Abstract
This study explores the effects of early-life and middle-life conditions on exceptional longevity using two matched case-control studies. The first study compares 198 validated centenarians born in the United States between 1890 and 1893 to their shorter-lived siblings. Family histories of centenarians were reconstructed and exceptional longevity validated using early U.S. censuses, the Social Security Administration Death Master File, state death indexes, online genealogies, and other supplementary data resources. Siblings born to young mothers (aged less than 25 years) had significantly higher chances of living to 100 compared to siblings born to older mothers (odds ratio = 2.03, 95% CI = 1.33–3.11, p = .001). Paternal age and birth order were not associated with exceptional longevity. The second study explores whether people living to 100 years and beyond differ in physical characteristics at a young age from their shorter-lived peers. A random representative sample of 240 men who were born in 1887 and survived to age 100 was selected from the U.S. Social Security Administration database and linked to U.S. World War I civil draft registration cards collected in 1917 when these men were 30 years old. These validated centenarians were then compared to randomly selected controls who were matched by calendar year of birth, race, and place of draft registration in 1917. Results showed a negative association between “stout” body build (being in the heaviest 15 percent of the population) and survival to age 100. Having the occupation of “farmer” and a large number of children (4 or more) at age 30 increased the chances of exceptional longevity. The results of both studies demonstrate that matched case-control design is a useful approach in exploring effects of early-life conditions and middle-life characteristics on exceptional longevity.
Acknowledgments
This study was supported by the U.S. National Institute on Aging (Grant R01 AG028620). We are grateful to two anonymous reviewers for their constructive criticism and useful suggestions. Earlier results of this study were presented and discussed at the 2006 and 2008 annual meetings of the Population Association of America, the 2008 annual meeting of the Gerontological Society of America, the 2008 Society of Actuaries “Living to 100 and Beyond” international symposium, and the 2007 and 2009 annual meetings of the International Network on Health Expectancy and the Disability Process (REVES).