Exploration of correlation of oral hygiene and condition with influenza infection.

Influenza viruses are known to be infected through epithelial cells of the upper respiratory tract. The oral cavity is in close anatomical proximity to the upper respiratory tract, and it is conceivable that the viruses could pass through the oral cavity and infect to the upper respiratory tract. Several researchers have suggested that colonization of certain pathogenic bacteria such as Staphylococcus aureus or Streptococcus pneumoniae might affect the risk of influenza viral disease, indicating that oral hygiene and/or condition might play an important role in respiratory viral infection. Therefore, the purpose of this study was to investigate whether an oral hygiene/condition might impact influenza infection. We conducted a retrospective observational study of Japanese citizens' regional cohort (N = 2,904) consisting of National Health Insurance beneficiaries who underwent annual health/dental examination with data entries in the Kokuho database (KDB). Trained dentists checked the oral hygiene/condition, and saliva specimens were examined using the LION dental saliva multi-test (SMT) kit. Influenza infection was identified from the diagnosis recorded in the KDB. The correlations between influenza infection and oral hygiene, dryness of the mouth, or various salivary test results were examined by a multivariate analysis adjusting for confounding factors such as gender, age, recent smoking, alcohol drinking, BMI, HbA1c, RBC for influenza infection. The logistic regression model showed that age significantly correlated with influenza infection. In addition, oral hygiene status had a nearly significant impact on influenza infection (p = 0.061), whereby, the subjects with poor oral hygiene had a higher risk of influenza infection than those with good oral hygiene (odds ratio: 1.63, 95% confidence interval: 0.89-2.95). Further, the prevalence of influenza infection was lower in the subjects with saliva weakly acidic and/or containing higher protein level. The results of this study suggested that the maintenance of oral health conditions might be one of the pivotal factors for preventing and reducing influenza infection.

Accuracy of a salivary examination kit for the screening of periodontal disease in a group medical check-up (Japanese-specific health check-up).

ABSTRACT: The purpose of the present study was to investigate the accuracy of a screening method using salivary tests to screen for periodontal disease.In total, 1888 individuals older than 30 years in 2017 and 2296 in 2018 who underwent medical check-ups for metabolic syndrome agreed to participate and simultaneously underwent a dental examination by dentists and salivary tests. Salivary occult blood, protein, and ammonia levels and white blood cell counts were evaluated in salivary tests using commercially available kits. The relationship between the results of the salivary tests and dental examination was examined and classification performance was analyzed.The prevalence of periodontal disease was 69.9% in 2017 and 66.8% in 2018. Salivary ammonia showed the highest classification performance in both years (sensitivity 83.5 and 83.1%, precision 73.0 and 69.3%, F-measure 0.779 and 0.756). Occult blood, which was assessed using a monoclonal antibody to human hemoglobin, also showed good performance (sensitivity 69.5%, precision 70.6%, F-measure 0.701). Questions regarding self-reported gingival bleeding were not sufficient to screen for periodontitis. The present results suggest that screening tests using salivary samples may detect periodontal disease in approximately 70% to 80% of subjects in a large population.Conclusion: Salivary ammonia and hemoglobin have potential as salivary markers in the screening of periodontal disease.

Correlations between the properties of saliva and metabolic syndrome: A prospective observational study.

ABSTRACT: Saliva tests, which are easy to perform and non-invasive, can be used to monitor both oral disease (especially periodontal disease) and physical conditions, including metabolic syndrome (MetS). Therefore, in the present study the associations between saliva test results and MetS were investigated based on medical health check-up data for a large population. In total, 1,888 and 2,296 individuals underwent medical check-ups for MetS and simultaneous saliva tests in 2017 and 2018, respectively. In the saliva tests, the buffer capacity of saliva, salivary pH, the salivary white blood cell count, the number of cariogenic bacteria in saliva, salivary occult blood, protein, and ammonia levels were tested using a commercially available kit. The relationships between the results of the saliva tests and MetS components were examined in cross-sectional and longitudinal multivariate analyses. Significant relationships were detected between salivary protein levels and serum HbA1c levels or blood pressure levels and between the buffer capacity of saliva and serum triglyceride levels. In addition, salivary pH was increased irreversibly by impaired renal function. This study suggested that saliva tests conducted during health check-ups of large populations might be a useful screening tool for periodontal disease and MetS/MetS components.

A longitudinal study on the relationship between dental health and metabolic syndrome in Japan.

BACKGROUND: A close relationship has been reported between metabolic syndrome (MetS) and periodontitis. However, as there are only a few longitudinal studies, the association between MetS and periodontitis has not been fully elucidated. The aim of the present study was to investigate the relationships between periodontal conditions and internal changes in MetS components using a longitudinal analysis. METHODS: A total of 985 out of 2716 individuals who underwent systemic medical checkups in 2014 and 754 out of 2454 in 2016 received dental checkups including Community Periodontal Index. Of these, 390 individuals underwent medical and dental checkups in 2014 and 2016 and were included and reviewed. RESULTS: Of the 390 individuals, the positive number of MetS components decreased in 62 individuals (15.9%) and increased in 104 (26.7%). A multivariate analysis identified sex (risk ratio (RR): 0.55, 95% confidence interval (CI): 0.37-0.82, P < 0.05), alcohol intake (RR:2.06, 95%CI:1.14-3.73, P < 0.05), and the mediation of glycemia (RR:6.45, 95%CI:1.45-27.9, P < 0.01) as significant influencing factors for MetS. The number of MetS components was higher in individuals with persistent or progressive periodontitis than in those with no/improved periodontitis (RR:1.75, 95%CI:1.14-2.70, P < 0.01)). Improvements in periodontitis had a significant positive impact on MetS components, including hypertension (RR:2.14, 95%CI:1.03-4.43, P < 0.05) and hyperglycemia (RR:2.52, 95%CI:1.27-4.98, P < 0.01), but a negative impact on hypertension. CONCLUSIONS: The results of the present study suggest that since the prevalence of individuals with more positive MetS components was higher in those with persistent/progressive periodontitis than in those with no/improved periodontitis, reducing periodontitis may be important for preventing pre-MetS and MetS.