Oral health related quality of life and the prevalence of ageusia and xerostomia in active and recovered COVID-19 Patients

Introduction

The recent coronavirus disease-19 (COVID-19) pandemic is the great challenge to the health care system and the general population. Along with the global health crisis, it has also brought an unprecedented socio-economic crisis, which continues to have a devastating effect  (Xie et al., 2020; Ali et al., 2020). Patients with COVID-19 present with mild flu-like condition leading to life-threatening multi-organ failure, lasting for up to two weeks, with high mortality among patients with co-morbidities  (Ahmed et al., 2020c; Ahmed et al., 2020a; Neto et al., 2020; Abbasi et al., 2020; Zhou et al., 2020).

The infected individuals primarily contract the virus from other infected humans by respiratory droplets produced by sneezing and coughing. Primary symptoms that are displayed by the infected patient include fever, dry cough, sore throat, shortness of breath, and myalgia  (Wang et al., 2020b). Furthermore, as the disease progresses, other symptoms which may develop include disturbed taste and smell sensations, along with gastric upset such as diarrhea and constipation (Ali et al., 2020; Neto et al., 2020; Abduljabbar et al., 2020). Literature suggests that the viral infection of the salivary gland cells may alter the salivary constituents and composition. Critical salivary compounds like proteins, enzymes and hormones play an important part in perception of taste. Therefore, it is likely that the ageusia associated in COVID-19 patients is the result of changes in salivary composition associated with the salivary gland infection (Abduljabbar et al., 2020). The mechanism of COVID-19 disease as presented in previous studies, includes an interaction with angiotensin-converting enzyme inhibitor 2 (ACE-2) receptors, which are present throughout the body including lungs, blood vessels, brain, and salivary glands (Sarfaraz et al., 2020). Additionally, tissues present in the body that express ACE-2 receptors are prone to invasion of this virus and may display various symptoms according to the system being affected. Since ACE-2 receptors are present in the salivary glands, there is a possibility that the coronavirus can invade the salivary glands and cause inflammatory reactions leading to acute and chronic sialadenitis and dry mouth (Wang et al., 2020a; Fantozzi et al., 2020; Freni et al., 2020).

Xerostomia is a condition whereby secretion or production of saliva is reduced causing compromised oral functions (Villa, Connell & Abati, 2014; Mulyani et al., 2019). It is associated with burning sensation, abnormal taste, dysarthria, dysphagia, dysgeusia, and halitosis, having a negative impact on the quality of life (Abduljabbar et al., 2020; Millsop, Wang & Fazel, 2017; Niklander et al., 2017). It occurs in 5.5% to 46% of the general world population with females being most affected (Anwar et al., 2022). It is also common in healthy individuals, although most commonly associated with many underlying systemic conditions. Increasing age along with polypharmacy are reported as risk markers for xerostomia especially inhaled anti-asthmatic drugs (Kishore et al., 2022). Other agents that contribute to xerostomia are caffeine, alcohol, tobacco, and carbonated beverages. COVID-19 infection along with xerostomia will compromise the oral health-related quality of life of patients and an improvement in quality of life for recovered individuals is expected. However, to our knowledge from indexed literature, there limited evidence related to oral health and quality of life of active and recovered COVID-19 patients.

Timely identification and management of COVID-19 induced dry mouth could prove to be beneficial for the already suffering patient to maintain their diet and health with improved quality of life. Therefore, this study aimed to investigate the possible correlation between coronavirus and Xerostomia and to determine the prevalence of ageusia and xerostomia in active and recovered COVID-19 patients. In addition, the impact of coronavirus on quality of life regarding oral health will also be assessed.

Materials & Methods

Results

A total of 301 COVID-19 patients participated in the study in two phases (infection and recovery). The response rate from participants was 86%. More than one-half (54.8%) of the participants were females. The majority of participants (126 (41.9%)) were undergraduates by education status and mostly students (130 (43.2%)) from occupation. More than two-thirds of participants were nonsmokers as far as habits are concerned. While 87 (28.9%) participants were taking some medicines, bronchodilators (6.89%) were the most common medicine used by the participants. Similarly, 81 (26.9%) participants were suffering from a systematic illness, and hypertension was the most common illness 52 (17.3%). Furthermore, 167 (55.48%) participants were younger than 30 years of age, 121 (40.19%) were from the age group of 31 to 60 years and 13 patients were older than 60 years of age as presented in Table 1.

The distribution of xerostomia inventory scale XI score for active and recovered COVID-19 patients is presented in Table 2. On the basis of scores 3, 4 and 5 from item 4 of the xerostomia inventory scale, the prevalence of xerostomia in participants with active COVID-19 disease was 39.53% and after recovery was 34.88%. The mean summative xerostomia inventory scale score was 22.36 ± 12.96 in active COVID-19 patients while in recovered patients 20.85 ± 12.59 as shown in Fig. 1. A significant difference was found between the mean scores of the xerostomia inventory scale among infected and recovered patients (paired t-test: p = 0.011). Additionally, a significant difference was also found between gender and xerostomia inventory scale scores in active (p = 0.002) and recovered COVID-19 patients (p = 0.001) (Chi-square test). Xerostomia was prevalent in young individuals between 18 to 30 years of age, with 17.60% in active while 15.61% in recovered cases. For older individuals of 60 years and above, xerostomia was in 4.98% and 4.31% active and recovered cases respectively. A significant difference was seen between the age of participants and xerostomia inventory scale scores in the active phase of COVID-19 infection (Chi-square test: p = 0.016). However, no significant difference (p = 0.473) was observed between age and recovered patient scores.

The distribution of oral health impact profile scale 14 scores for active and recovered COVID-19 patients is described in Table 3. The total OHIP-14 score for patients in the active phase of infection was 12.09 ± 14.49, while 12.68 ± 12.43 in recovered patients as presented in Fig. 1. The prevalence of different domains in the OHIP-14 scale was as follows: Functional limitation was seen in 224 (74.41%) participants when assessed by scores 3 and 4 (Q1 and Q2). While physical pain was observed in 40 (13.28%) after summing up score 3 and 4 (Q3 and Q4). Psychological discomfort was found in 74 (24.58) (Q5 and Q6). Physical disability was seen in 81(26.91%) (Q7 and Q8). Psychological disability was found in 89 (29.56%) participants (Q9 and 10), whereas social disability (Q11, Q12) was evident in 86 (28.57%) participants. Being handicap was (Q13 and Q14) found in 77 (25.58%) subjects respectively (patients with active COVID-19 infection). Additionally, the highest individual OHIP-14 scale score was recorded for taste loss (70.09%) amongst the participants as described in Table 3.

The domains of OHIP-14 scale in COVID-19 recovered patients were observed in the study. The functional limitation was compromised in 54 (17.94%) participants when assessed by scores 3 and 4 (Q1 and Q2), while physical pain was felt by 42 (13.95%) individuals, when summed up by score 3 and 4 (Q3 and Q4). Psychological discomfort was evident in 72 (23.92%) participants (item Q5 and Q6). Physical disability was seen in 51 (16.94%) subjects (Q7 and Q8) and psychological disability was found in 64 (21.26%) (Q9 and Q10). Social disability was apparent in 60 (19.93.%) participants (Q11 and Q12) and handicap was found in 71 (23.58%) patients (Q13 and Q14) respectively. Similarly, the highest individual OHIP-14 scale score was recorded for taste loss (73.42%) amongst the participants (sum of negative answers 3 and 4 in item number 2) as presented in Table 3. There was a significant difference (paired t-test: p = 0.001) between the mean scores of the OHIP-14 scale in active and recovered COVID-19 patients. Furthermore, a significant difference was also found between gender and OHIP-14 scale score in active COVID-19 patients (Chi-square tests: p = 0.002) and recovered patients (p = 0.003). The loss of taste was prevalent in young individuals 18 to 30 years of age (42.19%) while (10.29%). in older individuals 60 years and above. Moreover, there was no significant difference between the age of participants and OHIP-14 scores in active and recovered patients (Chi-square test: p = 0.076, p = 0.069) as shown in Table 4.

Discussion

Currently, COVID-19 is one of the major threats to the health of human life. Its early detection is critical in prevention and management of the disease. In the present study, it was observed COVID-19 was more prevalent in females then and majority of the participants were younger than 30 years of age which is in contrast to a study by Ali et al. (2020) which reported that adult male patients with a median age between 34–59 years have a greater incidence of developing SARS-CoV-2 infection. Our findings are supported by the fact that 63% of population of the country where the data was collected (Pakistan) is comprised of youth aged individuals (Hafeez & Fasih, 2018). The present study also supports the findings of Berlin et al. (2020) who suggested that the published data on the association of COVID-19 with smoking status are only descriptive and conclusions from it cannot be drawn (Ahmed et al., 2020b). Furthermore, evidence suggests that underlying health conditions such as hypertension, diabetes, and coronary heart disease increase the risk of morbidity in COVID-19 patients (Abbasi et al., 2020; Wang et al., 2020a; Berlin et al., 2020). Nearly 27% of the participants in the present study suffered with systematic illness with hypertension being the most common. Studies by Zhou et al. (2020) and Wang et al. (2020a) are also in accordance to the findings by the current study as majority (48%) of patients had comorbidity, with hypertension being the most common followed by diabetes (Abbasi et al., 2020).

Furthermore, this study reported on the prevalence of xerostomia in patients with active COVID-19 disease, which was 39.53% and after recovery 34.88%. Earlier studies have also reported that COVID-19 patients experiences xerostomia though the temporal sequence of xerostomia and COVID-19 diagnosis is not clear and warrants further exploration (Abrar et al., 2021; Anzar et al., 2021; Rodríguez, Romera & Villarroel, 2020). In addition, xerostomia is known to be related to a wide range of viral infections (Nasiri, 2020) and SARS-CoV-1 has been shown to infect epithelial cells in salivary gland ducts in rhesus macaques  (Nigar et al., 2022). Moreover, Freni et al. (2020) reported xerostomia in COVID-19 patients with a statistically significant difference between active and recovered patients (Fantozzi et al., 2020). This is similar to the observations in the present study, as a significant difference was found between the mean scores of xerostomia inventory scale between active and recovered patients. Additionally, a significant difference was also found between gender and xerostomia inventory scale scores in active and recovered COVID-19 patients with the female having more prevalence. This corresponds to the study by Biadsee et al. (2020), where 56.2% experienced xerostomia with females having more prevalence (61%).

Xerostomia is multifactorial and is commonly associated with old age and polypharmacy (Mulyani et al., 2019; Nigar et al., 2022). Other factors include emotional stress and anxiety disorders, along with agents like caffeine, alcohol, tobacco, and carbonated beverages (Ahmed et al., 2020c). Many of these contributing factors are also associated with COVID-19 patients, so the exact cause of xerostomia in COVID-19 is yet to be discovered, either it is due to the mentioned conditions or due to viral infection of salivary glands impeding the salivary flow (Mulyani et al., 2019; Nasiri, 2020; Ahmed et al., 2020c; Fathi et al., 2021). As all the above-mentioned studies are observational and the literature lacks objective evidence, therefore, it is recommended that objective evaluation with validated, repeatable and standardized tests to establish the frequency, extent, and cause of xerostomia in COVID-19 patients are performed.

COVID-19, affects the oral health-related quality of life of patients and OHIP-14 score among patients in the present study with active infection and recovery were 12.09 ± 14.49 and 12.68 ± 12.43 respectively. This is in line with the study by Niklander et al. (2017) with OHIP-14 scores among COVID-19 patients to be 20.1 ± 14.32 (Millsop, Wang & Fazel, 2017). A high prevalence of functional limitation was seen in participants of present study, which includes difficulty in speech and loss/altered taste. These findings are in accordance with a study by Vaira et al. (2020) in which majority of the patients reported gustatory disorders during SARS-CoV-2 infection (Chen et al., 2020). Similar findings are also observed in other studies (Mohamud et al., 2020; Giacomelli et al., 2020). Moreover, a smaller number of patients also complained of a painful mouth and discomfort in eating food which is also supported by Lechien et al. (2020) who reported loss of appetite and dysphagia amongst COVID-19 patients (Wee et al., 2020).

It is also established that COVID-19 is associated with psychiatric implications including delirium, depression, anxiety, and insomnia  (Holmes et al., 2020). Other coronaviruses also induce psychopathological sequelae through direct viral infection of the central nervous system (CNS) or indirectly via an immune response (Holmes et al., 2020; Wu et al., 2020). Moreover, psychological stressors such as social isolation, the psychological impact of a novel severe and potentially fatal illness, concerns about infecting others, and stigma are implicated in COVID-19 related psychiatric manifestation (Mazza et al., 2020). In the present study as well, psychological and social disability along with handicap symptoms were observed in more than a quarter of subjects.

The study showed that xerostomia and ageusia are associated with COVID-19 infections and quality of life including difficulty in eating, speech difficulty, social and psychological disorders are augmented in infection. Therefore, it is important that a detailed and comprehensive intraoral assessment should be performed in patients that were diagnosed with COVID-19 in order to establish any oral manifestation that might be related. Moreover, the dentist should improve the examination of salivary glands and saliva flow in order to perform early diagnoses related to changes in the glandular parenchyma that might be affected by the virus.

The study has some limitations. First, the sample size is small and includes mild-moderate patients, thus cannot represent general COVID-19 patients. Some of the COVID-19 survivors that we were able to reach did not want to participate in the study. In addition, the salivary flow before the infection and other factors like stress, that might have affected the oral health could not have been evaluated. The occurrence of xerostomia is a possible outcome of the viral infection in the patients observed, however it should also be associated with treatment of the infection. In addition, it may be essential to carry out the measurement of the salivary flow before and after the COVID-19 diagnosis to demonstrate a close correlation of it with the virus. The study targeted only COVID-19 patients. There may be a bias because people who have xerostomia or any oral problem would intend to reply to the questionnaire. Healthy people who do not have any oral problems would not want to participate in this study.

Conclusions

Both active and recovered COVID-19 patients reported decreased salivation and altered taste sensation but much higher prevalence was reported in infected ones. Similarly, oral health impact profile was much more compromised in active infected patients compared to recovered patients.

Supplemental Information