hyposmia

Olfactory changes connection to deteriorated quality of life in chronic kidney disease cases (CKD) and diabetes mellitus (DM). The nutritional status is altered in CKD and DM and it closely interconnected with olfactory function. We aimed to study the olfactory dysfunction in these populations.

We conducted a cross-sectional research on CKD and DM cases aged 20-50 (27 healthy controls, 77 CKD patients, and 36 DM patients). We used the Iran Smell Identification Test (Iran-SIT) version of the University of Pennsylvania Smell Identification Test (UPSIT) to evaluate the olfactory function. The significant level was set as <0.05.

Our 140 cases included 51.4% of men (mean age of 46.7±10.6 years). The total score of the Iran-SIT test indicated that olfactory impairment in the CKD was higher (16.2±4.2) than in the DM (18.8±2.1) and control groups (20.4±1.2) (P=0.001). It was determined that 54.5% of CKD patients and 38.9% of the DM group had olfactory dysfunction compared to 7.4% of the controls (P=0.001). Multiple regression analysis indicated that being men and low-density lipoprotein cholesterol (LDL-C) were related to olfactory dysfunction in the total population (OR: 4.55, P=0.037, and OR: 0.94, P=0.037). Still, it was only associated with LDL-C in the CKD group (OR: 0.93, P=0.013).

Based on the findings of this study, CKD and DM patients had a higher prevalence of olfactory dysfunction than the controls, which could be associated with some preventive nutritional factors. This information may help perform a screening program and early intervention on olfactory dysfunction in these systematic diseases.

The rate of olfactory loss related to COVID-19 was reported between 4-89 percent. There is no approved treatment for patients who experience anosmia after the mentioned infection. This systematic review aimed to assess the therapeutic effects of corticosteroids on anosmia in COVID-19 patients.

Databases including PubMed, ISI Web of Sciences, Scopus, and Cochrane Library. Databases were searched up to September 2022 to find out randomized controlled trials that assessed the effect of corticosteroids on post-COVID anosmia/hyposmia. Only studies published in the English language were entered in this review.

Among the six relevant trials with a total population of 712, one study administered the combination therapy of both systemic and nasal corticosteroids, while others used intranasal corticosteroids. No significant difference was observed between the intervention (IG) and control (CG) groups in terms of duration of improvement from anosmia (mean difference:-1.799). The pooled effect of self-rating olfactory scores was assessed at 2 weeks and at the end point of the studies which revealed no significant effect in favor of the IG (pooled effect in 2 weeks: 0.739; in the endpoint: 1.32). The objective evaluation with different tools indicated that IG obtained higher scores at the endpoint of treatment. The pooled results showed that the number of patients who recovered from anosmia is higher in IG compared to CG (Odds Ratio: 1.719).

It appears that the duration of corticosteroid therapy more than two weeks may be a considerable effect on the recovery of smell dysfunction in COVID-19 patients

The global public health and economic systems have been severely damaged by the coronavirus disease 2019 (COVID-19) pandemic. Olfactory dysfunction (OD) is one of the most prevalent symptoms experienced by COVID-19 patients, documented in clinical practice. In some individuals, OD is the first or the sole clinical symptom. In this review, the clinical characteristics, causes, evaluation procedures, prognosis, and available treatments of COVID-19-induced OD were examined.

The PubMed, Scopus, Web of Sciences, and Google Scholar databases were searched for the related articles from inception until August 2022.

OD appears to be common in COVID-19, particularly in younger individuals and women and those with milder disease. Even though the issue is still unresolved, current research suggests that COVID-19-related OD is not caused by direct injury to olfactory sensory neurons but instead is a result of indirect injury to these cells. Moreover, effective therapeutic methods are inadequate despite the high prevalence of COVID-19-related OD.

The focus of medical practice regarding COVID-19-related OD should be on identifying individuals with a poor prognosis who may benefit from early management to prevent complications, e.g., depression and anxiety, because COVID-19 OD generally has a good prognosis and quick recovery time.

Olfactory training is accounted as a significantly beneficial therapy for hyposmia or anosmia. There is some evidence about methylxanthine usage for this issue. In the present study, we have investigated the effects of topical aminophylline in hyposmic and anosmic patients. In this clinical trial study, patients were randomly divided into two groups (n= 20/each), the case group was given aminophylline drops over a three-month period (using the contents of the vial aminophylline in the form of nasal drops, 250 micrograms daily) with olfactory training and the control group was given normal saline drops with olfactory training over a three-month period. The olfactory capacities were assessed before the start and after the completion of treatments using a valid and reliable smell identification test.In the saline and aminophylline groups, the mean ± SD relative changes in SIT score were 0.55±0.31 and 0.85±0.56, respectively. As a result, the SIT score in the saline group climbed by 55 percent but increased by 85 percent in the aminophylline group. The difference in SIT score between pre- and post-test was meaningful in both groups (P< 0.001). The aminophylline group scored significantly higher according to the marginal longitudinal regression model, adjusting baseline parameters.Intranasal aminophylline plus olfactory training significantly improved SIT scores in severe hyposmia or anosmia. Hypothetically, these effects are mediated through changes in cAMP and cGMP.

The number of patients with COVID-19-induced olfactory dysfunction has consistently increased since the onset of the pandemic. Since a considerable proportion of these patients have olfactory dysfunction for a relatively long period of time, their quality of life (QOL) may considerably be impacted as a result.

The aim of the present study was to investigate the adverse effects of olfactory dysfunction on QOL in patients with COVID-19-induced hyposmia or anosmia.

The data were obtained via self-reported online questionnaire in individuals who met the inclusion criteria. The questionnaire included demographics, olfactory status and Questionnaire of Olfactory Disorders-Negative Statements (QOD-NS).

Among1531 participants, 1072 individuals met the inclusion criteria, with 588 (54.85%) having hyposmia and 484 (45.15%) anosmia. Average age was 35.7 in the hyposmic group and 34.5 in the anosmic group. Concurrent hypogeusia/ageusia was reported in 398 (67.7%) of cases with hyposmia and in 346 (71.5%) of participants with anosmia. Lack of enjoyment of eating food was the most negative effect in both hyposmic and anosmic groups, followed by annoyance when eating food and a continuous awareness of the olfactory problem. The mean QOD-NS score was 20.5±10.2 in the hyposmic group and 23.3±10.4 in the anosmic group, demonstrating significant adverse impact on QOL.

Persistent olfactory dysfunction in patients with COVID-19 has adverse effects on QOL. Early diagnosis and treatment of olfactory dysfunction may be crucial in limiting the adverse impact on QOL by psychological and nutritional support and olfactory rehabilitation.

Xp22.3 region is characterized by low frequency of interspersed repeats and low GC content. Several clinically important genes including ANOS1 (KAL1) reside in this region. This gene was first identified due to translocation between chromosomes X and Y in a patient with Kallmann syndrome.

A 20 year old male presented with complaints of delayed secondary sexual characteristics, impaired sense of smell, and poor scholastic performance. On examination, he had short stature (151 cm; <3rd centile). His sexual maturity corresponded to Tanner stage 3. Stretched penile length was 3.6 cm (<3rd centile). Right testis was undescended with low left testicular volume (12 ml). There was mild ichthyosis over abdomen and back. He had hyposmia, hoarse voice, and synkinesia. Investigations were suggestive of hypogonadotrophic hypogonadism. Karyotype revealed an extra chromosomal material on p arm of chromosome X (46,Xp+,Y). On cytogenetic microarray, deletion of 8.3 Mb on Xp22.33 region and duplication of 12.8 Mb on Yq11.22 region were identified. The breakpoint on X chromosome resulted in deletion of exons 7-14 of ANOS1 gene and complete STS, NLGN4X, ARSL (ARSE), SHOX, and VCX genes.

Patients diagnosed with Kallmann syndrome should receive careful clinical evaluation to detect presence of a contiguous gene syndrome.

The occurrence of anosmia/hyposmia during novel Coronavirus disease 2019 (COVID-19) may indicate a relationship between coincidence of olfactory dysfunction and coronavirus disease 2019 (COVID-19). This study aimed to assess the frequency of self-reported anosmia/hyposmia during COVID-19 epidemic in Iran.

This population-based cross sectional study was performed through an online questionnaire from March 12 to 17, 2020. Cases from all provinces of Iran voluntarily participated in this study. Patients completed a 33-item patient-reported online questionnaire, including smell and taste dysfunction and their comorbidities, along with their basic characteristics and past medical histories. The inclusion criteria were self-reported anosmia/hyposmia during the past 4 weeks, from the start of COVID-19 epidemic in Iran.

A total of 10 069 participants aged 32.5±8.6 (7-78) years took part in this study, of them 71.13% women and 81.68% nonsmokers completed the online questionnaire. The correlation between the number of olfactory disorders and reported COVID-19 patients in all provinces up to March 17, 2020 was highly significant (Spearman correlation coefficient = 0.87, P< 0.001). A sudden onset of olfactory dysfunction was reported in 76.24% of the participations and persistent anosmia in 60.90% from the start of COVID-19 epidemic. In addition, 80.38% of participants reported concomitant olfactory and gustatory dysfunctions.

An outbreak of olfactory dysfunction occurred in Iran during the COVID-19 epidemic. The exact mechanisms by which anosmia/hyposmia occurred in patients with COVID-19 call for further investigations.