Preclinical studies are important in identifying the underlying mechanisms contributing to frailty. Frailty studies have mainly focused on male rodents with little directed at female rodents. Therefore, the purposes of this study were to identify the onset and prevalence of frailty across the lifespan in female mice, and to determine if frailty predicts mortality. Female C57BL/6 (n=27) mice starting at 17 months of age were assessed across the lifespan using a frailty phenotype, which included body weight, walking speed, strength, endurance and physical activity. The onset of frailty occurred at approximately 17 months (1/27 mice), with the prevalence of frailty increasing thereafter. At 17 months 11.1% of the mice were pre-frail and by 26 months peaked at 36.9%. The percentage of frail mice progressively increased up to 66.7% at 32 months. Non-frail mice lived to 29 months while pre-frail/frailty only lived to 26 months (p=0.04). In closing, using a mouse frailty phenotype, we are able to identify that the prevalence of frailty in female mice increases across the lifespan and accurately predicts mortality. Together, this frailty phenotype has potential to yield information about the underlying mechanisms contributing to frailty.

中文翻译：

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使用表型评估工具鉴定雌性小鼠的虚弱特征。

临床前研究对于确定导致虚弱的潜在机制很重要。脆弱性研究主要集中在雄性啮齿动物上，很少针对雌性啮齿动物。因此，这项研究的目的是确定衰弱在雌性小鼠中的发病率和患病率，并确定衰弱是否可以预测死亡率。使用脆弱表型评估了始于17个月大的雌性C57BL / 6（n = 27）小鼠的寿命，该表型包括体重，步行速度，力量，耐力和身体活动。脆弱的发作发生在大约17个月（1/27只小鼠），此后脆弱的患病率增加。在17个月时，有11.1％的小鼠是脆弱的，到26个月时达到了36.9％的峰值。脆弱小鼠的百分比在32个月时逐渐增加至66.7％。非脆弱小鼠存活至29个月，而脆弱/脆弱小鼠仅存活至26个月（p = 0.04）。最后，使用小鼠脆弱表型，我们能够确定雌性小鼠的脆弱性在整个生命周期中都在增加，并且可以准确地预测死亡率。总之，这种脆弱的表型有可能产生有关导致脆弱的潜在机制的信息。