The effects of muscle mass and quality on mortality of patients with acute kidney injury requiring continuous renal replacement therapy

www.nature.com/scientificreports OPEN The effects of muscle mass and quality on mortality of patients with acute kidney injury requiring continuous renal replacement therapy Jiyun Jung 1,2,15, Jangwook Lee 2,3,15, Jeong‑Hoon Lim 4, Yong Chul Kim 5, Tae Hyun Ban 6, Woo Yeong Park 7, Kyeong Min Kim 8, Kipyo Kim 9, Sung Woo Lee 10, Sung Joon Shin 2,3,11, Seung Seok Han 5, Dong Ki Kim 5, Yousun Ko 12, Kyung Won Kim 13, Hyosang Kim 14,16,15,16* & Jae Yoon Park 2,3,11,16,15,16* This study examined the effects of muscle mass on mortality in patients with acute kidney injury requiring continuous renal replacement therapy. It was conducted in eight medical centers between 2006 and 2021. The data of 2200 patients over the age of 18 years with acute kidney injury who required continuous renal replacement therapy were retrospectively collected. Skeletal muscle areas, categorized into normal and low attenuation muscle areas, were obtained from computed tomography images at the level of the third lumbar vertebra. Cox proportional hazards models were used to investigate the association between mortality within 1, 3, and 30 days and skeletal muscle index. Sixty percent of patients were male, and the 30-day mortality rate was 52%. Increased skeletal muscle areas/body mass index was associated with decreased mortality risk. We also identified a 26% decreased risk of low attenuation muscle area/body mass index on mortality. We established that muscle mass had protective effects on the mortality of patients with acute kidney injury requiring continuous renal replacement therapy. This study showed that muscle mass is a significant determinant of mortality, even if the density is low. Acute kidney injury (AKI) is a common complication in critically ill patients during h ospitalization1 and a significant independent risk factor for patient survival and progression to chronic kidney disease (CKD)2. Continuous renal replacement therapy (CRRT) is a method of resolving the imbalance of metabolites and electrolytes without causing rapid hemodynamic and biochemical fluctuations; it plays a vital role in treating critically ill patients 1 Clinical Trial Center, Dongguk University Ilsan Hospital, Goyang, South Korea. 2Research Center for Chronic Disease and Environmental Medicine, Dongguk University College of Medicine, Gyeongju, South Korea. 3Department of Internal Medicine, Dongguk University Ilsan Hospital, Goyang, South Korea. 4Department of Internal Medicine, Kyungpook National University Chilgok Hospital, School of Medicine, Kyungpook National University, Daegu, South Korea. 5Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea. 6Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea. 7Department of Internal Medicine, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, South Korea. 8Department of Internal Medicine, Daejeon Eulji Medical Center, Eulji University, Daejeon, South Korea. 9Department of Internal Medicine, Inha University Hospital, Inha University College of Medicine, Incheon, South Korea. 10Department of Internal Medicine, Uijeongbu Eulji Medical Center, Eulji University, Gyeonggi‑Do, South Korea. 11Department of Internal Medicine, Dongguk University College of Medicine, Gyeongju, South Korea. 12Biomedical Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea. 13Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea. 14Division of Nephrology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea. 15These authors contributed equally: Jiyun Jung, Jangwook Lee, Hyosang Kim and Jae Yoon Park. 16These authors jointly supervised this work: Hyosang Kim and Jae Yoon Park. *email: ; Scientific Reports | (2023) 13:7311 | https://doi.org/10.1038/s41598-023-33716-9 1 Vol.:(0123456789) www.nature.com/scientificreports/ with severe A KI3. However, despite advances in critical care medicine over the past decades, the mortality rate of patients with severe AKI who undergo CRRT is reported to be 50–80%4,5. Thus, it is necessary to identify new factors to predict and reduce mortality risk in patients with severe AKI and progression to CKD in survivors after treatment. Since its first introduction by Irwin Rosenberg in 1989, sarcopenia has been used as a diagnostic tool for frailty6,7. Sarcopenia can cause obesity by reducing the basal metabolic rate and was found to be a risk factor for dysphagia and falls and a significant risk factor for mortality in critically ill p atients6,8,9. The Asian Working Group for Sarcopenia (AWGS) defined the diagnostic tools for sarcopenia as muscle strength, physical performance, and appendicular skeletal muscle mass in clinical research settings for A sians10. However, applying this method properly to critically ill patients who are bedridden and have difficulty in functional evaluation is difficult. The artificial intelligence (AI)-based diagnostic evaluation of sarcopenia using imaging data can be a standardized diagnostic tool with high a ccuracy11,12. It is possible to evaluate the effect of sarcopenia on mortality in critically ill patients who are difficult to evaluate functionally using this technique. Therefore, we measured the muscle mass of patients’ abdominal computed tomography (CT) images and evaluated the effect of sarcopenia on the mortality of critically ill patients who underwent CRRT in multiple medical centers in Korea. Methods In this retropecitve cohort study, data on 4955 patients with AKI aged over 18 years who required CRRT in eight multi-centers between 2006 and 2021 were collected. We excluded patients with end-stage renal disease (n = 635), without abdominal CT images (n = 1772), and with missing information on covariates (n = 332) (Fig. 1). Finally, 2200 patients were enrolled in the study. Demographic and laboratory information, including sex, age, height (m), weight (kg), body mass index (BMI; kg/m2), albumin, hemoglobin, C-reactive protein (CRP), prothrombin time and international normalized ratio (PT INR), Charlson comorbidity index (CCI), CRRT settings (including prescribed dose), sequential organ failure assessment (SOFA) score, and Acute Physiology and Chronic Health Evaluation (APACHE II) score, were retrospectively collected. The prescribed dose was calculated as the sum of dialysate flow rate, replacement flow rate, and fluid removal divided by weight. The CCI considers 19 diseases with different weights to show the severity of comorbidity13. The APACHE II is a representative scoring system for patients in the intensive care unit (ICU) using 12 physiological variables; in contrast, SOFA predicts mortality in the ICU according to the severity in six organ systems14,15. In addition, we investigated in-hospital mortality (...truncated)