The top row compares the control group with the OSA group, and the bottom row compares the control group with the UPPP group and the no-surgery group. Alzheimer disease, vascular dementia, and other dementia occur more frequently in the OSA group than in the control group, whereas they occur less frequently in the UPPP group. OSA = obstructive sleep apnea, UPPP = uvulopalatopharyngoplasty.