[Theory of resilience in geriatric medicine.]

This review examines current perspectives on the theory of resilience as a promising concept in geriatrics and longevity medicine. Modern data on the biological mechanisms of aging, risk factors for age-associated diseases, the concept of biological age, epigenetic clocks, and proxy diseases of aging were analyzed. It has been demonstrated that chronological age does not adequately reflect individual differences in aging rates and functional status. Therefore, particular importance is attributed to integrated indicators capable of assessing adaptive reserves and the organism's resistance to age-related changes. The review discusses the potential application of epigenetic clocks as molecular biomarkers of biological aging, as well as the role of sarcopenia, frailty, cognitive impairment, and metabolic disorders as proxy diseases of aging. These conditions are shown to reflect the systemic nature of age-related changes and to be associated with decreased functional independence and increased mortality risk. Resilience is considered a comprehensive proxy clinical characteristic integrating functional, cognitive, metabolic, and psychosocial aspects of aging. The use of resilience may facilitate early risk stratification, personalization of preventive interventions, and monitoring of the effectiveness of longevity medicine programs. The concept of age-related viability represents a promising direction in modern geriatrics and requires further standardization and clinical validation.