Expression of SIRT1–7 mRNA and Its Association with Clinical Characteristics in Patients with Chronic Otitis Media

Background: Sirtuins are recognized as critical regulators of various physiological processes, including aging, metabolic homeostasis, oxidative stress, and inflammatory responses. This study aimed to investigate whether sirtuin expression is associated with the pathogenesis and clinical manifestations of chronic otitis media (COM). Methods: Middle ear inflammatory tissues were obtained from 27 patients who underwent COM surgery. The mRNA expression levels of SIRT1–7 were measured using quantitative real-time polymerase chain reaction (qRT-PCR). The expression patterns of SIRT1–7 were comparatively analyzed according to bacterial culture results, the presence of otorrhea, and the type of hearing loss (conductive or sensorineural). Results: The study included 10 males and 17 females, with a mean age of 60.52 ± 9.79 years. Otorrhea was present in 51.9% of patients, whereas the bacterial culture-positive rate was 29.6%. Conductive hearing loss was more prevalent than sensorineural hearing loss. SIRT1–7 mRNA expression was detected in all inflamed COM tissues. Among the seven members, SIRT3 exhibited the highest expression level, followed in descending order by SIRT6, SIRT4, SIRT7, SIRT1, SIRT5, and SIRT2. Notably, the expression levels of SIRT1–4 were significantly higher in the culture-negative group compared to the culture-positive group (p < 0.05). However, no significant differences in SIRT1–7 mRNA expression were observed according to the presence of otorrhea or the type of hearing loss (p > 0.05). Conclusion: All seven sirtuin members (SIRT1–7) were expressed in inflamed COM mucosa, suggesting that the sirtuin family may be transcriptionally active in the inflamed middle ear microenvironment. Specifically, SIRT1–4 mRNA expression differed significantly according to bacterial culture status, suggesting a potential association between SIRT1–4 mRNA expression and local inflammatory processes in COM.