Does Cognitive Function at Kidney Transplant Predict Post-Transplant Outcomes?

Background: Children with kidney failure are at risk of neurocognitive impairments due to multiple factors, including kidney dysfunction and associated comorbidities. These impairments may affect post-transplant outcomes, given the complexity of the post-transplant course. This study aimed to evaluate the effects of pretransplant intelligence quotient (IQ) on posttransplant outcomes in children. Methods: This retrospective study included 100 pediatric kidney transplant candidates who underwent a Bayley Assessment of Infant and Toddler or Wechsler Intelligence Scale assessment as part of their pre-transplant neuropsychological evaluation between January 1, 2010, and October 31, 2022. Linear regression models were used to analyze the effect of baseline IQ on the 1-year estimated glomerular filtration rate (eGFR). Cox regression models were employed to determine the effect of IQ on patient and graft survival. Results: Table 1 presents clinical characteristics of the study cohort. The median IQ of participants was 89.00 (76.75, 99.00). In children aged 0–12 years, there was no statistically significant effect of pretransplant IQ on 1-year eGFR (β = −1.0; 95% CI: −6.0, 3.9; p = 0.66). Among adolescents aged 13–18 years, a higher IQ was associated with a lower 1-year eGFR (β = −7.1; 95% CI: −13.2, −1.1; p = 0.02). We found that higher pretransplant IQ was significantly associated with a lower risk of death across all age groups (HR per 10-point increase: 0.49; 95% CI: 0.27, 0.89; p = 0.02). However, we found no significant effect of pretransplant IQ on the hazard of graft loss (HR per 10-point increase: 1.16; 95% CI: 0.72, 1.85; p = 0.54). Conclusion: Higher pretransplant IQ was associated with improved posttransplant patient survival. However, among adolescents, higher IQ correlated with lower 1-year eGFR. Adolescents with higher IQ may exhibit greater cognitive independence, which may lead to reduced parental oversight and inconsistent medication adherence, ultimately contributing to reduced graft function.