In the critically ill patient, diabetes predicts mortality independent of statin therapy but is not associated with acute lung injury: a cohort study

Elevated Hemoglobin A1c and the Risk of Developing ARDS in Two Cohort Studies

BACKGROUND

Only a subset of patients at risk for ARDS go on to develop it, and the contribution of preexisting comorbidities (eg, diabetes) to ARDS risk is not well understood. Prior studies of the association between diabetes and ARDS have yielded conflicting results.

RESEARCH QUESTION

Does assessing ARDS risk based on hemoglobin A1c (HbA1c) as a marker of long-term blood glucose levels, rather than a charted diagnosis of diabetes, clarify the relationship between diabetes and ARDS?

STUDY DESIGN AND METHODS

Using data from two prospective observational cohorts of critically ill adults (Validating Acute Lung Injury Biomarkers for Diagnosis [VALID] and Early Assessment of Renal and Lung Injury [EARLI]), we analyzed the association between clinical HbA1c category and development of ARDS in patients with a risk factor for ARDS and at least one clinical HbA1c measurement within the 180 days prior through 14 days after enrollment.

RESULTS

A total of 599 patients in VALID and 276 in EARLI met inclusion criteria, of whom 164 and 58 developed ARDS, respectively. Patients with a charted diagnosis of diabetes were not shown to be more likely to develop ARDS (VALID: 24.6% ARDS in those categorized as nondiabetic vs 30.0% in those categorized as diabetic, P = .14; EARLI: 19.6% vs 22.8%, respectively; P = .55). However, in VALID, patients categorized as diabetic with inadequate glycemic control based on their HbA1c had an increased risk of developing ARDS compared with those with nondiabetic HbA1c (20.9% vs 34.0%, respectively; P = .0073), a finding that persisted in multivariable analysis (OR for those categorized as diabetic with inadequate glycemic control vs those categorized as nondiabetic range HbA1c, 1.25; 95% CI, 1.01-1.57). These findings were not reproduced in the smaller EARLI cohort, but were appreciated when the cohorts were combined for analysis.

INTERPRETATION

Elevated HbA1c may be associated with risk of developing ARDS, independent of clinical diagnosis of diabetes, but prospective validation is needed. If confirmed, these findings suggest that inadequate glycemic control could be an unrecognized risk factor for ARDS.

Persistent Hyperglycemia Worsens the Oleic Acid Induced Acute Lung Injury in Rat Model of Type II Diabetes Mellitus

Aim

This research aimed to study the impacts of persistent hyperglycemia on oleic acid (OA)-induced acute lung injury (ALI) in a rat model of type II diabetes mellitus.

Materials and Methods

Healthy adult male albino rats that weigh 150 to 180 g were divided into four groups (n = 6). Group I-saline (75 μL i.v.) was injected and served as a control; group II-OA (75 μL i.v.) was injected to induce ALI. Group III-pretreated with a high-fat diet and streptozotocin (35 mg/kg), was injected with saline, and served as a control for group IV. Group IV was pretreated with a high-fat diet, and streptozotocin (35 mg/kg) was injected with OA (75 μL i.v). Urethane was used to anesthetize the animal. The jugular venous cannulation was done for drug/saline administration, carotid artery cannulation was done to record blood pressure, and the tracheal cannulation was done to maintain the respiratory tract's patent. Heart rate, mean arterial pressure, and respiratory frequency were recorded on a computerized chart recorder; an arterial blood sample was collected to measure PaO2/FiO2. Additionally, the pulmonary water content and lung histology were examined.

Result

Hyperglycemic rats showed no significant change in the cardio-respiratory parameter. Histology of the lungs shows fibroblastic proliferation; however, rats survived throughout the observation period. There was an early deterioration of all the cardio-respiratory parameters in hyperglycemic rats when induced ALI (OA- induced), and survival time was significantly less compared to nonhyperglycemic rats.

Conclusion

Persistent hyperglycemia may cause morphological changes in the lungs, which worsens the outcome of acute lung injury.

Risk of ICU Admission and Related Mortality in Patients With Sodium-Glucose Cotransporter 2 Inhibitors and Dipeptidyl Peptidase-4 Inhibitors: A Territory-Wide Retrospective Cohort Study

OBJECTIVES

The benefit of sodium-glucose cotransporter 2 (SGLT2) inhibitors in reducing the occurrence rate of adverse cardiac and renal outcomes in patients with type 2 diabetes has been well described in randomized trials. Whether this benefit extends to patients at the most severe end of the disease spectrum requiring admission to the ICU remains to be examined.

DESIGN

Retrospective observational study.

SETTING

Data were obtained from a territory-wide clinical registry in Hong Kong (Clinical Data Analysis and Reporting System).

PATIENTS

All adult patients (age ≥ 18 yr) with type 2 diabetes and newly prescribed SGLT2 inhibitors or dipeptidyl peptidase-4 (DPP-4) inhibitors between January 1, 2015, and December 31, 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

After 1:2 propensity score matching, a total of 27,972 patients (10,308 SGLT2 inhibitors vs 17,664 DPP-4 inhibitors) were included in the final analysis. The mean age was 59 ± 11 years, and 17,416 (62.3%) were male. The median follow-up period was 2.9 years. The use of SGLT2 inhibitors was associated with decreased ICU admission (286 [2.8%] vs 645 [3.7%]; hazard ratio [HR], 0.79; 95% CI, 0.69-0.91; p = 0.001) and lower risks of all-cause mortality (315 [3.1%] vs 1,327 [7.5%]; HR, 0.44; 95% CI, 0.38-0.49; p < 0.001), compared with DPP-4 inhibitors. The severity of illness upon ICU admission by Acute Physiology and Chronic Health Evaluation IV-predicted risk of death was also lower in SGLT2 inhibitors users. Admissions and mortality due to sepsis were lower in SGLT2 inhibitor users compared with DPP-4 inhibitor users (admissions for sepsis: 45 [0.4%] vs 134 [0.8%]; p = 0.001 and mortality: 59 [0.6%] vs 414 [2.3%]; p < 0.001, respectively).

CONCLUSIONS

In patients with type 2 diabetes, SGLT2 inhibitors were independently associated with lower rates of ICU admission and all-cause mortality across various disease categories.

Effect of Uncomplicated Diabetes Mellitus on Acute Respiratory Distress Syndrome Among COVID-19 Patients in Aseer Region, Saudi Arabia

BACKGROUND

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; an ssRNA virus), which mainly affects the respiratory system but can also cause damage to other body systems. Acute respiratory distress syndrome (ARDS) is a serious complication of COVID-19 that requires early recognition and comprehensive management. ARDS is a diffuse inflammatory process that causes diffuse alveolar damage in the lung.  Aim: The study aimed to assess the effect of uncomplicated diabetes mellitus on ARDS among COVID-19 patients in the Aseer region.

METHODOLOGY

 A retrospective cohort study was conducted in Aseer Central Hospital between July 10, 2021 to Jan 15, 2022 where confirmed inpatient COVID-19 cases in the Aseer region were classified into two groups. The first group was diabetic patients without any diabetes-related complications and confirmed for COVID-19 infection (diabetes group). The second group was confirmed COVID-19 patients free from any chronic disease. Extracted data included patients' diabetes status, medical history, socio-demographic data, COVID-19 infection data and vaccination, experienced signs and symptoms, tachypnea, use of accessory muscles of respiration, nasal flaring, grunting, cyanosis, need for hospitalization, need for mechanical ventilation and ICU admission.  Results: The study included 144 patients with uncomplicated diabetes and 323 healthy patients with COVID-19 infection. The mean age of the diabetic group was 65.4 ± 12.9 years old compared to 40.2 ± 11.9 years old for the healthy group. Only one case of the diabetic group was vaccinated against COVID-19 at the study period versus two cases of the healthy group (P=.925). Also, 14 (9.7%) of the diabetic group were contacted with confirmed COVID-19 cases in comparison to 44 (13.6%) healthy cases (P=.238). A total of five (3.5%) diabetic cases needed mechanical ventilation during hospitalization compared to 23 (7.1%) healthy cases with no statistical significance (P=.125). Also, 12 (8.3%) diabetic cases admitted to ICU versus 42 (13%) of healthy cases (P=.145).  Conclusions: In conclusion, there is a great controversy regarding the effect of diabetes on the progression of COVID-19 infection to ARDS. The current study showed that there was no significant difference between diabetic and healthy COVID-19 infected cases regarding ARDS related clinical factors mainly need of ICU admission and mechanical ventilation.

Effects of aerobic exercise on lipopolysaccharide-induced experimental acute lung injury in the animal model of type 1 diabetes mellitus

NEW FINDINGS

What is the central question of this study? We evaluated the effects of diabetes and exercise on lipopolysaccharide-induced acute lung injury. By providing a comprehensive analysis of redox status, blood gases and histological parameters, we aimed to contribute to the ongoing debate in the literature. What are the main findings and its importance? We demonstrated the preventive effect of exercise, but diabetes did not alter the severity of acute lung injury.

ABSTRACT

Acute lung injury (ALI) is a life-threatening respiratory condition. Diabetes (DM) is a metabolic disease characterized by hyperglycaemia. There is an ongoing debate concerning whether there is a protective effect of diabetes in ALI. Exercise is a special type of physical activity that has numerous beneficial effects. The aim of our study was to investigate the effects of diabetes and exercise on the prognosis of ALI. Male Wistar albino rats were divided into two groups (sedentary and exercise). Both groups were divided into four subgroups: Control, ALI, DM, DM+ALI (n = 6 each). Diabetes was induced by injection of streptozotocin (50 mg/kg i.p.). The maximal exercise capacity was determined with the incremental load test. Animals were exercised on a treadmill for 45 min at 70% of maximal exercise capacity, 5 days a week for 12 weeks. Acute lung injury was induced by intratracheal injection of lipopolysaccharide (100 μg/100 g body weight) 24 h before the end of the experiment. We performed arterial blood gas analysis. Redox status was measured in both plasma and lung tissue. Malondialdehyde and 8-hydroxy-2'-deoxyguanosine levels were measured in lung tissue. Lung tissue was evaluated histologically. Acute lung injury caused significant damage in the lung tissue, which was verified histologically, with an increase in oxidative stress parameters. Exercise prevented the lung damage induced by ALI and reduced oxidative stress in the lung tissue. Diabetes did not alter the magnitude of damage done by ALI. Exercise showed a protective effect against DM and ALI in rats. The effect of DM was insignificant for the prognosis of ALI.

Identification of macrophage activation-related biomarkers in obese type 2 diabetes that may be indicative of enhanced respiratory risk in COVID-19

Hyperactivation of the immune system through obesity and diabetes may enhance infection severity complicated by Acute Respiratory Distress Syndrome (ARDS). The objective was to determine the circulatory biomarkers for macrophage activation at baseline and after serum glucose normalization in obese type 2 diabetes (OT2D) subjects. A case-controlled interventional pilot study in OT2D (n = 23) and control subjects (n = 23). OT2D subjects underwent hyperinsulinemic clamp to normalize serum glucose. Plasma macrophage-related proteins were determined using Slow Off-rate Modified Aptamer-scan plasma protein measurement at baseline (control and OT2D subjects) and after 1-h of insulin clamp (OT2D subjects only). Basal M1 macrophage activation was characterized by elevated levels of M1 macrophage-specific surface proteins, CD80 and CD38, and cytokines or chemokines (CXCL1, CXCL5, RANTES) released by activated M1 macrophages. Two potent M1 macrophage activation markers, CXCL9 and CXCL10, were decreased in OT2D. Activated M2 macrophages were characterized by elevated levels of plasma CD163, TFGβ-1, MMP7 and MMP9 in OT2D. Conventional mediators of both M1 and M2 macrophage activation markers (IFN-γ, IL-4, IL-13) were not altered. No changes were observed in plasma levels of M1/M2 macrophage activation markers in OT2D in response to acute normalization of glycemia. In the basal state, macrophage activation markers are elevated, and these reflect the expression of circulatory cytokines, chemokines, growth factors and matrix metalloproteinases in obese individuals with type 2 diabetes, that were not changed by glucose normalisation. These differences could potentially predispose diabetic individuals to increased infection severity complicated by ARDS.

Clinical trial reg. no: NCT03102801; registration date April 6, 2017.

Diabetic lung disease: fact or fiction?

Diabetes mellitus is a chronic, progressive, incompletely understood metabolic disorder whose prevalence has been increasing steadily worldwide. Even though little attention has been paid to lung disorders in the context of diabetes, its prevalence has recently been challenged by newer studies of disease development. In this review, we summarize and discuss the role of diabetes mellitus involved in the progression of pulmonary diseases, with the main focus on pulmonary fibrosis, which represents a chronic and progressive disease with high mortality and limited therapeutic options.

The effect of diabetes on the risk and mortality of acute lung injury/acute respiratory distress syndrome: A meta-analysis

BACKGROUND

The role of pre-existing diabetes in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is still controversial. This systematic review and meta-analysis of observational studies aimed to evaluate the effect of diabetes on the risk and mortality of ALI/ARDS.

METHODS

A comprehensive literature search was performed in PubMed, Scopus, Cochrane Central Register of Controlled Trails and Web of Science for their inception to September 2018. Summary risk estimates were calculated with a DerSimonian and Laird random-effects model. Heterogeneity was evaluated using Cochran chi-square test and the I statistic.

RESULTS

Ultimately, 14 studies with a total of 6613 ALI/ARDS cases were included. The risk of ALI/ARDS was not significantly reduced in diabetes patients (OR 0.82, 95% CI 0.57-1.18, P = .283), with obvious heterogeneity across studies (I = 72.5%, P < .001). Further analyses in the meta-analysis also showed no statistically significant associations between pre-existing diabetes and in-hospital mortality (OR 0.79, 95% CI 0.51-1.21, P = .282) or 60-day mortality of ALI/ARDS (OR 0.91, 95% CI 0.75-1.11, P = .352).

CONCLUSION

This systematic review and meta-analysis of observational studies indicates that pre-existing diabetes have no effect on the risk and mortality of ALI/ARDS.

Identifying associations between diabetes and acute respiratory distress syndrome in patients with acute hypoxemic respiratory failure: an analysis of the LUNG SAFE database

BACKGROUND

Diabetes mellitus is a common co-existing disease in the critically ill. Diabetes mellitus may reduce the risk of acute respiratory distress syndrome (ARDS), but data from previous studies are conflicting. The objective of this study was to evaluate associations between pre-existing diabetes mellitus and ARDS in critically ill patients with acute hypoxemic respiratory failure (AHRF).

METHODS

An ancillary analysis of a global, multi-centre prospective observational study (LUNG SAFE) was undertaken. LUNG SAFE evaluated all patients admitted to an intensive care unit (ICU) over a 4-week period, that required mechanical ventilation and met AHRF criteria. Patients who had their AHRF fully explained by cardiac failure were excluded. Important clinical characteristics were included in a stepwise selection approach (forward and backward selection combined with a significance level of 0.05) to identify a set of independent variables associated with having ARDS at any time, developing ARDS (defined as ARDS occurring after day 2 from meeting AHRF criteria) and with hospital mortality. Furthermore, propensity score analysis was undertaken to account for the differences in baseline characteristics between patients with and without diabetes mellitus, and the association between diabetes mellitus and outcomes of interest was assessed on matched samples.

RESULTS

Of the 4107 patients with AHRF included in this study, 3022 (73.6%) patients fulfilled ARDS criteria at admission or developed ARDS during their ICU stay. Diabetes mellitus was a pre-existing co-morbidity in 913 patients (22.2% of patients with AHRF). In multivariable analysis, there was no association between diabetes mellitus and having ARDS (OR 0.93 (0.78-1.11); p = 0.39), developing ARDS late (OR 0.79 (0.54-1.15); p = 0.22), or hospital mortality in patients with ARDS (1.15 (0.93-1.42); p = 0.19). In a matched sample of patients, there was no association between diabetes mellitus and outcomes of interest.

CONCLUSIONS

In a large, global observational study of patients with AHRF, no association was found between diabetes mellitus and having ARDS, developing ARDS, or outcomes from ARDS.

TRIAL REGISTRATION

NCT02010073 . Registered on 12 December 2013.

Long-term mortality of critically ill patients with diabetes who survive admission to the intensive care unit

OBJECTIVE

Long-term outcomes of critically ill patients with diabetes are unknown. Our objectives were to evaluate the effect of diabetes on both long-term survival rates and the average number of years of life lost for patients admitted to an intensive care unit who survived to hospital discharge.

DESIGN AND PARTICIPANTS

A data linkage study evaluating all adult patients in South Australia between 2004 and 2011 who survived hospitalisation that required admission to a public hospital ICU.

MAIN OUTCOME MEASURES

All patients were evaluated using hospital coding for diabetes, which was crossreferenced with registration with the Australian National Diabetes Services Scheme for a diagnosis of diabetes. This dataset was then linked to the Australian National Death Index. Longitudinal survival was assessed using Cox proportional hazards regression. Life-years lost were calculated using age- and sex-specific life-tables from the Australian Bureau of Statistics.

RESULTS

5450 patients with diabetes and 17 023 patients without diabetes were included. Crude mortality rates were 105.5 per 1000 person-years (95% CI, 101.6-109.6 per 1000 person-years) for patients with diabetes, and 67.6 per 1000 person-years (95% CI, 65.9-69.3 per 1000 personyears) for patients without diabetes. Patients with diabetes were older and had higher illness severity scores on admission to the ICU, were more likely to die after hospital discharge (unadjusted hazard ratio [HR], 1.52 [95% CI, 1.45-1.59]; adjusted HR, 1.16 [95% CI, 1.10-1.21]; P < 0.0001) and suffered a greater number of average lifeyears lost.

CONCLUSIONS

Our study indicates that crude mortality for ICU survivors with pre-existing diabetes is considerable after hospital discharge, and the risk of mortality is greater than for survivors without diabetes.

Atorvastatin reduces β-Adrenergic dysfunction in rats with diabetic cardiomyopathy

Background

In the diabetic heart the β-adrenergic response is altered partly by down-regulation of the β1-adrenoceptor, reducing its positive inotropic effect and up-regulation of the β3-adrenoceptor, increasing its negative inotropic effect. Statins have clinical benefits on morbidity and mortality in diabetic patients which are attributed to their “pleiotropic” effects. The objective of our study was to investigate the role of statin treatment on β-adrenergic dysfunction in diabetic rat cardiomyocytes.

Methods

β-adrenergic responses were investigated in vivo (echocardiography) and ex vivo (left ventricular papillary muscles) in healthy and streptozotocin-induced diabetic rats, who were pre-treated or not by oral atorvastatin over 15 days (50 mg.kg^-1.day^-1). Micro-array analysis and immunoblotting were performed in left ventricular homogenates. Data are presented as mean percentage of baseline ± SD.

Results

Atorvastatin restored the impaired positive inotropic effect of β-adrenergic stimulation in diabetic hearts compared with healthy hearts both in vivo and ex vivo but did not suppress the diastolic dysfunction of diabetes. Atorvastatin changed the RNA expression of 9 genes in the β-adrenergic pathway and corrected the protein expression of β1-adrenoceptor and β1/β3-adrenoceptor ratio, and multidrug resistance protein 4 (MRP4). Nitric oxide synthase (NOS) inhibition abolished the beneficial effects of atorvastatin on the β-adrenoceptor response.

Conclusions

Atorvastatin restored the positive inotropic effect of the β-adrenoceptor stimulation in diabetic cardiomyopathy. This effect is mediated by multiple modifications in expression of proteins in the β-adrenergic signaling pathway, particularly through the NOS pathway.

Clinical Predictors of Hospital Mortality Differ Between Direct and Indirect ARDS

BACKGROUND

Direct (pulmonary) and indirect (extrapulmonary) ARDS are distinct syndromes with important pathophysiologic differences. The goal of this study was to determine whether clinical characteristics and predictors of mortality differ between direct or indirect ARDS.

METHODS

This retrospective observational cohort study included 417 patients with ARDS. Each patient was classified as having direct (pneumonia or aspiration, n = 250) or indirect (nonpulmonary sepsis or pancreatitis, n = 167) ARDS.

RESULTS

Patients with direct ARDS had higher lung injury scores (3.0 vs 2.8; P < .001), lower Simplified Acute Physiology Score II scores (51 vs 62; P < .001), lower Acute Physiology and Chronic Health Evaluation II scores (27 vs 30; P < .001), and fewer nonpulmonary organ failures (1 vs 2; P < .001) compared with patients with indirect ARDS. Hospital mortality was similar (28% vs 31%). In patients with direct ARDS, age (OR, 1.29 per 10 years; P = .01; test for interaction, P = .03), lung injury scores (OR, 2.29 per point; P = .001; test for interaction, P = .058), and number of nonpulmonary organ failures (OR, 1.67; P = .01) were independent risk factors for increased hospital mortality. Preexisting diabetes mellitus was an independent risk factor for reduced hospital mortality (OR, 0.47; P = .04; test for interaction, P = .02). In indirect ARDS, only the number of organ failures was an independent predictor of mortality (OR, 2.08; P < .001).

CONCLUSIONS

Despite lower severity of illness and fewer organ failures, patients with direct ARDS had mortality rates similar to patients with indirect ARDS. Factors previously associated with mortality during ARDS were only associated with mortality in direct ARDS. These findings suggest that direct and indirect ARDS have distinct features that may differentially affect risk prediction and clinical outcomes.

Prognostic factors in the acute respiratory distress syndrome

Despite improvements in critical care, acute respiratory distress syndrome (ARDS) remains a devastating clinical problem with high rates of morbidity and mortality. A better understanding of the prognostic factors associated with ARDS is crucial for facilitating risk stratification and developing new therapeutic interventions that aim to improve clinical outcomes. In this article, we present an up-to-date summary of factors that predict mortality in ARDS in four categories: (1) clinical characteristics; (2) physiological parameters and oxygenation; (3) genetic polymorphisms and biomarkers; and (4) scoring systems. In addition, we discuss how a better understanding of clinical and basic pathogenic mechanisms can help to inform prognostication, decision-making, risk stratification, treatment selection, and improve study design for clinical trials.

Obesity-induced adipokine imbalance impairs mouse pulmonary vascular endothelial function and primes the lung for injury

Obesity is a risk factor for the development of acute respiratory distress syndrome (ARDS) but mechanisms mediating this association are unknown. While obesity is known to impair systemic blood vessel function, and predisposes to systemic vascular diseases, its effects on the pulmonary circulation are largely unknown. We hypothesized that the chronic low grade inflammation of obesity impairs pulmonary vascular homeostasis and primes the lung for acute injury. The lung endothelium from obese mice expressed higher levels of leukocyte adhesion markers and lower levels of cell-cell junctional proteins when compared to lean mice. We tested whether systemic factors are responsible for these alterations in the pulmonary endothelium; treatment of primary lung endothelial cells with obese serum enhanced the expression of adhesion proteins and reduced the expression of endothelial junctional proteins when compared to lean serum. Alterations in pulmonary endothelial cells observed in obese mice were associated with enhanced susceptibility to LPS-induced lung injury. Restoring serum adiponectin levels reversed the effects of obesity on the lung endothelium and attenuated susceptibility to acute injury. Our work indicates that obesity impairs pulmonary vascular homeostasis and enhances susceptibility to acute injury and provides mechanistic insight into the increased prevalence of ARDS in obese humans.

Diabetes increases pancreatitis induced systemic inflammation but has little effect on inflammation and cell death in the lung

Acute pancreatitis (AP) can lead to a systemic inflammatory response that often results in acute lung injury and single or multiple organ failure. In a previous study we demonstrated that diabetes aggravates the local pathophysiological process during AP. In this study we explore, if diabetes also increases pancreatitis induced systemic inflammation and causes lung injury. Acute pancreatitis was induced in untreated and streptozotocin-treated diabetic mice by injection of cerulein. Systemic inflammation was studied by IL-6 ELISA in blood plasma and white blood cell count. Lung inflammation and lung injury were quantified by chloroacetate esterase staining, evaluation of the alveolar cellularity index and cleaved caspase-3 immunohistochemistry. In normoglycaemic mice AP increased the IL-6 concentration in plasma and caused lymphocytopenia. Diabetes significantly increased the IL-6 concentration in plasma and further reduced the number of lymphocytes during AP, whereas diabetes had little effect on these parameters in the absence of pancreatitis. However, diabetes only marginally increased lung inflammation and did not lead to cell death of the lung epithelium during AP. We conclude that diabetes increases parameters of systemic inflammation during AP, but that this increase is insufficient to cause lung injury.

Statin use and risk of delirium in the critically ill

RATIONALE

Delirium is common in intensive care unit (ICU) patients and is a predictor of worse outcomes and neuroinflammation is a possible mechanism. The antiinflammatory actions of statins may reduce delirium.

OBJECTIVES

To determine whether critically ill patients receiving statin therapy had a reduced risk of delirium than those not on statins.

METHODS

A prospective cohort analysis of data from consecutive ICU patients admitted to a UK mixed medical and surgical critical care unit between August 2011 and February 2012; the Confusion Assessment Method for ICU was used to determine the days each patient was assessed as being free of delirium during ICU admission.

MEASUREMENTS AND MAIN RESULTS

Delirium-free days, daily administration of statins, and serum C-reactive protein (CRP) were recorded. Four hundred and seventy consecutive critical care patients were followed, of whom 151 patients received statins. Using random-effects multivariable logistic regression, statin administration the previous evening was associated with the patient being assessed as free of delirium (odds ratio, 2.28; confidence interval, 1.01-5.13; P < 0.05) and with lower CRP (β = -0.52; P < 0.01) the following day. When the association between statin and being assessed as free of delirium was controlled for CRP, the effect size became nonsignificant (odds ratio, 1.56; confidence interval, 0.64-3.79; P = 0.32).

CONCLUSIONS

Ongoing statin therapy is associated with a lower daily risk of delirium in critically ill patients. An ongoing clinical trial, informed by this study, is investigating if statins are a potential therapy for delirium in the critically ill.

Risk of acute lung injury/acute respiratory distress syndrome in critically ill adult patients with pre-existing diabetes: a meta-analysis

Background

The impact of pre-existing diabetes on the development of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) in critically ill patients remains unclear. We performed a meta-analysis of cohort studies to evaluate the risk of ALI/ARDS in critically ill patients with and without pre-existing diabetes.

Materials and Methods

We searched PubMed and Embase from the inception to September 2013 for cohort studies assessing the effect of pre-existing diabetes on ALI/ARDS occurrence. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using random- or fixed-effect models when appropriate.

Results

Seven cohort studies with a total of 12,794 participants and 2,937 cases of pre-existing diabetes, and 2,457 cases of ALI/ARDS were included in the meta-analysis. A fixed-effects model meta-analysis showed that pre-existing diabetes was associated with a reduced risk of ALI/ARDS (OR 0.66; 95% CI, 0.55–0.80; p<0.001), with low heterogeneity among the studies (I² = 18.9%; p = 0.286). However, the asymmetric funnel plot and Egger's test (p = 0.007) suggested publication bias may exist.

Conclusions

Our meta-analysis suggests that pre-existing diabetes was associated with a decreased risk of ALI/ARDS in critically ill adult patients. However, the result should be interpreted with caution because of the potential bias and confounding in the included studies.

Role of diabetes in the development of acute respiratory distress syndrome

OBJECTIVES

Diabetes has been associated with decreased development of acute respiratory distress syndrome in some, but not all, previous studies. Therefore, we examined the relationship between diabetes and development of acute respiratory distress syndrome and whether this association was modified by type of diabetes, etiology of acute respiratory distress syndrome, diabetes medications, or other potential confounders.

DESIGN

Observational prospective multicenter study.

SETTING

Four adult ICUs at two tertiary academic medical centers.

PATIENTS

Three thousand eight hundred sixty critically ill patients at risk for acute respiratory distress syndrome from sepsis, pneumonia, trauma, aspiration, or massive transfusion.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Diabetes history was present in 25.8% of patients. Diabetes was associated with lower rates of developing acute respiratory distress syndrome on univariate (odds ratio, 0.79; 95% CI, 0.66-0.94) and multivariate analysis (adjusted odds ratio, 0.76; 95% CI, 0.61-0.95). After including diabetes medications into the model, diabetes remained protective (adjusted odds ratio, 0.75; 95% CI, 0.59-0.94). Diabetes was associated with decreased development of acute respiratory distress syndrome both in the subgroup of patients with sepsis (adjusted odds ratio, 0.77; 95% CI, 0.61-0.97) and patients with noninfectious etiologies (adjusted odds ratio, 0.30; 95% CI, 0.10-0.90). The protective effect of diabetes on acute respiratory distress syndrome development is not clearly restricted to either type 1 (adjusted odds ratio, 0.50; 95% CI, 0.26-0.99; p = 0.046) or type 2 (adjusted odds ratio, 0.77; 95% CI, 0.60-1.00; p = 0.050) diabetes. Among patients in whom acute respiratory distress syndrome developed, diabetes was not associated with 60-day mortality on univariate (odds ratio, 1.11; 95% CI, 0.80-1.52) or multivariate analysis (adjusted odds ratio, 0.81; 95% CI, 0.56-1.18).

CONCLUSIONS

Diabetes is associated with a lower rate of acute respiratory distress syndrome development, and this relationship remained after adjusting for clinical differences between diabetics and nondiabetics, such as obesity, acute hyperglycemia, and diabetes-associated medications. In addition, this association was present for type 1 and 2 diabetics and in all subgroups of at-risk patients.

Outcomes of diabetic and nondiabetic patients undergoing general and vascular surgery

Aims. Preoperative diabetic and glycemic screening may or may not be cost effective. Although hyperglycemia is known to compromise surgical outcomes, the effect of a diabetic diagnosis on outcomes is poorly known. We examine the effect of diabetes on outcomes for general and vascular surgery patients. Methods. Data were collected from the Michigan Surgical Quality Collaborative for general or vascular surgery patients who had diabetes. Primary and secondary outcomes were 30-day mortality and 30-day overall morbidity, respectively. Binary logistic regression analysis was used to identify risk factors. Results. We identified 177,430 (89.9%) general surgery and 34,006 (16.1%) vascular surgery patients. Insulin and noninsulin diabetics accounted for 7.1% and 9.8%, respectively. Insulin and noninsulin dependent diabetics were not at increased risk for mortality. Diabetics are at a slight increased odds than non-diabetics for overall morbidity, and insulin dependent diabetics more so than non-insulin dependent. Ventilator dependence, 10% weight loss, emergent case, and ASA class were most predictive. Conclusions. Diabetics were not at increased risk for postoperative mortality. Insulin-dependent diabetics undergoing general or vascular surgery were at increased risk of overall 30-day morbidity. These data provide insight towards mitigating poor surgical outcomes in diabetic patients and the cost effectiveness of preoperative diabetic screening.

Inhaled aerosolized insulin ameliorates hyperglycemia-induced inflammatory responses in the lungs in an experimental model of acute lung injury

Introduction

Previous studies have shown that patients with diabetes mellitus appear to have a lower prevalence of acute lung injury. We assumed that insulin prescribed to patients with diabetes has an anti-inflammatory property and pulmonary administration of insulin might exert beneficial effects much more than intravenous administration.

Methods

Twenty-eight mechanically ventilated rabbits underwent lung injury by saline lavage, and then the animals were allocated into a normoglycemia group (NG), a hyperglycemia group (HG), an HG treated with intravenous insulin (HG-VI) group or an HG treated with aerosolized insulin (HG-AI) group with continuous infusion of different fluid solutions and treatments: normal saline, 50% glucose, 50% glucose with intravenous insulin, or 50% glucose with inhaled aerosolized insulin, respectively. After four hours of treatment, the lungs and heart were excised en bloc, and then high-mobility group B1 concentration in bronchoalveolar lavage fluid, interleukin-8 and toll-like receptor 4 mRNA expression in bronchoalveolar lavage fluid cells, and lung myeloperoxidase activity were measured.

Results

Treatment with both aerosolized insulin and intravenous insulin attenuated toll-like receptor 4 mRNA expressions in the bronchoalveolar lavage fluid cells. Interleukin-8 and toll-like receptor 4 mRNA expression was significantly lower in the HG-AI group than in the HG-IV group. The lung myeloperoxidase activity in the normal healthy group showed significantly lower levels compared to the NG group but not different compared to those of the HG, HG-VI and HG-AI groups.

Conclusions

The results suggest that insulin attenuates inflammatory responses in the lungs augmented by hyperglycemia in acute lung injury and the insulin's efficacy may be better when administered by aerosol.

Type 2 diabetes and 1-year mortality in intensive care unit patients

BACKGROUND

Data on the prognostic impact of diabetes and diabetic complications in intensive care unit (ICU) patients are limited and inconsistent. We, therefore, examined mortality in ICU patients with type 2 diabetes with and without pre-existing heart and kidney diseases compared with nondiabetic patients.

DESIGN

We conducted this population-based cohort study in Northern Denmark during 2005-2011. We included all ICU patients aged 40 years or older from the 17 ICUs in the area and identified type 2 diabetes by either a filled prescription for an antidiabetic drug, a previous diagnosis of diabetes, or an elevated glycosylated haemoglobin level. Diabetic patients were disaggregated according to pre-existing diagnoses of heart disease (myocardial infarction or heart failure) and kidney disease. We estimated 1-year mortality by the Kaplan-Meier method and hazard ratios of death (HRs) during follow-up using Cox regression, controlling for confounding factors and stratified by relevant subgroups.

RESULTS

Among 45 018 ICU patients, 7219 (16·0%) had type 2 diabetes. Overall, 1-year mortality was 36·0% in ICU patients with type 2 diabetes, rising to 54·6% in patients with pre-existing heart and kidney diseases, compared with 29·1% in nondiabetic patients. Comparing diabetic with nondiabetic patients, the adjusted 0- to 30-day HR was 1·20 (95% confidence interval (CI): 1·13-1·26) and 1·19 (95% CI: 1·10-1·28) during the 31- to 365-day follow-up period. Pre-existing kidney disease further increased the impact of diabetes, while heart disease alone had no such effect.

CONCLUSIONS

ICU patients with type 2 diabetes had higher 1-year mortality compared with nondiabetic ICU patients, particularly those with pre-existing kidney disease.