Insulin attenuates the systemic inflammatory response to thermal trauma

Area of Science:

• Critical care medicine
• Immunology
• Endocrinology

Background:

• Insulin therapy is linked to reduced mortality and multi-organ failure in critically ill patients.
• The precise mechanisms by which insulin improves survival remain unclear.
• This study investigated insulin's impact on the systemic inflammatory response following thermal injury.

Purpose of the Study:

• To determine the effect of insulin therapy on the inflammatory cascade induced by thermal injury.
• To elucidate the molecular mechanisms underlying insulin's survival-promoting effects.

Main Methods:

• Thermally injured rats (30% TBSA) were randomized to receive either saline or insulin.
• Serum levels of pro-inflammatory and anti-inflammatory cytokines were measured.
• Hepatic signal transducer and activator of transcription (STAT) and CCAAT/enhancer-binding protein (C/EBP) mRNA expression was analyzed.

Main Results:

• Insulin significantly reduced serum levels of pro-inflammatory cytokines (IL-1beta, IL-6, MIF, TNF) post-injury.
• Insulin administration increased anti-inflammatory cytokines (IL-2, IL-4, IL-10) levels.
• Insulin modulated hepatic mRNA expression, decreasing pro-inflammatory factors (STAT-5, C/EBP-beta) and increasing anti-inflammatory factors (SOCS-3, RANTES).

Conclusions:

• Insulin therapy effectively attenuates the systemic inflammatory response in a model of thermal injury.
• By modulating cytokine profiles and signal transduction pathways, insulin restores systemic homeostasis.
• These findings highlight insulin's potential therapeutic role in improving outcomes for critically ill patients with inflammatory conditions.