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Explore the idea of high initial damage load in biological systems and its implications on health, longevity, and aging. Discover predictors of exceptional longevity and factors correlated with remarkable survival success.
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Biodemography of Exceptional Longevity Leonid A. Gavrilov, Ph.D. Natalia S. Gavrilova, Ph.D. Center on Aging NORC and The University of Chicago Chicago, USA
Source of Inspiration Fatal Years : Child Mortality in Late Nineteenth-Century America by Samuel H. Preston, Michael R. Haines Elo, I.T. and Preston, S.H., Effects of early-life condition on adult mortality: A review, Population Index, 58 (1992) 186-222. Preston, S.H., Hill, M.E. and Drevenstedt, G.L., Childhood conditions that predict survival to advanced ages among African-Americans, Social Science & Medicine, 47 (1998) 1231-1246.
Statement of the HIDL hypothesis:(Idea of High Initial Damage Load ) "Adult organisms already have an exceptionally high load of initial damage, which is comparable with the amount of subsequent aging-related deterioration, accumulated during the rest of the entire adult life." Source: Gavrilov, L.A. & Gavrilova, N.S. 1991. The Biology of Life Span: A Quantitative Approach. Harwood Academic Publisher, New York.
Why should we expect high initial damage load in biological systems? • General argument:-- biological systems are formed by self-assembly without helpful external quality control. • Specific arguments: • Most cell divisions responsible for DNA copy-errors occur in early development leading to clonal expansion of mutations • Loss of telomeres is also particularly high in early-life • Cell cycle checkpoints are disabled in early development
Spontaneous mutant frequencies with age in heart and small intestine Source: Presentation of Jan Vijg at the IABG Congress, Cambridge, 2003
Practical implications from the HIDL hypothesis: "Even a small progress in optimizing the early-developmental processes can potentially result in a remarkable prevention of many diseases in later life, postponement of aging-related morbidity and mortality, and significant extension of healthy lifespan." Source: Gavrilov, L.A. & Gavrilova, N.S. 1991. The Biology of Life Span: A Quantitative Approach. Harwood Academic Publisher, New York.
Life Expectancy and Month of Birth Data source: Social Security Death Master File Published in: Gavrilova, N.S., Gavrilov, L.A. Search for Predictors of Exceptional Human Longevity. In: “Living to 100 and Beyond” Monograph. The Society of Actuaries, Schaumburg, Illinois, USA, 2005, pp. 1-49.
Approach To study “success stories” in long-term avoidance of fatal diseases (survival to 100 years) and factors correlated with this remarkable survival success
Centenarians represent the fastest growing age group in the industrialized countries Yet, factors predicting exceptional longevity and its time trends remain to be fully understood In this study we explored the new opportunities provided by the ongoing revolution in information technology, computer science and Internet expansion to explore early-childhood predictors of exceptional longevity Jeanne Calment (1875-1997)
Revolution in Information TechnologyWhat does it mean for longevity studies? Millions of official census, birth, marriage, death and other records are available onlinenow!
Study 1 How centenarians are different from their shorter-lived sibling?
Within-Family Study of Exceptional Longevity Cases - 198 Centenarians born in U.S. in 1890-1893 Controls – Their own siblings Method: Conditional logistic regression Advantage: Allows researchers to eliminate confounding effects of between-family variation
First-born siblings are more likely to become centenarians (odds = 1.8)
Can the birth-order effect be a result of selective child mortality, thus not applicable to adults? Approach: • To compare centenarians with those siblings only who survived to adulthood (age 20)
First-born adult siblings (20+years) are more likely to become centenarians (odds = 1.95)
Birth order is more important than paternal age for chances to become a centenarian
Maternal Age at Person’s Birth and Odds to Become a Centenarian
Even at age 75 it still helps to be born to young mother (age <25)(odds = 1.9)
Being born to Young Mother Helps Laboratory Mice to Live Longer • Source: Tarin et al., Delayed Motherhood Decreases Life Expectancy of Mouse Offspring. Biology of Reproduction 2005 72: 1336-1343.
Possible explanation These findings are consistent with the 'best eggs are used first' hypothesis suggesting that earlier formed oocytes are of better quality, and go to fertilization cycles earlier in maternal life.
Study 2 How centenarians are different from their shorter-lived peers when compared at young adult age?
Physical Characteristics at Young Age and Survival to 100 A study of height and build of centenarians when they were young using WWI civil draft registration cards
Height – What to Expect Height seems to be a good indicator of nutritional status and infectious disease history in the past. Historical studies showed a negative correlation between height and mortality. Hence we may expect that centenarians were taller than average
Build – What to Expect Slender build may suggest a poor nutrition during childhood. We may expect that centenarians were less likely to be slender when young. On the other hand, biological studies suggest that rapid growth may be harmful and somewhat delayed maturation may be beneficial for longevity.
Small Dogs Live Longer Miller RA. Kleemeier Award Lecture: Are there genes for aging? J Gerontol Biol Sci 54A:B297–B307, 1999.
Small Mice Live Longer Source: Miller et al., 2000. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences 55:B455-B461
Data Sources Social Security Administration Death Master File WWI civil draft registration cards (completed for almost 100 percent men born between 1873 and 1900)
WWI Civilian Draft Registration In 1917 and 1918, approximately 24 million men born between 1873 and 1900 completed draft registration cards. President Wilson proposed the American draft and characterized it as necessary to make "shirkers" play their part in the war. This argument won over key swing votes in Congress.
WWI Draft Registration Registration was done in three parts, each designed to form a pool of men for three different military draft lotteries. During each registration, church bells, horns, or other noise makers sounded to signal the 7:00 or 7:30 opening of registration, while businesses, schools, and saloons closed to accommodate the event.
Information Available in the Draft Registration Card • age, date of birth, race, citizenship • permanent home address • occupation, employer's name • height (3 categories), build (3 categories), eye color, hair color, disability
Study Design Cases: men centenarians born in 1887 (randomly selected from the SSA Death Master File) and linked to the WWI civil draft records. Out of 240 selected men, 15 were not eligible for draft. The linkage success for remaining records was 77.5% (174 records) Controls: men matched on birth year, race and county of WWI civil draft registration
Multivariate Analysis • Conditional multiple logistic regression model for matched case-control studies to investigate the relationship between an outcome of being a case (extreme longevity) and a set of prognostic factors (height, build, occupation, marital status, number of children, immigration status) • Statistical package Stata-10, command clogit
Other physical characteristics Other variables include body build and farming
