[Post-COVID-19 symptoms and sleep-wake abnormalities during the COVID-19 pandemic waves in Hungary]

Introduction: Mutations carried by SARS-CoV-2 variants in the spike protein and other regions influence the clinical presentation of COVID−19. However, the significance of SARS-CoV-2 variants concerning post-COVID−19 complications persisting beyond four weeks remains poorly understood. Objective: To assess post-COVID−19 symptoms and sleep-wake disorders induced by different SARS-CoV-2 variants. Method: We retrospectively analyzed hospital records of patients infected with SARS-CoV-2 during the third (February−July 2021; B.1.1.7, Alpha variant, n = 88), fourth (August−December 2021; B.1.617.2, Delta variant, n = 60), and fifth (January−June 2022; B.1.1.529, Omicron variant, n = 41) epidemiological waves in Hungary, and presented >4 weeks after the infection with post-COVID−19 symptoms at the Department of Pulmonology, Semmelweis University. Sleep-wake disturbances were assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. PSQI score >5 was considered as poor sleep quality. Results: Fatigue was the most common post-COVID−19 symptom for all three variants (61.7−64.8−65.9%). Over successive epidemiological waves, the occurrence of dyspnea decreased, whereas cough and palpitations increased. Comparing the subgroups based on the PSQI score, fatigue was more frequent in poor sleepers for the Alpha and Delta variants, and remained common (≥60%) for the Omicron variant, regardless of sleep quality. Cough and dyspnea were more frequent in poor sleepers for all three variants. Tachycardia was rare (<25%) for the Alpha variant, frequent (50%) among poor sleepers for the Delta variant, and consistently high (≥50%) for the Omicron variant, regardless of sleep quality. Our sleep-wake rhythms analysis revealed a delayed bedtime for the Omicron variant, an earlier wake-up time for the Alpha variant, and prolonged sleep latency with reduced sleep duration across all three variants in poor sleepers. Conclusion: Our study confirms the variant-dependent heterogeneity of post-COVID−19 symptoms and sleep-wake disturbances. Understanding the relationship between post-COVID−19 complications and viral variants may help elucidate the significance of SARS-CoV-2 genetic changes. Orv Hetil. 2025; 166(21): 817–825.