Development of a Rat Clinical Frailty Index.

Rats are a commonly used model for aging studies, and a frailty assessment tool for rats would be of considerable value. There has been a recent focus on the development of preclinical models of frailty in mice. A mouse clinical frailty index (FI) was developed based on clinical frailty assessment tools. This FI measures the accumulation of clinically evident health-related deficits in mice. This paper aimed to develop a rat clinical FI. Male Fischer 344 rats were aged from 6 to 9 months (n = 12), and from 13 to 21 months (n = 41). A FI comprised of 27 health-related deficits was developed from a review of the literature and consultation with a veterinarian. Deficits were scored 0 if absent, 0.5 if mild, or 1 if severe. A FI score was determined for each rat every 3-4 months, and for the older group mortality was assessed up to 21 months. Mean FI scores significantly increased at each time point for the older rats. A high FI score measured at both 17 months of age and terminally was also associated with decreased probability of survival as assessed with Kaplan-Meier curves. The rat clinical FI has significant value for use in aging and interventional studies.

Yorke A ，Kane AE ，Hancock Friesen CL ，Howlett SE ，O'Blenes S ... -  《-》

A Comparison of Two Mouse Frailty Assessment Tools.

The mouse clinical frailty index and the mouse frailty phenotype assessment are two recently developed tools used to assess frailty in mice. The objectives of this study were to investigate whether the same mice are identified as frail with both tools and to examine the association of each of the assessment tools with age and frailty-related outcomes. Frailty was measured using both tools in old (~24 months; n = 36) C57BL/6 male mice. After 2 weeks, blood pressure and heart rate were measured and serum samples were collected for analysis of alanine aminotransferase, creatinine, and albumin levels. The mouse frailty phenotype assessment identified no mice as frail but modification of the assessment tool identified six mice as frail. The mouse clinical frailty index identified 16 mice as frail and the agreement between the two scales was 50.0%. Increasing clinical frailty index scores were correlated with low serum alanine aminotransferase, as well as decreased heart rate, and reduced heart rate variance. We conclude that, consistent with equivalent frailty assessment scales in humans, both tools have value but do not necessarily identify the same mice as frail.

Kane AE ，Huizer-Pajkos A ，Mach J ，Mitchell SJ ，de Cabo R ，Le Couteur DG ，Howlett SE ，Hilmer SN ... -  《-》

Development and validation of a frailty index in the Longitudinal Aging Study Amsterdam.

Hoogendijk EO ，Theou O ，Rockwood K ，Onwuteaka-Philipsen BD ，Deeg DJH ，Huisman M ... -  《-》

A Clinically Relevant Frailty Index for Aging Rats.

Frailty is a clinical syndrome that is increasingly prevalent during aging. Frailty involves the confluence of reduced strength, speed, physical activity, and endurance and is associated with adverse health outcomes. The present study adapts existing clinical and preclinical indices of frailty to the Fischer (F344) rat. Male F344 rats (n = 133; 17 mo) completed a battery of behavioral tasks, including forelimb wire suspension (strength), rotarod (speed), open field (physical activity), and inclined screen (endurance). Rats that performed poorly (lowest quintile) on two tasks were considered mildly frail (17.29%, n = 23), and rats that performed poorly on 3-4 tasks were considered frail (2.26%, 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 nonfrail rats (p = .038; 95% confidence interval: 2.030, 372.564). The selected criterion tests, cutoff points, and index provide a potential tool for identifying frailty in aged F344 rats, which is consistent with existing frailty indices for humans and mice.

Miller MG ，Thangthaeng N ，Shukitt-Hale B 《-》

Frail-VIG index: a concise frailty evaluation tool for rapid geriatric assessment.

Amblàs-Novellas J ，Martori JC ，Espaulella J ，Oller R ，Molist-Brunet N ，Inzitari M ，Romero-Ortuno R ... -  《BMC Geriatrics》