Effects of exercise training on brain metabolism and cognitive functioning in sleep apnea

Impaired glucose metabolism reflects neuronal/synaptic dysfunction and cognitive function decline in patients with obstructive sleep apnea (OSA). The study investigated the extent to which exercise training (ET) improves cerebral metabolic glucose rate (CMRgl) and cognitive function in patients with OSA. Patients with moderate to severe OSA were randomly assigned to ET (3 times/week, n = 23) or no intervention (control, n = 24). Echocardiography and apolipoprotein ε4 (APOEε4) genotyping were obtained at baseline. Both groups underwent cardiopulmonary exercise testing, polysomnography, cognitive tests, brain magnetic resonance imaging, and 18 F-fluoro-2-deoxy- d -Glucose positron emission tomography ( 18 FDG-PET) at baseline and study end. Compared with control, exercise-trained group had improved exercise capacity, decreased apnea–hypopnea index (AHI), oxygen desaturation and arousal index; increased attention/executive functioning, increased CMRgl in the right frontal lobe ( P