Differences in health status among individuals at older ages are the result of genetic predispositions and lifelong physiological responses to lifestyle, diet, or sleep quality. An international team, with the participation of the Superior Council for Scientific Research (CSIC), suggests two ways of estimating biological age with greater predictive power than existing ones and synthesizing information on health measures such as height, weight or blood pressure. The work, published in the journal Nexus PNASshows that biological age can predict a person’s life expectancy.
“Have one Biological age greater than chronological carries a higher risk of dying at an early age. The calculation of biological age is relatively easy, as it uses information obtained routinely: height, weight, blood pressure, and biochemical measurements of the blood, such as glucose or cholesterol. This can help early diagnosis of physiological deterioration and anticipate potential health problems and other underlying health conditions,” he says. Alberto Palloni, Researcher at CSIC at the Institute of Economics, Geography and Demography.
The research proposes two forms of estimation: dependent estimation and non-dependent estimation. In both cases, biological deterioration is achieved through a structural equation model (a multivariate statistical analysis technique) and is associated with additional information.
Calculating biological age is relatively easy because it uses information that is routinely obtained: height, weight, blood pressure, and biochemical measurements of the blood, such as glucose or cholesterol.
“In dependent estimation, biological deterioration is associated with the risk of dying, so the resulting biological age is a very accurate indicator of premature death. This form of estimation makes it possible to associate biological deterioration not only with the risk of dying, but also with other factors. indicators of future diseases, for example, the risk of having a disability or cardiovascular disease. In turn, in the non-dependent estimation, biological deterioration is associated with chronological age to estimate biological age, it does not depend on additional information”, points out the CSIC researcher.
The impact of older biological age
In the work, in which, in addition to the CSIC, scientists from the University of California at Los Angeles (UCLA) and the University of Wisconsin participate, the largest health database in the United States, the National Health and Nutrition Examination Survey, which includes information on 9,389 men and women between 30 and 75 years old. These individuals were interviewed between 1988 and 1994 and during these years different health measures were taken. In addition, they were followed until December 2015 to find out how many of them had died.
“The analyzed data suggest that physiological deterioration progresses more rapidly among women, people with less education, people of Mexican origin and non-Hispanic Afro-descendants in the United States, that is, the most disadvantaged individuals have a higher biological age and, therefore, therefore, an accelerated aging”, comments Hiram Beltran-Sánchez, professor in the Department of Community Health Sciences at UCLA. Among women, for example, the risk of dying increases by 129% for each year of biological age greater than chronological age. For men, the risk is slightly lower, around 124%.
The analyzed data suggest that physiological deterioration progresses more rapidly among women
The results, which were obtained under the ERC Advanced Grant project THREW AWAYled by the CSIC researcher, provide relevant information about the life expectancy after 65 years. “From that age onwards, when the biological age exceeds the chronological age by one year, it implies a reduction in life expectancy by around two years. If the biological age is five years older, the decrease is even greater, living on average nine years less. The surprising thing was to see how small increases in biological age in relation to chronological age translate into a greater risk of dying,” says Beltrán-Sánchez.
Future illnesses and early mortality
Biological indicators of age are already beginning to be used in the clinical area. “Those using biological information like the one we propose and epigenetic indicators have been implemented as alternative measures of people’s biological age. These indicators, often called biological clocks, are used as measures of the possible physiological deterioration that the patient has accumulated and would be related to the development of future diseases,” says Palloni.
Although the study does not include epigenetic markers in estimating biological age, the authors indicate that their method has the potential to aggregate such information and, thus, obtain greater prediction accuracy.
