Differences Between Cystatin C– and Creatinine-Based Estimated GFR—Early Evidence of a Clinical Marker for Frailty

Frailty is defined as a medical syndrome of multisystem dysregulation and is manifested as compromised resistance to stressors that increases vulnerability to dependence and mortality.1 Although frailty was originally identified and validated in community-dwelling older adults, there is increasing evidence that frailty is a marker of health status for adult nephrology patients of all ages.2-4 Frailty is common among patients with kidney disease, likely due to elevated levels of inflammation, lack of physical activity, and sarcopenia.