학술논문
The impact of disease severity on paradoxical association between body mass index and mortality in patients with acute kidney injury undergoing continuous renal replacement therapy
Document Type
Report
Author
Source
BMC Nephrology. February 7, 2018, Vol. 19 Issue 1
Subject
Language
English
ISSN
1471-2369
Abstract
Author(s): Hyoungnae Kim[sup.1,2] , Hyunwook Kim[sup.1] , Misol Lee[sup.1] , Min-Uk Cha[sup.1] , Ki Heon Nam[sup.1] , Seong Yeong An[sup.1] , Su-Young Jung[sup.1] , Jong Hyun Jhee[sup.1] , Seohyun Park[sup.1] [...]
Background Association between high body mass index (BMI) and survival benefit is confounded by comorbid conditions such as nutritional status and inflammation. Patients with acute kidney injury (AKI), particularly those receiving continuous renal replacement therapy (CRRT), are highly catabolic and more susceptible to loss of energy. Herein, we evaluated whether disease severity can modify the relationship between BMI and mortality. Methods We conducted an observational study in 1144 patients who had undergone CRRT owing to various causes of AKI between 2010 and 2014. Patients were categorized into four groups; underweight (< 18.5 kg/m.sup.2), normal (18.5-22.99 kg/m.sup.2), overweight (23.0-24.99 kg/m.sup.2), and obesity ([greater than or equai to]25 kg/m.sup.2) according to BMI classification by the Committee of Clinical Practice Guidelines and Korean Society for the Study of Obesity. More severe disease was defined as sepsis-related organ failure assessment (SOFA) score of [greater than or equai to] a median value of 12. The study endpoint was death that occurred within 30 days after the initiation of CRRT. Results The mean age was 63.2 years and 439 (38.4%) were females. The median BMI was 23.6 (20.9-26.2) kg/m.sup.2. The obese group were younger and higher SOFA score than normal BMI group. In a multivariable Cox regression analysis, we found a significant interaction between BMI and SOFA score (P < 0.001). Furthermore, obese patients were significantly associated with a lower risk of death as compared to normal BMI group after adjusting confounding factors [hazard ratio (HR), 0.81; 95% confidence interval (CI), 0.68-0.97; P = 0.03]. This association was only evident among patients with high severity (HR, 0.61; 95% CI, 0.48-0.76, P < 0.001). In contrast, in those with low severity, survival benefit of high BMI was lost, whereas underweight was associated with an increased risk of death (HR, 1.74; 95% CI, 1.16-2.60; P = 0.007). Conclusion In this study, we found a survival benefit of high BMI in AKI patients undergoing CRRT, particularly in those with more disease severity; the effect was not observed in those with less disease severity. Keywords: Acute kidney injury, Body mass index, Continuous renal replacement therapy, Disease severity, Mortality
Background Association between high body mass index (BMI) and survival benefit is confounded by comorbid conditions such as nutritional status and inflammation. Patients with acute kidney injury (AKI), particularly those receiving continuous renal replacement therapy (CRRT), are highly catabolic and more susceptible to loss of energy. Herein, we evaluated whether disease severity can modify the relationship between BMI and mortality. Methods We conducted an observational study in 1144 patients who had undergone CRRT owing to various causes of AKI between 2010 and 2014. Patients were categorized into four groups; underweight (< 18.5 kg/m.sup.2), normal (18.5-22.99 kg/m.sup.2), overweight (23.0-24.99 kg/m.sup.2), and obesity ([greater than or equai to]25 kg/m.sup.2) according to BMI classification by the Committee of Clinical Practice Guidelines and Korean Society for the Study of Obesity. More severe disease was defined as sepsis-related organ failure assessment (SOFA) score of [greater than or equai to] a median value of 12. The study endpoint was death that occurred within 30 days after the initiation of CRRT. Results The mean age was 63.2 years and 439 (38.4%) were females. The median BMI was 23.6 (20.9-26.2) kg/m.sup.2. The obese group were younger and higher SOFA score than normal BMI group. In a multivariable Cox regression analysis, we found a significant interaction between BMI and SOFA score (P < 0.001). Furthermore, obese patients were significantly associated with a lower risk of death as compared to normal BMI group after adjusting confounding factors [hazard ratio (HR), 0.81; 95% confidence interval (CI), 0.68-0.97; P = 0.03]. This association was only evident among patients with high severity (HR, 0.61; 95% CI, 0.48-0.76, P < 0.001). In contrast, in those with low severity, survival benefit of high BMI was lost, whereas underweight was associated with an increased risk of death (HR, 1.74; 95% CI, 1.16-2.60; P = 0.007). Conclusion In this study, we found a survival benefit of high BMI in AKI patients undergoing CRRT, particularly in those with more disease severity; the effect was not observed in those with less disease severity. Keywords: Acute kidney injury, Body mass index, Continuous renal replacement therapy, Disease severity, Mortality