key: cord-1051899-zcppkngo authors: Asadi, M. Mahdi; Shankayi, Zeinab; Bahrami, Farideh; Mohammadzadeh, Tahereh; Amini, Hossein; Naderi, Maryam title: Quantitative analysis of taste disorder in COVID-19 patients, the hypersensitivity to salty quality date: 2021-07-17 journal: New Microbes New Infect DOI: 10.1016/j.nmni.2021.100919 sha: 925870fb7b78bed647071ce2b69970d8d1760266 doc_id: 1051899 cord_uid: zcppkngo Recently, many of studies have illustrated that the new pandemic SARS-CoV-2 can affect Central Nervous System through olfactory bulb. In addition to investigating anosmia or hyposmia induced by this virus, the quantitative analysis was needed to clarify the taste and smell disorder of the new corona virus. The four basic taste quality with five concentrations for sweet, sour, bitter and salty were administered in to 75 subject divided in to three groups: COVID-19 patients with taste disorder, COVID-19 patients without taste disorder and control group. The results indicated the increment of sweet (2.68±0.14), sour (3.34±0.12) and bitter (3.39±0.2) thresholds in COVID-19 patients with taste disorder in comparison with patients without taste disorder that the threshold were: 2±0.16, 2.11±0.2 and 2.55±0.5 for sweet, sour and bitter respectively. On the other-hand the patients inversely showed significant decrease in salty taste threshold (0.51±0.03) compared to COVID-19 positive control groups (1.11±0.11). Additionally, despite taste disorder in almost all of patients with smell deficiency, only 30% of cases with taste disorder reported smell deficiency. It may be concluded that some of taste disorders in patients with COVID-19 disorder could be associated with taste receptors dysfunction or the spread of infection to the cranial nerves responsible for conduction of tastes sensation. group. 10 The results indicated the increment of sweet (2.68±0.14), sour (3.34±0.12) and bitter (3.39±0.2) 11 thresholds in COVID-19 patients with taste disorder in comparison with patients without taste 12 disorder that the threshold were: 2±0.16, 2.11±0.2 and 2.55±0.5 for sweet, sour and bitter 13 respectively. On the other-hand the patients inversely showed significant decrease in salty taste 14 threshold (0.51±0.03) compared to COVID-19 positive control groups (1.11±0.11). 15 Additionally, despite taste disorder in almost all of patients with smell deficiency, only 30% of 16 cases with taste disorder reported smell deficiency. It may be concluded that some of taste 17 disorders in patients with COVID-19 disorder could be associated with taste receptors 18 dysfunction or the spread of infection to the cranial nerves responsible for conduction of tastes 19 sensation. After the wide spread of the new SARS-CoV-12 around the world, many studies were 24 conducted to investigate its severe respiratory syndrome. However, several studies focused on 25 the effect of this virus on other organs such as cardiovascular systems and neural systems (1, 26 2). The studies demonstrated that the new corona virus could affect central nervous system 27 through olfactory bulb or blood circulation. Furthermore, it addition to anosmia or hyposmia 28 induction as well as taste disorders, the virus may cause headache, eye-ache, earache, dizziness (4) . Owing to taste problems in many patients with smell loss as well as the 33 interaction between smell and taste sensations, it appeared that quantitative taste test was 34 necessary to determine whether COVID-19 could damage taste afferent or not (5) . 35 Accordingly, in this study, we attempted to quantitatively measure the threshold of four basic 36 tastes, namely sweet, salty, sour and bitter in patients suffered from COVID-19 and to assay 37 the correlation of this sense with other disorders such as pains and some autonomic disorders 38 in order to better identify the neurological effect of virus. We searched for the validation of 39 hypothesis of measuring taste and smell as an easy and effective method to identify the disease 40 and improve the medical decision-making. The current study was approved by ethic committee of Baqiyatallah university of medical (Table 1 ). In this study we added three lower concentrations of salty quality to the table: the 57 1/2, 1/5 and 1/10 of the lowest concentration. These three concentrations were indicated with 58 asterisk in the Table 1 . The results revealed an increase in the threshold for sweet, sour, and bitter tastes in the COVID- As Table 1 presents, owing to the high sensitivity of patients to salty taste, we followed the (Table 3) . (Table 4 ). The quantitative and subjective assessment of the four taste qualities showed an increase in the 107 threshold of sweet, sour, and bitter qualities in COVID-19 patients. But, the threshold for salty 108 taste was considerably reduced. The epidemiological studies showed that 41%-62% of COVID-19 patients were diagnosed 110 with smell and taste disorders so that some studies suggested these disorders could be COVID- 111 19 related (6, 7) . Most of the data reported that taste pathogenesis in COVID-19 is based on 112 self-reporting through questionnaires or phone interviews. They reported gustatory 113 dysfunctions as ageusia or hypogeusia with prevalence ranged from 5.6% to 62.7% (6) (7) (8) . According to a one study, 48-49% of COVID-19 patients experienced impairment of two or 115 more taste qualities, and 60% of those who reported a taste loss also described a decrease in 116 their perception of at least one specific taste quality (8) . There is a directly proportional connection between olfactory and gustatory, and the pathology 118 of these two is closely related to each other (9, 10).There are many reasons for gustatory 119 pathology, including upper airway infection, destruction of papillae or taste buds, poor oral 120 J o u r n a l P r e -p r o o f health, and post-viral cranial nerve damage (9, 11) . In COVID-19 patients with taste and smell 121 disorder, the lack of nasal congestion or discharge could be attributed to sensorineural damage 122 (7) . 123 Structurally, though, gustatory cells are located in the sensory ganglion of the facial, 124 glossopharyngeal, and vagus nerve. They serve the taste buds located on two-thirds of the 125 anterior tongue, baseline tongue, pharynx, and larynx, respectively (9, 12) . 126 This study demonstrates the correlation between changes in taste thresholds and some The CT, MRI, and the neurologic examination are the complementary methods that suggested 137 a better understanding of the taste disorder mechanism (14) . and aldosterone, a slow enhancer, may play a role in this hypersensitivity. These vital hormones 147 may exist in peripheral taste organs and contribute to salt intake and ingestive behavior (16) . 148 Based on the investigations, the relationship between salt taste sensitivity threshold (STST), 149 blood pressure, and sodium intake (17) may be considered in COVID-19 patients. Other studies addressed the regulatory role of salt taste sensitivity in sodium homeostasis (18) . 151 It is suggested that (angiotensin II and aldosterone), sodium concentration of plasma and saliva, 152 and amiloride-sensitive receptors facilitate the mechanism of this hypersensitivity19. Considering that changes in sodium hemostasis and sodium regulator hormone imbalance have 154 been reported in COVID-19 infection (19, 20) . 155 Moreover, the components of saliva could explain the differences in salt perception among 156 patients. It is reported that higher amounts of endopeptidases in saliva liquid could increase 157 salt sensitivity. The researchers suggest that the saliva enzymes cloud produce salt-enhancing 158 peptides and increase the sodium entrance through modifying sodium channels (21) . COVID-19 and cardiac 168 arrhythmias Effects of COVID-19 on the Nervous System Command Suicidal Hallucination 172 COVID-19): A Case Report Smell 175 dysfunction: a biomarker for COVID-19 Taste test using an edible taste film kit: a 177 randomised controlled trial in Patients With COVID-19: A Systematic Review and Meta-analysis Smell and taste disorders in COVID-19: From 182 pathogenesis to clinical features and outcomes More than smell is associated with severe impairment of smell, taste, and chemesthesis. Chemical Senses Taste and smell disorders Anormalidades sensoriais: olfato e paladar. Arquivos Internacionais de Otorrinolaringologia 189 (Impresso) Symposium overview: Impact of oronasal inflammation on taste and 191 smell Basic science of the oral cavity and gustation Otolaryngology Basic science and clinical review Thieme Medical Publishers How COVID-19 can damage the brain Neurologic Manifestations of Hospitalized 196 Patients With Coronavirus Disease COVID-19 and olfactory dysfunction-an ENT perspective to the current COVID-19 pandemic. B-ENT Evidence of the COVID-19 Virus Targeting the CNS: Tissue 201 Host-Virus Interaction, and Proposed Neurotropic Mechanisms Association between salt taste sensitivity 204 threshold and blood pressure in healthy individuals: a cross-sectional study Angiotensin II and taste sensitivity Electrolyte imbalances in patients with severe coronavirus 209 disease 2019 (COVID-19) Evaluation of electrolyte status 211 of sodium, potassium and magnesium, and fasting blood sugar at the initial admission of individuals 212 with COVID-19 without underlying disease in Golestan Hospital Patterns Affecting Human Salt Taste Sensitivity The authors wish to thank all members of the research team and others who facilitated this study.