Biomarkers of aging. Part 1. General state of the problem and approaches to assessing biological age

Given the heterogeneity of the aging process for various tissues, organs and systems of a person and significant differences in the rate of aging between people, an objective idea of the biological age — individual rates of aging is of great clinical importance. Identification of reliable biomarkers capable of predicting the aging profile and the risk of developing age-related pathology can play a key role in the prevention of accelerated aging, geroprotective therapy and timely diagnosis and treatment of age-associated diseases. By now, a wide range of biomarkers of aging has been developed at the cellular, organ and molecular levels. Based on these biomarkers, models of “biological clocks” (phenotypic, epigenetic, immune, metabolic and many others) have been proposed, which, with varying degrees of accuracy, make it possible to determine a person’s biological age and the risks of diseases of specific organs and systems. Combinations of different types of biomarkers can be used to assess the potential for health and healthy longevity in humans and serve as objective criteria for the effectiveness of geroprotective strategies when testing new methods and technologies. However, today very high demands are placed on biomarkers of aging, which, unfortunately, the proposed markers and models do not yet fully meet. It is noted that since most modern biomarkers reflect changes that are a consequence of aging, but not its cause, which in turn limits the accuracy of the biological clock and its clinical significance. This determines the relevance of the development of new, accessible, non-invasive, sensitive to age-related changes and “reliable” biomarkers of aging, which will be useful for the early prevention of age-related diseases. This part of the review provides a brief excursion into the state of the problem of predicting biological age and a description of approaches to biological clock models. The second part of the review will be devoted to markers of normal and pathological aging of the retina and the problem of predicting age-associated pathology of the visual system. The fundamental knowledge about biological age can be applied to promising research in ophthalmology, in particular with the aim of developing new biomarkers of retinal aging.

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