Abstract Type : Oral presentation
Abstract Submission No.: A-0772
Abstract Topic : Renal Conservative Care + Geriatric Nephrology + Sarcopenia

Comparison of eGFR Discordance Metrics for Predicting Activities of Daily Living Dependence in Older Adults With Chronic Kidney Disease

Sojung Youn¹, Sungmi Kim², Young Youl Hyun³, Sungjin Chung⁴, Soon Hyo Kwon⁵, Sung Joon Shin⁶, Gang-Jee Ko⁷, Jae Won Yang⁸, Suk Young Kim⁹, Yu Ah Hong⁹
¹Department of Internal Medicine-Nephrology, The Catholic University of Korea Bucheon St. Mary's Hospital , Korea, Republic of
²Department of Internal Medicine-Nephrology, The Catholic University of Korea Eunpyeong St. Mary's Hospital, Korea, Republic of
³Department of Internal Medicine-Nephrology, Kangbuk Samsung Medical Center, Korea, Republic of
⁴Department of Internal Medicine-Nephrology, The Catholic University of Korea Yeouido St. Mary's Hospital , Korea, Republic of
⁵Department of Internal Medicine-Nephrology, Soonchunhyang University Seoul Hospital, Korea, Republic of
⁶Department of Internal Medicine-Nephrology, Dongguk University Ilsan Hospital, Korea, Republic of
⁷Department of Internal Medicine-Nephrology, Korea University Guro Hospital, Korea, Republic of
⁸Department of Internal Medicine-Nephrology, Wonju Severance Christian Hospital, Korea, Republic of
⁹Department of Internal Medicine-Nephrology, The Catholic University of Korea Daejeon St. Mary's Hospital , Korea, Republic of

Objectives : In older adults, reduced muscle mass may cause creatinine-based eGFR (eGFRcr) to overestimate kidney function compared with cystatin C–based eGFR (eGFRcys), resulting in eGFR discordance. This discrepancy may reflect frailty and functional decline. We examined the association between eGFR discordance and ADL dependence and compared four discordance metrics.
Methods : This cross-sectional study used baseline data from 497 patients aged ≥70 years from 17 Korean multicenter prospective chronic kidney disease (CKD) cohorts. eGFRcr and eGFRcys were calculated using the 2021 CKD-EPI creatinine and 2012 CKD-EPI cystatin C equations, respectively. Discordance metrics included eGFR_diff_1 (eGFRcys−eGFRcr), eGFR_diff_2 ((eGFRcys−eGFRcr)/eGFRcr), eGFR_ratio (eGFRcys/eGFRcr), and eGFR_log_diff (log(eGFRcys)−log(eGFRcr)). ADL dependence was defined as a Korean Activities of Daily Living score ≥8. Logistic regression and ROC analyses were performed with adjustment for age, sex, diabetes, hypertension, BMI, albumin, hemoglobin, and hsCRP.
Results : The mean age was 78.7±5.5 years, 54.3% were male, and 53.9% had diabetes. ADL dependence was observed in 89 participants (17.9%). In univariate analyses, all discordance metrics were significantly associated with ADL dependence (diff_1 OR 0.964, 95% CI 0.948–0.980; diff_2 OR 0.128, 95% CI 0.054–0.304; ratio OR 0.128, 95% CI 0.054–0.304; log_diff OR 0.558, 95% CI 0.401–0.777; all p<0.001). These associations remained significant after multivariable adjustment (diff_1 OR 0.931, 95% CI 0.903–0.960; diff_2 OR 0.029, 95% CI 0.005–0.167; ratio OR 0.029, 95% CI 0.005–0.167; log_diff OR 0.422, 95% CI 0.223–0.801). In ROC analyses, adjusted AUC values were 0.718 for diff_1, 0.753 for diff_2, 0.753 for ratio, and 0.763 for log_diff, indicating the best discriminative performance for the logarithmic discordance metric.
Conclusions : eGFR discordance was independently associated with ADL dependence in older adults with CKD. Among the evaluated metrics, logarithmic discordance showed the best predictive performance, although the overall discriminative ability remained modest.