March 16, 2011

Longevity of people with long-lived relatives

European Journal of Human Genetics , (16 March 2011) | doi:10.1038/ejhg.2011.40

The genetic component of human longevity: analysis of the survival advantage of parents and siblings of Italian nonagenarians

Alberto Montesanto et al.

Many epidemiological studies have shown that parents, siblings and offspring of long-lived subjects have a significant survival advantage when compared with the general population. However, how much of this reported advantage is due to common genetic factors or to a shared environment remains to be resolved.

We reconstructed 202 families of nonagenarians from a population of southern Italy. To estimate the familiarity of human longevity, we compared survival data of parents and siblings of long-lived subjects to that of appropriate Italian birth cohorts. Then, to estimate the genetic component of longevity while minimizing the variability due to environment factors, we compared the survival functions of nonagenarians' siblings with those of their spouses (intrafamily control group).

We found that both parents and siblings of the probands had a significant survival advantage over their Italian birth cohort counterparts. On the other hand, although a substantial survival advantage was observed in male siblings of probands with respect to the male intrafamily control group, female siblings did not show a similar advantage. In addition, we observed that the presence of a male nonagenarians in a family significantly decreased the instant mortality rate throughout lifetime for all the siblings; in the case of a female nonagenarians such an advantage persisted only for her male siblings.

The methodological approach used here allowed us to distinguish the effects of environmental and genetic factors on human longevity. Our results suggest that genetic factors in males have a higher impact than in females on attaining longevity.



Annie Mouse said...

I dont see how a study like this can be done with out allowing for child birth. The single greatest factor for female longevity is childbrith. Women who dont have any children live longest. Women who have children and survive, have shorter lifespans than their single sisters.

A typical male nonagenerian would be embedded in his family, cared for by his womenfolk.

A typical female nonagenarian is alone, or in a nunnery. Even if she is embedded in her family, she will have supported the household activities until she was no longer able to.

I am not convenced social aspects are compensated for here.

princenuadha said...

It makes perfect sense that men's health would vary more by genetics than women's health. Conversely women's healthy varies more by social environment than men's.

Women as a group tend to hoard more health recourses and services in a given community. In the US more money is spent on women's health services, even apart from reproductive care, and more money is also spent on researching women's health. The disproportionate funding of breast cancer is very emblematic of the health industry's focus on women. Despite the fact that prostate cancer effects about the same number of men funding for research on prostate cancer is far less.

Men as a group are at greatr risk for most diseases, while having shorter lifespans, yet there is less spending in men's health research and services. This means that there is less opportunity for men to receive different outcomes based on non genetic health services. On the other hand because more research and services are geared towards women, women of greater means will be on the receiving end of health services that skew outcomes for non genetic reasons.

To continue with my analogy breast cancer (for women) far out funds prostate cancer (for men) while at the same time white middle class women receive most the health benefits of said research over black or poor women.

Fanty said...

On my mothers side, my grandmom and all her sisters have had 7-10 Children and lived 90+ years each of them.

Their mother had 11 children and smoked. Still she died in the age of 102 years.

There must clearly be other factors than childbirth and smoking/drinking influencing longlivety.

Well, that lineage is a "K" lineage and I once read about that people with mtDNA K would live longer than average. But never heard about that again.