Exploring domains, clinical implications and environmental associations of a deep learning marker of biological ageing

Deep Neural Networks (DNN) have been recently developed for the estimation of Biological Age (BA), the hypothetical underlying age of an organism, which can differ from its chronological age (CA). Although promising, these population-specific algorithms warrant further characterization and validation, since their biological, clinical and environmental correlates remain largely unexplored. Here, an accurate DNN was trained to compute BA based on 36 circulating biomarkers in an Italian population (N = 23,858; age >= 35 years; 51.7% women). This estimate was heavily influenced by markers of metabolic, heart, kidney and liver function. The resulting Delta age (BA-CA) significantly predicted mortality and hospitalization risk for all and specific causes. Slowed biological aging (Delta age < 0) was associated with higher physical and mental wellbeing, healthy lifestyles (e.g. adherence to Mediterranean diet) and higher socioeconomic status (educational attainment, household income and occupational status), while accelerated aging (Delta age > 0) was associated with smoking and obesity. Together, lifestyles and socioeconomic variables explained similar to 48% of the total variance in Delta age, potentially suggesting the existence of a genetic basis. These findings validate blood-based biological aging as a marker of public health in adult Italians and provide a robust body of knowledge on its biological architecture, clinical implications and potential environmental influences.

Automated summary

The use of Deep Neural Networks in estimating Biological Age has shown promise in an Italian population, with markers of metabolic, heart, kidney, and liver function heavily influencing the estimated age. The difference between Biological Age and Chronological Age has been linked to mortality, hospitalization risks, lifestyles, and socioeconomic status, with genetic factors potentially playing a role in the variance of Biological Age.