Biologic Mechanisms Underlying the Heterogeneous Response to Tight Glycemic Control among Differentially Inflamed...

Area of Science:

• Pediatric critical care medicine
• Immunology
• Metabolic disorders

Background:

• Tight glycemic control (TGC) with insulin has inconsistent benefits in critically ill patients.
• Previous studies suggested a benefit in children with a hyperinflammatory subphenotype.
• The biological mechanisms for this differential response remain unclear.

Purpose of the Study:

• To understand inflammatory subphenotypes in critically ill children.
• To explore biological mechanisms of heterogeneous responses to TGC.
• To identify cytokine and gene expression signatures related to TGC response.

Main Methods:

• Analyzed plasma cytokines and whole blood transcriptomics from 740 samples.
• Included 293 participants from the HALF-PINT study (250 hypoinflammatory, 43 hyperinflammatory).
• Assessed gene expression on study days 0, 2, and 4.

Main Results:

• Hyperinflammatory patients showed higher baseline inflammation, cell cycle, and immunometabolism gene expression.
• TGC (80-110 mg/dL) in hyperinflammatory patients reduced inflammatory cytokines and innate immune gene expression.
• TGC also decreased heme metabolism gene expression and increased lymphocyte gene expression in this subgroup.
• Causal mediation analysis linked these changes to the mortality benefit of TGC.

Conclusions:

• Findings enhance understanding of inflammatory subphenotypes in critically ill children.
• Biological insights are provided into the mortality benefit of TGC in hyperinflammatory children.
• This research clarifies the role of inflammation in TGC response.