Platelet-to-Lymphocyte Ratio: A Novel Prognostic Factor for Prediction of 90-day Outcomes in Critically Ill Patients With Diabetic Ketoacidosis

Abstract

Diabetic ketoacidosis (DKA) is a life-threatening acute complication of diabetes mellitus and the novel systemic inflammation marker platelet-to-lymphocyte ratio (PLR) may be associated with clinical outcome in patients with DKA. This study aimed to investigate the utility of PLR in predicting 90-day clinical outcomes in patients with DKA. Patient data exacted from the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC II) database was analyzed. A cutoff value for PLR of 267.67 was determined using Youden index (P < 0.05) and used to categorize subjects into a high PLR group and a low PLR group. The hazard ratios (HRs) and 95% confidence intervals (CIs) for DKA were calculated across PLR. Clinical outcomes in our study were defined as intensive care unit (ICU) 90-day readmission and all-cause mortality. A total of 278 ICU admissions were enrolled and stratified by cutoff value of PLR. The incidence of readmission and mortality was 17.8% in the high PLR group, significantly higher than 7.4% in the low PLR group. In the multivariable model, after adjusting for known confounding variables including clinical parameters, comorbidities, laboratory parameters, the HRs for DKA were 2.573 (95% CI 1.239-5.345; P = 0.011), 2.648 (95% CI 1.269-5.527; P = 0.009), and 2.650 (95% CI 1.114-6.306; P = 0.028), respectively. The Kaplan-Meier survival curve showed that a high PLR level was associated with a higher risk for 90-day outcomes in patients with DKA. The authors report that higher PLR presents a higher risk for 90-day incidence of readmission and mortality in patients with DKA. It appears to be a novel independent predictor of 90-day outcomes in critically ill DKA patients in ICU units.

FIGURE 1

Study flow diagram. A total of 32,535 patients were recorded in Multiparameter Intelligent Monitoring in Intensive Care II database. After exclusion of those individuals who did not meet the inclusion criteria, 278 patients were included.

FIGURE 2

Kaplan–Meier survival curve showing mortality and readmission status of the groups above and below platelet to lymphocyte ratio cutoff.