Effect of vitamin B12 deficiency on olfactory function

Linking the relationship between dietary folic acid intake and risk of osteoporosis among middle-aged and older people: A nationwide population-based study

Among middle-aged and older people, balanced and nutritious diets are the foundation for maintaining bone health and preventing osteoporosis. This study is aimed at investigating the link between dietary folic acid intake and the risk of osteoporosis among middle-aged and older people. A total of 20,686 people from the National Health and Nutritional Examination Survey (NHANES) 2007-2010 are screened and included, and 5312 people aged ≥45 years with integral data are ultimately enrolled in evaluation. Demographics and dietary intake-related data are gathered and analyzed, and the odds ratio (OR) and 95% confidence interval (CI) of each tertile category of dietary folic acid intake and each unit increase in folic acid are assessed via multivariate logistic regression models. On this basis, the receiver operating characteristic (ROC) curve is used to identify the optimal cutoff value of dietary folic acid intake for indicating the risk of osteoporosis. Of 5312 people with a mean age of 62.4 ± 11.0 years old, a total of 513 people with osteoporosis are screened, and the dietary folic acid intake amount of the osteoporosis group is significantly lower than that of the non-osteoporosis group (p < .001). The lowest tertile category is then used to act as a reference category, and a higher dietary folic acid intake amount is observed to be positively related to lower odds for risk of osteoporosis. This trend is also not changed in adjustments for combinations of different covariates (p all < .05). Based on this, a dietary folic acid intake of 475.5 μg/day is identified as an optimal cutoff value for revealing osteoporosis. Collectively, this nationwide population-based study reveals that a higher daily dietary folic acid intake has potential protective effects on osteoporosis in middle-aged and older people.

Factors Associated with Poor Olfaction and Olfactory Decline in Older Adults in the ARIC Neurocognitive Study

Olfactory function has significant implications for human health, but few risk factors for olfactory decline have been identified. We examined the factors associated with olfactory status and decline over five years in the Atherosclerosis Risk in Communities (ARIC) Neurocognitive Study. A 12-item odor identification test was used to assess olfaction in 6053 participants in 2011-2013 (ARIC visit 5, mean age: 75.6, 41% male, 23% Black race) and in 3235 participants in 2016-2017 (visit 6). We used Poisson regression models to examine cross-sectional associations of a range of potential factors with the total odor identification errors (mean errors: 2.8 ± 2.4) in visit 5 participants. We used mixed-effect Poisson regression to examine associations with olfactory decline between visits 5 and 6. We also examined associations with visit 5 anosmia prevalence (847 cases, 14%) and incident anosmia between the two visits (510 cases, 16%) using Poisson models. Older age, male sex, lower education, Black race, APOE ε4 alleles, and diabetes were associated with higher odor identification errors and higher anosmia prevalence, and greater physical activity and hypertension with better olfaction. Age, male sex, lower education, Black race, APOE ε4 allele, and vitamin B12 levels were associated with incident anosmia over 5 years. Older age was associated with faster olfactory decline. Future studies with longer follow-ups are warranted.

Lithium-Induced Dysgeusia and Hyposmia: A Case Report and a Literature Review

BACKGROUND

Bipolar disorder is a complex psychiatric disorder where long-term treatment is crucial to maintain stabilization. Although largely well tolerated, lithium has a wide spectrum of adverse effects in different organs and seems to also cause taste and smell disorders, which remain rare and not largely described. We aim to present a rare case of hyposmia and dysgeusia secondary to lithium treatment in a bipolar patient and also conduct a review on these rare lithium adverse effects.

CASE PRESENTATION

The case is a 43-year-old woman with type I bipolar disorder who became stabilized and fully functional with lithium therapy. After 4 months of treatment, she began to notice progressive hyposmia and dysgeusia. After multiple diagnostic and screening tests, lithium was implicated as the cause of the symptoms, which led to a switch to valproic acid. After 3 months, she was not compensated with valproic acid treatment, returned to lithium therapy despite its adverse effects, and became stabilized again.

CONCLUSIONS

There are few data on lithium therapy taste and smell adverse effects. Most studies on this topic are likely to be case reports. Lithium therapy may cause dysgeusia and hyposmia, although mechanisms are not fully understood. These adverse effects can interfere negatively in patient's treatment adherence. Therefore, physicians who prescribe lithium should be aware of them. Further structured studies are needed to better understand these lithium rare adverse effects and the appropriate way to assess and monitoring them.

Relation between Vitamin B12 Levels and Smell Affection in COVID-19 Patients

Introduction  Olfactory and gustative alterations are frequent in the initial stages of the COVID-19 infection. Vitamin B12 deficiency has been linked to olfactory dysfunction.

Objective  The present study aimed to assess the relationship between vitamin B12 levels and smell affection in COVID-19 patients.

Methods  The present study included 201 laboratory-confirmed COVID-19 patients. Smell affection was assessed using self-rated olfactory function. Serum vitamin B12 levels were assessed using commercial enzyme-linked immunosorbent assay (ELISA) kits.

Results  According to the smell function assessment, the patients were classified into three categories: normal osmesis ( n  = 77), hyposmia ( n  = 49), and anosmia ( n  = 75) ( Fig. 1 ). Four weeks later, 195 patients (97.0%) had their normal smell function restored. The remainder 6 patients included 4 anosmic and 2 hyposmic patients. Patients with hyposmia or anosmia had significantly lower vitamin B12 levels when compared with patients with normal osmesis (median [IQR]: 363.0 [198.0–539.0] versus 337.0 [175.0–467.0] and 491.0 [364.5–584.5] pg/ml, respectively, p  < 0.001).

Conclusion  Vitamin B12 appears to have some contribution to smell affection in patients with COVID-19 infection.

Interventions for the treatment of persistent post-COVID-19 olfactory dysfunction

BACKGROUND

Olfactory dysfunction is a common consequence of COVID-19 infection and persistent symptoms can have a profound impact on quality of life. At present there is little guidance on how best to treat this condition. A variety of interventions have been suggested to promote recovery, including medication and olfactory training. However, it is uncertain whether any intervention is of benefit. This is an update of the 2021 review with one additional study added.  OBJECTIVES: 1) To evaluate the benefits and harms of any intervention versus no treatment for people with persisting 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 that had persisted for at least 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 recovery of sense of smell, disease-related quality of life and serious adverse effects. Secondary outcomes were the change in sense of smell, general quality of life, prevalence of parosmia 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 two studies with 30 participants. The studies evaluated the following interventions: systemic corticosteroids plus intranasal corticosteroid/mucolytic/decongestant and palmitoylethanolamide plus luteolin.  Systemic corticosteroids plus intranasal corticosteroid/mucolytic/decongestant compared to no intervention We included a single RCT with 18 participants who had anosmia for at least 30 days following COVID-19 infection. Participants received a 15-day course of oral corticosteroids combined with nasal irrigation (consisting of an intranasal corticosteroid/mucolytic/decongestant solution) or no intervention. Psychophysical testing was used to assess olfactory function at 40 days. This is a single, small study and for all outcomes the certainty of evidence was very low. We are unable to draw meaningful conclusions from the numerical results. Palmitoylethanolamide plus luteolin compared to no intervention We included a single RCT with 12 participants who had anosmia or hyposmia for at least 90 days following COVID-19 infection. Participants received a 30-day course of palmitoylethanolamide and luteolin or no intervention. Psychophysical testing was used to assess olfactory function at 30 days. This is a single, small study and for all outcomes the certainty of evidence was very low. We are unable to draw meaningful conclusions from the numerical results.

AUTHORS' CONCLUSIONS

There is very limited evidence available on the efficacy and harms of treatments for 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.

Interventions for the prevention of persistent post-COVID-19 olfactory dysfunction

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.

B12 vitamin eksikliği olan kişilerin tam kan, ortalama trombosit hacmi (MPV) ve nötrofil-lenfosit oranlarının (NLR) değerlendirilmesi

Giriş: B12 vitamin eksikliğinin; kan tetkiklerine, ortalama trombosit hacmine (MPV) ve inflamasyon markerlarından nötrofil-lenfosit oranına (NLR) etkilerinin araştırılması amaçlanmıştır.Yöntem: Çalışmamız 375 hasta üzerinde yapılmıştır. B12’si düşük (&lt;130 pg/dL) saptanan 170 hasta deney grubu olarak, B12 düzeyleri normal olan 205 kişide kontrol grubu olarak kabul edilmiştir. Bu iki grup arasında beyaz kan hücreleri (WBC), trombosit sayısı (Plt), hemoglobin (Hgb), ortalama eritrosit hacmi (MCV), MPV, nötrofil, lenfosit sayıları ve nötrofil-lenfosit oranları (NLR) incelenmiştir.Bulgular: Yaş ortalaması B12 eksik grupta 48.45 ±17.497 yıl, kontrol grubunda ise 51.93 ±16.175 yıl idi. Eksik grupta B12vitamini ortalaması 101,41 ± 20,50 pg/mL (min-max; 37-130), kontrol grubunda ise 257,24 ± 88,13 pg/mL (min-max; 131-498) idi. WBC, Hgb, Plt, nötrofil, lenfosit, MVC, MPV ve NLR arasında istatiksel açıdan anlamlı bir fark olmadığı gözlendi.Sonuç: Çalışmamızda B12 eksikliği ile kan tetkikleri arasında anlamlı bir ilişki bulamadık. Önceki çalışmalarda B12 eksikliğinde MPV değerlerinin etkilendiğine dair bilgiler bulunmaktadır. Yaptığımız çalışmada da B12 eksikliği ile MPV ve NLR arasında anlamlı bir ilişkinin olmadığını saptadık (p&gt;0,05). B12 eksikliğinin derecesi ve süresi uzadıkça nasıl değişiklikler meydana geleceği ve özellikle de aterojenik olaylara etkisi hakkında yapılacak yeni çalışmalara ihtiyaç vardır. 

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

Possible Role of Endocannabinoids in Olfactory and Taste Dysfunctions in COVID-19 Patients and Volumetric Changes in the Brain

Introduction

COVID-19 infection develops neurologic symptoms such as smell and taste loss. We aimed to determine the volumetric changes in the brain and correlation of possible related biochemical parameters and endocannabinoid levels after COVID-19 recovery.

Methods

Brain magnetic resonance images of recovered COVID-19 patients and healthy volunteers, whose olfactory and gustatory scores were obtained through a questionnaire, were taken, and the volumes of the brain regions associated with taste and smell were measured by automatic and semiautomatic methods. Endocannabinoids (EC), which are critical in the olfactory system, and vitamin B12, zinc, iron, ferritin, thyroid-stimulating hormone (TSH), and thyroxine (T4) levels, which are reported to have possible roles in olfactory disorders, were measured in peripheral blood.

Results

Taste and smell disorder scores and EC levels were found to be higher in recovered COVID-19 patients compared to controls. EC levels were negatively correlated with bilateral entorhinal cortex (ENT) volumes in the COVID-19 group. Subgenual anterior cingulate cortex volumes showed correlations with gustatory complaints and ferritin in recovered COVID-19 patients.

Conclusions

The critical finding of our study is the high EC levels and negative correlation between EC levels and left ENT volumes in recovered COVID-19 patients.

Implications

It is possible that ECs are potential neuromodulators in many conditions leading to olfactory disorders, including COVID-19.

Interventions for the prevention of persistent post-COVID-19 olfactory dysfunction

BACKGROUND

Loss of olfactory function is well recognised as a cardinal symptom of COVID-19 infection, and the ongoing pandemic has resulted in a large number of affected 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.  OBJECTIVES: To assess the effects (benefits and harms) of interventions that have been used, or proposed, to prevent persisting olfactory dysfunction due to COVID-19 infection. A secondary objective is to keep the evidence up-to-date, using a living systematic review approach.  SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane COVID-19 Study Register; Cochrane ENT Register; CENTRAL; Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished studies. The date of the search was 16 December 2020.

SELECTION CRITERIA

Randomised controlled trials including participants who had symptoms of olfactory disturbance following COVID-19 infection. Individuals who had symptoms for less than four weeks were included in this review. Studies compared any intervention with no treatment or placebo.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. 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 one study of 100 participants, which compared an intranasal steroid spray to no intervention. Participants in both groups were also advised to undertake olfactory training for the duration of the trial. Data were identified for only two of the prespecified outcomes for this review, and no data were available for the primary outcome of serious adverse effects. Intranasal corticosteroids compared to no intervention (all using olfactory training) Presence of normal olfactory function after three weeks of treatment was self-assessed by the participants, using a visual analogue scale (range 0 to 10, higher scores = better). A score of 10 represented "completely normal smell sensation". The evidence is very uncertain about the effect of intranasal corticosteroids on self-rated recovery of sense of smell (estimated absolute effect 619 per 1000 compared to 520 per 1000, risk ratio (RR) 1.19, 95% confidence interval (CI) 0.85 to 1.68; 1 study; 100 participants; very low-certainty evidence).  Change in sense of smell was not reported, but the self-rated score for sense of smell was reported at the endpoint of the study with the same visual analogue scale (after three weeks of treatment). The median scores at endpoint were 10 (interquartile range (IQR) 9 to 10) for the group receiving intranasal corticosteroids, and 10 (IQR 5 to 10) for the group receiving no intervention (1 study; 100 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

There is very limited evidence regarding the efficacy of different interventions at preventing persistent olfactory dysfunction following COVID-19 infection. However, we have identified a small number of additional ongoing studies in this area. As this is a living systematic review, the evidence will be updated regularly to incorporate new data from these, and other relevant studies, as they become available.  For this (first) version of the living review, we identified a single study of intranasal corticosteroids to include in this review, which provided data for only two of our prespecified outcomes. The evidence was of very low certainty, therefore we were unable to determine whether intranasal corticosteroids may have a beneficial or harmful effect.

Interventions for the treatment of persistent post-COVID-19 olfactory dysfunction

BACKGROUND

Olfactory dysfunction is an early and sensitive marker of COVID-19 infection. Although self-limiting in the majority of cases, when hyposmia or anosmia persists it can have a profound effect on quality of life. Little guidance exists on the treatment of post-COVID-19 olfactory dysfunction, however several strategies have been proposed from the evidence relating to the treatment of post-viral anosmia (such as medication or olfactory training).

OBJECTIVES

To assess the effects (benefits and harms) of interventions that have been used, or proposed, to treat persisting olfactory dysfunction due to COVID-19 infection. A secondary objective is to keep the evidence up-to-date, using a living systematic review approach.  SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane COVID-19 Study Register; Cochrane ENT Register; CENTRAL; Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished studies. The date of the search was 16 December 2020.

SELECTION CRITERIA

Randomised controlled trials including participants who had symptoms of olfactory disturbance following COVID-19 infection. Only individuals who had symptoms for at least four weeks were included in this review. Studies compared any intervention with no treatment or placebo.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Primary outcomes were the recovery of sense of smell, disease-related quality of life and serious adverse effects. Secondary outcomes were the change in sense of smell, general quality of life, prevalence of parosmia 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 one study with 18 participants, which compared the use of a 15-day course of oral steroids combined with nasal irrigation (consisting of an intranasal steroid/mucolytic/decongestant solution) with no intervention. Psychophysical testing was used to assess olfactory function at baseline, 20 and 40 days. Systemic corticosteroids plus intranasal steroid/mucolytic/decongestant compared to no intervention Recovery of sense of smell was assessed after 40 days (25 days after cessation of treatment) using the Connecticut Chemosensory Clinical Research Center (CCCRC) score. This tool has a range of 0 to 100, and a score of ≥ 90 represents normal olfactory function. The evidence is very uncertain about the effect of this intervention on recovery of the sense of smell at one to three months (5/9 participants in the intervention group scored ≥ 90 compared to 0/9 in the control group; risk ratio (RR) 11.00, 95% confidence interval (CI) 0.70 to 173.66; 1 study; 18 participants; very low-certainty evidence). Change in sense of smell was assessed using the CCCRC score at 40 days. This study reported an improvement in sense of smell in the intervention group from baseline (median improvement in CCCRC score 60, interquartile range (IQR) 40) compared to the control group (median improvement in CCCRC score 30, IQR 25) (1 study; 18 participants; very low-certainty evidence). Serious adverse events andother adverse events were not identified in any participants of this study; however, it is unclear how these outcomes were assessed and recorded (1 study; 18 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

There is very limited evidence available on the efficacy and harms of treatments for persistent olfactory dysfunction following COVID-19 infection. However, we have identified other ongoing trials in this area. As this is a living systematic review we will update the data regularly, as new results become available. For this (first) version of the living review we identified only one study with a small sample size, which assessed systemic steroids and nasal irrigation (intranasal steroid/mucolytic/decongestant). However, the evidence regarding the benefits and harms from this intervention to treat persistent post-COVID-19 olfactory dysfunction is very uncertain.

Sudden Sensorineural Hearing Loss Associated with Nutritional Anemia: A Nested Case-Control Study Using a National Health Screening Cohort

Previous studies have suggested an association of anemia with hearing loss. The aim of this study was to investigate the association of nutritional anemia with sudden sensorineural hearing loss (SSNHL), as previous studies in this aspect are lacking. We analyzed data from the Korean National Health Insurance Service-Health Screening Cohort 2002-2015. Patients with SSNHL (n = 9393) were paired with 37,572 age-, sex-, income-, and region of residence-matched controls. Both groups were assessed for a history of nutritional anemia. Conditional logistic regression analyses were performed to calculate the odds ratios (ORs) (95% confidence interval, CI) for a previous diagnosis of nutritional anemia and for the hemoglobin level in patients with SSNHL. Subgroup analyses were conducted for age and sex. Age, sex, income, and region of residence were stratified. Obesity, smoking, drinking alcohol, systolic/diastolic blood pressure, fasting blood glucose, total cholesterol, and the Charlson Comorbidity Index were considered in the regression models. Nutritional anemia was present in 4.8% (449/9393) of patients with SSNHL and 4.0% (1494/37,572) of controls (p < 0.001). The SSNHL group demonstrated 1.20-fold higher odds for nutritional anemia (95% CI = 1.08-1.34, p = 0.001). Hemoglobin levels were not associated with SSNHL. In subgroups <60 years old, there was a consistent positive association of nutritional anemia with SSNHL (adjusted OR = 1.55, 95% CI = 1.11-2.15, p = 0.010 for men <60 years old, and adjusted OR = 1.22, 95% CI = 1.02-1.45, p = 0.028 for women <60 years old). Nutritional anemia, but not hemoglobin level, was associated with an increased risk of SSNHL.

Age-related Smell and Taste Impairments and Vitamin D Associations in the U.S. Adults National Health and Nutrition Examination Survey

Smell and taste decline with aging, and markedly deteriorate when nutritional deficiencies occur. This study aims to examine the associations between Vitamin D (VD) deficiency and smell and taste impairments among adults. This paper details a cross-sectional study utilizing data from the US National Health and Nutrition Examination Survey (NHANES, 2013–2014.). Smell impairment was assessed by the Pocket Smell Test and defined as failing to correctly identify six or more of the eight odors. Taste impairment was defined as failing to correctly identify quinine or sodium chloride. VD was measured as serum 25-hydroxyvitamin. Multivariable weighted logistic regressions were utilized. Adjusted odds ratio (OR) and 95% confidence interval (CI) were presented. Overall, 2216 (smell sample) and 2636 (taste sample) participants were included, aged between 40 and 80 years old. Of those, 18.3% had taste impairment, 12.2% had smell impairment, and 20% had VD deficiency (<20 ng/mL). Compared to participants with sufficient VD (>30 ng/mL), those with VD deficiency were more likely by 39% to report a higher prevalence of smell impairment (OR = 1.39, 95%CI: 1.02–1.89); and only participants aged 70–80 years with VD inadequacy (20–30 ng/mL) were more likely by 96% to report a higher prevalence of taste impairment (OR = 1.96, 95%CI: 1.35–1.85). VD may have a significant role in age-related smell impairment in adults aged 40 years or older, and in age-related taste impairment in the elderly aged 70–80 years.

Effect of Malnutrition on Hearing Loss in Children

OBJECTIVE

To characterize the relation between protein-calorie malnutrition (PCM) and hearing loss (HL) in children.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary referral hospital.

PATIENTS

Children in the Audiological and Genetic Database with a diagnosis of protein-calorie malnutrition, marasmus, and/or kwashiorkor.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Prevalence, type, severity (4-tone pure-tone average, PTA), and progression of HL.

RESULTS

Of 770 children with PCM, 57.8% had HL, compared to 45.5% of children without PCM (p < 0.001). Severely malnourished children had significantly higher odds of moderate-profound HL (aOR 2.27, 95% CI 1.47-3.43), high-frequency HL (aOR 1.82, 95% CI 1.21-2.75), and sensorineural or mixed HL (aOR 1.60, 95% CI 1.05-2.41) compared to children without PCM. Severely malnourished children had significantly worse initial (35.0 dB vs 25.0 dB, p < 0.001), and final median PTA (31.3 dB vs 20.0 dB, p < 0.001) compared to children without PCM. Additionally, HL in children who were moderately and severely malnourished was significantly less likely to improve (aOR 0.47, 95% CI 0.25-0.82 and aOR 0.4, 95% CI 0.2-0.9) when compared to those without PCM.

CONCLUSIONS

Given the greater prevalence and severity of hearing loss, children with PCM should be considered an at-risk group for poor audiological outcomes, and clinical practice should focus on early treatment and intervention for malnourished children. Routine audiological evaluation should be considered in this population.

Treatments for smell and taste disorders: A critical review

A key concern of both the patient and physician is whether treatment is available that will eliminate or quell a given chemosensory disturbance. In cases where obvious oral, nasal, or intracranial pathology is involved, rational straightforward approaches to treatment are often available. In cases where damage to the sensory pathways is secondary to chronic inflammatory disease, trauma, viral invasion, toxic exposure, or unknown causes, the direction for therapy is more challenging. Indeed, many chemosensory disorders, if present for any period of time, cannot be reversed, while others spontaneously remit without any therapeutic intervention. This review assesses the strengths and weaknesses of more than two dozen approaches to treatment that have been suggested for a wide range of taste and smell disorders.

Cobalamin production by Lactobacillus coryniformis: biochemical identification of the synthetized corrinoid and genomic analysis of the biosynthetic cluster

Background

Despite the fact that most vitamins are present in a variety of foods, malnutrition, unbalanced diets or insufficient intake of foods are still the cause of vitamin deficiencies in humans in some countries. Vitamin B₁₂ (Cobalamin) is a complex compound that is only naturally produced by bacteria and archea. It has been reported that certain strains belonging to lactic acid bacteria group are capable of synthesized water-soluble vitamins such as those included in the B-group, as vitamin B₁₂. In this context, the goal of the present paper was to evaluate and characterize the production of vitamin B₁₂ in Lactobacillus coryniformis CRL 1001, a heterofermentative strain isolated from silage.

Results

Cell extract of L. coryniformis CRL 1001, isolated from silage, is able to correct the coenzyme B₁₂ requirement of Salmonella enterica serovar Typhimurium AR 2680 in minimal medium. The chemical characterization of the corrinoid-like molecule isolated from CRL 1001 cell extract using HPLC and mass spectrometry is reported. The majority of the corrinoid produced by this strain has adenine like Coα-ligand instead 5,6-dimethylbenzimidazole. Genomic studies revealed the presence of the complete machinery of the anaerobic biosynthesis pathway of coenzyme B₁₂. The detected genes encode all proteins for the corrin ring biosynthesis and for the binding of upper (β) and lower (α) ligands in one continuous stretch of the chromosome.

Conclusions

The results here described show for the first time that L. coryniformis subsp. coryniformis CRL 1001 is able to produce pseudocobalamin containing adenine instead of 5,6-dimethlbenzimidazole in the Coα-ligand. Genomic analysis allowed the identification and characterization of the complete de novo biosynthetic pathway of the corrinoid produced by the CRL 1001 strain.

Intake of vitamin B before onset of Parkinson's disease and atypical parkinsonism and olfactory function at the time of diagnosis

BACKGROUND/OBJECTIVES

To investigate whether vitamin-B density in the diet 2-8 years before diagnosis is associated with olfactory function at the time of diagnosis.

SUBJECTS/METHODS

This prospective nested case-control study included patients with Parkinson's disease (PD), multiple system atrophy and progressive supranuclear paralysis identified between 2004 and 2009 in the county of Västerbotten in northern Sweden. The case database (NYPUM study; Newly Diagnosed Parkinson in Umeå; n=147) was cross-linked to the Northern Sweden Health and Disease Study (NSHDS). Identified patients (n=96) and controls (n=375) were matched for sex, age, year of health survey, sub-cohort and geographical area. Dietary intake was assessed by a food frequency questionnaire, and the brief smell identification test (B-SIT) was used to measure olfactory function at the time of diagnosis.

RESULTS

There was no difference in vitamin-B or any other macro- or micro-nutrient densities, energy intake or body mass index (kg/m²; BMI) between patients and controls at baseline at the time of the healthcare survey. A lower thiamin and folate density, amount per 1 megajoule, was reported in patients who scored below median on B-SIT (<7) when compared with that in patients who scored ⩾7 at the time of diagnosis. After adjusting for age, sex and BMI using linear and logistic regressions, an even stronger association was found between thiamin density and olfactory function.

CONCLUSIONS

A low thiamin and folate density in the reported diet, 2-8 years before PD diagnosis, was significantly associated with olfactory dysfunction at the time of PD diagnosis.