Relative Hyperglycemia, a Marker of Critical Illness: Introducing the Stress Hyperglycemia Ratio

J Clin Endocrinol Metab. 2015 Dec;100(12):4490-7. doi: 10.1210/jc.2015-2660. Epub 2015 Oct 20.

Abstract

Context: Hyperglycemia in hospitalized patients is associated with increased morbidity and mortality.

Objective: We examined whether critical illness is more strongly associated with relative or absolute hyperglycemia.

Design: The study was an observational cohort study.

Patients and setting: A total of 2290 patients acutely admitted to a tertiary hospital.

Main outcome measure: The relative hyperglycemia (stress hyperglycemia ratio [SHR]) was defined as admission glucose divided by estimated average glucose derived from glycosylated hemoglobin. The relationships between glucose and SHR with critical illness (in-hospital death or critical care) were examined.

Results: In univariable analyses, SHR (odds ratio, 1.23 per 0.1 increment [95% confidence interval, 1.18-1.28]; P < .001) and glucose (odds ratio, 1.18 per mmol/L [1.13-1.23]; P < .001) were associated with critical illness. In multivariable analysis, the association was maintained for SHR (odds ratio, 1.20 per 0.1 increment [1.13-1.28]; P < .001), but not glucose (odds ratio, 1.03 per mmol/L [0.97-1.11]; P = .31). Background hyperglycemia affected the relationship between glucose (P = .002) and critical illness, but not SHR (P = .35) and critical illness. In patients with admission glucose ≤ 10 mmol/L, the odds ratio for critical illness was higher in the fourth (2.4 [1.4-4.2]; P = .001) and fifth (3.9 [2.3-6.8]; P < .001) SHR quintiles than in the lowest SHR quintile.

Conclusions: SHR controls for background glycemia and is a better biomarker of critical illness than absolute hyperglycemia. SHR identifies patients with relative hyperglycemia at risk of critical illness. Future studies should explore whether basing glucose-lowering therapy on relative, rather than absolute, hyperglycemia improves outcomes in hospitalized patients.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Australia / epidemiology
  • Biomarkers / blood*
  • Blood Glucose / metabolism
  • Cohort Studies
  • Critical Care
  • Critical Illness / mortality*
  • Female
  • Glycated Hemoglobin A / analysis
  • Hospital Mortality
  • Hospitalization
  • Humans
  • Hyperglycemia / blood*
  • Male
  • Middle Aged
  • Stress, Physiological*

Substances

  • Biomarkers
  • Blood Glucose
  • Glycated Hemoglobin A