|Scott, Tammy - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
Submitted to: Society for Neuroscience Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/29/2016
Publication Date: 11/12/2016
Citation: Miller, M.G., Thangthaeng, N., Scott, T.M., Shukitt Hale, B. 2016. A clinically relevant frailty index for aging rats. Society for Neuroscience Abstracts and Proceedings. Program No. 596.17.
Technical Abstract: Frailty is a clinical syndrome that is increasingly prevalent during aging. Frailty involves the confluence of reduced strength, speed, physical activity, and endurance, and it is associated with adverse health outcomes. Frailty indices have been developed to diagnose frailty in older adult populations, and a pre-clinical frailty index has been developed for the C57BL/6 mouse. The present study adapts these existing clinical and pre-clinical indices of frailty to the Fischer (F344) rat, which is commonly used in aging research. One hundred and thirty-three male F344 rats (17mo) completed a battery of commonly administered behavioral tasks, including: forelimb wire-hang (strength), rotarod (speed), open field (physical activity), and inclined screen (endurance). This age was selected because it provides adequate remaining lifespan in which to conduct an intervention study without undo mortality and at which age-related risk factors may still be modifiable. Within this cohort, rats whose performance put them in the lowest quintile were identified for each task, and the number of tasks on which a rat performed poorly determined their frailty index. Rats that performed poorly on two tasks were considered mildly frail (17.29 percent, n = 23), and rats that performed poorly on 3-4 tasks were considered frail (2.26 percent, n = 3). Logistic regression of 100-day survival revealed that mildly frail rats were 3.8 times and frail rats were 27.5 times more likely to die during that period than non-frail rats (p = 0.038; 95 percent CI: 2.030, 372.564). The selected criterion tests, cutoff points, and index provide a potential standardized definition for frailty in aged F344 rats that is consistent with existing frailty indices for humans and mice, and present a potentially useful tool for excluding frail animals which may not survive a chronic intervention study.