Methods for assessing biological age: relevance, clock types, and clinical significance

Over the past century, humanity has witnessed an unprecedented increase in life expectancy, which has naturally led to global population aging. Paradoxically, despite the impressive achievements of modern medicine, the prevalence of age-related noncommunicable diseases continues to steadily increase. The fundamental goal of longevity medicine interventions is not simply to increase the number of years lived, but to significantly extend the healthy lifespan (Healthspan), slow the rate of biological aging, and improve quality of life, regardless of an individual’s chronological age. In this context, aging biomarkers represent critical tools for achieving these goals. Biological age is considered by the modern scientific community as the most promising integrated indicator combining biomarker signatures and possessing clinical and prognostic significance in longevity medicine. Epigenetic clocks, based on a thorough analysis of DNA methylation patterns, are currently recognized as the gold standard for quantitative assessment of biological age. Among the most thoroughly studied and validated models are the Horvath clock, the Hannum clock, the PhenoAge formula, the GrimAge formula, and the DunedinPACE formula, each with specific advantages in different clinical contexts. At the same time, the dynamics of many biomarkers throughout the life cycle are distinctly nonlinear and exhibit complex patterns of interaction with a nonlinear increase in mortality and the risk of developing age-associated pathologies. Therefore, the implementation of artificial intelligence technologies for multimodal data analysis opens up fundamentally new prospects for the creation of highly accurate and personalized models for assessing biological age.