Familial Aggregation of Survival and Late Female Reproduction

Abstract

Women giving birth at advanced reproductive ages in natural fertility conditions have been shown to have superior postmenopausal longevity. It is unknown whether improved survival is more likely among relatives of late-fertile women. This study compares survival past age 50 of men with and without a late-fertile sister in two populations: Utahns born in 1800-1869 identified from the Utah Population Database and Québec residents born in 1670-1750 identified from the Programme de recherche en démographie historique. Male survival was greater for those with, rather than without, a sister reproducing after age 45, particularly among men with at least three sisters (Utah rate ratio [RR] = .801, 95% CI = 0.687-0.940; Quebec RR = .786, 95% CI = 0.664-0.931). Survival of wives was unaffected by whether their husbands had a late-fertile sister, suggesting a weak influence of unmeasured socioenvironmental factors. These results support the hypothesis that late female fertility and slow somatic aging may be promoted by the same genetic variants.

The Epidemiology of Longevity and Exceptional Survival

“…Centenarian women, for example, are more likely to have borne children late in life than women who died at an earlier age (67,68). Furthermore, according to data from historical population databases, late ability to reproduce is associated with improved survival not only in the women (69) but also in their male family members (70), which supports the hypothesis that late fertility and slower somatic aging might share underlying genetic determinants.…”

How grandmother effects plus individual variation in frailty shape fertility and mortality: Guidance from human–chimpanzee comparisons

“…Life history variation among individuals of the same population often seems to go in the opposite direction as well. Women with higher fertility rates and later ages at last birth also have higher subsequent survival rates (23)(24)(25)(67)(68)(69). Such apparent absence of the expected tradeoffs within populations is a regular finding in field studies in animal behavior (70)(71)(72).…”

Rivalry, solidarity, and longevity among siblings

“…We included two variables occurring in early life as proxies for potential health implications during development. The first is mother's age at birth which has been associated with child health even in the long-term (KemkesGrottenthaler 2004;Smith et al 2009). We categorized it as ages 15-24, 25-34, and 35+.…”

“…A growing number of medical, epidemiological, and historical demographic studies find a relationship between early life conditions and later life mortality (Oris 2005;Bengtsson and Mineau 2009;Ben-Shlomo and Kuh 2002;Smith et al 2009). Although the discussion on the causal mechanisms behind this link continues, it is clear that exposure to various risk factors in childhood has major negative effects on health and life expectancy in later life.…”