Annotation. The pathogenetic mechanisms of the triad "Metabolic syndrome (MS) – obstructive sleep apnea (OSA) – atrial fibrillation (AF)" remain poorly understood, depending on the paroxysmal or permanent form of AF. The aim of the study was to evaluate the association of biomarkers of systemic inflammation (CRP, NLR, MLR, SII, SIRI) depending on the form of atrial fibrillation (paroxysmal or persistent) in elderly patients with comorbidity of metabolic syndrome and obstructive sleep apnea. Materials and methods of research. A single-stage comparative study included 148 elderly patients (68.2±3.3 years). The main group consisted of 52 patients with paroxysmal AF, the comparison group consisted of 48 patients with permanent AF, and the control group consisted of 48 elderly patients without AF. Results. In patients with AF, there is a progressive increase in body mass index, waist circumference, metabolic disorders (glucose, HbA1c, HOMA-IR), inflammatory markers (CRP, NLR, MLR, SII, SIRI) compared with the group without AF, with maximum changes in the constant form of AF. All intergroup comparisons were adjusted for the apnea-hypopnea index (a fixed value of 22 events/hour), after which the differences between the groups remained, indicating an independent contribution of the AF form. Metabolic differences (glucose, HbA1c, HOMA-IR, lipids) have become insignificant — they are determined by the severity of apnea. Inflammatory markers (NLR, SII, SIRI) and NT-proBNP remained significant, indicating an independent effect of the AF form on inflammation and neurohormonal activation. All the studied biomarkers of inflammation (NLR, MLR, SII, SIRI, CRP) significantly correlate with IAG (p