Serum adiponectin upon admission to the intensive care unit may predict mortality in critically ill patients

Obesity Prevalence and Associated Outcomes in Cardiothoracic Patients: A Single-Centre Experience

The objective of this study was to investigate the prevalence of obesity and its relationship with adverse outcomes in ICU cardiothoracic patients. We performed a retrospective analysis of cardiothoracic patients admitted to The Royal Melbourne Hospital ICU between 2002 and 2014. Eight thousand and sixty-four patients who underwent coronary artery bypass, valve replacement/repair, or both, were divided into six categories of body mass index using World Health Organization criteria. Prevalence of obesity over time in the ICU was measured and compared to prevalence of obesity in the adult Australian population. The association between obesity and adverse postoperative outcomes was then analysed. Obesity is currently 1.2 times more prevalent in the Royal Melbourne Hospital ICU cardiothoracic patients than in the adult Australian population, with 33.5% of patients having a body mass index ≥30 kg/m2. Over time, this was relatively constant, but an increasing proportion were morbidly obese. Obesity, but not morbid obesity, was associated with reduced 30-day mortality (odds ratio [OR] 0.41). Both obese and morbidly obese patients had reduced odds of return to theatre for bleeding (OR 0.49 and OR 0.19, respectively), but increased odds of new-onset renal failure (OR 1.62 and OR 3.17, respectively). Morbidly obese patients had double the odds of an ICU stay longer than 14 days (OR 2.05). In summary, a growing proportion of our obese ICU patients are morbidly obese, with a dramatically increased length of ICU stay. This has major implications for resource allocation in the ICU, and may inform modelling of future bed utilisation. Obesity, but not morbid obesity, conferred a mortality benefit.

Circulating microRNA-223 serum levels do not predict sepsis or survival in patients with critical illness

Background and Aims. Dysregulation of miR-223 was recently linked to various diseases associated with systemic inflammatory responses such as type 2 diabetes, cancer, and bacterial infections. However, contradictory results are available on potential alterations of miR-223 serum levels during sepsis. We thus aimed to evaluate the diagnostic and prognostic value of miR-223 serum concentrations in patients with critical illness and sepsis. Methods. We used i.v. injection of lipopolysaccharide (LPS) as well as cecal pole ligation and puncture (CLP) for induction of polymicrobial sepsis in mice and measured alterations in serum levels of miR-223. These results from mice were translated into a large and well-characterized cohort of critically ill patients admitted to the medical intensive care unit (ICU). Finally, results from analysis in patients were correlated with clinical data and extensive sets of routine and experimental biomarkers. Results. Although LPS injection induced moderately elevated serum miR-223 levels in mice, no significant alterations in miR-223 serum levels were found in mice after CLP-induced sepsis. In accordance with these results from animal models, serum miR-223 levels did not differ between critically ill patients and healthy controls. However, ICU patients with more severe disease (APACHE-II score) showed moderately reduced circulating miR-223. Strikingly, no differences in miR-223 levels were found in critically ill patients with or without sepsis, and serum levels of miR-223 did not correlate with classical markers of inflammation or bacterial infection. Finally, low miR-223 serum levels were moderately associated with an unfavorable prognosis of patients during the ICU treatment but did not predict long-term mortality. Conclusion. Recent reports on alterations in miR-223 serum levels during sepsis revealed contradictory results, preventing a potential use of this miRNA in clinical routine. We clearly show that miR-223 serum levels do not reflect the presence of sepsis neither in mouse models nor in a large cohort of ICU patients and do not indicate clinical outcome of critically ill patients. Thus miR-223 serum levels should not be used as a biomarker in this setting.

Impact of obesity on sepsis mortality: A systematic review

PURPOSE

Sepsis and severe sepsis are the most common cause of death among critically ill patients admitted in medical intensive care units. As more than one-third of the adult population of the United States is obese; we undertook a systematic review of the association between obesity and mortality among patients admitted with sepsis, severe sepsis, or septic shock.

MATERIALS AND METHODS

A systematic review was conducted to identify pertinent studies using a comprehensive search strategy. Studies reporting mortality in obese patients admitted with sepsis were identified.

RESULTS

Our initial search identified 183 studies of which 7 studies met our inclusion criteria. Three studies reported no significant association between obesity and mortality, 1 study observed increased mortality among obese patients, whereas 3 studies found lower mortality among obese patients.

CONCLUSION

Our review of the current clinical evidence of association of obesity with sepsis mortality revealed mixed results. Clinicians are faced with a number of challenges while managing obese patients with sepsis and should be mindful of the impact of obesity on antibiotics administration, fluid resuscitation, and ventilator management. Further studies are needed to elicit the impact of obesity on mortality in patients with sepsis.

Serum adiponectin is associated with worsened overall survival in a prospective cohort of hepatocellular carcinoma patients

BACKGROUND

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. The rise in metabolic syndrome has contributed to this trend. Adipokines, such as adiponectin, are associated with prognosis in several cancers, but have not been well studied in HCC.

METHODS

We prospectively enrolled 140 patients with newly diagnosed or recurrent HCC with Child-Pugh (CP) class A or B cirrhosis. We examined associations between serum adipokines, clinicopathological features of HCC, and time to death. We also examined a subset of tumors with available pathology for tissue adiponectin receptor (AR) expression by immunohistochemistry.

RESULTS

The median age of subjects was 62 years; 79% were men, 59% had underlying hepatitis C, and 36% were diabetic. Adiponectin remained a significant predictor of time to death (hazard ratio 1.90; 95% confidence interval 1.05-3.45; p = 0.03) in a multivariable adjusted model that included age, alcohol history, CP class, stage, and serum α-fetoprotein level. Cytoplasmic AR expression (AR1 and AR2) in tumors trended higher in those with higher serum adiponectin levels and in those with diabetes mellitus, but the association was not statistically significant.

CONCLUSIONS

In this hypothesis-generating study, we found the serum adiponectin level to be an independent predictor of overall survival in a diverse cohort of HCC patients.

IMPACT

Understanding how adipokines affect the HCC outcome may help develop novel treatment and prevention strategies.

Plasma Adiponectin, clinical factors, and patient outcomes during the acute respiratory distress syndrome

Objective

Adiponectin (APN) is an anti-inflammatory hormone derived from adipose tissue that attenuates acute lung injury in rodents. In this study, we investigated the association between circulating APN and outcomes among patients with acute respiratory distress syndrome (ARDS).

Methods

We performed a retrospective cohort study using data and plasma samples from participants in the multicenter ARDS Network Fluid and Catheter Treatment Trial.

Results

Plasma APN concentrations were measured in 816 (81.6%) trial participants at baseline and in 568 (56.8%) subjects at both baseline and day 7 after enrollment. Clinical factors associated with baseline APN levels in multivariable-adjusted models included sex, body mass index, past medical history of cirrhosis, and central venous pressure (model R² = 9.7%). We did not observe an association between baseline APN and either severity of illness (APACHE III) or extent of lung injury (Lung Injury Score). Among patients who received right heart catheterization (n = 384), baseline APN was inversely related to mean pulmonary artery pressure (β = −0.015, R² 1.5%, p = 0.02); however, this association did not persist in multivariable models (β = −0.009, R² 0.5%, p = 0.20). Neither baseline APN levels [HR per quartile1.04 (95% CI 0.91–1.18), p = 0.61], nor change in APN level from baseline to day 7 [HR 1.04 (95% CI 0.89–1.23), p = 0.62)] were associated with 60 day mortality in Cox proportional hazards regression models. However, subgroup analysis identified an association between APN and mortality among patients who developed ARDS from extra-pulmonary etiologies [HR per quartile 1.31 (95% CI 1.08–1.57)]. APN levels did not correlate with mortality among patients developing ARDS in association with direct pulmonary injury [HR 0.96 (95% CI 0.83–1.13)], p_interaction = 0.016.

Conclusions

Plasma APN levels did not correlate with disease severity or mortality in a large cohort of patients with ARDS. However, higher APN levels were associated with increased mortality among patients developing ARDS from extra-pulmonary etiologies.

Adiponectin gene polymorphisms and acute respiratory distress syndrome susceptibility and mortality

RATIONALE

Adiponectin is an anti-inflammatory adipokine that is the most abundant gene product of adipose tissue. Lower levels have been observed in obesity, insulin resistance, and in critical illness. However, elevated levels early in acute respiratory failure have been associated with mortality. Polymorphisms in adiponectin-related genes (ADIPOQ, ADIPOR1, ADIPOR2) have been examined for relationships with obesity, insulin resistance and diabetes, cardiovascular disease, and to circulating adipokine levels, but many gaps in knowledge remain. The current study aims to assess the association between potentially functional polymorphisms in adiponectin-related genes with acute respiratory distress syndrome (ARDS) risk and mortality.

METHODS

Consecutive patients with risk factors for ARDS admitted to the ICU were enrolled and followed prospectively for development of ARDS. ARDS cases were followed through day 60 for all-cause mortality. 2067 patients were successfully genotyped using the Illumina CVD BeadChip high-density platform. Of these, 567 patients developed ARDS. Forty-four single nucleotide polymorphisms (SNPs) on ADIPOQ, ADIPOR1 and ADIPOR2 were successfully genotyped. Of these, 9 SNPs were hypothesized to be functional based on their location (promoter, exon, or 3' untranslated region). These 9 SNPs were analyzed for association with ARDS case status and mortality among ARDS cases.

RESULTS

After multivariable analysis and adjustment for multiple comparisons, no SNPs were significantly associated with ARDS case status. Among ARDS cases, homozygotes for the minor allele of rs2082940 (ADIPOQ) had increased mortality (hazard ratio 2.61, 95% confidence interval 1.36-5.00, p = 0.0039) after adjustment for significant covariates. The significance of this association persisted after adjustment for multiple comparisons (FDR_q = 0.029).

CONCLUSIONS

A common and potentially functional polymorphism in ADIPOQ may impact survival in ARDS. Further studies are required to replicate these results and to correlate genotype with circulating adiponectin levels.

Random measurements of adiponectin and IL-6 may not be indicative of the 24-h profile in critically ill patients

CONTEXT

The anti-inflammatory role of adiponectin has prompted interest in a potential role in acute inflammatory conditions associated with critical illness. It is unclear whether a random adiponectin measurement adequately reflects the 24-h profile in critically ill patients.

OBJECTIVE

To assess the temporal profile of total and high molecular weight (HMW) adiponectin and interleukin-6 (IL-6) in 15 critically ill patients.

DESIGN

A prospective, observational study.

SETTING

Level II intensive care unit in a metropolitan hospital.

PATIENTS OR OTHER PARTICIPANTS

Fifteen critically ill patients expected to stay in the ICU for longer than 48 h were eligible for enrolment.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Serial, hourly measurements of total and HMW adiponectin and IL-6.

RESULTS

Over a 24-h period, total and HMW adiponectin display considerable within-patient variability (coefficient of variation 34% and 87% respectively) and show no trend over time. Averaging 2 or 3 continuous measures reduced within-patient variability of both total and HMW adiponectin by up to 50% compared to one measure. There was a negative correlation between serum glucose and adiponectin (total P = 0·016, HMW P = 0·039). No relationship existed between adiponectin and IL-6 (total P = 0·62, HMW P = 0·35).

CONCLUSIONS

Marked within-patient, hourly variability in total and HMW adiponectin is evident in critically ill patients. A random measurement may not be reflective of the 24-h profile in these patients. A negative correlation exists between adiponectin and blood glucose levels and a positive correlation between adiponectin and oxygen saturation. No clear relationship exists between adiponectin and IL-6.

Association of serum adiponectin, leptin, and resistin concentrations with the severity of liver dysfunction and the disease complications in alcoholic liver disease

Background and aims. There is growing evidence that white adipose tissue is an important contributor in the pathogenesis of alcoholic liver disease (ALD). We investigated serum concentrations of total adiponectin (Acrp30), leptin, and resistin in patients with chronic alcohol abuse and different grades of liver dysfunction, as well as ALD complications. Materials and Methods. One hundred forty-seven consecutive inpatients with ALD were prospectively recruited. The evaluation of plasma adipokine levels was performed using immunoenzymatic ELISA tests. Multivariable logistic regression was applied in order to select independent predictors of advanced liver dysfunction and the disease complications. Results. Acrp30 and resistin levels were significantly higher in patients with ALD than in controls. Lower leptin levels in females with ALD compared to controls, but no significant differences in leptin concentrations in males, were found. High serum Acrp30 level revealed an independent association with advanced liver dysfunction, as well as the development of ALD complications, that is, ascites and hepatic encephalopathy. Conclusion. Gender-related differences in serum leptin concentrations may influence the ALD course, different in females compared with males. Serum Acrp30 level may serve as a potential prognostic indicator for patients with ALD.

Elevated asymmetric dimethylarginine levels predict short- and long-term mortality risk in critically ill patients

OBJECTIVE

Serum concentrations of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, may contribute to endothelial dysfunction and organ failure in sepsis. We aimed at investigating ADMA levels as a potential diagnostic or prognostic biomarker in critically ill patients.

METHODS

Two hundred fifty-five patients (164 with sepsis, 91 without sepsis) were studied prospectively upon admission to the medical intensive care unit (ICU) and on day 7, in comparison to 78 healthy controls. ADMA serum concentrations were correlated with clinical data and extensive laboratory parameters. Patients' survival was followed up for up to 3 years.

RESULTS

ADMA serum levels were significantly elevated in critically ill patients at admission compared to controls. ADMA levels did not differ between patients with or without sepsis, but were closely related to hepatic and renal dysfunction, metabolism and clinical scores of disease severity. ADMA levels further increased during the first week of ICU treatment. ADMA serum levels at admission were an independent prognostic biomarker in critically ill patients not only for short-term mortality at the ICU, but also for unfavorable long-term survival.

CONCLUSION

Serum ADMA concentrations are significantly elevated in critically ill patients, associated with organ failure and related to short- and long-term mortality risk.

Serum adipocyte fatty acid-binding protein levels in patients with critical illness are associated with insulin resistance and predict mortality

INTRODUCTION

Hyperglycemia and insulin resistance are commonplace in critical illness, especially in patients with sepsis. Recently, several hormones secreted by adipose tissue have been determined to be involved in overall insulin sensitivity in metabolic syndrome-related conditions, including adipocyte fatty-acid binding protein (A-FABP). However, little is known about their roles in critical illness. On the other hand, there is evidence that several adipose tissue gene expressions change in critically ill patients.

METHODS

A total of 120 patients (72 with sepsis, 48 without sepsis) were studied prospectively on admission to a medical ICU and compared with 45 healthy volunteers as controls. Various laboratory parameters and metabolic and inflammatory profiles were assessed within 48 hours after admission. Clinical data were collected from medical records.

RESULTS

Compared with healthy controls, serum A-FABP concentrations were higher in all critically ill patients, and there was a trend of higher A-FABP in patients with sepsis. In multivariate correlation analysis in all critically ill patients, the serum A-FABP concentrations were independently related to serum creatinine, fasting plasma glucose, total cholesterol, TNF-alpha, albumin, and the Acute Physiology and Chronic Health Evaluation II scores. In survival analysis, higher A-FABP levels (> 40 ng/ml) were associated with an unfavorable overall survival outcome, especially in sepsis patients.

CONCLUSIONS

Critically ill patients have higher serum A-FABP concentrations. Moreover, A-FABP may potentially serve as a prognostic biomarker in critically ill patients with sepsis.

Circulating microRNA-150 serum levels predict survival in patients with critical illness and sepsis

Background and Aims

Down-regulation of miR-150 was recently linked to inflammation and bacterial infection. Furthermore, reduced serum levels of miR-150 were reported from a small cohort of patients with sepsis. We thus aimed at evaluating the diagnostic and prognostic value of miR-150 serum levels in patients with critically illness and sepsis.

Methods

miR-150 serum levels were analyzed in a cohort of 223 critically ill patients of which 138 fulfilled sepsis criteria and compared to 76 healthy controls. Results were correlated with clinical data and extensive sets of routine and experimental biomarkers.

Results

Measurements of miR-150 serum concentrations revealed only slightly reduced miR-150 serum levels in critically ill patients compared to healthy controls. Furthermore miR-150 levels did not significantly differ in critically ill patients with our without sepsis, indicating that miR-150 serum levels are not suitable for diagnostic establishment of sepsis. However, serum levels of miR-150 correlated with hepatic or renal dysfunction. Low miR-150 serum levels were associated with an unfavorable prognosis of patients, since low miR-150 serum levels predicted mortality with high diagnostic accuracy compared with established clinical scores and biomarkers.

Conclusion

Reduced miR-150 serum concentrations are associated with an unfavorable outcome in patients with critical illness, independent of the presence of sepsis. Besides a possible pathogenic role of miR-150 in critical illness, our study indicates a potential use of circulating miRNAs as a prognostic rather than diagnostic marker in critically ill patients.

Alterations of adiponectin in the course of inflammation and severe sepsis

The adipocyte-specific protein adiponectin reveals anti-inflammatory, antioxidant, antiatherosclerotic and vasoprotective effects. This study aims to investigate adiponectin expression in cultured human adipocytes within an inflammatory model and in patients with severe sepsis and evaluates treatment effects of drotrecogin α (activated) (DAA). In an in vitro inflammatory model of adipocyte cell culture, the effect of DAA on adiponectin mRNA expression was evaluated. Synthesis of mRNA was measured by quantitative polymerase chain reaction. Supernatants of these adipocytes and serum levels of adiponectin were measured in blood of 104 patients by enzyme-linked immunosorbent assay on days 1, 3, and 5 of severe sepsis. Twenty-six patients were treated with DAA (DAA), 78 patients without DAA (DAA). Stimulation of human adipocytes with tumor necrosis factor α over 6 and 24 h resulted in a significant decrease in adiponectin mRNA transcripts. After 24 h of incubation, adiponectin mRNA expression was significantly upregulated according to applied dosages of DAA at 50 ng/mL and 5 μg/mL (P < 0.05). Accordingly, adiponectin levels of supernatants of adipocyte culture increased after 24 h (P < 0.05). DAA patients revealed significantly higher adiponectin serum levels compared with healthy controls (P < 0.1) and DAA patients (P < 0.05) at days 1 and 3. On day 5 after 96-h infusion of DAA (24 μg/kg per hour), adiponectin levels significantly increased in DAA patients and equalized toward DAA patients (P > 0.1). Adiponectin might be involved in the pathogenesis of the systemic inflammatory response during sepsis. Administration of DAA upregulates adiponectin expression under circumstances of systemic inflammation.

Adiponectin diminishes organ-specific microvascular endothelial cell activation associated with sepsis

Experimental sepsis was induced in male C57BL/6j, adiponectin-deficient mice (ADPNKO), and wild-type littermates by i.p. injection of 16 mg/kg lipopolysaccharide or cecal ligation and puncture. Blood and tissue samples were harvested 24 h after model induction. Circulating adiponectin is reduced in mice with endotoxemic challenge and after cecal ligation and puncture compared with healthy control mice. Quantitative reverse transcriptase-polymerase chain reaction for adiponectin reveals a pattern of response that is both model- and organ-specific. When challenged with sepsis, adiponectin deficiency results in increased expression of endothelial adhesion and coagulation molecules in the lung, liver, and kidney as quantified by reverse transcriptase-polymerase chain reaction, increased macrophage and neutrophil infiltration by immunohistochemistry, and vascular leakage in the liver and kidney. Adiponectin-deficient mice have reduced survival following cecal ligation and puncture and increased blood levels of interleukin 6, soluble vascular endothelial growth factor receptor 1, and soluble endothelial adhesion molecules E-selectin and intercellular adhesion molecule 1. Finally, ADPNKO promoted end-organ injury in the liver and kidney, whereas the lungs were not affected. These data suggest a protective role of adiponectin in diminishing microvascular organ-specific endothelial cell activation during sepsis.

Serial changes in adiponectin and resistin in critically ill patients with sepsis: associations with sepsis phase, severity, and circulating cytokine levels

PURPOSE

The aim of the present study was to describe the variation in adiponectin and resistin levels, 2 adipokines with opposing effects on metabolism, in mechanically ventilated patients with sepsis and their relationships to disease severity and cytokine levels.

MATERIALS AND METHODS

An observational prospective study was conducted in a secondary/tertiary unit. Forty-one mechanically ventilated patients diagnosed as having sepsis were included in the study. The Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores were estimated. Adiponectin, resistin, and cytokines were measured upon sepsis diagnosis and every 3 to 4 days thereafter until day 30. Adiponectin and resistin were also measured in 40 controls.

RESULTS

The patients had higher adiponectin (10.9 ± 6.1 μg/mL vs 6.0 ± 2.9 μg/mL, P < .001) and resistin (24.7 ng/mL vs 3.8 ng/mL, P < .001) levels compared with the controls. Adiponectin increased and resistin decreased significantly over time in the entire cohort. Resistin correlated with Acute Physiology and Chronic Health Evaluation II, Sequential Organ Failure Assessment, interleukin (IL)-6, IL-8, and IL-10 and was significantly higher in severe sepsis/septic shock compared with sepsis. No correlations between adiponectin and clinical scores were noted.

CONCLUSIONS

Adiponectin and resistin change reciprocally during the course of sepsis. Resistin relates to the severity of sepsis and the degree of inflammatory response. Adiponectin and resistin may play a critical role in the metabolic adaptations observed in sepsis.

Obesity and the risk and outcome of infection

The interactions between obesity and infectious diseases have recently received increasing recognition as emerging data have indicated an association between obesity and poor outcome in pandemic H1N1 influenza infection. Obesity is an established risk factor for surgical-site infections, nosocomial infections, periodontitis and skin infections. Several studies indicate that acute pancreatitis is more severe in the obese. Data are controversial and limited as regards the association between obesity and the risk and outcome of community-acquired infections such as pneumonia, bacteremia and sepsis and obesity and the course of HIV infection. As the cause-effect relationship between obesity and infection remains obscure in many infectious diseases, further studies are warranted. The consequences of obesity may have substantial effects on the global burden of infectious diseases.