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Gavrilov LA, Gavrilova NS. Trends in Human Species-Specific Lifespan and Actuarial Aging Rate. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:1622-1633. [PMID: 36717451 PMCID: PMC11090257 DOI: 10.1134/s0006297922120173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/16/2022] [Accepted: 11/16/2022] [Indexed: 01/15/2023]
Abstract
The compensation effect of mortality (CEM) was tested and species-specific lifespan was estimated using data on one-year age-specific death rates from the Human Mortality Database (HMD). CEM was confirmed using this source of the data and human species-specific lifespan estimates were obtained, which were similar to the estimates published before. Three models (Gompertz-Makeham, Gompertz-Makeham with mean-centered age, and Gompertz) produced similar estimates of the species-specific lifespan. These estimates demonstrated some increase over time. Attempts to measure aging rates through the Gompertz slope parameter led to the conclusion that actuarial aging rates were stable during most of the 20th century, but recently demonstrated an increase over time in the majority (74%) of studied populations. This recent phenomenon is most likely caused by more rapid historical decline of mortality at the younger adult age groups compared to the older age groups, thus making the age gradient in mortality steeper over time. There is no biomedical reason to believe that human aging rates accelerated recently, so that the actuarial aging rate is probably not a good measure of true aging rate (rate of functional loss). Therefore, better measures of aging rate need to be developed.
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Affiliation(s)
- Leonid A Gavrilov
- Academic Research Centers, NORC at the University of Chicago, 60637 Chicago, IL, USA.
- Institute for Demographic Research, Federal Center of Theoretical and Applied Sociology, Russian Academy of Sciences, Moscow, 109028, Russia
| | - Natalia S Gavrilova
- Academic Research Centers, NORC at the University of Chicago, 60637 Chicago, IL, USA
- Institute for Demographic Research, Federal Center of Theoretical and Applied Sociology, Russian Academy of Sciences, Moscow, 109028, Russia
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Zanotto L, Canudas-Romo V, Mazzuco S. A Mixture-Function Mortality Model: Illustration of the Evolution of Premature Mortality. EUROPEAN JOURNAL OF POPULATION = REVUE EUROPEENNE DE DEMOGRAPHIE 2021; 37:1-27. [PMID: 33597834 PMCID: PMC7865056 DOI: 10.1007/s10680-019-09552-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 12/11/2019] [Indexed: 11/30/2022]
Abstract
Premature mortality is often a neglected component of overall deaths, and the most difficult to identify. However, it is important to estimate its prevalence. Following Pearson's theory about mortality components, a definition of premature deaths and a parametric model to study its transformations are introduced. The model is a mixture of three distributions: a Half Normal for the first part of the death curve and two Skew Normals to fit the remaining pieces. One advantage of the model is the possibility of obtaining an explicit equation to compute life expectancy at birth and to break it down into mortality components. We estimated the mixture model for Sweden, France, East Germany and Czech Republic. In addition, to the well-known reduction in infant deaths, and compression and shifting trend of adult mortality, we were able to study the trend of the central part of the distribution of deaths in detail. In general, a right shift of the modal age at death for young adults is observed; in some cases, it is also accompanied by an increase in the number of deaths at these ages: in particular for France, in the last twenty years, premature mortality increases.
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Affiliation(s)
- Lucia Zanotto
- Department of Economics, Ca’ Foscari University of Venice, Venice, Italy
| | | | - Stefano Mazzuco
- Department of Statistical Sciences, University of Padua, Padua, Italy
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A 2D analysis of correlations between the parameters of the Gompertz-Makeham model (or law?) of relationships between aging, mortality, and longevity. Biogerontology 2019; 20:799-821. [PMID: 31392450 DOI: 10.1007/s10522-019-09828-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 07/25/2019] [Indexed: 12/23/2022]
Abstract
When mortality (μ), aging rate (γ) and age (t) are treated according to the Gompertz model μ(t) = μ0eγt (GM), any mean age corresponds to a manifold of paired reciprocally changing μ0 and γ. Therefore, any noisiness of data used to derive GM parameters makes them negatively correlated. Besides this artifactual factor of the Strehler-Mildvan correlation (SMC), other factors emerge when the age-independent mortality C modifies survival according to the Gompertz-Makeham model μ(t) = C+μ0eγt (GMM), or body resources are partitioned between survival and protection from aging [the compensation effect of mortality (CEM)]. Theoretical curves in (γ, logμ0) coordinates show how μ0 decreases when γ increases upon a constant mean age. Within a species-specific range of γ, such "isoage" curves look as nearly parallel straight lines. The slopes of lines constructed by applying GM to survival curves modeled according to GMM upon changes in C are greater than the isoage slopes. When CEM is modeled, the slopes are still greater. Based on these observations, CEM is shown to contribute to SMC associated with sex differences in lifespan, with the effects of several life-extending drugs, and with recent trends in survival/mortality patterns in high-life-expectancy countries; whereas changes in C underlie differences between even high-life-expectancy countries, not only between high- and low-life-expectancy countries. Such interpretations make sense only if GM is not merely a statistical model, but rather reflects biological realities. Therefore, GM is discussed as derivable by applying certain constraints to a natural law termed the generalized Gompertz-Makeham law.
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Janssen F, de Beer J. The timing of the transition from mortality compression to mortality delay in Europe, Japan and the United States. GENUS 2019. [DOI: 10.1186/s41118-019-0057-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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5
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Wagner P. Vitality heterogeneity in the Strehler-Mildvan theory of mortality. Math Biosci 2018; 300:27-35. [PMID: 29571812 DOI: 10.1016/j.mbs.2018.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 01/31/2018] [Accepted: 02/05/2018] [Indexed: 11/27/2022]
Abstract
In this paper the Strehler-Mildvan theory of mortality and aging is generalised to cover heterogeneity effects in the population. The theory is based on the concept of environmental shocks that cause death of an individual when exceeding its vitality. Heterogeneity is introduced via the value of the vitality of an individual at birth. The main result of the paper is an expression for the observed mortality rate of the heterogeneous population. This mortality rate grows according to Gompertz's Law at midlife-ages, then its growth declines, levelling off at high ages. This behaviour is qualitatively consistent with real mortality rates, which is illustrated for period data of Japanese females in the years 1947, 1967, 1987 and 2007. Finally, the duality between a continuous SM-version and the ρ - γ - Gompertz model is discussed.
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Affiliation(s)
- Peter Wagner
- Institut für Mathematik, Universität Rostock, Ulmenstr. 69, Haus 3, Rostock 18057, Germany.
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6
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Abstract
Abstract
We analyze human aging—understood as health deficit accumulation—for a panel of European individuals, using four waves of the Survey of Health, Aging and Retirement in Europe (SHARE data set) and constructing a health deficit index. Results from log-linear regressions suggest that, on average, elderly European men and women develop approximately 2.5 % more health deficits from one birthday to the next. In nonlinear regressions (akin to the Gompertz-Makeham model), however, we find much greater rates of aging and large differences between men and women as well as between countries. Interestingly, these differences follow a particular regularity (akin to the compensation effect of mortality) and suggest an age at which average health deficits converge for men and women and across countries. This age, which may be associated with human life span, is estimated as 102 ± 2.6 years.
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Zheng H, Yang YC, Land KC. Age-Specific Variation in Adult Mortality Rates in Developed Countries. POPULATION RESEARCH AND POLICY REVIEW 2016; 35:49-71. [PMID: 28133402 PMCID: PMC5270709 DOI: 10.1007/s11113-015-9379-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This paper investigates historical changes in both single-year-of-age adult mortality rates and variation of the single-year mortality rates around expected values within age intervals over the past two centuries in 15 developed countries. We apply an integrated Hierarchical Age-Period-Cohort-Variance Function Regression Model to data from the Human Mortality Database. We find increasing variation of the single-year rates within broader age intervals over the life course for all countries, but the increasing variation slows down at age 90 and then increases again after age 100 for some countries; the variation significantly declined across cohorts born after the early 20th century; and the variation continuously declined over much of the last two centuries but has substantially increased since 1980. Our further analysis finds the recent increases in mortality variation are not due to increasing proportions of older adults in the population, trends in mortality rates, or disproportionate delays in deaths from degenerative and man-made diseases, but rather due to increasing variations in young and middle-age adults.
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Modeling the fertility impact of the proximate determinants: Time for a tune-up. DEMOGRAPHIC RESEARCH 2015. [DOI: 10.4054/demres.2015.33.19] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Yashin AI, Arbeev KG, Arbeeva LS, Wu D, Akushevich I, Kovtun M, Yashkin A, Kulminski A, Culminskaya I, Stallard E, Li M, Ukraintseva SV. How the effects of aging and stresses of life are integrated in mortality rates: insights for genetic studies of human health and longevity. Biogerontology 2015; 17:89-107. [PMID: 26280653 DOI: 10.1007/s10522-015-9594-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/25/2015] [Indexed: 12/21/2022]
Abstract
Increasing proportions of elderly individuals in developed countries combined with substantial increases in related medical expenditures make the improvement of the health of the elderly a high priority today. If the process of aging by individuals is a major cause of age related health declines then postponing aging could be an efficient strategy for improving the health of the elderly. Implementing this strategy requires a better understanding of genetic and non-genetic connections among aging, health, and longevity. We review progress and problems in research areas whose development may contribute to analyses of such connections. These include genetic studies of human aging and longevity, the heterogeneity of populations with respect to their susceptibility to disease and death, forces that shape age patterns of human mortality, secular trends in mortality decline, and integrative mortality modeling using longitudinal data. The dynamic involvement of genetic factors in (i) morbidity/mortality risks, (ii) responses to stresses of life, (iii) multi-morbidities of many elderly individuals, (iv) trade-offs for diseases, (v) genetic heterogeneity, and (vi) other relevant aging-related health declines, underscores the need for a comprehensive, integrated approach to analyze the genetic connections for all of the above aspects of aging-related changes. The dynamic relationships among aging, health, and longevity traits would be better understood if one linked several research fields within one conceptual framework that allowed for efficient analyses of available longitudinal data using the wealth of available knowledge about aging, health, and longevity already accumulated in the research field.
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Affiliation(s)
- Anatoliy I Yashin
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA. .,The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Room A102E, Durham, NC, 27705, USA.
| | - Konstantin G Arbeev
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Liubov S Arbeeva
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Deqing Wu
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Igor Akushevich
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Mikhail Kovtun
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Arseniy Yashkin
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Alexander Kulminski
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Irina Culminskaya
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Eric Stallard
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Miaozhu Li
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA
| | - Svetlana V Ukraintseva
- The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, USA.,The Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, 2024 W. Main Street, Room A105, Durham, NC, 27705, USA
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Li T, Anderson JJ. The Strehler-Mildvan correlation from the perspective of a two-process vitality model. Population Studies 2015; 69:91-104. [PMID: 25633895 DOI: 10.1080/00324728.2014.992358] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The Strehler and Mildvan (SM) general theory of ageing and mortality provides a mechanism-based explanation of Gompertz's law and predicts a log-linear relationship between the two Gompertz coefficients, known as the SM correlation. While the SM correlation is supported by data from developed countries before the second half of the twentieth century, the recent breakdown of the correlation pattern in these countries has prompted demographers to conclude that SM theory needs to be reassessed. In this paper we use a newly developed two-process vitality model to explain the SM correlation and its breakdown in terms of asynchronous trends in acute (extrinsic) and chronic (intrinsic) mortality factors. We propose that the mortality change in the first half of the twentieth century is largely determined by the elimination of immediate hazards to death, whereas the mortality change in the second half is primarily driven by the slowdown of the deterioration rate of intrinsic survival capacity.
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Affiliation(s)
- Ting Li
- a Renmin University of China
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12
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Abstract
This study examines historical patterns of aging through the perspectives of cohort evolution and mortality selection, where the former emphasizes the correlation across cohorts in the age dependence of mortality rates, and the latter emphasizes cohort change in the acceleration of mortality over the life course. In the analysis of historical cohort mortality data, I find support for both perspectives. The rate of demographic aging, or the rate at which mortality accelerates past age 70, is not fixed across cohorts; rather, it is affected by the extent of mortality selection at young and late ages. This causes later cohorts to have higher rates of demographic aging than earlier cohorts. The rate of biological aging, approximating the rate of the senescence process, significantly declined between the mid- and late-nineteenth century birth cohorts and stabilized afterward. Unlike the rate of demographic aging, the rate of biological aging is not affected by mortality selection earlier in the life course but rather by cross-cohort changes in young-age mortality, which cause lower rates of biological aging in old age among later cohorts. These findings enrich theories of cohort evolution and have implications for the study of limits on the human lifespan and evolution of aging.
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Affiliation(s)
- Hui Zheng
- Department of Sociology, The Ohio State University, 107 Townsend Hall, 1885 Neil Avenue Mall, Columbus, OH, 43210, USA,
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13
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Kulminski AM. Unraveling genetic origin of aging-related traits: evolving concepts. Rejuvenation Res 2014; 16:304-12. [PMID: 23768105 DOI: 10.1089/rej.2013.1441] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Discovering the genetic origin of aging-related traits could greatly advance strategies aiming to extend health span. The results of genome-wide association studies (GWAS) addressing this problem are controversial, and new genetic concepts have been fostered to advance the progress in the field. A limitation of GWAS and new genetic concepts is that they do not thoroughly address specifics of aging-related traits. Integration of theoretical concepts in genetics and aging research with empirical evidence from different disciplines highlights the conceptual problems in studies of genetic origin of aging-related traits. To address these problems, novel approaches of systemic nature are required. These approaches should adopt the non-deterministic nature of linkage of genes with aging-related traits and, consequently, reinforce research strategies for improving our understanding of mechanisms shaping genetic effects on these traits. Investigation of mechanisms will help determine conditions that activate specific genetic variants or profiles and explore to what extent these conditions that shape genetic effects are conserved across human lives and generations.
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Affiliation(s)
- Alexander M Kulminski
- Center for Population Health and Aging, Duke University, Durham, North Carolina 27708, USA.
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Shaping human mortality patterns through intrinsic and extrinsic vitality processes. DEMOGRAPHIC RESEARCH 2013. [DOI: 10.4054/demres.2013.28.12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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15
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Yashin AI, Arbeev KG, Ukraintseva SV, Akushevich I, Kulminski A. Patterns of Aging-Related Changes on the Way to 100. ACTA ACUST UNITED AC 2012. [DOI: 10.1080/10920277.2012.10597640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
The ageing of the population is an issue in wealthy countries worldwide because of increasing costs for health care and welfare. Survival curves taken from demographic life tables may help shed light on the hypotheses that humans are living longer and that human populations are growing older. We describe a methodology that enables us to obtain separate measurements of scale and shape variances in survival curves. Specifically, 'living longer' is associated with the scale variance of survival curves, whereas 'growing older' is associated with the shape variance. We show how the scale and shape of survival curves have changed over time during recent decades, based on period and cohort female life tables for selected wealthy countries. Our methodology will be useful for performing better tracking of ageing statistics and it is possible that this methodology can help identify the causes of current trends in human ageing.
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Affiliation(s)
- Byung Mook Weon
- X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea
| | - Jung Ho Je
- X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea
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Yashin AI, Arbeev KG, Akushevich I, Kulminski A, Ukraintseva SV, Stallard E, Land KC. The quadratic hazard model for analyzing longitudinal data on aging, health, and the life span. Phys Life Rev 2012; 9:177-88; discussion 195-7. [PMID: 22633776 PMCID: PMC3392540 DOI: 10.1016/j.plrev.2012.05.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 05/15/2012] [Indexed: 01/10/2023]
Abstract
A better understanding of processes and mechanisms linking human aging with changes in health status and survival requires methods capable of analyzing new data that take into account knowledge about these processes accumulated in the field. In this paper, we describe an approach to analyses of longitudinal data based on the use of stochastic process models of human aging, health, and longevity which allows for incorporating state of the art advances in aging research into the model structure. In particular, the model incorporates the notions of resistance to stresses, adaptive capacity, and "optimal" (normal) physiological states. To capture the effects of exposure to persistent external disturbances, the notions of allostatic adaptation and allostatic load are introduced. These notions facilitate the description and explanation of deviations of individuals' physiological indices from their normal states, which increase the chances of disease development and death. The model provides a convenient conceptual framework for comprehensive systemic analyses of aging-related changes in humans using longitudinal data and linking these changes with genotyping profiles, morbidity, and mortality risks. The model is used for developing new statistical methods for analyzing longitudinal data on aging, health, and longevity.
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Affiliation(s)
- A I Yashin
- Center for Population Health and Aging, Duke University, Durham, NC 27708, United States.
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Yashin AI, Wu D, Arbeev KG, Stallard E, Land KC, Ukraintseva SV. How genes influence life span: the biodemography of human survival. Rejuvenation Res 2012; 15:374-80. [PMID: 22607627 DOI: 10.1089/rej.2011.1290] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND In genome-wide association studies (GWAS) of human life span, none of the genetic variants has reached the level of genome-wide statistical significance. The roles of such variants in life span regulation remain unclear. DATA AND METHOD A biodemographic analyses was done of genetic regulation of life span using data on low-significance longevity alleles selected in the earlier GWAS of the original Framingham cohort. RESULTS Age-specific survival curves considered as functions of the number of longevity alleles exhibit regularities known in demography as "rectangularization" of survival curves. The presence of such pattern confirms observations from experimental studies that regulation of life span involves genes responsible for stress resistance. CONCLUSION Biodemographic analyses could provide important information about the properties of genes affecting phenotypic traits.
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Affiliation(s)
- Anatoliy I Yashin
- Center for Population Health and Aging, Duke University, Durham, North Carolina 27708-0408, USA.
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Zheng H, Yang Y, Land KC. Heterogeneity in the Strehler-Mildvan general theory of mortality and aging. Demography 2012; 48:267-90. [PMID: 21347805 DOI: 10.1007/s13524-011-0013-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This study examines and further develops the classic Strehler-Mildvan (SM) general theory of mortality and aging. Three predictions from the SM theory are tested by examining the age dependence of mortality patterns for 42 countries (including developed and developing countries) over the period 1955-2003. By applying finite mixture regression models, principal component analysis, and random-effects panel regression models, we find that (1) the negative correlation between the initial adulthood mortality rate and the rate of increase in mortality with age derived in the SM theory exists but is not constant; (2) within the SM framework, the implied age of expected zero vitality (expected maximum survival age) also is variable over time; (3) longevity trajectories are not homogeneous among the countries; (4) Central American and Southeast Asian countries have higher expected age of zero vitality than other countries in spite of relatively disadvantageous national ecological systems; (5) within the group of Central American and Southeast Asian countries, a more disadvantageous national ecological system is associated with a higher expected age of zero vitality; and (6) larger agricultural and food productivities, higher labor participation rates, higher percentages of population living in urban areas, and larger GDP per capita and GDP per unit of energy use are important beneficial national ecological system factors that can promote survival. These findings indicate that the SM theory needs to be generalized to incorporate heterogeneity among human populations.
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Affiliation(s)
- Hui Zheng
- Department of Sociology, Duke University, Durham, NC 27708-0088, USA.
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Hawkes K, Smith KR, Blevins JK. Human actuarial aging increases faster when background death rates are lower: a consequence of differential heterogeneity? Evolution 2011; 66:103-14. [PMID: 22220868 DOI: 10.1111/j.1558-5646.2011.01414.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Many analyses of human populations have found that age-specific mortality rates increase faster across most of adulthood when overall mortality levels decline. This contradicts the relationship often expected from Williams' classic hypothesis about the effects of natural selection on the evolution of senescence. More likely, much of the within-species difference in actuarial aging is not due to variation in senescence, but to the strength of filters on the heterogeneity of frailty in older survivors. A challenge to this differential frailty hypothesis was recently posed by an analysis of life tables from historical European populations and traditional societies that reported variation in actuarial aging consistent with Williams' hypothesis after all. To investigate the challenge, we reconsidered those cases and aging measures. Here we show that the discrepancy depends on Ricklefs' aging rate measure, ω, which decreases as mortality levels drop because it is an index of mortality level itself, not the rate of increase in mortality with age. We also show unappreciated correspondence among the parameters of Gompertz-Makeham and Weibull survival models. Finally, we compare the relationships among mortality parameters of the traditional societies and the historical series, providing further suggestive evidence that differential heterogeneity has strong effects on actuarial aging.
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Affiliation(s)
- Kristen Hawkes
- Department of Anthropology, University of Utah, Salt Lake City, Utah, USA.
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Novoseltsev VN, Mikhalskii AI. Mathematical modeling and aging: Research program. ADVANCES IN GERONTOLOGY 2011. [DOI: 10.1134/s2079057011010097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
Kannisto (2001) has shown that as the frequency distribution of ages at death has shifted to the right, the age distribution of deaths above the modal age has become more compressed. In order to further investigate this old-age mortality compression, we adopt the simple logistic model with two parameters, which is known to fit data on old-age mortality well (Thatcher 1999). Based on the model, we show that three key measures of old-age mortality (the modal age of adult deaths, the life expectancy at the modal age, and the standard deviation of ages at death above the mode) can be estimated fairly accurately from death rates at only two suitably chosen high ages (70 and 90 in this study). The distribution of deaths above the modal age becomes compressed when the logits of death rates fall more at the lower age than at the higher age. Our analysis of mortality time series in six countries, using the logistic model, endorsed Kannisto's conclusion. Some possible reasons for the compression are discussed.
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Engelman M, Canudas-Romo V, Agree EM. The implications of increased survivorship for mortality variation in aging populations. POPULATION AND DEVELOPMENT REVIEW 2010; 36:511-39. [PMID: 20882704 DOI: 10.1111/j.1728-4457.2010.00344.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The remarkable growth in life expectancy during the twentieth century inspired predictions of a future in which all people, not just a fortunate few, will live long lives ending at or near the maximum human life span. We show that increased longevity has been accompanied by less variation in ages at death, but survivors to the oldest ages have grown increasingly heterogeneous in their mortality risks. These trends are consistent across countries, and apply even to populations with record-low variability in the length of life. We argue that as a result of continuing improvements in survival, delayed mortality selection has shifted health disparities from early to later life, where they manifest in the growing inequalities in late-life mortality.
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Affiliation(s)
- Michal Engelman
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
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Hawkes K, Smith KR, Robson SL. Mortality and fertility rates in humans and chimpanzees: How within-species variation complicates cross-species comparisons. Am J Hum Biol 2009; 21:578-86. [PMID: 19213006 PMCID: PMC6121812 DOI: 10.1002/ajhb.20890] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A grandmother hypothesis may explain why humans evolved greater longevity while continuing to end female fertility at about the same age as do the other great apes. With that grandmother hypothesis in mind, we sought to compare age-specific mortality and fertility rates between humans and chimpanzees, our closest living relatives, and found two puzzles. First, we expected that lower adult mortality in humans would be associated with slower senescence, but the rate of chimpanzee demographic aging falls within the human range. Second, we expected declines in age-specific fertility to be similar in the two species but instead of falling in the thirties as it does in women, fertility remains high into the forties in some chimpanzee populations. We report these puzzles using data from nine human populations and both wild and captive chimpanzees, and suggest that systematic differences in the heterogeneity of surviving adults may explain them.
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Affiliation(s)
- Kristen Hawkes
- Department of Anthropology, University of Utah, Salt Lake City, 84112-0600, USA.
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Golubev A. How could the Gompertz–Makeham law evolve. J Theor Biol 2009; 258:1-17. [PMID: 19490880 DOI: 10.1016/j.jtbi.2009.01.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 12/11/2008] [Accepted: 01/15/2009] [Indexed: 01/17/2023]
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Milne EMG. The natural distribution of survival. J Theor Biol 2008; 255:223-36. [PMID: 18692509 DOI: 10.1016/j.jtbi.2008.07.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 07/17/2008] [Accepted: 07/17/2008] [Indexed: 11/16/2022]
Affiliation(s)
- Eugene M G Milne
- Institute for Ageing and Health, University of Newcastle upon Tyne, c/o Government Office for the North East, Citygate, Newcastle upon Tyne NE1 4WH, UK.
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Wu D, Cypser JR, Yashin AI, Johnson TE. The U-Shaped Response of Initial Mortality in Caenorhabditis elegans to Mild Heat Shock: Does It Explain Recent Trends in Human Mortality? J Gerontol A Biol Sci Med Sci 2008; 63:660-8. [DOI: 10.1093/gerona/63.7.660] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Abstract
This review deals with computer simulation of biological aging, particularly with the Penna model of 1995. They are based on the mutation accumulation theory of half a century ago. The results agree well with demographical reality, and also with the seemingly contradictory influence of predators on the aging of prey.
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Affiliation(s)
- D. Stauffer
- Institute for Theoretical Physics, Cologne University, D-50923 Köln, Euroland
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31
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Hallén A. Gompertz law and aging as exclusion effects. Biogerontology 2007; 8:605-12. [PMID: 17647087 DOI: 10.1007/s10522-007-9087-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Accepted: 02/19/2007] [Indexed: 10/23/2022]
Abstract
The exponential increase with age in mortality rate, the Gompertz law, indicates that the decrease in vitality and viability linked to aging depends on phenomena with exponential or logarithmic dynamics. Gompertz slope (alpha) is assumed to be a measure of aging rate, provided the studied cohort is homogeneous and in a supporting environment. The law provides no clue about the cause of aging, but may be formally correlated with various physical or mathematical functions. A possible correlation between the Ogston-Laurent exclusion equation and human aging is examined. An increase with age of an inert cross-linked insoluble protein network is assumed to result in a logarithmic decrease in water volume available to colloidal macromolecules. In this model, alpha is assumed to be a measure of the rate of accumulation of the polypeptide network.
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Affiliation(s)
- Anund Hallén
- Department of Medical Biochemistry and Microbiology, University of Uppsala, Biomedical Center, P.O. Box 582, 75123 Uppsala, Sweden.
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32
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Milne EMG. Postponement of postmenopausal mortality acceleration in low-mortality populations. Ann N Y Acad Sci 2007; 1100:46-59. [PMID: 17460164 DOI: 10.1196/annals.1395.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Mortality analyses commonly disregard postmenopausal acceleration. This study examined period log mortality in World Health Organization (WHO) data for 34 low-mortality countries in 2000, demonstrating significant gradient increases for women (33/34 countries) and men (22/34), from a later age than previously reported, dividing the postmenopausal period into phases. "Break points" were identified as intersects of lines of best fit to these and the same approach was used in analysis of Human Mortality Database data for 19 countries. There has been an upward migration of about 10 years in female age at break point since 1850. Male data flipped from mortality acceleration to deceleration and back in the late 20th century with no apparent shift in break point. Altered age at mortality acceleration appears genuine, gender-specific, and internationally consistent. Its timing prompts the hypothesis that it may relate to falling fertility.
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Affiliation(s)
- Eugene M G Milne
- Riverside House, The Waterfront, Goldcrest Way, Newburn Riverside, Newcastle upon Tyne, NE15 8NY, UK.
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33
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Hallén A. Gompertz law and aging as exclusion effects. Biogerontology 2007; 8:595-603. [PMID: 17468939 DOI: 10.1007/s10522-007-9092-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Accepted: 02/22/2007] [Indexed: 11/29/2022]
Abstract
The exponential increase with age in mortality rate, the Gompertz law, indicates that the decrease in vitality and viability linked to aging depends on phenomena with exponential or logarithmic dynamics. Gompertz slope (alpha) is assumed to be a measure of aging rate, provided the studied cohort is homogeneous and in a supporting environment. The law provides no clue about the cause of aging, but may be formally correlated with various physical or mathematical functions. A possible correlation between the Ogston-Laurent exclusion equation and human aging is examined. An increase with age of an inert cross-linked insoluble protein network is assumed to result in a logarithmic decrease in water volume available to colloidal macromolecules. In this model, alpha is assumed to be a measure of the rate of accumulation of the polypeptide network.
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Affiliation(s)
- Anund Hallén
- Department of Medical Biochemistry and Microbiology, Biomedical Center, University of Uppsala, Box 582, 75123 Uppsala, Sweden.
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34
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Trovato F, Heyen NB. A divergent pattern of the sex difference in life expectancy: Sweden and Japan, early 1970s-late 1990s. SOCIAL BIOLOGY 2006; 50:238-58. [PMID: 16382814 DOI: 10.1080/19485565.2003.9989074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
For most of the 20th century the sex gap in life expectancy in the industrialized countries has widened in favor of women. By the early 1980s a reversal in the long-term pattern of this differential had occurred in some countries, where it reached a maximum and thereafter followed a declining trend. Of particular interest to the present investigation is the anomalous experience of Japan, where unlike other high-income countries the female advantage in life expectancy has been expanding. We contrast the case of Japan with that of Sweden, where, like many other high-income nations, the sex differential in longevity has been narrowing in recent years. We observe that in Sweden, until the early 1980s, the sex gap in life expectancy (female-male) exceeded that of Japan; but this situation reversed in subsequent periods, when the Swedish differential narrowed and that of Japan widened. A decomposition analysis indicates that these divergent patterns since 1980 have resulted mainly from larger than expected reductions in male mortality in Sweden due to heart disease and from accidents and violence, lung cancer and "other" cancers. In Japan, death rates for men and women from heart disease--which is a leading cause of death--have tended to decline more or less at the same pace since the early 1980s; and with regard to lung cancer, and "other" neoplasms, male death rates in Japan have been rising while those of women have either declined or risen more slowly. Moreover, during the 1990s, male and female suicide rates rose in Japan, but the rates for men went up faster. Altogether, the net effect of these divergent mortality trends for men and women in Japan underlie much of the observed widening of its sex differential in longevity in recent years.
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Affiliation(s)
- Frank Trovato
- Department of Sociology and Population Research Laboratory, The University of Alberta, Edmonton, Canada.
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Stauffer D, de Oliveira SM, de Oliveira P, Martins JS. Biology, Sociology, Geology by Computational Physicists. MONOGRAPH SERIES ON NONLINEAR SCIENCE AND COMPLEXITY 2006. [DOI: 10.1016/s1574-6917(05)01001-9] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Cheung SLK, Robine JM, Tu EJC, Caselli G. Three dimensions of the survival curve: horizontalization, verticalization, and longevity extension. Demography 2005; 42:243-58. [PMID: 15986985 DOI: 10.1353/dem.2005.0012] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Three dimensions of the survival curve have been developed: (1) "horizontalization," which corresponds to how long a cohort and how many survivors can live before aging-related deaths significantly decrease the proportion of survivors; (2) "verticalization," which corresponds to how concentrated aging-related ("normal") deaths are around the modal age at death (M); and (3) "longevity extension," which corresponds to how far the highest normal life durations can exceed M. Our study shows that the degree of horizontalization increased relatively less than the degree of verticalization in Hong Kong from 1976 to 2001. After age normalization, the highest normal life durations moved closer to M, implying that the increase in human longevity is meeting some resistance.
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Affiliation(s)
- Siu Lan Karen Cheung
- INSERM/Démographie et Santé, Val d'Aurelle, Parc Euromédecine, 34298 Montpellier 5, France.
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de Grey ADNJ. The unfortunate influence of the weather on the rate of ageing: why human caloric restriction or its emulation may only extend life expectancy by 2-3 years. Gerontology 2005; 51:73-82. [PMID: 15711074 DOI: 10.1159/000082192] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Much research interest, and recently even commercial interest, has been predicated on the assumption that reasonably closely-related species--humans and mice, for example--should, in principle, respond to ageing-retarding interventions with an increase in maximum lifespan roughly proportional to their control lifespan (that without the intervention). Here, it is argued that the best-studied life-extending manipulations of mice are examples of a category that is highly unlikely to follow this rule, and more likely to exhibit only a similar absolute increase in maximum lifespan from one species to the next, independent of the species' control lifespan. That category--reduction in dietary calories or in the organism's ability to metabolize or sense them--is widely recognized to extend lifespan as an evolutionary adaptation to transient starvation in the wild, a situation which alters the organism's optimal partitioning of resources between maintenance and reproduction. What has been generally overlooked is that the extent of the evolutionary pressure to maintain adaptability to a given duration of starvation varies with the frequency of that duration, something which is--certainly for terrestrial animals and less directly for others--determined principally by the weather. The pattern of starvation that the weather imposes is suggested here to be of a sort that will tend to cause all terrestrial animals, even those as far apart phylogenetically as nematodes and mice, to possess the ability to live a similar maximum absolute (rather than proportional) amount longer when food is short than when it is plentiful. This generalization is strikingly in line with available data, leading (given the increasing implausibility of further extending human mean but not maximum lifespan in the industrialized world) to the biomedically and commercially sobering conclusion that interventions which manipulate caloric intake or its sensing are unlikely ever to confer more than 2 or 3 years' increase in human mean or maximum lifespan at the most.
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Arking R, Novoseltsev V, Novoseltseva J. The human life span is not that limited: the effect of multiple longevity phenotypes. J Gerontol A Biol Sci Med Sci 2004; 59:697-704. [PMID: 15304534 DOI: 10.1093/gerona/59.7.b697] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
There is an ongoing debate as to whether or not human longevity is approaching its limits. The debate and its outcome are important since they might affect public policy. We review the evidence presented by both schools. We add our empirical observation that there exist multiple longevity phenotypes, each of which arises from the alteration of fundamental aging processes. The current debate only considers two of the three known mammalian longevity phenotypes. The overlooked phenotype is the delayed onset of senescence phenotype, which can be induced by various interventions, including pharmaceuticals. The existence of multiple phenotypes means that an overview of potential life expectancy outcomes for a species should be based on the analysis of all longevity phenotypes likely to occur in that species.
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Affiliation(s)
- Robert Arking
- Department of Biological Sciences, Biological Sciences Building, 5705 Gullen Mall, Wayne State University, Detroit, MI 48202, USA.
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Yashin AI, Ukraintseva SV, Boiko SI, Arbeev KG. Individual aging and mortality rate: how are they related? SOCIAL BIOLOGY 2004; 49:206-17. [PMID: 14652918 DOI: 10.1080/19485565.2002.9989059] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Many researchers working in the area of aging and longevity base their conclusions on the behavior of empirical age trajectories of mortality rates. In such analyses, changes in the slope of the logarithm of the mortality curve are often associated with changes in the rate of individual aging. We show that such interpretation may be incorrect: the changes in the slope of this curve do not necessarily correspond to the changes in the rate of individual aging. We use three models of mortality and aging to illustrate this statement. The first one is based on the idea of frailty. We show that changes in frailty distribution alone may be responsible for changes in the slope. The second model exploits the idea of saving lives. It evaluates changes in mortality rate after elimination of lethal stressful events. The third model uses the idea of Strehler and Mildvan (1960). It shows that changes in the rate of individual aging may take place without changes in the slope of the logarithm of the mortality curve.
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40
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Novoseltsev VN, Novoseltseva JA, Boyko SI, Yashin AI. What fecundity patterns indicate about aging and longevity: insights from Drosophila studies. J Gerontol A Biol Sci Med Sci 2003; 58:484-94. [PMID: 12807919 DOI: 10.1093/gerona/58.6.b484] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The age pattern of fecundity is represented as a result of a superposition of two processes: the genetic fecundity program encoded in the organism's reproductive machinery and senescence of the reproductive system. Accumulation of oxidative damage produces the energy decline, which could potentially be used in reproduction. As a result, the age-declining process arises in the reproductive machinery at a critical age. We show that this mechanism is common for different species. It establishes a connection between the decline of organism vitality and reproductive senescence. We suggest a parametric description of a fecundity pattern that allows for prediction of reproductive longevity. We apply the approach to Drosophila studies to analyze the relation between fecundity and survival. We show that fecundity patterns may predict a mean life span in Drosophila under specified environmental conditions.
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Abstract
The metabolic characteristics of a yeast cell determine its life span. Depending on conditions, stress resistance can have either a salutary or a deleterious effect on longevity. Gene dysregulation increases with age, and countering it increases life span. These three determinants of yeast longevity may be interrelated, and they are joined by a potential fourth, genetic stability. These factors can also operate in phylogenetically diverse species. Adult longevity seems to borrow features from the genetic programs of dormancy to provide the metabolic and stress resistance resources necessary for extended survival. Both compensatory and preventive mechanisms determine life span, while epigenetic factors and the element of chance contribute to the role that genes and environment play in aging.
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Affiliation(s)
- S Michal Jazwinski
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, New Orleans 70112, USA.
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43
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Stauffer D. Simple tools for forecasts of population ageing in developed countries based on extrapolations of human mortality, fertility and migration. Exp Gerontol 2002; 37:1131-6. [PMID: 12213564 DOI: 10.1016/s0531-5565(02)00084-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Suitable assumptions for the Gompertz mortality law take into account the break in the time development observed recently by Wilmoth et al. They show how a drastic reduction in the birth rate and improved living conditions lead to a drastic increase in the fraction of old people in the population, and how immigration of half a percent of the population per year can mostly stop this increase.
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Affiliation(s)
- Dietrich Stauffer
- Institute for Theoretical Physics, Cologne University, D-50923 Köln, Germany.
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Nekhaeva E, Kraytsberg Y, Khrapko K. mtLOH (mitochondrial loss of heteroplasmy), aging, and 'surrogate self'. Mech Ageing Dev 2002; 123:891-8. [PMID: 12044937 DOI: 10.1016/s0047-6374(02)00026-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In tribute to Dr Strehler, an attempt is made to use a style of reasoning found in some of his later papers as an outline of this article. First, general arguments in favor of the involvement of somatic mutations in mtDNA in the aging process are presented. Second, evidence is provided in support of a general tendency of mitochondrial genomes to reach homoplasmic state at the cellular level, for which we propose the term mitochondrial loss of heteroplasmy (mtLOH). This process is likely to facilitate the involvement of mtDNA mutations in the aging process by streamlining the phenotypic expression of the mutant genotype. Third, preliminary evidence of the very high incidence of clonal deletions in pigmented neurons of substantia nigra is reported. This observation highlights the possibility that accumulation of mtDNA mutations specific in certain cell types of a complex tissue may account for the involvement of mtDNA mutations in the aging process despite the relatively low average incidence of these mutations in the tissue as a whole. High incidence of mtDNA deletions in pigmented neurons evokes Strehler's idea that efforts to delay aging may not be the most cost-efficient way of preserving 'self awareness and a joyful sense of life', as he put it. A potential alternative suggested by Strehler, i.e. creation of a 'surrogate self' by computer simulation may deserve more attention than it currently enjoys.
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Affiliation(s)
- Ekaterina Nekhaeva
- Beth Israel Deaconess Medical Center and Harvard Medical School, Rm. 921, 77 Ave. L. Pasteur, Boston, MA 02115, USA
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Affiliation(s)
- Caleb E Finch
- Ethel Percy Andrus Gerontology Center and the Department of Biological Sciences, University of Southern California, 3715 McClintock Avenue, 90089-0191, Los Angeles, CA, USA
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