Predicting 72-h mortality in patients with extremely high random plasma glucose levels: A case-controlled cross-sectional study

Abstract

The risk factors associated with 72-hours mortality in patients with extremely high levels of random plasma glucose (RPG) remain unclear.To explore the risk factors predictive of 72-hours mortality in patients with extremely high RPG under heterogenos pathophysiological conditions.Retrospective, single-center, case-controlled cross-sectional study.University teaching hospital.Adults over age 18 were selected from the medical records of patients at the Saitama Medical Center, Japan, from 2004 to 2013.Extremely high RPG (≥500 mg/dl).Mortality at 72 hours following the RPG test, regardless of hospitalization or in an outpatient setting. Multivariate logistic regression analysis was performed with adjustment for age, sex, body mass index (BMI), and RPG level. The final prediction model was built using the logistic regression model with a higher C-statistic, specificity, and sensitivity.A total of 351 patients with RPG ≥500 mg/dl were identified within the 10-year period. The 72-hours mortality rate was 16/351 (4.6%). The C-statistics of the 72-hours mortality prediction model with serum albumin (ALB) and creatine kinase (CK) was 0.856. The probability of 72-hours mortality was calculated as follows: 1/[1 + exp (-5.142 + 0.901log (CK) -1.087 (ALB) + 0.293 (presence (1) or absence (0) of metastatic solid tumor)]. The sensitivity and specificity of this model was 75.5%.The independent risk factors associated with 72-hours mortality in patients with RPG ≥500 mg/dl are hypoalbuminemia, elevated CK, and presence of a metastatic solid tumour. Further research is needed to understand the mechanisms and possible interventions to prevent mortality associated with extremely high RPG.

Figure 1

Flow diagram for patient selection.

Figure 2

Comparison of the receiver-operating curves of predictive models for the 72-hour mortality of patients with extremely high outlier random plasma glucose values between Dataset-A and Dataset-B. The ROC was generated using Dataset-A for derivation and Dataset-B for validation. In order to test the specificity of the regression model for patients with RPG ≥ 500 mg/dl (Dataset-A), Dataset-B (patients with 300≤ RPG < 500 mg/dl) was applied to the following formula to compute the probability for fatal outcome. P = 1/[1 + exp (−5.142 + 0.901log (CK) - 1.087 (ALB) + 0.293 (metastatic solid tumour)]. The solid line shows the model of Dataset-A (C-statistics of 0.856 [95% CI = 0.775–0.937]), and the dotted line shows the ROC of Dataset-B (0.732 [95% CI = 0.535–0.929]).