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Frailty, fitness and late-life mortality in relation to chronological and biological age.

Mitnitski AB, Graham JE, Mogilner AJ, Rockwood K - BMC Geriatr (2002)

Bottom Line: From the frailty index, relative (to CA) fitness and frailty were estimated, as was an individual's biological age.The average value of the frailty index increased with age in a log-linear relationship (r = 0.91; p < 0.001).The frailty index is a sensitive predictor of survival.

View Article: PubMed Central - HTML - PubMed

Affiliation: Ecole Polytechnique, Montreal QB, Canada. arnold@grbb.polymtl.ca

ABSTRACT

Background: People age at remarkably different rates, but how to estimate trajectories of senescence is controversial.

Methods: In a secondary analysis of a representative cohort of Canadians aged 65 and over (n = 2914) we estimated a frailty index based on the proportion of 20 deficits observed in a structured clinical examination. The construct validity of the index was examined through its relationship to chronological age (CA). The criterion validity was examined in its ability to predict mortality, and in relation to other predictions about aging. From the frailty index, relative (to CA) fitness and frailty were estimated, as was an individual's biological age.

Results: The average value of the frailty index increased with age in a log-linear relationship (r = 0.91; p < 0.001). In a Cox regression analysis, biological age was significantly more highly associated with death than chronological age. The average increase in the frailty index (i.e. the average accumulation of deficits) amongst those with no cognitive impairment was 3 per cent per year.

Conclusions: The frailty index is a sensitive predictor of survival. As the index includes items not traditionally related to adverse health outcomes, the finding is compatible with a view of frailty as the failure to integrate the complex responses required to maintain function.

No MeSH data available.


Related in: MedlinePlus

Time to death by cognitive diagnostic groups as a function of chronological and biological age. Solid circles correspond to average values of time to death (across all subjects of the particular diagnostic group) with respect to averaged BA distributed along a straight line (r = - 0.98, p < 0.001). Empty circles, (o) correspond to time to death with respect to CA and did not show such a pattern. The following abbreviations are used for the diagnostic groups: NCI (No Cognitive Impairment), CIND (Cognitive Impairment No Dementia), AD (Alzheimer's disease), VD (vascular dementia).
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Figure 5: Time to death by cognitive diagnostic groups as a function of chronological and biological age. Solid circles correspond to average values of time to death (across all subjects of the particular diagnostic group) with respect to averaged BA distributed along a straight line (r = - 0.98, p < 0.001). Empty circles, (o) correspond to time to death with respect to CA and did not show such a pattern. The following abbreviations are used for the diagnostic groups: NCI (No Cognitive Impairment), CIND (Cognitive Impairment No Dementia), AD (Alzheimer's disease), VD (vascular dementia).

Mentions: Figure 5 presents the mean months to death, plotted against mean chronological and biological age, for the main CSHA cognitive diagnostic groups. As hypothesised, biological age predicts death in a dose-response relationship. While chronological age has only a weak relationship to time to death, given diagnosis, biological age is strongly inversely correlated with the time to death (r = -0.98, p < 0.01).


Frailty, fitness and late-life mortality in relation to chronological and biological age.

Mitnitski AB, Graham JE, Mogilner AJ, Rockwood K - BMC Geriatr (2002)

Time to death by cognitive diagnostic groups as a function of chronological and biological age. Solid circles correspond to average values of time to death (across all subjects of the particular diagnostic group) with respect to averaged BA distributed along a straight line (r = - 0.98, p < 0.001). Empty circles, (o) correspond to time to death with respect to CA and did not show such a pattern. The following abbreviations are used for the diagnostic groups: NCI (No Cognitive Impairment), CIND (Cognitive Impairment No Dementia), AD (Alzheimer's disease), VD (vascular dementia).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC88955&req=5

Figure 5: Time to death by cognitive diagnostic groups as a function of chronological and biological age. Solid circles correspond to average values of time to death (across all subjects of the particular diagnostic group) with respect to averaged BA distributed along a straight line (r = - 0.98, p < 0.001). Empty circles, (o) correspond to time to death with respect to CA and did not show such a pattern. The following abbreviations are used for the diagnostic groups: NCI (No Cognitive Impairment), CIND (Cognitive Impairment No Dementia), AD (Alzheimer's disease), VD (vascular dementia).
Mentions: Figure 5 presents the mean months to death, plotted against mean chronological and biological age, for the main CSHA cognitive diagnostic groups. As hypothesised, biological age predicts death in a dose-response relationship. While chronological age has only a weak relationship to time to death, given diagnosis, biological age is strongly inversely correlated with the time to death (r = -0.98, p < 0.01).

Bottom Line: From the frailty index, relative (to CA) fitness and frailty were estimated, as was an individual's biological age.The average value of the frailty index increased with age in a log-linear relationship (r = 0.91; p < 0.001).The frailty index is a sensitive predictor of survival.

View Article: PubMed Central - HTML - PubMed

Affiliation: Ecole Polytechnique, Montreal QB, Canada. arnold@grbb.polymtl.ca

ABSTRACT

Background: People age at remarkably different rates, but how to estimate trajectories of senescence is controversial.

Methods: In a secondary analysis of a representative cohort of Canadians aged 65 and over (n = 2914) we estimated a frailty index based on the proportion of 20 deficits observed in a structured clinical examination. The construct validity of the index was examined through its relationship to chronological age (CA). The criterion validity was examined in its ability to predict mortality, and in relation to other predictions about aging. From the frailty index, relative (to CA) fitness and frailty were estimated, as was an individual's biological age.

Results: The average value of the frailty index increased with age in a log-linear relationship (r = 0.91; p < 0.001). In a Cox regression analysis, biological age was significantly more highly associated with death than chronological age. The average increase in the frailty index (i.e. the average accumulation of deficits) amongst those with no cognitive impairment was 3 per cent per year.

Conclusions: The frailty index is a sensitive predictor of survival. As the index includes items not traditionally related to adverse health outcomes, the finding is compatible with a view of frailty as the failure to integrate the complex responses required to maintain function.

No MeSH data available.


Related in: MedlinePlus