Comparative analysis of parameters of human senescence

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Comparative analysis of parameters of human
senescence

• Natalia S. Gavrilova
• Leonid A. Gavrilov
• Center on Aging, NORC/University of Chicago,
• 1155 East 60th Street, Chicago, IL 60637

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The idea of this study has been suggested by
Fedor Severin in order to test whether aging is
programmed or not.
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• The idea of this study is to compare
  variability for traits, which are known to be
  determined by the developmental program (such as
  ages at sexual maturity) with variability of
  traits related to aging (such as ages at
  menopause and death).

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One of the arguments used by the opponents of
programmed aging is a too high variation in
individual lifespans compared to the observed
variation of programmed events (such as the age
of sexual maturation).

• The main goal of this study was to test the
  validity of this argument.

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Measures of variability

• Absolute measure standard deviation
• For distribution of lifespan, demographers often
  calculate standard deviation at age 10 SD10
  (Edwards Tuljapurkar 2005).
• Relative measure coefficient of variation.
  Equals the standard deviation divided by the mean

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Historical Changes in Mortality Swedish Females
Data source Human Mortality Database
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Age at onset of menarche is an example of
characteristic determined by developmental
program
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Age at onset of menarche was declining in the XX
century. Norway data.
Source "Age of Menarche in Norway Chart," in
Children and Youth in History, Item 207,
http//chnm.gmu.edu/cyh/primary-sources/207
(accessed February 13, 2010). Annotated by
Stephen Robertson
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Similar results are obtained for Korean girls
Source Age at menarche in a Korean population
secular trends and influencing factors. Geum Joon
Cho et al. EUROPEAN JOURNAL OF PEDIATRICS 169 1
89-94 JAN 2010
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Declining of the menarche age decelerated in
developed countries now.

• Helm P, Grolund L (1998) A halt in the secular
  trend towards earlier menarche in Denmark. Acta
  Obstet Gynecol Scand 77198200
• Similar results obtained for Finland and Iceland
• Mean age 13.00 years, SD 1.15 years for Danish
  girls in 1996

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What studies tell us about the variation of
menarche age?
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Mean age at menarche, its standard deviation and
coefficient of variation for European women (The
EPIC Study)
Country Birth years Mean age at menarche (SD) Coefficient of variation (CV)
France 1921-1956 12.84 (1.40) 10.9
Italy 1920-1962 12.54 (1.46) 11.6
Spain 1925-1961 12.91 (1.56) 12.1
United Kingdom 1918-1963 12.89 (1.54) 12.0
Greece 1920-1964 13.19 (1.52) 11.5
Source Onland-Moret et al., American Journal of
Epidemiology 2005 162(7)623-632
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Mean age at menarche, its standard deviation and
coefficient of variation for European women
(continue)
Country Birth years Mean age at menarche (SD) Coefficient of variation (CV)
The Netherlands 1924-1962 13.28 (1.56) 11.8
Germany 1926-1963 13.16 (1.48) 11.2
Sweden 1923-1950 13.59 (1.41) 10.4
Denmark 1929-1947 13.56 (1.53) 11.3
Greece 1920-1964 13.19 (1.52) 11.5
Source Onland-Moret et al., American Journal of
Epidemiology 2005 162(7)623-632
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Age at menarche in other countries

• Iran Mean age (SD) in the urban areas was 12.4
  (1.1) years and in rural areas it was 12.6 (1.1)
  years (Delavar and Hajian-Tilaki, 2008)
• Korea Mean age at menarche of girls born between
  1986 and 1995 was 13.10 (1.49) (Cho et al. , 2010)

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What about boys?

• Third National Health and Nutrition Examination
  Survey (NHANES III)
• Sexual maturity stages based on the
  recommendations of Tanner were assigned to each
  maturity indicator
• Pubic hair development using stages from 1
  (immaturity) to 5 (complete maturity)
• Genitalia development using stages from 1
  (immaturity) to 5 (complete maturity)

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Mean age (SD) of some characteristics of sexual
maturation for U.S. boys (NHANES study)
Characteristic Non-Hispanic whites Non-Hispanic blacks Mexican Americans
Pubic hair development, stage 5 16.84 (1.50) 16.67 (1.23) 17.14 (1.45)
Genitalia development, stage 5 16.64 (1.64) 16.42 (1.43) 16.85 (1.92)
Source Sun et al., PEDIATRICS, 2002, 110
911-919
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Age at natural menopause as a marker of
reproductive aging
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Mean age (SD) at natural menopause
Population Mean age (SD) at menopause, years Source
South Korean women 46.9 (4.9) Hong et al., MATURITAS, 2007
Viennese women aged 47 to 68 49.2 (3.6) Kirchengast et al., International Journal of Anthropology , 1999
Mexico Puebla Mexico city 46.7 (4.77) 46.5 (5.00) Sievert, Hautaniemi, Human Biology, 2003
Black women in South Africa rural urban 49.5 (4.7) 48.9 (4.2) Walker et al., International Journal of Obstetrics Gynaecology, 2005
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Our results using the MIDUS study
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• National survey conducted in 1994/95
• Americans aged 25-74
• core national sample (N3,485)
• city oversamples (N957)
• Additional samples twins, siblings
• Subsample used in this study women having
  natural menopause (no surgeries affecting the age
  at menopause) aged 60-74

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A 30-40 minute telephone survey
A 114 page mail survey Number of respondents
4,242 Number of respondents 3,690
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MIDUS SAMPLE POPULATION DISTRIBUTIONS ()
Women Aged 25-74 (n2,087) Women Aged 25-74 (n2,087)
AGE
25-54 68.8
55-64 19.8
65-74 11.4
RACE/ETHNICITY
White 86.9
African-American 7.7
Other 8.9
RELATIONSHIP STATUS RELATIONSHIP STATUS
Married 54.2
Other intimate relationship 4.7



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DISTRIBUTION OF AGE AT MENARCHE IN THE MIDUS
SAMPLE
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DISTRIBUTION OF AGE AT MENOPAUSE IN THE MIDUS
SAMPLE
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DISTRIBUTION OF AGE AT DEATH, SWEDISH FEMALES,
1995
Data source Human Mortality Database
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Variation for characteristics of human aging and
development
Characteristic Mean age (SD) years Coefficient of variation Source
Age at onset of menarche 12.9 (1.6) 12.4 MIDUS data
Age at onset of menopause 49.7 (5.2) 10.5 MIDUS data
Age at death 78.7 (16.1) 20.5 USA, women, 1995. Human mortality database
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Variation of age at onset of menarche and age at
death (in 2005)
Country Mean age (SD) for onset of menarche CV Mean age (SD) at death CV
France 12.84 (1.40) 10.9 83.3 (13.8) 16.6
Italy 12.54 (1.46) 11.6 83.3 (13.1) 15.7
Sweden 13.59 (1.41) 10.4 82.3 (12.9) 15.7
UK 12.89 (1.54) 12.0 80.2 (14.0) 17.5
USA 12.9 (1.60) 12.4 78.7 (16.1) 20.5
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Variation of age at onset of menarche and age at
death (in 2005) after 10 years
Country Mean age (SD) for onset of menarche CV Mean age (SD10) at death after 10 CV10
France 12.84 (1.40) 10.9 83.7 (12.7) 15.2
Italy 12.54 (1.46) 11.6 83.7 (11.9) 14.2
Sweden 13.59 (1.41) 10.4 82.5 (12.0) 14.5
UK 12.89 (1.54) 12.0 81.2 (12.6) 15.5
USA 12.9 (1.60) 12.4 79.4 (14.3) 18.0
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Mean Values and Standard Deviations for Human
Developmental Characteristics
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Conclusions

• Standard deviations for age at onset of menarche
  are about 10 times lower than standard deviations
  for ages at death
• Coefficients of variation for ages at onset of
  menarche and ages at death for contemporary
  populations are of the same order of magnitude

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