Establishment and validation of an Alzheimer’s disease diagnostic model on the basis of exhaled volatile organic compound characteristics

(P < 0.001). The AD diagnostic model had an accuracy of 0.93 in the identification cohort according to internal validation and 0.75 in the validation cohort for external validation. The model for discriminating AD dementia patients from non-AD dementia patients had an accuracy of 0.90. Fourteen of the 60 AD-specific VOCs were retrieved from the HMDB, from which the three most significant metabolic pathways were identified, namely, butyrate metabolism, pyruvate metabolism, and glycolysis/gluconeogenesis. These results indicate that exhaled VOC measurement may be a promising approach for diagnosing and differentiating AD, but further validation is needed.