Transcript Testing Biological Ideas on Evolution, Aging and Longevity

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
The idea of this study has
been suggested by Fedor
Severin in order to test
whether aging is programmed
or not.
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).
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.
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
Historical Changes in Mortality
Swedish Females
1
1925
1960
1980
1999
Log (Hazard Rate)
0.1
0.01
0.001
0.0001
0
20
40
60
Age
Data source: Human Mortality Database
80
100
Age at onset of menarche is
an example of characteristic
determined by developmental
program
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
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
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 77:198–200
Similar results obtained for
Finland and Iceland
Mean age 13.00 years, SD 1.15
years for Danish girls in 1996
What studies tell us about the
variation of menarche age?
Mean age at menarche, its standard
deviation and coefficient of variation for
European women (The EPIC Study)
Country
Birth years
Mean age at
Coefficient of
menarche (SD) 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
Mean age at menarche, its standard
deviation and coefficient of variation
for European women (continue)
Country
Birth years
Mean age at
Coefficient of
menarche (SD) 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
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)
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)
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
Age at natural menopause as a
marker of reproductive aging
Mean age (SD) at natural menopause
Population
South Korean women
Mean age (SD)
at menopause,
years
46.9 (4.9)
Source
Hong et al., MATURITAS,
2007
Viennese women aged 47 49.2 (3.6)
to 68
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
49.5 (4.7)
48.9 (4.2)
Walker et al., International
Journal of Obstetrics &
Gynaecology, 2005
Black women in South
Africa: rural
urban
Our results using
the MIDUS study

National survey conducted in 1994/95

Americans aged 25-74


core national sample (N=3,485)
city oversamples (N=957)

Additional samples: twins, siblings

Subsample used in this study: women having
natural menopause (no surgeries affecting the age at
menopause) aged 60-74
A 30-40 minute telephone survey
survey
Number of respondents: 4,242
A 114 page mail
Number of respondents: 3,690
MIDUS SAMPLE POPULATION
DISTRIBUTIONS (%)
Women Aged 25-74 (n=2,087)
AGE
25-54
55-64
65-74
RACE/ETHNICITY
White
African-American
Other
RELATIONSHIP STATUS
Married
Other intimate relationship
68.8
19.8
11.4
86.9
7.7
8.9
54.2
4.7
0
.1
Density
.2
.3
DISTRIBUTION OF AGE AT MENARCHE
IN THE MIDUS SAMPLE
8
10
12
14
age of menarche
16
18
.04
0
.02
Density
.06
.08
DISTRIBUTION OF AGE AT
MENOPAUSE IN THE MIDUS
SAMPLE
20
30
40
50
age of menopause
60
70
.02
0
.01
Density
.03
.04
DISTRIBUTION OF AGE AT
DEATH, SWEDISH FEMALES, 1995
0
50
100
age
Data source: Human Mortality Database
Variation for characteristics of human
aging and development
Characteristic
Mean age Coefficient
(SD) years
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
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
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
Mean Values and Standard Deviations for
Human Developmental Characteristics
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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