The metabolic topography of normal aging

Area of Science:

• Neuroscience
• Radiology
• Gerontology

Background:

• Normal aging is characterized by the degeneration of specific neural systems.
• Understanding the metabolic changes associated with aging is crucial for identifying biomarkers.

Purpose of the Study:

• To explore the metabolic topography of normal aging using [18F] fluorodeoxyglucose (FDG)/positron emission tomography (PET).
• To identify age-related metabolic profiles and assess their validity as aging markers.

Main Methods:

• Utilized FDG/PET to measure global and regional glucose metabolic rates (GMR and rCMRglc) in two independent groups of normal subjects.
• Applied the Scaled Subprofile Model (SSM) to regional metabolic data to identify age-related topographic profiles.
• Correlated subject scores for identified profiles with chronological age in normal populations and compared with Parkinson's disease patients.

Main Results:

• Two significant age-related topographic profiles were identified: one with relative frontal hypometabolism and another with relative basal ganglia hypermetabolism.
• Both profiles showed significant correlations with chronological age in normal subjects.
• A shared metabolic topography was observed between normal aging and Parkinson's disease, particularly involving the basal ganglia.

Conclusions:

• Healthy aging is associated with reproducible metabolic covariation profiles in specific neural systems.
• FDG/PET imaging can serve as a valuable metabolic marker for the normal aging process.
• Metabolic changes in aging may share similarities with neurodegenerative conditions like Parkinson's disease.