Correlating Progressive Frailty in Aging With Parental Longevity
A nice demonstration of the degree to which the pace of aging is inherited - but remember that for the vast majority of us, lifestyle choices have more influence than genes, while progress in medical technology trumps all such concerns: "Various measures incorporated in geriatric assessment have found their way into frailty indices (FIs), which have been used as indicators of survival/mortality and longevity. Our goal is to understand the genetic basis of healthy aging to enhance its evidence base and utility. We constructed a FI as a quantitative measure of healthy aging and examined its characteristics and potential for genetic analyses. Two groups were selected from two separate studies. One group (OLLP for offspring of long-lived parents) consisted of unrelated participants at least one of whose parents was age 90 or older, and the other group of unrelated participants (OSLP for offspring of short-lived parents), both of whose parents died before age 76. FI(34) scores were computed from 34 common health variables and compared between the two groups. The FI(34) was better correlated than chronological age with mortality. The mean FI(34) value of the OSLP was 31% higher than that of the OLLP. The FI(34) increased exponentially, at an instantaneous rate that accelerated 2.0% annually in the OLLP and 2.7 % in the OSLP consequently yielding a 63% larger accumulation in the latter group. The results suggest that accumulation of health deficiencies over the life course is not the same in the two groups, likely due to inheritance related to parental longevity. Consistent with this, [sibling pairs] were significantly correlated regarding FI(34) scores, and heritability of the FI(34) was estimated to be 0.39. ... Variation in the FI(34) is, in part, due to genetic variation; thus, the FI(34) can be a phenotypic measure suitable for genetic analyses of healthy aging."