High concentrations of resistin in the peripheral blood of patients with acute basal ganglia hemorrhage are associated with poor outcome

Adipocyte lipolysis drives acute stress-induced insulin resistance

Stress hyperglycemia and insulin resistance are evolutionarily conserved metabolic adaptations to severe injury including major trauma, burns, or hemorrhagic shock (HS). In response to injury, the neuroendocrine system increases secretion of counterregulatory hormones that promote rapid mobilization of nutrient stores, impair insulin action, and ultimately cause hyperglycemia, a condition known to impair recovery from injury in the clinical setting. We investigated the contributions of adipocyte lipolysis to the metabolic response to acute stress. Both surgical injury with HS and counterregulatory hormone (epinephrine) infusion profoundly stimulated adipocyte lipolysis and simultaneously triggered insulin resistance and hyperglycemia. When lipolysis was inhibited, the stress-induced insulin resistance and hyperglycemia were largely abolished demonstrating an essential requirement for adipocyte lipolysis in promoting stress-induced insulin resistance. Interestingly, circulating non-esterified fatty acid levels did not increase with lipolysis or correlate with insulin resistance during acute stress. Instead, we show that impaired insulin sensitivity correlated with circulating levels of the adipokine resistin in a lipolysis-dependent manner. Our findings demonstrate the central importance of adipocyte lipolysis in the metabolic response to injury. This insight suggests new approaches to prevent insulin resistance and stress hyperglycemia in trauma and surgery patients and thereby improve outcomes.

Adipokines in critical illness: A review of the evidence and knowledge gaps

Adipose tissue products or adipokines play a major role in chronic endocrine and metabolic disorders; however, little is known about critical conditions. In this article, the experimental and clinical evidence of alterations of adipokines, adiponectin, leptin, resistin, visfatin, asymmetric dimethylarginine (ADMA), and ghrelin in critical illness, their potential metabolic, diagnostic, and prognostic value, and the gaps in the field have been reviewed. The results showed considerable changes in the concentration of the adipokines; while the impact of adipokines on metabolic disorders such as insulin resistance and inflammation has not been well documented in critically ill patients. There is no consensus about the circulatory and functional changes of leptin and adiponectin. However, it seems that lower concentrations of adiponectin at admission with gradual consequent increase might be a useful pattern in determining better outcomes of critical illness. Some evidence has suggested the adverse effects of elevated resistin concentration, potential prognostic importance of visfatin, and therapeutic value of ghrelin. High ADMA levels and low arginine:ADMA ratio were also proposed as predictors of ICU mortality and morbidities. However, there is no consensus on these findings. Although primary data indicated the role of adipokines in critical illness, further studies are required to clarify whether the reason of these changes is pathophysiological or compensatory. The relationship of pathophysiological background, disease severity, baseline nutritional status and nutrition support during hospitalization, and variations in body fat percentage and distribution with adipokines, as well as the potential prognostic or therapeutic role of these peptides should be further investigated in critically ill patients.

Cerebrovascular Disease: Consequences of Obesity-Induced Endothelial Dysfunction

Despite the well-known global impact of overweight and obesity in the incidence of cerebrovascular disease, many aspects of this association are still inconsistently defined. In this chapter we aim to present a critical review on the links between obesity and both ischemic and hemorrhagic stroke and discuss its influence on functional outcomes, survival, and current treatments to acute and chronic stroke. The role of cerebrovascular endothelial function and respective modulation is also described as well as its laboratory and clinical assessment. In this context, the major contributing mechanisms underlying obesity-induced cerebral endothelial function (adipokine secretion, insulin resistance, inflammation, and hypertension) are discussed. A special emphasis is given to the participation of adipokines in the pathophysiology of stroke, namely adiponectin, leptin, resistin, apelin, and visfatin.

Circulating resistin levels are early and significantly increased in deceased brain dead organ donors, correlate with inflammatory cytokine response and remain unaffected by steroid treatment

Introduction

Resistin is a pro-inflammatory adipokine that increases after brain injury (trauma, bleeding) and may initiate an inflammatory response. Resistin was found increased in deceased, brain dead organ donors (DBD) and correlated with delayed graft function after kidney transplantation. The kinetics of resistin during brain death (BD), its impact on the inflammatory response and the influence of several donor variables on resistin levels are still unknown.

Methods

Resistin along with a panel of Th1/Th2 cytokines [interferon (IFN)-gamma, interleukin (IL)-1beta, IL-2, IL-6, IL-8, IL10, IL-12, IL-13 and tumor necrosis factor (TNF)] was analyzed in 36 DBDs after the diagnosis of BD and before organ procurement and in 12 living kidney donors (LD). The cytokine levels and resistin were analyzed in relation to donor parameters including cause of death, donors’ age and steroid treatment.

Results

Resistin levels were higher in DBDs both at BD diagnosis and before organ procurement compared to LD (p < 0.001). DBDs had significantly increased IL-1beta, IL-6, IL-8, IL-10 and TNF levels at both time points compared with LD. In DBDs, resistin at BD diagnosis correlated positively with IL-1beta (r_s 0.468, p = 0.007), IL-6 (r_s 0.511, p = 0.002), IL-10 (r_s 0.372, p = 0.028), IL-12 (r_s 0.398, p = 0.024), IL-13 (r_s 0.397, p = 0.030) and TNF (r_s 0.427, p = 0.011) at procurement. The cause of death, age over 60 and steroid treatment during BD did not affect resistin levels. However, steroid treatment significantly decreased pro-inflammatory cytokines IL-1beta, IL-8, TNF and IFN-gamma at the time of organ procurement.

Conclusions

Resistin is increased early in DBDs, remains increased throughout the period of BD and correlates strongly with pro-inflammatory mediators. Resistin level, in contrast to cytokines, is not affected by steroid treatment. Resistin increase is related to the BD but is not influenced by age or cause of death. Resistin may be one of the initial triggers for the systemic inflammatory activation seen in DBDs.

Procoagulant phospholipids and tissue factor activity in cerebrospinal fluid from patients with intracerebral haemorrhage

Brain contains large amounts of tissue factor, the major initiator of the coagulation cascade. Neuronal apoptosis after intracerebral haemorrhage (ICH) leads to the shedding of procoagulant phospholipids (PPLs). The aim of this study was to investigate the generation of PPL, tissue factor activity (TFa), and D-Dimer (D-Di) in the cerebrospinal fluid (CSF) at the acute phase of ICH in comparison with other brain diseases and to examine the relationship between these factors and the outcome of ICH. CSF was collected from 112 patients within 48 hours of hospital admission. Thirty-one patients with no neurological or biochemical abnormalities were used to establish reference range in the CSF ("controls"). Thirty had suffered an ICH, and 51 other neurological diagnoses [12: ventricular drainage following brain surgery, 13: viral meningitis, 15: bacterial meningitis, and 11 a neurodegenerative disease (NDD)]. PPL was measured using a factor Xa-based coagulation assay and TFa by one home test. PPL, D-Di, and TFa were significantly higher (P < 0.001) in the CSF of patients with ICH than in controls. TFa levels were significantly (P < 0.05) higher in ICH than in patients with meningitides or NDD. Higher levels (P < 0.05) of TFa were observed in patients with ICH who died than in survivors. TFa measurement in the CSF of patients with ICH could constitute a new prognostic marker.

Increased resistin in brain dead organ donors is associated with delayed graft function after kidney transplantation

INTRODUCTION

Resistin increases during several inflammatory diseases and after intracerebral bleeding or head trauma. Resistin activates the endothelium and may initiate an inflammatory response. No data are available on resistin in brain dead donors (DBD) that regularly manifest a pronounced inflammatory state.

METHODS

We analyzed plasma resistin in 63 DBDs and correlated results with donor variables and the postoperative course following kidney transplantation using organs from these donors. Endocan and monocyte chemotactic protein (MCP)-1 were also studied. Twenty-six live kidney donors (LD) and the corresponding kidney transplantations were used as controls.

RESULTS

DBDs had higher resistin (median/range 30.75 ng/ml, 5.41-173.6) than LD (7.71 ng/ml, 2.41-15.74, p < 0.0001). Resistin in DBD correlated with delayed graft function (DGF) in the kidney recipients (r = 0.321, p < 0.01); receiver operating characteristic curve revealed an area under the curve of 0.765 (95% confidence interval [CI] 0.648-0.881, p < 0.01) and a cut-off value for resistin of 25 ng/ml; MCP-1 and endocan were higher in DBDs (p < 0.0001) but did not correlate with DGF or acute rejection. No relationship was found between the studied molecules and the postoperative course of LD kidney transplants.

CONCLUSIONS

High resistin levels in the DBD before organ retrieval are associated with DGF after kidney transplantation. The resistin increase seems related to the inflammatory state after brain death but not to the cause of death.

Resistin is associated with mortality in patients with traumatic brain injury

INTRODUCTION

Recently, we reported that high levels of resistin are present in the peripheral blood of patients with intracerebral hemorrhage and are associated with a poor outcome. However, not much is known regarding the change in plasma resistin and its relation with mortality after traumatic brain injury (TBI). Thus, we sought to investigate change in plasma resistin level after TBI and to evaluate its relation with disease outcome.

METHODS

Fifty healthy controls and 94 patients with acute severe TBI were included. Plasma samples were obtained on admission and at days 1, 2, 3, 5 and 7 after TBI. Its concentration was measured by enzyme-linked immunosorbent assay.

RESULTS

Twenty-six patients (27.7%) died from TBI within 1 month. After TBI, plasma resistin level in patients increased during the 6-hour period immediately after TBI, peaked within 24 hours, plateaued at day 2, decreased gradually thereafter and was substantially higher than that in healthy controls during the 7-day period. A forward stepwise logistic regression selected plasma resistin level (odds ratio, 1.107; 95% confidence interval, 1.014-1.208; P = 0.023) as an independent predictor for 1-month mortality of patients. A multivariate linear regression showed that plasma resistin level was negatively associated with Glasgow Coma Scale score (t = -6.567, P < 0.001). A receiver operating characteristic curve identified plasma resistin cutoff level (30.8 ng/mL) that predicted 1-month mortality with the optimal sensitivity (84.6%) and specificity (75.0%) values (area under curve, 0.854; 95% confidence interval, 0.766-0.918; P < 0.001).

CONCLUSIONS

Increased plasma resistin level is found and associated with Glasgow Coma Scale score and mortality after TBI.