OBJECTIVETo study the pattern of the alterations of blood glucose, insulin and insulin sensitivity after traumatic brain injury in rats, and verify the occurrence of insulin resistance after the injury.

METHODSBased on Feeney's model of brain injury, the blood glucose and insulin concentration of the dogs measured 30 min before and at 6, 12, 24, 48, 72 and 120 h after injury. BG60-120, GIR60-120, and insulin sensitivity index (ISI) reflecting the insulin sensitivity were measured at 6, 24, 48, and 72 hours following severe traumatic brain injury using euglycemic-hyperinsulinemic clamp.

RESULTSBoth the blood glucose and insulin concentration increased markedly in rats following moderate and severe brain injury. BG60-120 increased markedly, and GIR60-120 and ISI decreased significantly 6, 24, 48, and 72 h after severe brain trauma as compared with those of the sham operation group. Blood glucose concentration of rats following severe injury was positively correlated with insulin concentration and BG60-120 at the corresponding time points, but negatively with GIR60-120 and ISI.

CONCLUSIONBoth the blood glucose and insulin concentration increase markedly in rats following severe brain injury. Increased blood glucose even in the presence of high-level insulin is due to acute insulin resistance occurring after traumatic brain injury.