[Evaluation of the immunological profile of older adults according to Brazilian regions: results of ELSI-Brazil].

Immunosenescence refers to the changes in the immune system with aging, including the increase in inflammatory biomarkers, a phenomenon known as Inflammaging, which is related to the emergence of diseases associated with aging. This study aimed to describe the distribution of immunological biomarkers in the five Brazilian regions and to estimate the predicted probabilities of their concentrations in the tertiles of distribution, according to geographic regions. Serological samples from 2,111 participants (≥ 50 years) collected at the baseline (2015/2016) of ELSI-Brazil were analyzed. The geographic regions (North, Northeast, Central-West, Southeast, and South) were the exposure of interest for the study, and potential confounding factors included age, sex, educational level, area of residence, alcohol and tobacco consumption, physical activity, and self-reported medical diagnoses of hypertension, diabetes, asthma, arthritis, and cancer. The predicted probabilities of biomarker concentrations in each tertile were estimated using multinomial logistic regression models, adjusted for confounders. Notably, the North and Northeast regions had higher serum levels, while the Central-West Region had lower levels, suggesting differences in immunobiography, which may be the result of different environmental, socioeconomic, and infectious exposures throughout life. However, the reasons for these differences have not yet been elucidated and need to be investigated in further studies.