In vivo biomarkers of structural and functional brain development and aging in humans. (October 2020) - Franke, K.
Highlights: For brain aging, phenotypic-related markers appear superior to mechanistic markers. Telomere length in peripheral leukocytes is not yet suitable for estimating brain age. Accuracy of MRI-based brain age prediction is 1y for development and 4.3y for aging. Heart rate variability determines fetal brain development with an accuracy of 3wG. Cerebral information capacity shows potential to determine functional brain age. Abstract: Brain aging is a major determinant of aging. Along with the aging population, prevalence of neurodegenerative diseases is increasing, therewith placing economic and social burden on individuals and society. Individual rates of brain aging are shaped by genetics, epigenetics, and prenatal environmental. Biomarkers of biological brain aging are needed to predict individual trajectories of aging and the risk for age-associated neurological impairments for developing early preventive and interventional measures. We review current advances of in vivo biomarkers predicting individual brain age. Telomere length and epigenetic clock, two important biomarkers that are closely related to the mechanistic aging process, have only poor deterministic and predictive accuracy regarding individual brain aging due to their high intra- and interindividual variability. Phenotype-related biomarkers of global cognitive function and brain structure provide a much closer correlation to age at the individual level. During fetal and perinatal life, autonomic activity is a unique functional marker of brain development. The cognitive and structural biomarkers also boast high diagnostic specificity for determining individual risks for neurodegenerative diseases.