Abstract
The need to monitor the aging process as a risk factor for disease and mortality beyond chronological age (CA) has led to numerous investigations into the estimation of the biological age (BA) of individuals. However, the accuracy of BA estimation tools is often judged by their ability to approximate CA, questioning their value in capturing the variance in health status and thus correctly estimating BA. Their biological relevance is often assessed in relation to health outcomes or mortality, underexploiting their potential for real-time monitoring of BA. Furthermore, their complexity may limit their clinical translation to large populations. Here, we describe the gene expression-based age monitoring Clock (GamC), a simple biomarker of aging (BOA), and characterize its biological relevance with synchronous cardiovascular (CV) health-related functional data. GamC is calculated from the expression levels of three genes consistently dysregulated with age in blood (ABLIM1, CCR7, and LEF1). GamC shows moderate but reliable association with CA in three independent cohorts, supported by transcriptome-wide changes. It demonstrates specialized biological meaning, as it specifically describes current physical activity levels, but poorly correlates with autonomic nervous system function, both age-related factors associated with CV health. Finally, it expresses BA monitoring capacity by modestly responding to an effective exercise-based intervention in centenarians. In conclusion, GamC is proposed as a simple and affordable candidate BOA for reporting the individuals' current CV health-related BA, thus promoting its broad translation and application into measures aimed at promoting healthy aging in relation to CV health, the leading cause of death worldwide.