Progress in biological age research

Abstract

Biological age (BA) is a common model to evaluate the function of aging individuals as it may provide a more accurate measure of the extent of human aging than chronological age (CA). Biological age is influenced by the used biomarkers and standards in selected aging biomarkers and the statistical method to construct BA. Traditional used BA estimation approaches include multiple linear regression (MLR), principal component analysis (PCA), Klemera and Doubal’s method (KDM), and, in recent years, deep learning methods. This review summarizes the markers for each organ/system used to construct biological age and published literature using methods in BA research. Future research needs to explore the new aging markers and the standard in select markers and new methods in building BA models.

Sex and gender correlates of sexually polymorphic cognition

“…Although sex and gender factors other than birth-assigned sex did not strongly predict fine motor performance, age proved to be a highly significant predictor, in line with what has been observed in the literature [ 186 , 187 ]. In the same way as birth-assigned sex and sex hormones, age can be considered a biological variable [ 188 ]. Sex hormones interact with age and should be considered in future SPC studies [ 10 ].…”

Progress in the study of aging marker criteria in human populations

“…One of the main criteria for selecting aging markers is that they should be quantitative ( 29 , 67 ). Klemera and Doubal proposed using mathematical modeling to elaborate the association between CA and BA ( 12 , 70 ), which have a high, independent, and quantitative correlation ( 37 , 49 , 59 , 71 , 72 ). Aging markers can quantitatively assess the aging process and the degree of delayed aging, potentially assess the risk of aging-related diseases and provide direction for personalized interventions ( 52 , 64 , 73 ).…”

“…Previous studies have also explored different methods for screening biomarkers. In addition to statistical correlation, other noncorrelations, exponential correlations, power correlations and even some noncorrelations that are tried to be applied in the aging process can be used as aging markers ( 12 , 90 ). In addition to applying principal component or multivariate linearity after traditional dimensionality reduction, new machine learning methods may provide new ideas, such as using importance ranking ( 91 ).…”

“…CA is inadequate in assessing the aging process and aging rate of individuals ( 12 , 96 , 97 ). Thus, alternative indicators are needed to select appropriate aging markers, accurately evaluate and detect high-risk individuals, and intervene early to help improve the quality of survival and prolong the life span and healthy lifespan of patients ( 12 , 98 , 99 ). Therefore, it is critical to screen for appropriate and prospective markers.…”

There are multiple clocks that time us: Cross-sectional and longitudinal associations among 14 alternative indicators of age and aging

“…It is worth noting that certain associations between age indicators have been studied more extensively, whereas associations between other indicators remain largely unexplored. For example, several studies have investigated associations between indicators of aging developed from genetic, epigenetic, and clinical laboratory data 10,27 . Similarly, biological aging has been linked to cognitive and physical aging.…”