The Impact of Reduced Salivary Flow Rate and Aging on Oral Candidiasis in Patients with Stomatitis

Aim: We elucidated the relationship between the comorbidity of oral candidiasis and stomatitis and a reduced salivary flow rate, and identify predictors for oral candidiasis. Methods: A total of 259 patients with stomatitis (mean age 59.77±15.93 years, range 10 –87 years, 201 females) were diagnosed with oral candidiasis through Candida albicans culture test. Clinical characteristics of the Candida –positive and Candida –negative groups were statistically analyzed. Results: Out of the total 259 stomatitis patients, 81 (31.27%) had oral candidiasis based on Candida albicans culture. Regarding age, the stomatitis with oral candidiasis group (64.25 ± 14.66 years) was significantly older than the stomatitis without oral candidiasis group (57.73 ± 16.10 years) (p=0.002). Regarding salivary flow rates, both unstimulated salivary flow rate (UFR) (0.36 ± 0.32 mL/min vs. 0.47 ± 0.28 mL/min, p=0.006) and stimulated salivary flow rate (SFR) (1.21 ± 0.68 mL/min vs. 1.41 ± 0.69 mL/min, p=0.032) were significantly lower in patients with oral candidiasis compared to those without. The proportion of xerostomia based on UFR 0.2mL/min (xerostomia_UFR) was significantly higher in the stomatitis with oral candidiasis group (49.4%) compared to the stomatitis without oral candidiasis group (18.5%) (p<0.001). Similarly, the proportion of xerostomia based on SFR of 0.7mL/min was significantly higher in the stomatitis with oral candidiasis group (27.2%) compared to the stomatitis without oral candidiasis group (10.7%) (p<0.001). The prediction accuracy of oral candidiasis based on age was 62.2% (AUC=0.622, 95% CI: 0.547-0.696, p=0.002), with a cutoff value of 64.50 years for age. The prediction accuracy based on UFR was 65.8% (AUC=0.658, 95% CI: 0.582-0.734, p<0.001), with a cutoff value of 0.3350 mL/min for UFR. The prediction accuracy based on SFR was 58.7% (AUC=0.587, 95% CI: 0.510-0.663, p=0.025), with a cutoff value of 1.150 mL/min for SFR. From the generalized linear model for oral candidiasis, xerostomia_UFR was significant predictor (B=0.328, 95% CI: 0.177 - 0.480, p<0.001). Conclusion: Although a decrease in salivary flow rate and aging were associated with the occurrence of oral candidiasis in patients with stomatitis, these factors alone did not result in high predictive accuracy.