Age factor in clinical laboratory diagnostics: proxy diseases of aging and reference intervals

Age-associated diseases (AAD) remain an important medical and social problem. In relation to a group of diseases whose pathogenesis is similar to the main mechanisms of aging, the term «proxy diseases of aging» has been proposed. However, there are no generally accepted and standardized criteria for identifying a separate group of diseases associated with aging processes. Existing criteria are based on epidemiological data, laboratory confirmation of the relationship between individual diseases and aging processes remains important. The aim of the study. Calculate the reference interval (RI) in a subpopulation of middle-aged individuals with AAD and compare with the general population of individuals of different age groups. Material and methods. The materials for the study were anonymized retrospective laboratory data for 2016—2019. The RI was calculated using the Refine statistical approach in a subpopulation of middle-aged people with AAD, as well as four age populations (young, middle, elderly and senile age) — comparison groups. Results. Statistically significant RI changes for the AAD subpopulation compared to the general middle-aged population were characteristic of glucose, cholesterol and LDL. In terms of concentration, the general population observed a tendency to change the RI characteristic of the older age group. However, the opposite picture was observed for ALT: the reference values in the subpopulation of proxy diseases increased, which is not typical for the elderly. No significant changes were found for the remaining analytes. Conclusion. Thus, in the subpopulation of people with AAD, a statistically significant RI bias was observed characteristic of the older age group only for individual analytes. The discovered patterns do not allow to draw unambiguous conclusions about the presence of a connection between the studied group of diseases with aging processes, this problem requires further research.