste, disease-related quality of life and other adverse effects (including nosebleeds/bloody discharge). We used GRADE to assess the certainty of the evidence for each outcome. MAIN RESULTS: We included five studies with 691 participants. The studies evaluated the following interventions: intranasal corticosteroid sprays, intranasal corticosteroid drops, intranasal hypertonic saline and zinc sulphate. Intranasal corticosteroid spray compared to no intervention/placebo We included three studies with 288 participants who had olfactory dysfunction for less than four weeks following COVID-19. Presence of normal olfactory function The evidence is very uncertain about the effect of intranasal corticosteroid spray on both self-rated recovery of olfactory function and recovery of olfactory function using psychophysical tests at up to four weeks follow-up (self-rated: risk ratio (RR) 1.19, 95% confidence interval (CI) 0.85 to 1.68; 1 study; 100 participants; psychophysical testing: RR 2.3, 95% CI 1.16 to 4.63; 1 study; 77 participants; very low-certainty evidence). Change in sense of smell The evidence is also very uncertain about the effect of intranasal corticosteroid spray on self-rated change in the sense of smell (at less than 4 weeks: mean difference (MD) 0.5 points lower, 95% CI 1.38 lower to 0.38 higher; 1 study; 77 participants; at > 4 weeks to 3 months: MD 2.4 points higher, 95% CI 1.32 higher to 3.48 higher; 1 study; 100 participants; very low-certainty evidence, rated on a scale of 1 to 10, higher scores mean better olfactory function). Intranasal corticosteroids may make little or no difference to the change in sense of smell when assessed with psychophysical testing (MD 0.2 points, 95% CI 2.06 points lower to 2.06 points higher; 1 study; 77 participants; low-certainty evidence, 0- to 24-point scale, higher scores mean better olfactory function). Serious adverse effects The authors of one study reported no adverse effects, but their intention to collect these data was not pre-specified so we are uncertain if these were systematically sought and identified. The remaining two studies did not report on adverse effects. Intranasal corticosteroid drops compared to no intervention/placebo We included one study with 248 participants who had olfactory dysfunction for ≤ 15 days following COVID-19. Presence of normal olfactory function Intranasal corticosteroid drops may make little or no difference to self-rated recovery at > 4 weeks to 3 months (RR 1.00, 95% CI 0.89 to 1.11; 1 study; 248 participants; low-certainty evidence). No other outcomes were assessed by this study. Data on the use of hypertonic saline nasal irrigation and the use of zinc sulphate to prevent persistent olfactory dysfunction are included in the full text of the review.
AUTHORS' CONCLUSIONS
There is very limited evidence available on the efficacy and harms of treatments for preventing persistent olfactory dysfunction following COVID-19 infection. However, we have identified a number of ongoing trials in this area. As this is a living systematic review we will update the data regularly, as new results become available.
Topics: Adrenal Cortex Hormones; COVID-19; Chronic Disease; Humans; Olfaction Disorders; Randomized Controlled Trials as Topic; Rhinitis; Smell; Zinc Sulfate
PubMed: 36063364
DOI: 10.1002/14651858.CD013877.pub3 -
Neurology Dec 2021One year after the onset of the coronavirus disease 2019 (COVID-19) pandemic, we aimed to summarize the frequency of neurologic manifestations reported in patients with... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND OBJECTIVES
One year after the onset of the coronavirus disease 2019 (COVID-19) pandemic, we aimed to summarize the frequency of neurologic manifestations reported in patients with COVID-19 and to investigate the association of these manifestations with disease severity and mortality.
METHODS
We searched PubMed, Medline, Cochrane library, ClinicalTrials.gov, and EMBASE for studies from December 31, 2019, to December 15, 2020, enrolling consecutive patients with COVID-19 presenting with neurologic manifestations. Risk of bias was examined with the Joanna Briggs Institute scale. A random-effects meta-analysis was performed, and pooled prevalence and 95% confidence intervals (CIs) were calculated for neurologic manifestations. Odds ratio (ORs) and 95% CIs were calculated to determine the association of neurologic manifestations with disease severity and mortality. Presence of heterogeneity was assessed with , meta-regression, and subgroup analyses. Statistical analyses were conducted in R version 3.6.2.
RESULTS
Of 2,455 citations, 350 studies were included in this review, providing data on 145,721 patients with COVID-19, 89% of whom were hospitalized. Forty-one neurologic manifestations (24 symptoms and 17 diagnoses) were identified. Pooled prevalence of the most common neurologic symptoms included fatigue (32%), myalgia (20%), taste impairment (21%), smell impairment (19%), and headache (13%). A low risk of bias was observed in 85% of studies; studies with higher risk of bias yielded higher prevalence estimates. Stroke was the most common neurologic diagnosis (pooled prevalence 2%). In patients with COVID-19 ≥60 years of age, the pooled prevalence of acute confusion/delirium was 34%, and the presence of any neurologic manifestations in this age group was associated with mortality (OR 1.80, 95% CI 1.11-2.91).
DISCUSSION
Up to one-third of patients with COVID-19 analyzed in this review experienced at least 1 neurologic manifestation. One in 50 patients experienced stroke. In those >60 years of age, more than one-third had acute confusion/delirium; the presence of neurologic manifestations in this group was associated with nearly a doubling of mortality. Results must be interpreted with the limitations of observational studies and associated bias in mind.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42020181867.
Topics: COVID-19; Delirium; Humans; Observational Studies as Topic; SARS-CoV-2; Stroke
PubMed: 34635561
DOI: 10.1212/WNL.0000000000012930 -
International Forum of Allergy &... Jul 2021Posttraumatic olfactory dysfunction is a clinical challenge due to refractory characteristics and limited therapeutic options. Olfactory training has been proved to be... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Posttraumatic olfactory dysfunction is a clinical challenge due to refractory characteristics and limited therapeutic options. Olfactory training has been proved to be effective for olfactory dysfunction with varied etiologies. We pooled existing studies to evaluate the effects of olfactory training in patients with posttraumatic olfactory dysfunction.
METHODS
A systematic literature review using PubMed, Embase, Cochrane Library, and Web of Science was conducted to identify studies assessing olfactory change in patients with posttraumatic olfactory dysfunction after olfactory training.
RESULTS
Of the initial 812 abstracts reviewed, 13 full-text articles were included. Clinically significant results after olfactory training were defined as an improvement of threshold, discrimination, and identification (TDI) score ≥6 or University of Pennsylvania Smell Identification Test (UPSIT) score ≥4. Six studies were included in the meta-analysis, 36.31% (95% confidence interval [CI], 0.28 to 0.45) of posttraumatic patients would achieve clinically significant results after olfactory training with a mean increase of TDI score of 4.61.
CONCLUSION
Olfactory training might be a promising modality for the treatment of posttraumatic olfactory dysfunction. More high-quality studies with controls are needed to clarify the effect of olfactory training on total olfactory performance and subcomponents of olfaction.
Topics: Humans; Olfaction Disorders; Smell
PubMed: 33486898
DOI: 10.1002/alr.22758 -
The Journal of Allergy and Clinical... Feb 2024Increasing evidence supports the united airway disease concept for the management of upper and lower respiratory tract diseases, particularly in patients with asthma and...
BACKGROUND
Increasing evidence supports the united airway disease concept for the management of upper and lower respiratory tract diseases, particularly in patients with asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). However, evidence for a combined approach in asthma and CRSwNP is scarce.
OBJECTIVE
In this systematic review, we focused on the role of biologics in the lung function and quality of life in patients with severe asthma and CRSwNP.
METHODS
We conducted a systematic search of 3 electronic databases using 2 search strategies to identify studies published from January 2010 to March 2022. Quality assessment was performed with the Critical Appraisal Skills Programme.
RESULTS
Of 1030 studies identified, 48 original studies reporting data of benralizumab (12), dupilumab (14), mepolizumab (10), omalizumab (13), and reslizumab (2) were analyzed. Primary diagnosis was mostly asthma or CRSwNP, with only 15 studies, mainly observational, performed in populations with united airway disease. In total, 18 studies reported data on quality of life (mostly 22-item Sino-Nasal Outcome Test score), 8 on lung function (mostly FEV), and 22 on both outcomes. Significant FEV and 22-item Sino-Nasal Outcome Test score improvements were consistently observed after 24-week treatment, and thereafter, mostly in real-world studies that included variable proportions of patients with asthma/CRSwNP.
CONCLUSIONS
The use of biologics in patients with severe asthma and CRSwNP was overall associated with significant improvements in lung function and quality of life. However, we observed a high heterogeneity of populations and outcome measurements across studies. Notwithstanding the need of larger studies, our results reinforce the joint management of asthma and CRSwNP as united airway disease in clinical practice.
PubMed: 37915724
DOI: 10.1016/j.jacig.2023.100174 -
Metabolites Dec 2023Obesity, linked to chronic diseases, poses a global health challenge. While the role of the olfactory system in energy homeostasis is well-documented in rodents, its... (Review)
Review
Obesity, linked to chronic diseases, poses a global health challenge. While the role of the olfactory system in energy homeostasis is well-documented in rodents, its role in metabolism regulation and obesity in humans remains understudied. This review examines the interplay between olfactory function and metabolic alterations in human obesity and the effects of bariatric surgery on olfactory capabilities in humans. Adhering to PRISMA guidelines, a systematic review and meta-analysis was conducted, focusing exclusively on original human studies. From 51 articles, 14 were selected for the meta-analysis. It was found that variations in olfactory receptor genes influence the susceptibility to odors and predisposition to weight gain and poor eating habits. Bariatric surgery, particularly sleeve gastrectomy, shows significant improvements in olfactory function (SMD 2.37, 95% CI [0.96, 3.77], I = 92%, = 0.001), especially regarding the olfactory threshold (SMD -1.65, 95% CI [-3.03, -0.27], I = 81%, = 0.02). There is a bidirectional relationship between olfactory function and metabolism in humans. Bariatric surgery improves olfactory perception in obese patients, but it is still unclear if impacting the olfactory system directly affects eating behavior and the energy balance. However, these findings open novel avenues for future studies addressing the olfactory system as a novel target to alter systemic metabolism in humans.
PubMed: 38248819
DOI: 10.3390/metabo14010016 -
Frontiers in Neuroscience 2024Olfaction is understudied in neuroimaging research compared to other senses, but there is growing evidence of its therapeutic benefits on mood and well-being. Olfactory... (Review)
Review
Olfaction is understudied in neuroimaging research compared to other senses, but there is growing evidence of its therapeutic benefits on mood and well-being. Olfactory imagery can provide similar health benefits as olfactory interventions. Harnessing crossmodal visual-olfactory interactions can facilitate olfactory imagery. Understanding and employing these cross-modal interactions between visual and olfactory stimuli could aid in the research and applications of olfaction and olfactory imagery interventions for health and wellbeing. This review examines current knowledge, debates, and research on olfaction, olfactive imagery, and crossmodal visual-olfactory integration. A total of 56 papers, identified using the PRISMA method, were evaluated to identify key brain regions, research themes and methods used to determine the suitability of fNIRS as a tool for studying these topics. The review identified fNIRS-compatible protocols and brain regions within the fNIRS recording depth of approximately 1.5 cm associated with olfactory imagery and crossmodal visual-olfactory integration. Commonly cited regions include the orbitofrontal cortex, inferior frontal gyrus and dorsolateral prefrontal cortex. The findings of this review indicate that fNIRS would be a suitable tool for research into these processes. Additionally, fNIRS suitability for use in naturalistic settings may lead to the development of new research approaches with greater ecological validity compared to existing neuroimaging techniques.
PubMed: 38356646
DOI: 10.3389/fnins.2024.1266664