PP279 - UREA-TO-CREATININE RATIO AS A PRAGMATIC BIOMARKER OF PERSISTENT CATABOLISM AND ITS ASSOCIATION WITH MUSCLE COMPOSITION AT ICU DISCHARGE: A BRAZILIAN REAL-WORLD COHORT

PP279

UREA-TO-CREATININE RATIO AS A PRAGMATIC BIOMARKER OF PERSISTENT CATABOLISM AND ITS ASSOCIATION WITH MUSCLE COMPOSITION AT ICU DISCHARGE: A BRAZILIAN REAL-WORLD COHORT

J. R. Moraes¹, L. H. David Barrachi², H. S. Lima³, D. O. Toledo^1,*, G. B. Yacoub¹, F. A. Ribeiro¹, P. B. De Paula Nogueira¹, J. M. S. Junior^1,4

¹Clinical Nutrition, Einstein Israeli Hospital, ²Nutrition Student, Albert Einstein Israeli Faculty , ³Medicine Student, Albert Einstein Faculty , ⁴University of São Paulo, São Paulo, Brazil

Rationale: Critical illness induces sustained hypercatabolism and skeletal muscle loss that may persist after ICU discharge. The urea-to-creatinine ratio (UCR), derived from routine laboratory tests, has been proposed as a biomarker of protein catabolism. We evaluated its association with muscle quantity and quality at ICU discharge in a real-world cohort.

Methods: This observational study included adult ICU survivors with available laboratory and body composition data at discharge. UCR was calculated from serum urea and creatinine. Muscle quantity and quality were assessed by bioelectrical impedance analysis (skeletal muscle mass, phase angle) and calf circumference. Associations were tested using Pearson correlation and adjusted linear models controlling for sex and ICU length of stay.

Results: Among 107 patients, ICU discharge occurred with marked muscle impairment: mean skeletal muscle mass was 23.0 ± 6.2 kg, mean phase angle 3.13 ± 1.15°, reduced calf circumference was present in 68.5%, and low muscularity in 77.6%. Median UCR was 3.29 (IQR 2.12–4.41). Higher UCR was associated with lower creatinine (r = -0.25, p = 0.0098), phase angle (r = -0.29, p = 0.0024), and calf circumference (r = -0.30, p = 0.0037). In adjusted models, UCR remained independently associated with phase angle (β = -0.013, p = 0.0038) and calf circumference (β = -0.060, p = 0.0040), while the association with skeletal muscle mass remained inverse but non-significant.

Conclusion: ICU discharge occurred in a context of substantial muscle depletion and metabolic heterogeneity. UCR was independently associated with markers of muscle quality and peripheral muscle reserve, supporting its role as a pragmatic biomarker of persistent catabolism. Further studies should define actionable thresholds and prognostic value.

Disclosure of Interest: None declared