Altered brain glucose metabolism and connectivity in young adults with obstructive sleep apnea

INTRODUCTION: Obstructive sleep apnea syndrome (OSAS) is a recognized risk fac-tor for neurodegenerative disorders. However, a causal link between OSAS and brain damage has yet to be established. METHODS: Thirty cognitively normal patients with moderate-to-severe OSAS, free from systemic or neurological comorbidities, were enrolled and underwent18F-fluorodeoxyglucose positron emission tomography imaging. Their scans were compared to those of cognitively normal, OSAS-free controls from the Alzheimer’s Disease Neuroimaging Initiative database. Additional analyses included commonality map-ping, correlations with polysomnographic parameters, and seed-based metabolic connectivity of major resting-state networks. RESULTS: Group-level analyses showed fronto-parietal glucose hypometabolism and cerebellar glucose hypermetabolism in patients with OSAS compared to con-trols. Cerebellar glucose hypermetabolism was associated with reduced rapid eye movement sleep latency and duration. Seed-based connectivity analysis revealed alterations in attentional and limbic networks. DISCUSSION: Moderate-to-severe OSAS may represent a cause of brain dysfunc-tion, highlighting the importance of its early diagnosis and appropriate treatment to prevent worsening brain damage and possible future neurodegenerative processes.