A procedure for creating a frailty index based on deficit accumulation in aging mice.
This study developed an approach to quantify frailty with a frailty index (FI) and investigated whether age-related changes in contractions, calcium transients, and ventricular myocyte length were more prominent in mice with a high FI. The FI combined 31 variables that reflect different aspects of health in middle-aged (∼12 months) and aged (∼30 months) mice of both sexes. Aged animals had a higher FI than younger animals (FI = 0.43 ± 0.03 vs 0.08 ± 0.02, p < .001, n = 12). Myocyte hypertrophy increased by 30%-50% as the FI increased in aged animals. Peak contractions decreased more than threefold from lowest to highest FI values in aged mice (p < .037), but calcium transients were unaffected. Similar results were seen with an FI based on eight noninvasive variables identified as underlying factors. These results show that an FI can be developed for murine models and suggest that age-associated changes in myocytes are more prominent in animals with a high FI.
Department of Pharmacology, Dalhousie University, 5850 College Street, Sir Charles Tupper Medical Building, Halifax, Nova Scotia, Canada B3H 1X5.
Randi J
RJ
Parks
Elias
E
Fares
Jennifer K
JK
Macdonald
Matthew C
MC
Ernst
Christopher J
CJ
Sinal
Kenneth
K
Rockwood
Susan E
SE
Howlett
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000818:Animals; D015220:Calcium Channels / Q000502:physiology*; D006332:Cardiomegaly / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D008297:Male; D051379:Mice; D009200:Myocardial Contraction / Q000502:physiology*; D012720:Severity of Illness Index
D015220:Calcium Channels