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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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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
This study has been suggested by academician V.P. Skulachev in order to compare variability of ages of sexual maturation with ages of menopause and death.
The idea of this study is to compare standard deviations for parameters, which are known to be determined by the developmental program (such as ages of sexual maturity) with variation of characteristics related to aging (such as 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 objective of this study was to test the validity of this argument.
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
Mean age at menarche, its standard deviation and coefficient of variation for European women (The EPIC Study) 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) 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) Source: Sun et al., PEDIATRICS, 2002, 110: 911-919
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 A 114 page mail survey Number of respondents: 4,242 Number of respondents: 3,690
DISTRIBUTION OF AGE AT DEATH, SWEDISH FEMALES, 1995 Data source: Human Mortality Database
Variation for characteristics of human aging and development
Variation of age at onset of menarche and age at death (in 2005)
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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