A person-centered approach to capture health disparities and multidimensional impact of COVID-related stressors.

The COVID-19 pandemic has influenced people's lives in diverse ways. The authors utilized latent class analysis (LCA), a person-centered approach, to examine distinct patterns of COVID-related stressors and their associations with alcohol-related, mental health, and quality of life outcomes. Participants were 463 adults who completed the baseline assessment of the National Institute on Alcohol Abuse and Alcoholism COVID-19 Pandemic Impact on Alcohol Study from June 2020 to January 2022. Using cross-sectional data, three analytic methods (continuous sum score, categorical grouping, and LCA) were applied to model 17 COVID-related stressors. Regression analyses indicated higher COVID-related stress and endorsement of four or more COVID-related stressors were generally associated with worse health-related outcomes. LCA revealed four classes: Class 1: Minimal COVID-Related Impact (51.6%); Class 2: Work Interruptions (24.8%); Class 3: Family/Friends Affected by COVID (14.5%); and Class 4: Serious Financial Stress (9.1%). Racial/ethnic minorities were more likely to be in Class 3, whereas individuals with more years of education and higher income were less likely to be in Class 4. Individuals with a history of alcohol use disorder were more likely to be in Classes 2 and 4. Compared with Class 1, Class 4 reported highest levels of perceived stress, problematic alcohol use, anxiety symptoms, depressive symptoms, alcohol craving, loneliness, drinking to cope, and lowest levels of physical, psychological, social, and environment quality of life. COVID-related stressors disproportionately affected minority and vulnerable groups. Individuals who experienced multiple financial stressors had the greatest risk for negative health-related outcomes and may benefit from holistic interventions and community outreach. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A systematic review of the biological mediators of fat taste and smell.

Taste and smell play a key role in our ability to perceive foods. Overconsumption of highly palatable energy-dense foods can lead to increased caloric intake and obesity. Thus there is growing interest in the study of the biological mediators of fat taste and associated olfaction as potential targets for pharmacologic and nutritional interventions in the context of obesity and health. The number of studies examining mechanisms underlying fat taste and smell has grown rapidly in the last 5 years. Therefore, the purpose of this systematic review is to summarize emerging evidence examining the biological mechanisms of fat taste and smell. A literature search was conducted of studies published in English between 2014 and 2021 in adult humans and animal models. Database searches were conducted using PubMed, EMBASE, Scopus, and Web of Science for key terms including fat/lipid, taste, and olfaction. Initially, 4,062 articles were identified through database searches, and a total of 84 relevant articles met inclusion and exclusion criteria and are included in this review. Existing literature suggests that there are several proteins integral to fat chemosensation, including cluster of differentiation 36 (CD36) and G protein-coupled receptor 120 (GPR120). This systematic review will discuss these proteins and the signal transduction pathways involved in fat detection. We also review neural circuits, key brain regions, ingestive cues, postingestive signals, and genetic polymorphism that play a role in fat perception and consumption. Finally, we discuss the role of fat taste and smell in the context of eating behavior and obesity.

Chemosensory Alterations and Impact on Quality of Life in Persistent Alcohol Drinkers.

BACKGROUND: Heavy alcohol consumption-associated chemosensory dysfunction is understudied, and early detection can help predict disease-associated comorbidities, especially those related to four quality of life (QOL) domains (physical, psychological, social and environment). We examined self-reports of chemosensory ability of individuals with different alcohol drinking behaviors and their association with changes in QOL domains. METHODS: Participants (n = 466) were recruited between June 2020 and September 2021 into the NIAAA COVID-19 Pandemic Impact on Alcohol study. Group-based trajectory modeling was used to categorize participants without any known COVID-19 infection into three groups (non-drinkers, moderate drinkers and heavy drinkers) based on their Alcohol Use Disorders Identification Test consumption scores at four different time points (at enrollment, week 4, week 8 and week 12). Linear mixed models were used to examine chemosensory differences between these groups. The associations between chemosensory abilities and QOL were determined in each group. RESULTS: We observed significant impairment in self-reported smell ability of heavy drinking individuals compared to non-drinkers. In contrast, taste ability showed marginal impairment between these groups. There were no significant differences in smell and taste abilities between the moderate and non-drinking groups. Heavy drinkers' impairment in smell and taste abilities was significantly associated with deterioration in their physical, psychological, social and environmental QOL. CONCLUSION: Persistent heavy drinking was associated with lower chemosensory ability. Heavy drinkers' reduced smell and taste function and association with poorer QOL indicate that early assessment of chemosensory changes may be crucial in identifying poorer well-being outcomes in heavy drinkers at risk for alcohol use disorder.

The Adaptive Olfactory Measure of Threshold (ArOMa-T): A rapid test of olfactory function.

Many widely used psychophysical olfactory tests have limitations that can create barriers to adoption. For example, tests that measure the ability to identify odors may confound sensory performance with memory recall, verbal ability, and prior experience with the odor. Conversely, classic threshold-based tests avoid these issues, but are labor intensive. Additionally, many commercially available tests are slow and may require a trained administrator, making them impractical for use in situations where time is at a premium or self-administration is required. We tested the performance of the Adaptive Olfactory Measure of Threshold (ArOMa-T) - a novel odor detection threshold test that employs an adaptive Bayesian algorithm paired with a disposable odorant delivery card - in a non-clinical sample of individuals (n=534) at the 2021 Twins Day Festival in Twinsburg, OH. Participants successfully completed the test in under 3 min with a false alarm rate of 7.5% and a test-retest reliability of 0.61. Odor detection thresholds differed by sex (~3.2-fold lower for females) and age (~8.7-fold lower for the youngest versus the oldest age group), consistent with prior studies. In an exploratory analysis, we failed to observe evidence of detection threshold differences between participants who reported a history of COVID-19 and matched controls who did not. We also found evidence for broad-sense heritability of odor detection thresholds. Together, this study suggests the ArOMa-T can determine odor detection thresholds. Additional validation studies are needed to confirm the value of ArOMa-T in clinical or field settings where rapid and portable assessment of olfactory function is needed.

Chemosensory deficits are best predictor of serologic response among individuals infected with SARS-CoV-2.

OBJECTIVE: Smell and taste alteration are closely linked to infection with SARS-CoV-2 and may be associated with a more indolent disease course. Serologic response rates among individuals with mild disease remains limited. We sought to identify whether chemosensory changes associated with COVID-19 were predictive of a serologic response. STUDY DESIGN: Cross-sectional study. METHODS: The sample consisted of 306 adults (≥18 years old) volunteering for convalescent plasma donation following perceived COVID-19 illness from April-June 2020. Documentation of COVID-19 PCR status, clinical symptoms at time of illness, and treatment course occurred at the time of serologic analysis, where we assessed chemosensory function using patient-perceived deficits. We implemented previously validated ELISA screening to determine serologic status regarding anti-Spike immunoglobulins. Statistical analysis using stepwise logistic models were employed to identify predictive factors of serologic response. RESULTS: Of 306 patients undergoing serologic and chemosensory evaluation, 196 (64.1%) and 195 (63.7%) reported subjective olfactory and taste dysfunction, respectively, during the first two weeks of COVID-19 infection. In unadjusted models, the odds of developing suprathreshold IgG antibody titers were 1.98 times higher among those who reported altered smell (95% CI 1.14-3.42, p = 0.014) and 2.02 times higher among those with altered taste (95% CI 1.17-3.48, p = 0.011) compared to those with normal smell and taste. Multivariable logistic models adjusting for sex, age, race/ethnicity, symptom duration, smoking status and comorbidities index demonstrated that altered smell and taste remained significant predictors of positive anti-spike IgG response (smell OR = 1.90, 95% CI 1.05-3.44, p = 0.033; taste OR = 2.01, 95% CI = 1.12-3.61, p = 0.019). CONCLUSION: Subjective chemosensory dysfunction, as self-reported smell or taste deficiency, is highly predictive of serologic response following SARS-CoV-2 infection. This information may be useful for patient counseling. Additional longitudinal research should be performed to better understand the onset and duration of the serologic response in these patients.

Qualitative Olfactory Dysfunction and COVID-19: An Evidence-Based Review with Recommendations for the Clinician.

BACKGROUND: Nearly 40% of patients who experience smell loss during SARS-CoV-2 infection may develop qualitative olfactory dysfunction, most commonly parosmia. Our evidence-based review summarizes the evolving literature and offers recommendations for the clinician on the management of patients experiencing parosmia associated with COVID-19. METHODS: We performed a systematic search using independent queries in PubMed, Embase, Ovid, and Cochrane databases, then categorized articles according to themes that emerged regarding epidemiology, effect on quality of life, disease progression, prognosis, pathophysiology, diagnosis, and treatment of parosmia. RESULTS: We identified 123 unique references meeting eligibility and performed title and abstract review with 2 independent reviewers, with 74 articles undergoing full-text review. An inductive approach to thematic development provided 7 central themes regarding qualitative olfactory dysfunction following COVID-19. CONCLUSIONS: While other respiratory viruses are known to cause qualitative olfactory disturbances, the incidence of parosmia following COVID-19 is notable, and correlates negatively with age. The presence of parosmia predicts persistent quantitative olfactory dysfunction. Onset can occur months after infection, and symptoms may persist for well over 7 months. Affected patients report increased anxiety and decreased quality of life. Structured olfactory training with essential oils is the preferred treatment, where parosmia predicts recovery of aspects of quantitative smell loss when undergoing training. There is limited evidence that nasal corticosteroids may accelerate recovery of olfactory function. Patients should be prepared for the possibility that symptoms may persist for years, and providers should guide them to resources for coping with their psychosocial burden.

Taste loss as a distinct symptom of COVID-19: a systematic review and meta-analysis.

Chemosensory scientists have been skeptical that reports of COVID-19 taste loss are genuine, in part because before COVID-19 taste loss was rare and often confused with smell loss. Therefore, to establish the predicted prevalence rate of taste loss in COVID-19 patients, we conducted a systematic review and meta-analysis of 376 papers published in 2020-2021, with 241 meeting all inclusion criteria. Drawing on previous studies and guided by early meta-analyses, we explored how methodological differences (direct vs. self-report measures) may affect these estimates. We hypothesized that direct measures of taste are at least as sensitive as those obtained by self-report and that the preponderance of evidence confirms taste loss is a symptom of COVID-19. The meta-analysis showed that, among 138,897 COVID-19-positive patients, 39.2% reported taste dysfunction (95% confidence interval: 35.34%-43.12%), and the prevalence estimates were slightly but not significantly higher from studies using direct (n = 18) versus self-report (n = 223) methodologies (Q = 0.57, df = 1, P = 0.45). Generally, males reported lower rates of taste loss than did females, and taste loss was highest among middle-aged adults. Thus, taste loss is likely a bona fide symptom of COVID-19, meriting further research into the most appropriate direct methods to measure it and its underlying mechanisms.

Assessing the extent and timing of chemosensory impairments during COVID-19 pandemic.

Chemosensory impairments have been established as a specific indicator of COVID-19. They affect most patients and may persist long past the resolution of respiratory symptoms, representing an unprecedented medical challenge. Since the SARS-CoV-2 pandemic started, we now know much more about smell, taste, and chemesthesis loss associated with COVID-19. However, the temporal dynamics and characteristics of recovery are still unknown. Here, capitalizing on data from the Global Consortium for Chemosensory Research (GCCR) crowdsourced survey, we assessed chemosensory abilities after the resolution of respiratory symptoms in participants diagnosed with COVID-19 during the first wave of the pandemic in Italy. This analysis led to the identification of two patterns of chemosensory recovery, partial and substantial, which were found to be associated with differential age, degrees of chemosensory loss, and regional patterns. Uncovering the self-reported phenomenology of recovery from smell, taste, and chemesthetic disorders is the first, yet essential step, to provide healthcare professionals with the tools to take purposeful and targeted action to address chemosensory disorders and their severe discomfort.

Recent Smell Loss Is the Best Predictor of COVID-19 Among Individuals With Recent Respiratory Symptoms.

In a preregistered, cross-sectional study, we investigated whether olfactory loss is a reliable predictor of COVID-19 using a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0-100 visual analog scales (VAS) for participants reporting a positive (C19+; n = 4148) or negative (C19-; n = 546) COVID-19 laboratory test outcome. Logistic regression models identified univariate and multivariate predictors of COVID-19 status and post-COVID-19 olfactory recovery. Both C19+ and C19- groups exhibited smell loss, but it was significantly larger in C19+ participants (mean ± SD, C19+: -82.5 ± 27.2 points; C19-: -59.8 ± 37.7). Smell loss during illness was the best predictor of COVID-19 in both univariate and multivariate models (ROC AUC = 0.72). Additional variables provide negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms (e.g., fever). Olfactory recovery within 40 days of respiratory symptom onset was reported for ~50% of participants and was best predicted by time since respiratory symptom onset. We find that quantified smell loss is the best predictor of COVID-19 amongst those with symptoms of respiratory illness. To aid clinicians and contact tracers in identifying individuals with a high likelihood of having COVID-19, we propose a novel 0-10 scale to screen for recent olfactory loss, the ODoR-19. We find that numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4 < OR < 10). Once independently validated, this tool could be deployed when viral lab tests are impractical or unavailable.

NIH Workshop Report: sensory nutrition and disease.

In November 2019, the NIH held the "Sensory Nutrition and Disease" workshop to challenge multidisciplinary researchers working at the interface of sensory science, food science, psychology, neuroscience, nutrition, and health sciences to explore how chemosensation influences dietary choice and health. This report summarizes deliberations of the workshop, as well as follow-up discussion in the wake of the current pandemic. Three topics were addressed: A) the need to optimize human chemosensory testing and assessment, B) the plasticity of chemosensory systems, and C) the interplay of chemosensory signals, cognitive signals, dietary intake, and metabolism. Several ways to advance sensory nutrition research emerged from the workshop: 1) refining methods to measure chemosensation in large cohort studies and validating measures that reflect perception of complex chemosensations relevant to dietary choice; 2) characterizing interindividual differences in chemosensory function and how they affect ingestive behaviors, health, and disease risk; 3) defining circuit-level organization and function that link and interact with gustatory, olfactory, homeostatic, visceral, and cognitive systems; and 4) discovering new ligands for chemosensory receptors (e.g., those produced by the microbiome) and cataloging cell types expressing these receptors. Several of these priorities were made more urgent by the current pandemic because infection with sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the ensuing coronavirus disease of 2019 has direct short- and perhaps long-term effects on flavor perception. There is increasing evidence of functional interactions between the chemosensory and nutritional sciences. Better characterization of this interface is expected to yield insights to promote health, mitigate disease risk, and guide nutrition policy.

Objective Sensory Testing Methods Reveal a Higher Prevalence of Olfactory Loss in COVID-19-Positive Patients Compared to Subjective Methods: A Systematic Review and Meta-Analysis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has currently infected over 6.5 million people worldwide. In response to the pandemic, numerous studies have tried to identify the causes and symptoms of the disease. Emerging evidence supports recently acquired anosmia (complete loss of smell) and hyposmia (partial loss of smell) as symptoms of COVID-19, but studies of olfactory dysfunction show a wide range of prevalence from 5% to 98%. We undertook a search of Pubmed/Medline and Google Scholar with the keywords "COVID-19," "smell," and/or "olfaction." We included any study that quantified smell loss (anosmia and hyposmia) as a symptom of COVID-19. Studies were grouped and compared based on the type of method used to measure smell loss-subjective measures, such as self-reported smell loss, versus objective measures using rated stimuli-to determine if prevalence differed by method type. For each study, 95% confidence intervals (CIs) were calculated from point estimates of olfactory disturbances. We identified 34 articles quantifying anosmia as a symptom of COVID-19 (6 objective and 28 subjective), collected from cases identified from January 16 to April 30, 2020. The pooled prevalence estimate of smell loss was 77% when assessed through objective measurements (95% CI of 61.4-89.2%) and 44% with subjective measurements (95% CI of 32.2-57.0%). Objective measures are a more sensitive method to identify smell loss as a result of infection with SARS-CoV-2; the use of subjective measures, while expedient during the early stages of the pandemic, underestimates the true prevalence of smell loss.

COVID-19 and the Chemical Senses: Supporting Players Take Center Stage.

The main neurological manifestation of COVID-19 is loss of smell or taste. The high incidence of smell loss without significant rhinorrhea or nasal congestion suggests that SARS-CoV-2 targets the chemical senses through mechanisms distinct from those used by endemic coronaviruses or other common cold-causing agents. Here we review recently developed hypotheses about how SARS-CoV-2 might alter the cells and circuits involved in chemosensory processing and thereby change perception. Given our limited understanding of SARS-CoV-2 pathogenesis, we propose future experiments to elucidate disease mechanisms and highlight the relevance of this ongoing work to understanding how the virus might alter brain function more broadly.