Determinants of Exceptional Longevity

1
Determinants of Exceptional Longevity

• Dr. Leonid A. Gavrilov, Ph.D.
• Dr. Natalia S. Gavrilova, Ph.D.
• Center on Aging
• NORC and The University of Chicago
• Chicago, Illinois, USA

2
Approach

• To study success stories in long-term avoidance
  of fatal diseases (survival to 100 years) and
  factors correlated with this remarkable survival
  success

3
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)
4
Revolution in Information TechnologyWhat does
it mean for longevity studies?

• Over 75 millions of computerized genealogical
  records are available online now!

5
Computerized genealogies is a promising source of
information about potential predictors of
exceptional longevity life-course events,
early-life conditions and family history of
longevity
6
Computerized Genealogies as a Resource for
Longevity Studies

• Pros provide important information about family
  and life-course events, which otherwise is
  difficult to collect (including information about
  lifespan of parents and other relatives)
• Cons Uncertain data quality
  Uncertain validity and generalizability
  

7
For longevity studies the genealogies with
detailed birth dates and death dates for
long-lived individuals (centenarians) and their
relatives are of particular interest

• In this study 1,001 genealogy records for
  centenarians born in 1875-1899 were collected and
  used for further age validation

8
(No Transcript)
9
Steps of Centenarian Age Verification

• Internal consistency checks of dates
• Verification of death dates linkage to the
  Social Security Administration Death Master File
  (DMF)
• Verification of birth dates linkage to early
  Federal censuses (1900, 1910, 1920, 1930)

10
Results of Centenarian Age Verification
11
Conclusions of the Age Verification Study

• Death dates of centenarians recorded in
  genealogies always require verification because
  of strong outliers (1.3, misprints)
• Birth dates of centenarians recorded in
  genealogies are sufficiently accurate - 92 are
  correct for the remaining 8 only one-year
  disagreements
• Quality of genealogical data is good enough if
  these data are pre-selected for high data quality

12
Predictors of Exceptional Longevity
13
Study 1Compare centenarians with their
siblings (within-family study)
14
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
15
Design of the Study
16
A typical image of centenarian family in 1900
census
17
First-born siblings are more likely to become
centenarians (odds 1.8)
18
Birth Order and Odds to Become a Centenarian
19
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)

20
First-born adult siblings (20years) are more
likely to become centenarians (odds
1.95)
21
Are young fathers responsible for birth order
effect?
22
Birth order is more important than paternal age
for chances to become a centenarian
23
Are young mothers responsible for the birth order
effect?
24
Maternal Age at Persons Birth and Odds to Become
a Centenarian
25
Birth order effect explainedBeing born to young
mother!
26
Even at age 75 it still helps to be born to young
mother (age lt25)(odds 1.9)
27
Question

• Families were quite large in the past,
  particularly those covered by genealogical
  records (large family size bias).
• Is the "young mother effect" robust to the family
  size, and is it observed in smaller families too?
• Or is it confined to extremely large families
  only?
• Approach
• To split data in two equal parts by median family
  size (9 children) and re-analyze the data in each
  group separately.

28
Results

• In smaller families (less than 9 children) the
  effect of young mother is even larger
• Odds ratio 2.23, P0.004 95CI 1.30 - 3.98
• Compare to larger families (more than 9
  children)
• Odds ratio 1.72, P0.11 95CI 0.88 - 3.34
• Conclusion
• "Young mother effect" is not confined to
  extremely large family size

29
New Striking Findings Invitation for discussion
and brain-storming!

• The favorable "Young Mother Effect" is
  particularly strong when parents have
  particularly large differences in their lifespan

30
Odds Ratio to live to 100 years if born to young
motheras a function of maternal and paternal
lifespans (tertiles)
plt0.05
31
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.

32
Study 2Compare centenarians when they were
young adults to their peersusing WWI Civil
Draft Registration Cards
33
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
34
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

35
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.

36
Data Sources

• Social Security Administration Death Master File
• WWI civil draft registration cards (completed for
  almost 100 percent men born between 1873 and
  1900)

37
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
  120 selected men, 19 were not eligible for draft.
  The linkage success for remaining 101 records was
  75 (76 records)
• Controls men matched on birth year, race and
  county of WWI civil draft registration

38
Height and Survival to 100
39
Body Build and Survival to 100
40
Results of multivariate study
41
Conclusion

• The study of height and build among men born in
  1887 suggests that rapid growth and overweight at
  young adult age (30 years) might be harmful for
  attaining longevity

42
Study 3Mortality of the Entire Population of
the U.S. Elderly (85) Using Social Security
Administration Death Master File
43
What Is SSA DMF ?

• SSA DMF is a publicly available data resource
  (available at Rootsweb.com)
• Covers 93-96 percent deaths of persons 65
  occurred in the United States in the period
  1937-2003
• Some birth cohorts covered by DMF could be
  studied by method of extinct generations
• Considered superior in data quality compared to
  vital statistics records by some researchers

44
(No Transcript)
45
Month-of-Birth and Mortality at Advanced Ages

• SSA Death Master File allows researchers to study
  mortality in real birth cohorts by month-of-birth
• Provides more accurate and unbiased estimates of
  life expectancy by month of birth compared to
  usage of cross-sectional death certificates

46
Month of Birth Predicts the US Life Expectancy at
Age 80 Computed using the Social Security
Administration data
Source 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.
47
Seasonality (month-of-birth effects) for
US life expectancy
48
Study 4Compare centenarians found in
computerized genealogies with general population
49
Case-Control Study of Early-Life Conditions and
Exceptional Longevity
Cases - 382 white households where
centenarians (born in 1890-1899) were raised
(from centenarian records linked to 1900
census) Controls 1 random sample of white
households with children below age 10 enumerated
by 1900 census (from Integrated Public Use
Microdata Sample, IPUMS http//www.ipums.umn.edu/
usa/index.html)
50
Statistical Approach

• Logistic regression
• Dependent variable Households with child-future
  centenarian (y1) vs control households (y0)
• Predictor variables childhood residence,
  household property status, paternal immigration
  status, etc.

51
Childhood Residence and Survival to Age 100Odds
for household to be in a centenarian group

• A New England and Middle Atlantic (reference
  group)
• B Mountain West and Pacific West
• C Southeast and Southwest
• D North Central

52
Household Property Status During Childhood and
Survival to Age 100 Odds for household to be in
a centenarian group

• A Rented House
• B Owned House
• C Rented Farm
• D Owned farm
• (reference group)

53
Paternal Immigration Status and Survival to Age
100 Odds for household to be in a centenarian
group

• A Father immigrated
• B Father native-born
• (reference group)

54
No Association was Found (so far) Between Chances
to Become a Centenarian and

• Paternal literacy
• Child mortality of siblings

55
Limitations

• Reporting bias in genealogies
• People mentioned in genealogies may be not
  representative to the whole population
• more fertile, longer-living (?), wealthier (?),
  more educated (?)

56
General Conclusionof Centenarian Studies

• The shortest conclusion was suggested in the
  title of the New York Times article about our
  previous related study

57
(No Transcript)
58
Acknowledgments

• This study was made possible thanks to
• generous support from the National Institute on
  Aging and the Society of Actuaries

59
For More Information and Updates Please Visit Our
Scientific and Educational Website on Human
Longevity

• http//longevity-science.org

And Please Post Your Comments at our Scientific
Discussion Blog

• http//longevity-science.blogspot.com/