Glucose regulates the expression of Gi-proteins in cultured BC3H-1 myocytes

Intensive insulin therapy is associated with reduced infectious complications in burn patients

BACKGROUND

Intensive insulin therapy to control blood glucose levels has reduced mortality in surgical, but not medical, intensive care unit (ICU) patients. Control of blood glucose levels has also been shown to reduce morbidity in surgical ICU patients. There is very little data for use of intensive insulin therapy in the burn patient population. We sought to evaluate our experience with intensive insulin therapy in burn-injured ICU patients with regard to mortality, morbidity, and use of hospital resources.

STUDY DESIGN

Burn patients admitted to our American College of Surgeons verified burn center ICU from 7/1/2004 to 6/30/2006 were studied. An intensive insulin therapy protocol was initiated for ICU patients admitted starting 7/1/2005 with a blood glucose target of 100-140 mg/dL. The 2 groups of patients studied were control (7/1/2004 to 6/30/2005) and intensive insulin therapy (7/1/2005 to 6/30/2006). All glucose values for the hospitalization were analyzed. Univariate and multivariate analyses were performed.

RESULTS

Overall, 152 ICU patients admitted with burn injury were available for study. No difference in mortality was evident between the control and intensive insulin therapy groups. After adjusting for patient risk, the intensive insulin therapy group was found to have a decreased rate of pneumonia, ventilator-associated pneumonia, and urinary tract infection. In patients with a maximum glucose value of greater than 140 mg/dL, the risk for an infection was significantly increased (OR 11.3, 95% CI 4-32, P-value < .001). The presence of a maximum glucose value greater than 140 mg/dL was associated with a sensitivity of 91% and specificity of 62% for an infectious complication.

CONCLUSION

Intensive insulin therapy for burn-injured patients admitted to the ICU was associated with a reduced incidence of pneumonia, ventilator-associated pneumonia, and urinary tract infection. Intensive insulin therapy did not result in a change in mortality or length of stay when adjusting for confounding variables. Measurement of a blood glucose level greater than 140 mg/dL should heighten the clinical suspicion for the presence of an infection in patients with burn injury.

Influence of acute hyperglycemia in human sepsis on inflammatory cytokine and counterregulatory hormone concentrations

AIM: In human sepsis, a prominent component of the hypermetabolite is impaired glucose tolerance (IGT) and hyperglycemia. Elevations in plasma glucose concentration impair immune function by altering cytokine production from macrophages. We assessed the role of glucose in the regulation of circulating levels of insulin, glucagon, cortisol, IL-6 and TNF-α in human sepsis with normal or impaired glucose tolerance.

METHODS: According to the results of intravenous glucose tolerance test, forty patients were classified into two groups: control group (n = 20) and IGT group (n = 20). Plasma glucose levels were acutely raised in two groups and maintained at 15 mmol/L for 3 hours. Plasma insulin, glucagon and cortisol levels were measured by radioimmunoassay, the levels of TNF-α and IL-6 were detected by ELISA.

RESULTS: In IGT group, the fasting concentrations of plasma glucose, insulin, glucagon, cortisol, IL-6 and TNF-α levels were significantly higher than those in control group (P < 0.05). During clamp, the control group had a higher average amount of dextrose infusion than the IGT group (P < 0.01). In control group, plasma insulin levels rose from a basal value to a peak at an hour (P < 0.05) and maintained at high levels. Plasma glucagon levels descended from a basal value to the lowest level within an hour (P < 0.01) and low levels were maintained throughout the clamp. In IGT group, plasma insulin was more significantly elevated (P < 0.01), and plasma glucagon levels were not significantly declined. Plasma cortisol levels were not significantly changed in two groups. In control group, plasma IL-6 and TNF-α levels rose (P < 0.01) within 2 hours of the clamp and returned to basal values at 3 hours. In IGT group, increased levels of plasma cytokine lasted longer than in control group (3 hours vs. 2 hours, P < 0.05), and the cytokine peaks of IGT group were higher (P < 0.05) than those of control group.

CONCLUSION: Acute hyperglycemia pricks up hyperinsulinemia and increases circulating cytokine concentrations and these effects are more pronounced in sepsis with IGT. This suggests a potential modulation of immunoinflammatory responses in human sepsis by hyperglycemia.

Association of hyperglycemia with increased mortality after severe burn injury

BACKGROUND

Hyperglycemia is commonly associated with the hypermetabolic stress response. However, persistent hyperglycemia may adversely affect wound healing and immunity. The purpose of this study was to assess any relationship between hyperglycemia and clinical outcome after severe burn injury.

METHODS

Survey of the medical records from January 1996 to July 1999 identified 58 pediatric patients with burns > or = 60% body surface. Patients were categorized as having poor glucose control (n = 33) if > or = 40% of all plasma glucose determinations were > or = 7.8 mmol/L (140 mg/dL) and compared with patients deemed to have adequate glucose control (n = 25) in whom > or = 40% of all glucose values were > or = 7.8 mmol/L.

RESULTS

Despite similar age, burn size, caloric intake, and frequency of wound infection, patients categorized with poor glucose control had a significantly greater incidence of positive blood cultures (positive blood cultures/length of stay days, 0.42 +/- 0.04 for hyperglycemia patients vs. 0.30 +/- 0.03 for normoglycemia patients; mean +/- SEM, p > or = 0.05). This finding was especially prominent for blood cultures positive for yeast. Hyperglycemia patients had significantly less percentage of skin graft take than did the normoglycemic patients (percent take/operative procedure, 64 +/- 9 for hyperglycemia patients vs. 88 +/- 5 for normoglycemia patients; p < 0.05). Nine patients (27%) with persistent hyperglycemia died compared with only one death (4%) in patients with adequate glucose control (p > or = 0.05).

CONCLUSION

This association between poor glucose control, bacteremia/fungemia, reduced skin graft take, and subsequent mortality in severely burned children may be related to a hyperglycemia-induced detriment in antimicrobial defense. Although this report fails to establish cause and effect, these findings suggest that aggressive maneuvers to normalize plasma glucose in critically injured patients may be warranted.