Central GLP-1 Resistance Induced by Severe Traumatic Brain Injury Was Associated with Persistent Hyperglycemia in Humans.

INTRODUCTION: Whether central glucagon-like peptide 1 (GLP-1)/GLP-1 receptor system mediated peripheral glucose homeostasis in patients with traumatic brain injury (TBI) is not clear. We aim to determine if plasma GLP-1 level could distinguish the non-survivors from the survivors during the first 14 days after TBI that could prognose 6 months mortality. METHODS: Metabolic, inflammatory, and hematologic profiles were examined in 73 patients with TBI in neurological intensive care unit. Factors that discriminate non-survivors from survivors were determined by two-way ANOVA. Biomarkers associated with mortality were determined by binary logistic regression and Cox proportional hazard regression. RESULTS: The non-survivors had higher infectious SOFA scores (p < 0.001), lower first 3 days' body temperature (p = 0.017), greater chance of cerebral hernia (p = 0.048), and decompressive craniectomy (p = 0.001) than the survivors. Higher 14-day plasma GLP-1 (p < 0.0001), glucose (p = 0.002), and IL-6 (p = 0.005) levels, in contrast with lower insulin level at days 4-7 (p = 0.020) were found in non-survivors than in survivors. Except the survivors who had an increased 14-day platelet number (p < 0.001), the two groups did not differ in hematological profile and intestinal barrier function. Although GLP-1 correlated closely with IL-6 in both the groups, it correlated with neither insulin nor glucose in each group. GLP-1 on days 8-10 and IL-6 on days 1-3 were positively, while insulin on days 4-7 was negatively associated with mortality. CONCLUSION: Persistent higher GLP-1 level in non-survivors over the survivors may present more severe central resistance to endogenous GLP-1 in non-survivors, which may be associated with progressive hyperglycemia with increased mortality in TBI.

Prognostic Significance of Plasma Insulin Level for Deep Venous Thrombosis in Patients with Severe Traumatic Brain Injury in Critical Care.

BACKGROUND: Whether insulin resistance underlies deep venous thrombosis (DVT) development in patients with severe traumatic brain injury (TBI) is unclear. In this study, the association between plasma insulin levels and DVT was analyzed in patients with severe TBI. METHODS: A prospective observational study of 73 patients measured insulin, glucose, glucagon-like peptide 1 (GLP-1), inflammatory factors, and hematological profiles within four preset times during the first 14 days after TBI. Ultrasonic surveillance of DVT was tracked. Two-way analysis of variance was used to determine the factors that discriminated between patients with and without DVT or with and without insulin therapy. Partial correlations of insulin level with all the variables were conducted separately in patients with DVT or patients without DVT. Factors associated with DVT were analyzed by multivariable logistic regression. Neurological outcomes 6 months after TBI were assessed. RESULTS: Among patients with a mean (± standard deviation) age of 53 (± 16 years), DVT developed in 20 patients (27%) on median 10.4 days (range 4-22), with higher Acute Physiology and Chronic Health Evaluation II scores but similar Sequential Organ Failure Assessment scores and TBI severity. Patients with DVT were more likely to receive insulin therapy than patients without DVT (60% vs. 28%; P = 0.012); hence, they had higher 14-day insulin levels. However, insulin levels were comparable between patients with DVT and patients without DVT in the subgroups of patients with insulin therapy (n = 27) and patients without insulin therapy (n = 46). The platelet profile significantly discriminated between patients with and without DVT. Surprisingly, none of the coagulation profiles, blood cell counts, or inflammatory mediators differed between the two groups. Patients with insulin therapy had significantly higher insulin (P = 0.006), glucose (P < 0.001), and GLP-1 (P = 0.01) levels and were more likely to develop DVT (60% vs. 15%; P < 0.001) along with concomitant platelet depletion. Insulin levels correlated with glucose, GLP-1 levels, and platelet count exclusively in patients without DVT. Conversely, in patients with DVT, insulin correlated negatively with GLP-1 levels (P = 0.016). Age (P = 0.01) and elevated insulin levels at days 4-7 (P = 0.04) were independently associated with DVT. Patients with insulin therapy also showed worse Glasgow Outcome Scale scores (P = 0.001). CONCLUSIONS: Elevated insulin levels in the first 14 days after TBI may indicate insulin resistance, which is associated with platelet hyperactivity, and thus increasing the risk of DVT.