Prevalence and outcomes of fragility: a frailty-inflammation phenotype in children with chronic kidney disease

Background Frailty is a condition of decreased physiologic reserve and increased vulnerability to stressors. Frailty in combination with inflammation has been associated with increased mortality risk in adults with advanced chronic kidney disease (CKD). This study aimed to investigate prevalence and outcomes associated with a frailty-inflammation phenotype, or “fragility,” in children with CKD. Methods We analyzed 557 children (age 6–19 years, eGFR 30–90 ml/min/1.73 m 2 ) from the Chronic Kidney Disease in Children (CKiD) study. Based on adult models, the CKiD fragility model included four indicators: (1) suboptimal growth/weight gain (BMI 30% or initiation of renal replacement therapy within 3 years). Results Prevalence of fragility indicators 1 year after study entry were 39% (suboptimal growth/weight gain), 62% (low muscle mass), 29% (fatigue), and 18% (inflammation). Prevalence of adverse outcomes during the subsequent 3 years were 13% (frequent infection), 22% (hospitalization), and 17% (rapid CKD progression). Children with ≥ 3 fragility indicators had 3.16-fold odds of frequent infection and 2.81-fold odds of hospitalization, but did not have rapid CKD progression. Conclusions A fragility phenotype, characterized by the presence of ≥ 3 indicators, is associated with adverse outcomes, including infection and hospitalization in children with CKD.