Cross-Sectional Analysis of Hypoxia-Regulated miRNA-181a, miRNA-199a, HIF-1α, and SIRT1 in the Development of Type 2 Diabetes in Patients with Obstructive Sleep Apnea—Preliminary Study

Introduction: Obstructive sleep apnea (OSA) is recognized as an independent risk factor for diabetes mellitus type 2 (T2DM) development, which is twice as common in patients with OSA compared to non-OSA patients. Objectives: This study aimed to investigate changes in oxygen metabolism and their role in T2DM development among OSA patients through epigenetic processes via miRNA-181a, miRNA-199a, and enzymatic processes via SIRT1 and HIF-1α. Methods: Based on polysomnography, apnea–hypopnea index and the presence of T2DM patients were divided into three groups: control group (n = 17), OSA group (n = 11), OSA&T2DM (n = 20) group. Total RNA was extracted from the buffy coat. Moreover, HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) was counted. Results: Morning miRNA-181a expression was significantly higher in the OSA&T2DM group than in the control group: 67.618 vs. 32.685 (p = 0.036). Evening miRNA-199a expression was significantly higher in the OSA group than in the control group: 5.043 vs. 2.081 (p = 0.042), while its morning expression was significantly higher in the OSA&T2DM group when compared to the control: 4.065 vs. 1.605 (p = 0.036). MiRNA-181a evening expression revealed a negative correlation with the SIRT1 evening and morning expressions (R = −0.367, p = 0.010 and R = −0.405, p = 0.004, respectively). Moreover, morning miRNA-181a was positively correlated with HOMA-IR (R = 0.321, p = 0.034). MiRNA-199a evening expression presented a moderate positive correlation with the SIRT1 morning expressions (R = 0.48, p < 0.001) and HOMA-IR (R = 0.35, p = 0.02). Conclusions: Patients suffering from OSA and T2DM had an increased expression of miRNA-181a. Moreover, a negative correlation between miRNA-181a and SIRT1 expression was observed, while a correlation between miRNA-181a and insulin resistance was positive. This phenomenon might suggest a possible epigenetic pathway for an increased incidence of T2DM in OSA patients however further research is needed.