Increasing glucose load while maintaining normoglycemia does not evoke neuronal damage in prolonged critically ill...

Area of Science:

• Neuroscience
• Critical Care Medicine
• Metabolism

Background:

• Severe hyperglycemia during critical illness can cause neuropathological changes.
• Previous research indicated insulin-controlled normoglycemia mitigates these effects.
• The impact of varying glucose loads under normoglycemia on brain cells remained unclear.

Purpose of the Study:

• To investigate the effects of increasing intravenous glucose loads on neurons and glial cells in the frontal cortex of critically ill rabbits.
• To assess neuronal integrity, astrocyte and microglia activation, and oxidative stress markers under different glucose conditions.

Main Methods:

• Critically ill rabbits were randomized into fasting or parenteral nutrition groups with low, intermediate, or high glucose loads.
• Normoglycemia was strictly maintained using insulin in all groups.
• Neuropathological alterations in neurons, astrocytes, microglia, and MnSOD expression were analyzed on day 7.

Main Results:

• Neuronal damage was similar across all groups, including healthy controls.
• Astrocyte density and activation increased significantly in critically ill rabbits, independent of glucose load.
• Microglia activation and MnSOD expression remained comparable among groups, unaffected by glucose infusion.

Conclusions:

• Strictly maintaining normoglycemia during critical illness with increasing intravenous glucose infusion is safe for neuronal integrity.
• Elevated glucose loads under normoglycemia did not substantially alter glial cell status in the frontal cortex.
• These findings support the safety of glucose administration in critically ill patients when blood glucose is tightly controlled.