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Comparative analysis of parameters of human senescence

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

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  1. 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

  2. The idea of this study has been suggested by Fedor Severin in order to test whether aging is programmed or not.

  3. 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).

  4. 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.

  5. 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

  6. Historical Changes in MortalitySwedish Females Data source: Human Mortality Database

  7. Age at onset of menarche is an example of characteristic determined by developmental program

  8. 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

  9. 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

  10. 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

  11. What studies tell us about the variation of menarche age?

  12. 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

  13. 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

  14. 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)

  15. 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)

  16. Mean age (SD) of some characteristics of sexual maturation for U.S. boys (NHANES study) Source: Sun et al., PEDIATRICS, 2002, 110: 911-919

  17. Age at natural menopause as a marker of reproductive aging

  18. Mean age (SD) at natural menopause

  19. Our results using the MIDUS study

  20. 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

  21. A 30-40 minute telephone survey A 114 page mail survey Number of respondents: 4,242 Number of respondents: 3,690

  22. MIDUS SAMPLE POPULATION DISTRIBUTIONS (%)

  23. DISTRIBUTION OF AGE AT MENARCHE IN THE MIDUS SAMPLE

  24. DISTRIBUTION OF AGE AT MENOPAUSE IN THE MIDUS SAMPLE

  25. DISTRIBUTION OF AGE AT DEATH, SWEDISH FEMALES, 1995 Data source: Human Mortality Database

  26. Variation for characteristics of human aging and development

  27. Variation of age at onset of menarche and age at death (in 2005)

  28. Variation of age at onset of menarche and age at death (in 2005) after 10 years

  29. Mean Values and Standard Deviations for Human Developmental Characteristics

  30. 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

  31. For More Information and Updates Visit Our Website: http://longevity-science.org You are Welcome to Post Your Comments at our Blog: http://longevity-science.blogspot.com/

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