Prognostic Value of CRP-to-Albumin Ratio in Elderly ICU Patients: A Retrospective Study

Öz

Background: Systemic inflammation and malnutrition are key contributors to adverse outcomes among older adults admitted to the ICU. The prognostic relevance of CRP-to-albumin ratio (CAR), reflecting combined inflammatory and nutritional status, was evaluated in relation to 28-day mortality. Methods: A retrospective cohort of 207 older adults (≥65 years) admitted to the ICU between December 2024 and June 2025 was analyzed. Demographic variables, clinical features, and laboratory parameters were extracted from electronic health records. All-cause mortality at 28 days served as the primary outcome, while prognostic assessment was performed using ROC analysis alongside multivariable logistic regression models. Results: A 28-day all-cause mortality of 26.1% was observed. Non-survivors exhibited significantly higher CAR, CRP, APACHE II, and SOFA scores (p < 0.001). In multivariable models, CAR remained independently associated with mortality (OR 1.14, 95% CI 1.01–1.28, p = 0.034). An AUC of 0.77 (95% CI 0.70–0.84) was observed for CAR, indicating good discriminatory ability. Conclusions: The CAR independently associated with short-term mortality in geriatric ICU patients and may serve as a simple, inexpensive biomarker for early risk stratification and outcome prediction.

Anahtar Kelimeler

• Aged
• Biomarkers
• C-Reactive Protein
• Critical Care
• Serum Albumin

Etik Beyan

The Institutional Ethics Committee of the Gazi Yaşargil Training and Research Hospital approved the study protocol (Approval No: 632, September 19, 2025), and all study-related procedures adhered to the principles of the Declaration of Helsinki and subsequent revisions.

Yoğun Bakım Hastalarında C-Reaktif Protein/Albümin Oranının Prognostik Değeri: Geriatrik Hasta Grubunda Retrospektif Bir Çalışma

Öz

Amaç: Sistemik inflamasyon ve malnütrisyon, yaşlı yoğun bakım hastalarında olumsuz klinik sonuçların temel belirleyicileridir. Bu çalışmada, inflamatuvar yanıt ile beslenme durumunu bütüncül biçimde yansıtan entegre bir biyobelirteç olan C-reaktif protein/albumin oranının (CAR), 28 günlük mortaliteyi öngörmedeki prognostik değerinin değerlendirilmesi amaçlandı. Yöntemler: Bu retrospektif kohort çalışmasına Aralık 2024 – Haziran 2025 arasında yoğun bakım ünitesinde takip edilen, yaşları ≥65 olan toplam 207 hasta dâhil edildi. Demografik, klinik ve laboratuvar veriler elektronik kayıt sisteminden elde edildi. Yoğun bakıma yatıştan sonraki 28 gün içinde gelişen tüm nedenlere bağlı mortalite, birincil sonlanım ölçütü olarak kabul edildi. Bağımsız mortalite belirleyicilerini ortaya koymak için ROC eğrisi analizi ile çok değişkenli lojistik regresyon analizlerinden yararlanıldı. Bulgular: Toplam 28 günlük mortalite oranı %26,1 olarak saptandı. Kaybedilen hastalarda CAR, CRP, APACHE II ve SOFA skorları daha yüksekti (p < 0,001). Çok değişkenli analizde, CAR mortalitenin bağımsız bir öngördürücüsü olarak kaldı (OR: 1,14; %95 GA: 1,01–1,28; p = 0,034). CAR için ROC eğrisi altında kalan alan 0,77 (%95 GA: 0,70–0,84) olarak hesaplandı. Sonuç: CAR, yaşlı yoğun bakım hastalarında kısa dönem mortalite açısından bağımsız bir öngörü değeri taşımaktadır. Bu oran, erken risk sınıflandırması ve prognoz tahmininde kolay erişilebilir, düşük maliyetli ve klinik pratikte kullanılabilir bir biyobelirteçtir.

Anahtar Kelimeler

• Yaşlı
• Biyobelirteçler
• C-Reaktif Protein
• Yoğun Bakım
• Serum Albümini.

Kaynakça

1. 1.Vallet H, Schwarz GL, Flaatten H, et al. A. Mortalityof older patients admitted to an ICU: a systematicreview. Crit Care Med. 2021;49(2):324-34.
2. 2.Guidet B, de Lange DW, Boumendil A, et al. Thecontribution of frailty, cognition, activity of daily lifeand comorbidities on outcome in acutely admittedpatients over 80 years in European ICUs: the VIP2study. Intensive Care Med. 2020;46(1):57-69.
3. 3.Franceschi C, Garagnani P, Parini P, et al.Inflammaging: a new immune-metabolic viewpointfor age-related diseases. Nat Rev Endocrinol.2018;14(10):576-90.
4. 4.Volkert D, Beck AM, Cederholm T, et al. ESPENguideline on clinical nutrition and hydration ingeriatrics. Geriatr Psychol Neuropsychiatr Vieil.2024;22(3):273-315.
5. 5.Soeters PB, Wolfe RR, Shenkin A.Hypoalbuminemia: pathogenesis and clinicalsignificance. JPEN J Parenter Enteral Nutr.2019;43(2):181-93.
6. 6.Oh TK, Song IA, Lee JH. Clinical usefulness of C-reactive protein to albumin ratio in predicting 30-day mortality in critically ill patients: a retrospectiveanalysis. Sci Rep. 2018;8(1):14977.
7. 7.Liu Y, Gao Y, Liang B, et al. The prognostic value ofC-reactive protein to albumin ratio in patients withsepsis: a systematic review and meta-analysis. AgingMale. 2023;26(1):2261540.
8. 8.Liu B, Lv D. Prognostic value of C-reactive proteinto albumin ratio for mortality in acute kidney injury.BMC Nephrol. 2023;24(1):44.

9. 9.Wang Y, Gong Y, Chen D, et al. C-reactiveprotein/albumin ratio is associated with mortalityin patients with moderate to severe traumatic braininjury. World Neurosurg. 2023; 173: e234-40.
10. 10. Capurso C, Lo Buglio A, Bellanti F, et al. C-reactiveprotein to albumin ratio predicts early mortality inhospitalized older patients, independent of theadmission diagnosis. Nutrients. 2025;17(12):1984.
11. 11.Deng Y, Li S, Li J, et al. Enhancing mortalityprediction in intensive care units: improvingAPACHE II, SOFA, and SAPS II scoring systems usinglong short-term memory. Intern Emerg Med. 2025.
12. 12.Park JE, Chung KS, Song JH, et al. The C-reactiveprotein/albumin ratio as a predictor of mortality incritically ill patients. J Clin Med. 2018;7(10):333.
13. 13.Ranzani OT, Zampieri FG, Forte DN, et al. C-reactive protein/albumin ratio predicts 90-daymortality of septic patients. PLoS One. 2013;8(3):e59321.
14. 14.Flaatten H, de Lange DW, Morandi A, et al. Theimpact of frailty on ICU and 30-day mortality and the level of care in very elderly patients (≥80 years).Intensive Care Med. 2017;43(12):1820-8.
15. 15.Humble C, Schønemann-Lund M, Bruun-Rasmussen P, et al. Pro- and anti-inflammatoryresponses and clinical outcomes in critically illpatients with endotheliopathy: a cohort study. ActaAnaesthesiol Scand. 2025;69(9): e70117.
16. 16.Uluç K, Akkütük Öngel E, Çolakoğlu ŞM, et al.Effects of HALP score, C-reactive protein/albuminratio, and platelet/lymphocyte ratio on predictingmortality in geriatric patients in the respiratoryintensive care unit. Clin Interv Aging. 2025; 20:815-23.
17. 17.Heyland DK, Dhaliwal R, Jiang X, et al. Identifyingcritically ill patients who benefit the most fromnutrition therapy: the development and initialvalidation of a novel risk assessment tool. Crit Care.2011;15(6): R268.
18. 18.Stoppe C, Wendt S, Mehta NM, et al. Biomarkersin critical care nutrition. Crit Care. 2020;24(1):499.