Description: It is believed that exponential growth of mortality with age (Gompertz law) is followed by a period of deceleration, with slower rates of mortality increase at older ages. We compared the performance (goodness-of-fit) of two competing models-the Gompertz model and the logistic (Kannisto) model using data for 22 birth cohorts of U.S. men and women in the age interval 80-105 years. In all cases the Gompertz model fits mortality data significantly better than the Kannisto model. Another approach to study mortality patterns at advanced ages is based on Life table Aging Rate (LAR). It was found that for all studied 24 single-year birth cohorts LAR does not change significantly with age in the age interval 80-100 years suggesting the validity of Gompertz law. These results suggest that mortality deceleration at advanced ages is not a universal phenomenon, and human survival follows the Gompertz law up to very old ages.

Description: Earlier studies found that parental characteristics as well as early-life conditions and mid-life environment play a significant role in survival to advanced ages. However, little is known about simultaneous effects of all these three factors on longevity. This ongoing study attempts to fill this gap by comparing American centenarians born in 1890-1891 with their short-lived peers born in 1890 and died at age 65 years. The records were taken from computerized family histories, which were then linked to 1900 and 1930 U.S. censuses. The study found that parental longevity and some mid-life characteristics proved to be significant predictors of longevity while the role of childhood conditions was less important. More centenarians were born in the second half of the year compared to controls suggesting early origins of longevity. The results of this study suggest that familial background, early-life conditions and mid-life characteristics play an important role in longevity.