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Results for “Biological Aging”

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At least 19 recordsLinked to original sources

PubMed1986

[Results of experimental gerontology with respect to biological age].

Biological age may be defined as the state of the organism as a whole which is characteristic of the respective chronological age. Objective estimates of biological age are usually obtained by multiple regression analysis of a greater number of age parameters. However, this procedure should be based on a firm knowledge of the regularities of multicellular ageing. By means of a long-term study in male rats regularities of biological ageing have been demonstrated using multiple regression analysis, factor analysis and discriminant analysis. The multiple regression model pointed to an exponential relation between chronological and biological age. By factor analysis it has been shown that the change of the parameters represents to various extents primary ageing and system-specific secondary ageing. The results of discriminant analysis reveal a change in the ageing pattern during senescence. Consequently, test batteries for the objectivation of influences on the rate of ageing should be adapted to the respective phase of ageing in order to obtain maximum sensitivity.

Aging↗

PubMed1989

Improving the precision of biological age determinations. Part 1: A new approach to calculating biological age.

In calculating biological age, almost all prior studies used multiple regression of chronological age on scores of biomarkers of aging. Multiple regression is invalid for this purpose for three, and in some circumstances four, reasons. These are: a) weighting of the contribution of each biomarker's scores according to strength of association with chronological age; b) regression of calculated ages to sample mean age and the inadequacy of proposed corrections; c) frequent occurrence of regression coefficients whose sign equates poorer adult performance on a test to younger biological ages; and d) multicollinearity when lung function scores and height are on the same side of the regression equation. An alternative method for calculating biological age is outlined. Regression to sample mean age and its solution are illustrated on data for highest audible pitch, one of 12 biomarkers measured in a study of 2462 office workers. Prior published studies employing multiple regression to calculate biological age appear to have been in error.

Adult↗

PubMedDate not supplied

[Determination of biologic aging within the scope of the Halberstadt Gerontologic Study. 5. Correlation of physiologic parameters with calendar and biologic age. 1. Relative cell number of peripheral B and T lymphocytes].

There can occur considerable differences between the individual chronological age and the biological (functional) age of individuals. The relationship between chronological age, biological age and the relative number of T- and B-lymphocytes is examined. Whereas the number of B-lymphocytes does not show a dependence of biological age, the number of T-lymphocytes shows significant modifications dependent of biological age.

Aging↗

PubMed2026

Early life sugar rationing and ageing related diseases, biological ageing and mortality.

Early-life nutrition may influence lifelong ageing, yet human evidence is scarce. Using Britain's postwar sugar rationing as a natural experiment, we examine its long-term effects in 64,809 United Kingdom Biobank participants. Exposure to sugar rationing during the first 1,000 days of life is associated with a 9% lower incidence of hallmark-related disease, with a hazard ratio of 0.91 and a 95% confidence interval of 0.88-0.94, and a 19% lower risk of all-cause mortality, with a hazard ratio of 0.81 and a 95% confidence interval of 0.69-0.93. Mediation analysis indicates that the survival association is statistically mediated, by approximately 60%, through differences in incident hallmark-related disease. Rationed individuals show 1.0-1.2-year younger biological ages across multiple clocks and lower organ ages, particularly in the lung, heart, and liver. Proteomic profiling identifies 47 altered proteins, with enrichment of adenosine monophosphate-activated protein kinase and longevity pathways and suppression of mechanistic target of rapamycin signaling. These findings are consistent with international recommendations to limit free or added sugars from the World Health Organization, United States Dietary Guidelines, and American Heart Association, and may inform policy discussions related to sugar taxation and infant food and marketing policies under the United Nations 2030 Agenda.

Humans↗

PubMed1988

In defense of the concept of biological aging measurement--current status.

Biological age is the objective assessment of a person's health status. Theoretically, a 'normal' person's biological age--in terms of appearance, performance, and functional capacity--should be the same as his chronological age. Many scientists have attempted to develop systems to accurately determine individuals' biological age. Typically, the approach is to select a battery of test parameters comprised of tests which correlate closely with chronological age. This approach assumes that those traits which vary most closely with age are the best indicators of the aging process. The goal has been to compare an individual to his chronological age peers to determine his relative aging status. Two papers (Costa and McCrae, 1980 and 1985) that criticize this concept and approach have heretofore gone unanswered. Lack of published dissent has caused many gerontologists to assume that Costa and McCrae are correct in their assertions that biological age cannot be measured and is not a valid concept. Consequently, some scientists have been reluctant to pursue research in this area. The purposes of this paper are: to critically evaluate the questions raised by Costa and McCrae; to reaffirm the validity of the concept of biological age; and to urge continued research in this most important subject.

Aged↗

PubMedDate not supplied

Biological age in Italian adults: influence of social and behavioural factors.

This study investigated changes with age in biological characters in a sample of 571 Italian males aged between 25 and 64 years. The influence of environmental factors on inter-individual variation in physical efficiency was examined by biological age determination. Data on somatometric, physiometric, haematological variables, personal background and lifestyle, were collected. Principal-component analysis was used to study the patterns of relationship in these characters. Over 45% of the total variance is explained by the ageing process, but the secular trend also affects the variation of height and of height-related characters. Changes with age were investigated clustering the sample in eight 5-year classes: results are in agreement with previous findings in Western populations. Ten selected variables were transformed into biological age scores reflecting a man's status relative to his chronological age peers (Borkan and Norris 1980a). Biological age scores of subsamples characterized by different social and behavioural situations were compared. Occupation, educational level and physical activity seem to have the greatest influence on biological age status. The intensity or duration of some habits can induce a clear trend in biological age scores. Results suggest that the environmental influence could be related to the interindividual differences in physical efficiency and to the increase in variability with age observed for some characters.

Adult↗

PubMed1988

Assessment of biological age by principal component analysis.

A method of assessing biological age by the application of principal component analysis is reported. Healthy individuals (462) randomly selected from about 6000 men who had taken a 2-day health examination were studied. Out of the 30 physiological variables examined in routine check-ups, 11 variables were selected as suitable for the assessment of biological age based on the results of factor analysis and the physiological meaning of each test. This variable set was then submitted to principal component analysis, and the 1st principal component obtained from this analysis was used as an equation for assessing one's biological age. However, the biological age calculated from this equation is expressed as a score, so the estimated score was transformed to years (biological age) using the T-score idea. The biological age estimated by this method is practically useful and theoretically valid in contrast with the multiple regression model, because this approach eliminates and overcomes the following 2 big problems of the multiple regression model: (1) the distortion of the individual biological age at the regression edges; and (2) a theoretical contradiction in that a perfect model will merely be predicting the subject's chronological age, not his biological age.

Adult↗

PubMed1992

[Research on aging: biological perspectives].

Aging is a part of the continuous process from conception to death and is strongly modulated by environmental factors throughout the lifespan. Variability in functional capacity between different organs and between individuals therefore increases with aging. This review will discuss two tissues of importance for the fitness of the aging human being: connective tissue and bone. Connective tissues become stiffer with age, which can be mitigated by physical exercise. The physical-chemical stability of collagen is a precise measure for the functional age of the organism. While in the aged, the healing (formation of connective tissue scar) of uncomplicated incisional wounds is slightly impaired, the healing of ischemic wounds is endangered. The clinical observation that "simple" wounds also heal less well in the aged might be due to the presence of diseases with ischemia and other pathologies. During normal aging bone loses mass, structural continuity, and strength. When pronounced, these changes cause osteopenia and osteoporotic fractures. The age-adjusted incidence of osteoporotic fractures is increasing on account of changes in our lifestyle. Preventive efforts, with increased physical activity as the main feature, must be implemented to alter this trend. Our knowledge of the mechanisms of aging is not yet sufficient to formulate a policy containing preventive measures enabling man to achieve his maximum biological lifespan with good physical health and a high quality of life. Multidisciplinary efforts by biologists, clinicians and epidemiologists are warranted to achieve this goal.

Aged↗

PubMed1990

[Determination and assessment of biological age in 40-85-year-old persons].

Biological age was determined separately for men and for women in a series of 120 subjects (66 women) aged 40-85 years (mean age 66 +/- 11.6 years). The established biological age correlated significantly with the chronological age of the subjects investigated. For the calculation of functional age a battery of 10 tests covering 7 functional systems was developed to meet the requirements of the geriatrician and one of 6 tests covering 5 functional systems for the conditions of the general practitioner. The tests are undemanding as to time and procedure and reflect age and sex differences in the population of 40-85 year old people. A new method for the evaluation of biological age was suggested and used, namely the method of interval assessment and of correction of biological age with respect to the chronological age of the proband.

Adult↗

PubMed1990

[Biological age and longitudinal study of aging].

We assessed the biological aging status by multiple regression analysis of clinical parameters. Estimated ages of external appearance, physiological function, physical strength and general biological status were calculated. The aging grade was defined as the percent estimated age to chronological age. The aging grade was lower in the managers, and in nonsmokers. It was lower in subjects who drank a small amount of alcohol than in those who drank a large amount of alcohol or those who did not drink alcohol. We also studied the longitudinal changes of 27 clinical parameters. Physical, hematological and blood biochemical data were annually recorded for a 10-year period. Age-time matrix was made for each parameter and was analyzed in terms of aging, cohort and time, by utilizing [1] longitudinal, [2] cross-sectional and [3] time series approaches. The parameters that were considered to be affected by aging were right grip strength (reduced), and sedimentation rate (increased).

Adolescent↗

PubMed1986

[Significance of the determination of biological aging for medicine].

In the elaboration of methods of the determination of the biological age becomes evident that new approaches and models of thinking developed seem to require again to reason out the interdisciplinary position of gerontology. In the light of the results of clinical experimental examinations concerning the biological age which could be achieved by the traditional Leipzig gerontological school since Bürger's activities, the importance of biosocial norm values of age for multifarious theoretical and practical proceedings of medicine and their adjacent scientific fields is confirmed. Here the author sets out from the fact that it is possible nowadays to determine sufficiently and precisely the biological age of man by means of a multifactorial functional diagnostics. A phenotypical vitality measure, which takes into consideration the asynchronous biosocial dynamics of human ageing in the phase of development, maturity and involution, serves as criterion of the biological age. Thus there is the possibility to ascertain in all age-classes reference values ("normal values") for vitality and biological age which are obligatory according to sex. Here the gerontological research of the GDR may produce advances in international research. Furthermore the author elaborates the thoughts that in all phases of life the biological age represents a principal criterion of differentiation both in making the diagnosis by the physician and the judgment of the therapy ("revitalisation") and in the aptitude diagnostics for sports and regulation of training ("vitalisation"). From this aspect gerontology derives its specific importance as scientific theoretical link between medicine and sport sciences.

Aged↗

PubMed1981

[Problems of the assessment of biological age (author's transl)].

Biological age may be defined at the state of the organism as a whole which is characteristic of the respective chronological age. Usually, it is estimated by multivariate analysis of a battery of age parameters. However, this procedure requires the knowledge of the regularities of multicellular ageing since interferences about the behaviour of the total system from its subsystems may only drawn when the regularities of the total system are understood. By means of the ageing of the rat, the possibility is demonstrated to study these regularities by factor analysis. As a result, primary and system-specific secondary aging processes are postulated which are expressed to various extents in the individual age parameters.

Aging↗

PubMedDate not supplied

[The biological age of the respiratory system].

A model of the biological age of the respiratory system is described. The following biological age determinants are used: vital lung capacity, maximal breathing capacity, mid-expiratory flow rate, oxygen consumption. They commonly meet the requirements of the biological age measurement tests as well as reflect main symptoms of the respiratory system ageing. The proposed model has been used to study the peculiarities of the respiratory system ageing in the Abkhasian population and to assess the effect of smoking on this process.

Adult↗

PubMed2026

Sex-specific biological aging clocks across organs and omics.

Sex differentially shapes aging, neurodevelopment and neurodegenerative diseases such as Alzheimer's disease (AD). However, most biological aging clocks (artificial intelligence-predicted age minus chronological age) were trained on sex-pooled samples and implicitly assume sex invariance.Here we developed 38 sex-specific biological aging clocks across 15 organ systems. We first demonstrate the importance of sex-stratified training for constructing sex-specific healthy normative references and then reveal marked divergence between female and male clocks. Key genetic parameters and Mendelian randomization results indicate that organ-specific aging liability and its relationships to cardiometabolic, endocrine and mental traits are configured differently in females and males. Proteomic analyses identify distinct, organ-resolved synaptic, immune, vascular and metabolic networks that differentially track female and male biological aging. In longitudinal survival analyses, sex-specific clocks predict whole-body systemic diseases and all-cause mortality in a sex-dependent and organ-dependent manner. Further analyses reveal sex-dependent associations between the brain aging clock and cognitive decline trajectory during a preclinical AD clinical trial. Sex-stratified clocks may offer distinct value by defining biological age against sex-appropriate normative references and revealing sex-dependent genetic, molecular and clinical signatures that pooled models may obscure. Meanwhile, sex-pooled and sex-interaction approaches remain valuable, as human aging and disease also share fundamental biological similarities between females and males. Together, these findings reveal sex-specific biological aging signatures in aging, AD and systemic health, highlighting the need for explicitly sex-stratified modeling approaches.

Journal Article↗

PubMed1975

Current theories of biological aging.

Several lines of evidence have led to the notion that biological aging occurs as a result of changes in the information-containing molecules either at the genetic or epigenetic level. The error theory, the redundant message theory, the codon restriction theory, and the transcriptional event theory represent the major current conceptualizations of biological aging as held by most gerontologists. The finding that cultured normal human and animal cells undergo a finite number of population doublings in vitro has provided new insights into age changes at the cellular level. The number of mitotic events that cultured normal animal cells can undergo appears to be inversely related to the age of the donor. A direct proportionality exists, however, between the mean maximum life-span of a species and the number of population doublings that their cultured embryonic cells will undergo. The several biochemical decrements known to occur prior to the cessation of mitotic activity in vitro are thought to herald those manifestations of senescence seen in the whole animal. Yet to be explained is how those cell classes such as the germ plasm and continuously propagable cancer cells escape from the inevitability of biological aging.

Aging↗

PubMed1976

[Assessment of the biological age in the animal-experiment (author's transl)].

Experimental investigations of internal and external factors presumably influencing the aging process require an objective assessment of the biological age or vitality respectively by means of as many age parameters as possible. Using the rat, a valuable test animal in experimental gerontology, whose life expectancy of about 40 month allows longitudinal studies, a standard test programm for the estimation of the biological age has been developed. The age parameters used originate from investigations of 1. the tail tendon collagen, 2. the skin, 3. the aorta, 4. the ECG, 5. the lipofuscin content of brain and heart, 6. the tissue respiration of various organs, 7, the motor activity and 8. learning and memory. Using the above-mentioned age parameters a statistical measure for the biological age will be calculated by means of multivariate analysis and will allow the comparison of differeent age-and experimental-groups.

Aging↗

PubMed1985

A return to time, cells, systems, and aging: III. Gompertzian models of biological aging and some possible roles for critical elements.

In this paper, I continue my investigation into the modeling of senescence in biological hierarchies. Making use of my previous discussion on non-reestablishable biological components, I derive a mathematical model which has Gompertzian-like dynamics. I show how this model may be approximated, in certain instances, by a Gompertzian equation. I then demonstrate how our approach yields a biological interpretation for the parameters in the Gompertzian equation. I then demonstrate how changes in the parameter values may be interpreted in light of the biology. Subsequently, I review the literature on the allometry of aging, and I demonstrate how my reliability model may be used to obtain--in a qualitative manner--some of the lifespan curves found in the literature. I close my discussion by constructing a more complex reliability model which incorporates the deterministic failure of biological components with stochastic aspects of senescence.

Aging↗

PubMedDate not supplied

[Behavior of the biological aging index and serum lipids in treatment with X50].

Lipid metabolic disorders are clinical relevant for the middle and old age. The presented paper shows that decreased HDL-cholesterol and increased triglycerides enlarge the value of pre-ageing. Therefore is a lipid lowering treatment a special problem of gerontology. We have treated 15 patients (age 56.7 +/- 7.8 years) with hypercholesterolemia and hypertriglyceridemia with the new developed lipids regulans X50 = 1-benzyl-3-(1-carboxy-1-methylethoxy)-4-methylpyrazol. There was a significant decreases of serumtriglycerides (47%) in all patients. Half of the patients showed a significant decreases of total cholesterol (32%). Biological age index and biological age were not influenced. To demonstrate an influence of biological age there are needed longterm treatments in patients with lipid metabolic disorders.

Cholesterol↗