A clinical frailty index in aging mice: comparisons with frailty index data in humans.
We previously quantified frailty in aged mice with frailty index (FI) that used specialized equipment to measure health parameters. Here we developed a simplified, noninvasive method to quantify frailty through clinical assessment of C57BL/6J mice (5-28 months) and compared the relationship between FI scores and age in mice and humans. FIs calculated with the original performance-based eight-item FI increased from 0.06 ± 0.01 at 5 months to 0.36 ± 0.06 at 19 months and 0.38 ± 0.04 at 28 months (n = 14). By contrast, the increase was graded with a 31-item clinical FI (0.02 ± 0.005 at 5 months; 0.12 ± 0.008 at 19 months; 0.33 ± 0.02 at 28 months; n = 14). FI scores calculated from 70 self-report items from the first wave of the Survey of Health, Ageing and Retirement in Europe were plotted as function of age (n = 30,025 people). The exponential relationship between FI scores and age (normalized to 90% mortality) was similar in mice and humans for the clinical FI but not the eight-item FI. This noninvasive FI based on clinical measures can be used in longitudinal studies to quantify frailty in mice. Unlike the performance-based eight-item mouse FI, the clinical FI exhibits key features of the FI established for use in humans.
Department of Pharmacology.
Jocelyne C
JC
Whitehead
Carleton Animal Care Facility.
Barbara A
BA
Hildebrand
Department of Pharmacology.
Michael
M
Sun
Department of Medicine (Geriatric Medicine) and.
Michael R
MR
Rockwood
Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada.
Robert A
RA
Rose
Department of Medicine (Geriatric Medicine) and.
Kenneth
K
Rockwood
Department of Pharmacology, Department of Medicine (Geriatric Medicine) and Susan.Howlett@dal.ca.
Susan E
SE
Howlett
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000818:Animals; D005260:Female; D005500:Follow-Up Studies; D016330:Frail Elderly / Q000706:statistics & numerical data*; D015577:Geriatric Assessment / Q000379:methods*; D006304:Health Status; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013997:Time Factors
Deficit accumulation; Deficit index; Frailty index; Senescence.