Serum Creatinine/Cystatin C Ratio as a Predictor of In-hospital Mortality in Patients Hospitalized with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Predictive value of creatinine-cystatin C ratio for mortality and technique failure in anuric peritoneal dialysis patients

OBJECTIVES

Both serum creatinine and cystatin C serve as dependable markers of renal function and have demonstrated a correlation with clinical outcomes in diverse conditions, particularly through the ratio of creatinine to cystatin C (Cr/CysC). Anuric patients undergoing peritoneal dialysis (PD) depend entirely on the clearance of peritoneal solutes. This research posits that the Cr/CysC ratio may predict all-cause mortality and technique failure in anuric PD patients.

METHODS

A cohort of 224 anuric PD patients was recruited from January 1, 2014, to December 31, 2019, with follow-up extending until December 31, 2023. The Cr/CysC ratio was computed by dividing the serum creatinine concentration by the cystatin C concentration obtained on the same day. We evaluated the relationship between the Cr/CysC ratio and patient survival, as well as technique failure, utilizing Cox regression and competing risk analyses.

RESULTS

The average age of the participants was 50.46 ± 12.63 years, with 99 individuals (44.2%) being male. Among all subjects, the Cr/CysC ratio was found to be 1.85 ± 0.56. After controlling for potential confounders, Cox proportional hazards models revealed that the Cr/CysC ratio was significantly linked to the risk of all-cause mortality and technique failure (HR = 0.330, 95% CI 0.124-0.881, p = 0.027; HR = 0.440, 95% CI 0.267-0.726, p = 0.002). Importantly, the significant associations observed in the Cox regression analysis persisted even after accounting for competing risks.

CONCLUSION

The Cr/CysC ratio at baseline was recognized as an independent predictor of all-cause mortality and technique failure in anuric PD patients.

Relationship between creatinine-cystatin C ratio and all-cause mortality in hospitalized patients with COVID-19: A prospective study in China

Background

This study was conducted to investigate whether baseline creatinine-cystatin C ratio is associated with all-cause mortality in adult Chinese patients hospitalized with coronavirus disease 2019.

Methods

This study included 933 patients with coronavirus disease 2019 who were admitted to The Affiliated Hospital of Guangdong Medical University between December 2022 and March 2023. All-cause mortality was determined by telephone follow-up after 28 days. Multivariate Cox proportional risk models were used to investigate the relationship between baseline creatinine-cystatin C ratio and all-cause mortality. Restricted cubic spline and two-piecewise Cox proportional hazards risk models were used to identify non-linear correlations.

Results

Of the 933 patients, 128 died during the 28 days follow-up. The restricted cubic spline analysis of hospitalized patients with coronavirus disease 2019 revealed an L-shaped association between baseline creatinine-cystatin C ratio and all-cause mortality, with a threshold creatinine-cystatin C ratio of ≤0.93 predicting all-cause mortality. Specifically, a baseline creatinine-cystatin C ratio below this threshold value was negatively correlated with mortality (hazard ratio 0.12, 95 % confidence interval 0.03-0.48), but a creatinine-cystatin C ratio >0.93 was not correlated with mortality (hazard ratio 1.29, 95 % confidence interval 0.65-2.55).

Conclusions

In Chinese adult patients hospitalized with coronavirus disease 2019, an L-shaped relationship was observed between the baseline creatinine-cystatin C ratio and all-cause mortality.

Clinical significance and normal reference value of serum creatinine to cystatin C ratio in children

BACKGROUND & AIMS

Sarcopenia is a serious problem in adults and children. However, limited modalities are available for diagnosing pediatric sarcopenia. The serum creatinine to cystatin C ratio (Cre/CysC ratio) is a promising method for muscle quantification, although its clinical significance in the pediatric population is unknown. This study aimed to evaluate the relationship between the Cre/CysC ratio and physical performance.

METHODS

This was a single-center retrospective study. Patients aged <15 years who had visited the University of Tokyo Hospital for measurements of serum creatinine and cystatin C levels, body height, and body weight were included. The patients were assigned according to their age (<2 or ≥2 years), and the relationship between the Cre/CysC ratio and physical performance at the time of measurement was analyzed.

RESULTS

We included 266 patients, revealing a significant relationship between Cre/CysC ratio and physical performance in children aged ≥2 years (p < 0.001) but not in children aged <2 years (p = 0.42). The repeater-operator curve analysis of Cre/CysC to predict bedridden status showed good performance (the area under the curve was 0.82 (95% CI, 0.75-0.89)) and the cut-off value 0.44 had good accuracy (sensitivity 0.87, specificity 0.61).

CONCLUSIONS

The Cre/CysC ratio was a significant marker of impaired physical performance, and a Cre/CysC ratio <0.44 accurately predicted bedridden status in children aged >2 years.

Factors associated with risk of death in hospitalized patients for exacerbation of chronic obstructive pulmonary disease: an updated scoping review

INTRODUCTION

The Exacerbation of Chronic Obstructive Pulmonary Disease (ECOPD), especially if leading to hospitalization, increases the risk of death. Our scoping review aims to identify updated mortality risk factors for both short- and long-term periods.

AREAS COVERED

A comprehensive search, covering the period from January 2013 to February 2024, was performed to identify eligible studies that consider factors associated with death in hospitalized ECOPD. We considered short-term mortality, up to one year (including in-hospital mortality, IHM) and long-term mortality over one year, without time limits. We excluded studies concerning the intensive care area.

EXPERT OPINION

We considered 38 studies, 32 and 8 reporting data about short- and long-term mortality, respectively. Two studies consider both periods. Several factors, some already known, others newly identified, have been evaluated and discussed. Some of these were related to the characteristics and severity of COPD (age, body mass index, lung impairment), and some considered the response to ECOPD. In this last context, we focused on the increasing role of biomarkers in predicting the mortality of patients, particularly IHM. Our factors associated with a worse prognosis may be helpful in clinical practice to identify patients at risk and, subsequently, determine a personalized approach.

Clinical implications and predictive value of the creatinine‑cystatin C ratio in patients with multiple myeloma and renal impairment

The creatinine (Cr)-cystatin C ratio (CCR) at the time of cancer diagnosis is associated with survival; however, to the best of our knowledge, the association between this ratio and mortality in patients with multiple myeloma and renal impairment (RI) is unclear. Therefore, the present study aimed to assess this association, as well as disease prognosis and the clinical significance of the CCR in patients with multiple myeloma and RI. The present retrospective study included 191 patients diagnosed with multiple myeloma and RI between 2012 and 2022. The predictive value of the CCR was evaluated using area under the receiver operating characteristic curve (AUC) values. The factors affecting overall survival (OS) were assessed using uni- and multivariate logistic regression analyses. The effect of the CCR on survival was evaluated using a Cox regression model and the Kaplan-Meier method. There was a significant association between low CCR and poor progression-free survival (PFS) and overall survival (OS). The 1-, 2- and 3-year PFS and OS rates in patients with a low CCR were significantly lower than those in patients with a high CCR. The 1-, 2- and 3-year AUC values of the CCR were 0.712, 0.764 and 0.746 respectively. Multivariate analysis revealed sex, age, Cr levels, CCR and C-reactive protein levels as independent prognostic factors affecting OS rates. The CCR is a potential prognostic indicator in patients with multiple myeloma with RI and is associated with clinical stages.

Creatinine-cystatin C ratio and death with a functioning graft in kidney transplant recipients

Death with a functioning graft is important cause of graft loss after kidney transplantation. However, little is known about factors predicting death with a functioning graft among kidney transplant recipients. In this study, we evaluated the association between post-transplant creatinine-cystatin C ratio and death with a functioning graft in 1592 kidney transplant recipients. We divided the patients into tertiles based on sex-specific creatinine-cystatin C ratio. Among the 1592 recipients, 39.5% were female, and 86.1% underwent living-donor kidney transplantation. The cut-off value for the lowest creatinine-cystatin C ratio tertile was 0.86 in males and 0.73 in females. The lowest tertile had a significantly lower 5-year patient survival rate and was independently associated with death with a functioning graft (adjusted hazard ratio 2.574, 95% confidence interval 1.339-4.950, P < 0.001). Infection was the most common cause of death in the lowest tertile group, accounting for 62% of deaths. A low creatinine-cystatin C ratio was significantly associated with an increased risk of death with a functioning graft after kidney transplantation.

The creatinine-to-cystatin C ratio (a surrogate marker of muscle mass) as a predictor of lung function decline in older adults: A nationwide longitudinal study in China

BACKGROUND

Lung function decline is associated with sarcopenia, known as loss of skeletal muscle mass. The serum creatinine to cystatin C ratio (CCR) has been proposed as a biomarker of muscle mass. The associations between CCR and lung function decline are unknown.

METHODS

The study used two waves of data from China Health and Retirement Longitudinal Study (CHARLS) in 2011 and 2015. Serum creatinine and cystatin C were collected at baseline survey (2011). Lung function was assessed by peak expiratory flow (PEF) at 2011 and 2015. Linear regression models adjusted for potential confounders were conducted to analyze the cross-sectional association between CCR and PEF, and the longitudinal association between CCR and annual decline in PEF.

RESULTS

Totally, 5812 participants aged over 50 years (50.8% women; mean age 63.3 ± 6.5 years) were enrolled in a cross-sectional analysis in 2011, and further 4164 individuals were followed up in 2015. Serum CCR was positively associated with PEF and the PEF% pred. Per 1 SD higher of CCR was associated with 41.55 L/min increases in PEF (p < 0.001) and 10.77 (%) increase in PEF% pred (p < 0.001). Longitudinal analyses indicated that higher CCR level at baseline was related to slower annual decline in PEF and PEF% pred. And this relationship was significant only in women and in never smokers.

CONCLUSIONS

Higher CCR was associated with slower longitudinal PEF decline in women and never smokers. CCR may be a valuable marker to monitor and predict lung function decline in middle-aged and older adults.

The arrival ward requiring help by wheelchair or medical cart, arterial oxygenation index, age, albumin and neutrophil count score: Predicting in-hospital mortality in Chinese patients with acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

In this study, we will derive and validate a prognostic tool to predict in-hospital death based on Chinese acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients.

METHODS

Independent predictors of in-hospital death were identified by logistic regression analysis and incorporated into a clinical prediction tool.

RESULTS

The clinical prediction model was developed with data from 1121 patients and validated with data from 245 patients. The five predictors of in-hospital death from the development cohort (Arrival ward requiring help by wheelchair or medical cart, Arterial oxygenation index, Age, Albumin and Neutrophil count) were combined to form the AAAAN Score. The AAAAN Score achieved good discrimination (AUC = 0.85, 95% CI 0.81-0.89) and calibration (Hosmer-Lemeshow chi-square value was 3.33, p = 0.65). The AAAAN Score, which underwent internal bootstrap validation, also showed excellent discrimination for mortality (AUC = 0.85, 95% CI 0.81 to 0.89) and performed more strongly than other clinical prediction tools. Patients were categorized into 3 risk groups based on the scores: low risk (0-2 points, 0.7% in-hospital mortality), intermediate risk (3-4 points, 4.1% in-hospital mortality), and high risk (5-7 points, 23.4% in-hospital mortality). Predictive performance was confirmed by external validation.

CONCLUSIONS

The AAAAN Score is a prognostic tool to predict in-hospital death in Chinese AECOPD patients.