Effects of aging become more evident after 60 – 04/11/2023 – Equilíbrio

A study carried out with 118 healthy people of different age groups shows that it is from the age of 60 that the damage caused by aging in the control of heart rate at rest and in cardiorespiratory fitness becomes more evident.

This means that there are more visible changes in the body’s ability to capture (respiratory system), transport (cardiovascular system) and consume (muscles) oxygen during physical exercise. However, certain changes were observed in the metabolic profile, that is, in the concentration of substances in the blood, which apparently are related to the mitigation of the deleterious effects of senescence.

“Studying aging is important, as it causes changes in several of our organic systems. Metabolism has been extensively studied, as well as cardiac autonomic modulation [o controle da frequência cardíaca pelo sistema nervoso] and cardiorespiratory fitness, however, almost always in isolation”, says Aparecida Maria Catai, professor at UFSCar (Federal University of São Carlos) and research coordinator.

“In our study, we sought to investigate the changes resulting from the aging process in an integrated way. By analyzing these three components concomitantly, we discovered a possible turning point of aging at 60 years of age. Although senescence is a process that lasts decades, it is mainly after the age of 60 that the changes in the three analyzed components become more significant”, says the researcher.

Published in the magazine Scientific Reportsthe study was supported by FAPESP through a Thematic Project.

“Over time, the organism, even in healthy people, is showing some compromises. Because of this, some ‘physiological adjustments’ are being made so that it remains in balance [homeostase]. However, these mechanisms are limited and are exhausted with advancing age. We identified in this study that some alterations in the serum levels of certain metabolites may be related to these homeostatic mechanisms”, indicates Étore de Favari Signini, FAPESP doctoral fellow and first author of the article.

Thus, the researchers observed that some metabolites may be associated with the mitigation of the deleterious effects of aging.

“It is a significant increase, in the range between 60 and 70 years, in serum levels of hippuric acid, a metabolite associated with a number of different functions, including the diversity of the intestinal microbiota and metabolic health”, explains the researcher. The finding may contribute to new strategies aimed at reducing the deleterious effects of aging.

The researchers point out that, although the increase in this metabolite may indicate impaired kidney function, recent studies have proposed that hippuric acid may be a marker and mediator of metabolic health, and may be related to the complexity of the intestinal microbiota (with a direct influence on the absorption of nutrients in the intestine) and a possible protective effect on pancreatic beta cells.

“Since these were apparently healthy elderly people, with no indication of renal impairment, we suggested that the increase in hippuric acid would be linked to the enrichment of the intestinal microbiota and, consequently, to better absorption of nutrients in the intestine. And we know that the better the intestinal absorption of nutrients, considering the context of aging, better the body’s health in general”, he says.

Another important aspect investigated by the researchers was the reduction of essential amino acids, such as valine, leucine and isoleucine – known by the acronym BCAAs (which in English means branched chain amino acids).

“The decline of BCAAs in healthy aging may be linked to the body’s strategy to preserve itself. We know that BCAAs are directly linked to protein synthesis. And, with aging, anabolic activity declines”, he says.

Signini points out that the benefits of supplementing BCAAs in the elderly, by favoring protein synthesis, is still a much-discussed subject. “Reduced anabolic activity has also been touted to some extent as beneficial in some studies,” he says.

“Research has pointed out that the accentuated anabolic activity in the context in which there are several compromises in the cell machinery, such as, for example, in the function of organelles and enzymes, can bring unwanted consequences, including cancer”, he completes.

Methodology

The aim of this study was to evaluate issues related to metabolism, cardiac autonomic modulation and cardiorespiratory fitness in 118 individuals divided into five age groups (20 to 29 years old, 30 to 39 years old, 40 to 49 years old, 50 to 59 years old, and 60 to 70 years old). . Only apparently healthy participants were included in all groups, that is, without a diagnosis of cardiovascular, respiratory or metabolism-related impairment, such as metabolic syndrome, obesity or diabetes. In addition to going through a rigorous battery of exams and tests, the volunteers were also not allowed to take controlled medications, such as, for example, for hypertension.

To assess cardiorespiratory fitness, all performed the cardiopulmonary exercise test, which allows measuring the maximum consumption of oxygen. Analyzes on cardiac autonomic modulation were performed by measuring the variability of cardiac periods, at rest and with individuals in the supine position (lying on their backs). Metabolism was investigated by means of metabolomics (analysis of the set of metabolites present), from blood serum samples.

These analyzes were conducted in the Physiotherapy and Chemistry departments at UFSCar, in laboratories coordinated by Catai, Regina Vincenzi Oliveira and Antonio Gilberto Ferreira.