Sepsis and the Obesity Paradox: Size Matters in More Than One Way

Association between the triglyceride glucose index and short-term mortality in septic patients with or without obesity: a retrospective cohort study

BACKGROUND

Sepsis is a significant contributor to both intensive care unit (ICU) admissions and mortality among patients in ICU, with a rising prevalence of obesity. There is a lack of extensive research on the correlation between TyGI and findings in patients with sepsis, especially in obese patients.

METHODS

This study used a retrospective cohort design and included patients with sepsis (≥18 years) from the Medical Information Mart for Intensive Care IV database. The association between TyGI and outcome was examined using multivariable logistic regression analysis.

RESULTS

8,840 patients with sepsis were included in the analysis. The in-ICU mortality rate was 9.7%. Non-survivors exhibited significantly greater TyGI levels than survivors [9.19(8.76-9.71) vs. 9.10(8.67-9.54), p < 0.001]. The adjusted multivariate regression model showed that elevated TyGI values were linked to a greater likelihood of death in ICU (odds ratio [OR] range 1.072-1.793, p < 0.001) and hospital (OR range 1.068-1.445, p = 0.005). Restricted Cubic Spline analysis revealed a nonlinear association between TyGI and in-ICU and in-hospital mortality risks within specified ranges. Subgroup analysis revealed interaction effects in the general obesity, abdominal obesity, and impaired fasting glucose subgroups (p = 0.014, 0.016, and < 0.001, respectively).

CONCLUSION

TyGI was associated with an increased sepsis-related short-term mortality risk and adverse outcomes after ICU admission.

Obesity is associated with improved early survival but increased late mortality in surgical patients with Sepsis: A propensity matched analysis

BACKGROUND

While obesity is a risk factor for postoperative complications, its impact following sepsis is unclear. The primary objective of this study was to evaluate the association between obesity and mortality following admission to the surgical intensive care unit (SICU) with sepsis.

METHODS

We conducted a single center retrospective review of SICU patients grouped into obese (n = 766, body mass index ≥30 kg/m 2 ) and nonobese (n = 574; body mass index, 18-29.9 kg/m 2 ) cohorts. Applying 1:1 propensity matching for age, sex, comorbidities, sequential organ failure assessment, and transfer status, demographic data, comorbidities, and sepsis presentation were compared between groups. Primary outcomes included in-hospital and 90-day mortality, ICU length of stay, need for mechanical ventilation (IMV) and renal replacement therapy (RRT). p < 0.05 was considered significant.

RESULTS

Obesity associates with higher median ICU length of stay (8.2 vs. 5.6, p < 0.001), need for IMV (76% vs. 67%, p = 0.001), ventilator days (5 vs. 4, p < 0.004), and RRT (23% vs. 12%, p < 0.001). In-hospital (29% vs. 18%, p < 0.0001) and 90-day mortality (34% vs. 24%, p = 0.0006) was higher for obese compared with nonobese groups. Obesity independently predicted need for IMV (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.2-2.1), RRT (OR, 2.2; 95% CI, 1.5-3.1), in-hospital (OR, 2.1; 95% CI, 1.5-2.8), and 90-day mortality (HR, 1.4; 95% CI, 1.1-1.8), after adjusting for sequential organ failure assessment, age, sex, and comorbidities. Comparative survival analyses demonstrate a paradoxical early survival benefit for obese patients followed by a rapid decline after 7 days (logrank p = 0.0009).

CONCLUSION

Obesity is an independent risk factor for 90-day mortality for surgical patients with sepsis, but its impact appeared later in hospitalization. Understanding differences in systemic responses between these cohorts may be important for optimizing critical care management.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

The obesity paradox and 90 day mortality in chronic critically ill patients: a cohort study using a large clinical database

BACKGROUND

This study investigates the obesity paradox, where obesity is linked to lower mortality in certain patient groups, focusing on its impact on long-term mortality in chronic critically ill (CCI) patients.

METHODS

We retrospectively analyzed CCI patients from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database's Intensive Care Unit, categorizing them into six groups based on Body Mass Index (BMI). Using stepwise multivariable Cox regression and restricted cubic spline models, we examined the association between BMI and 90 day mortality, accounting for confounding variables through subgroup analyses.

RESULTS

The study included 1996 CCI patients, revealing a 90 day mortality of 34.12%. Overweight and obese patients exhibited significantly lower mortality compared to normal-weight individuals. Adjusted analysis showed lower mortality risks in overweight and obese groups (HRs 0.60 to 0.72, p < 0.001). The cubic spline model indicated a negative correlation between BMI and 90 day mortality, with subgroup analyses highlighting interactions with age.

CONCLUSION

Our findings confirm the obesity paradox in CCI patients, especially among the elderly (65-85 years) and very elderly (≥ 85 years). The results suggest a beneficial association of higher BMI in older CCI patients, though caution is advised for those under 45.

Exploring the relationship between life course adiposity and sepsis: insights from a two-sample Mendelian randomization analysis

Objectives

The relationship between adiposity and sepsis has received increasing attention. This study aims to explore the causal relationship between life course adiposity and the sepsis incidence.

Methods

Mendelian randomization (MR) method was employed in this study. Instrumental variants were obtained from genome-wide association studies for life course adiposity, including birth weight, childhood body mass index (BMI), childhood obesity, adult BMI, waist circumference, visceral adiposity, and body fat percentage. A meta-analysis of genome-wide association studies for sepsis including 10,154 cases and 454,764 controls was used in this study. MR analyses were performed using inverse variance weighted, MR Egger regression, weighted median, weighted mode, and simple mode. Instrumental variables were identified as significant single nucleotide polymorphisms at the genome-wide significance level (P < 5×10-8). The sensitivity analysis was conducted to assess the reliability of the MR estimates.

Results

Analysis using the MR analysis of inverse variance weighted method revealed that genetic predisposition to increased childhood BMI (OR = 1.29, P = 0.003), childhood obesity (OR = 1.07, P = 0.034), adult BMI (OR = 1.38, P < 0.001), adult waist circumference (OR = 1.01, P = 0.028), and adult visceral adiposity (OR = 1.53, P < 0.001) predicted a higher risk of sepsis. Sensitivity analysis did not identify any bias in the MR results.

Conclusion

The results demonstrated that adiposity in childhood and adults had causal effects on sepsis incidence. However, more well-designed studies are still needed to validate their association.

Sepsis and Septic Shock in Patients Undergoing Thyroidectomy: Incidence, Risk Factors, and Outcomes

INTRODUCTION

Postoperative sepsis represents a rare complication following thyroidectomy. We aimed to explore the incidence, risk factors, sources, and outcomes of postoperative sepsis and septic shock among adult patients undergoing thyroidectomy.

METHODS

Data from the American College of Surgeons National Surgical Quality Improvement Program were used in this retrospective cohort study. Patients aged ≥18 y who underwent elective thyroidectomy between 2005 and 2019 were included. Multivariable binary logistic regression models were computed to explore risk factors and outcomes of 30-d sepsis and septic shock.

RESULTS

Among the 180,373 included patients, 0.1% developed sepsis or septic shock. Male gender, low body mass index, American Society of Anesthesiologists classes 3-5, functional dependence, smoking, diabetes mellitus, pulmonary disease, inpatient surgery, malignant indication, clean-contaminated wound classification, and operation time ≥150 min were significant risk factors for development of sepsis or septic shock. Common infectious sources of sepsis included surgical site infections (29.6%), pneumonia (18.6%), urinary tract infections (16.2%), and multiple infections (6.9%). Patients with postoperative sepsis or septic shock were significantly more likely to develop complications, including wound disruption, stroke, cardiac and renal complications, thromboembolism, prolonged length of stay, unplanned reoperation, and mortality.

CONCLUSIONS

Sepsis is rare following thyroidectomy. Our study provides insight into risk factors and procedural characteristics which may contribute to the development of postoperative sepsis or septic shock in this population.

The obesity paradox in younger adult patients with sepsis: analysis of the MIMIC-IV database

BACKGROUND

The obesity paradox suggests that individuals with obesity may have a survival advantage against specific critical illnesses, including sepsis. However, whether this paradox occurs at younger ages remains unclear. Therefore, we aimed to investigate whether obesity could improve survival in younger adult patients with sepsis.

METHODS

We used clinical data sourced from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients with Sequential Organ Failure Assessment score ≥2 and suspected infection at the time of ICU admission were identified as having sepsis, following the Sepsis-3 definition. Individuals were classified into the obesity (BMI ≥30 kg/m²) and non-obesity (BMI <30 kg/m²) groups. Patients aged <50 and ≥50 years were categorized as younger adult patients and older patients, respectively.

RESULTS

Of 73,181 patients in the MIMIC-IV ICU database, 18,120 satisfied the inclusion criteria: 2642 aged <50 years and 15,478 aged ≥50 years. The Kaplan-Meier curve showed that obesity was not associated with an improved mortality rate among younger adult patients with sepsis (log-rank test: P = 0.197), while obesity exhibited a survival benefit in older patients with sepsis (log-rank test: P < 0.001). After propensity score matching, in-hospital mortality did not differ significantly between the obesity and non-obesity groups (13.3% vs. 12.2%; P = 0.457) in the younger adult patients with sepsis. Multivariate logistic regression analysis revealed that BMI was not an independent risk factor for in-hospital mortality in younger adult patients with sepsis (underweight: adjusted odds ratio [aOR] 1.72, P = 0.076; overweight: aOR 0.88, P = 0.437; obesity: aOR 0.93, P = 0.677; and severe obesity: aOR 1.22, P = 0.580, with normal weight as the reference).

CONCLUSION

Contrary to findings regarding older patients with sepsis, our findings suggest that the obesity paradox does not apply to younger adult patients with sepsis.

Obesity and septic patient outcomes: Shaping the puzzle through age and sex perspectives

BACKGROUND & AIMS

While obesity has been reported as a protective factor in septic patients, little is known about the potential modifying effects of age and sex. The objective of this study is to investigate age and sex-specific associations between obesity and the prognosis of septic patients.

METHODS

A retrospective analysis was conducted on a cohort of 15,464 septic patients, categorized by body mass index (BMI) into four groups: underweight (<18.5 kg/m2, n = 483), normal (18.5-24.9 kg/m2, n = 4344), overweight (25-29.9 kg/m2, n = 4949) and obese (≥30 kg/m2, n = 5688). Multivariable logistic regression and inverse probability weighting were employed to robustly confirm the protective effect of a higher BMI on 28-day mortality, with normal weight serving as the reference category. Subgroup analyses based on age (young: 18-39, middle-aged: 40-64 and elderly: ≥65) and sex were performed.

RESULTS

The findings demonstrate that high BMI independently confers a protective effect against 28-day mortality in septic patients. However, the relationship between BMI and 28-day mortality exhibits a non-linear trend, with a BMI of 34.5 kg/m2 displaying the lowest odds ratio. Notably, the survival benefits associated with a high BMI were not observed in the young group. Moreover, being underweight emerges as an independent risk factor for middle-aged and elderly female patients, while in males it is only a risk factor in the elderly group. Interestingly, being overweight and obese were identified as independent protective factors in middle-aged and elderly male patients, but not in females.

CONCLUSIONS

The effect of BMI on mortality in septic patients varies according to age and sex. Elderly individuals with sepsis may derive more prognostic benefits from obesity.

Genetic correlations and causal relationships between cardio-metabolic traits and sepsis

Cardio-metabolic traits have been reported to be associated with the development of sepsis. It is, however, unclear whether these co-morbidities reflect causal associations, shared genetic heritability, or are confounded by environmental factors. We performed three analyses to explore the relationships between cardio-metabolic traits and sepsis. Mendelian randomization (MR) study to evaluate the causal effects of multiple cardio-metabolic traits on sepsis. Global genetic correlation analysis to explore the correlations between cardio-metabolic traits and sepsis. Local genetic correlation (GC) analysis to explore shared genetic heritability between cardio-metabolic traits and sepsis. Some loci were further examined for related genes responsible for the causal relationships. Genetic associations were obtained from the UK Biobank data or published large-scale genome-wide association studies with sample sizes between 200,000 to 750,000. In MR, we found causality between BMI and sepsis (OR: 1.53 [1.4-1.67]; p < 0.001). Body mass index (BMI), which is confirmed by sensitivity analyses and multivariable MR adjusting for confounding factors. Global GC analysis showed a significant correlation between BMI and sepsis (rg = 0.55, p < 0.001). More cardio-metabolic traits were identified to be correlated to the sepsis onset such as CRP (rg = 0.37, p = 0.035), type 2 diabetes (rg = 0.33, p < 0.001), HDL (rg = - 0.41, p < 0.001), and coronary artery disease (rg = 0.43, p < 0.001). Local GC revealed some shared genetic loci responsible for the causality. The top locus 1126 was located at chromosome 7 and comprised genes HIBADH, JAZF1, and CREB5. The present study provides evidence for an independent causal effect of BMI on sepsis. Further detailed analysis of the shared genetic heritability between cardio-metabolic traits and sepsis provides the opportunity to improve the preventive strategies for sepsis.

Early Sepsis-Associated Acute Kidney Injury and Obesity

Importance

The prevalence of obesity is increasing in the intensive care unit (ICU). Although obesity is a known risk factor for chronic kidney disease, its association with early sepsis-associated acute kidney injury (SA-AKI) and their combined association with patient outcomes warrant further investigation.

Objective

To explore the association between obesity, early SA-AKI incidence, and clinical outcomes in patients with sepsis.

Design, Setting, and Participants

This nationwide, prospective cohort study analyzed patients aged 19 years or older who had sepsis and were admitted to 20 tertiary hospital ICUs in Korea between September 1, 2019, and December 31, 2021. Patients with preexisting stage 3A to 5 chronic kidney disease and those with missing body mass index (BMI) values were excluded.

Exposures

Sepsis and hospitalization in the ICU.

Main Outcomes and Measures

The primary outcome was SA-AKI incidence within 48 hours of ICU admission, and secondary outcomes were mortality and clinical recovery (survival to discharge within 30 days). Patients were categorized by BMI (calculated as weight in kilograms divided by height in meters squared), and data were analyzed by logistic regression adjusted for key characteristics and clinical factors. Multivariable fractional polynomial regression models and restricted cubic spline models were used to analyze the clinical outcomes with BMI as a continuous variable.

Results

Of the 4041 patients (median age, 73 years [IQR, 63-81 years]; 2349 [58.1%] male) included in the study, 1367 (33.8%) developed early SA-AKI. Obesity was associated with a higher incidence of SA-AKI compared with normal weight (adjusted odds ratio [AOR], 1.40; 95% CI, 1.15-1.70), as was every increase in BMI of 10 (OR, 1.75; 95% CI, 1.47-2.08). While obesity was associated with lower in-hospital mortality in patients without SA-AKI compared with their counterparts without obesity (ie, underweight, normal weight, overweight) (AOR, 0.72; 95% CI, 0.54-0.94), no difference in mortality was observed in those with SA-AKI (AOR, 0.85; 95% CI, 0.65-1.12). Although patients with obesity without SA-AKI had a greater likelihood of clinical recovery than their counterparts without obesity, clinical recovery was less likely among those with both obesity and SA-AKI.

Conclusions and Relevance

In this cohort study of patients with sepsis, obesity was associated with a higher risk of early SA-AKI and the presence of SA-AKI modified the association of obesity with clinical outcomes.

Steatotic Liver Disease and Sepsis Outcomes-A Prospective Cohort Study (SepsisFAT)

Background: While it has been shown that steatotic liver disease (SLD) is associated with systemic changes in immune response, the impact of SLD on sepsis outcomes has not yet been established. The aim of this study was to investigate the association between SLD and sepsis severity and outcomes. Methods: A prospective observational study included consecutively hospitalized adult patients with community-acquired sepsis during a 16-month period. Results: Of the 378 included patients (49.5% male, median age of 69, IQR 57-78 years), 174 (46%) were diagnosed with SLD. Patients with SLD were older and more frequently fulfilled the criteria for metabolic syndrome. There were no differences in the source and etiology of sepsis between the groups. Patients with SLD exhibited a higher incidence of acute kidney injury (29.3% vs. 17.6%), the need for renal replacement therapy (16.1% vs. 8.8%), and more frequent use of invasive mechanical ventilation (29.3% vs. 18.1%). In-hospital mortality was significantly higher in the SLD group (18.39% vs. 9.8%). The multivariable analysis indicated that SLD was associated with mortality (HR 2.82, 95% CI 1.40-5.71) irrespective of the other elements within metabolic syndrome. Conclusions: SLD might be associated with higher sepsis in-hospital mortality, and more frequent development of acute kidney and respiratory insufficiency requiring more critical care support.

The impact of body mass index on long-term survival after ICU admission due to COVID-19: A retrospective multicentre study

Objective

The impact of obesity on long-term survival after intensive care unit (ICU) admission with severe coronavirus disease 2019 (COVID-19) is unclear. We aimed to quantify the impact of obesity on time to death up to two years in patients admitted to Australian and New Zealand ICUs.

Design

Retrospective multicentre study.

Setting

92 ICUs between 1st January 2020 through to 31st December 2020 in New Zealand and 31st March 2022 in Australia with COVID-19, reported in the Australian and New Zealand Intensive Care Society adult patient database.

Participants

All patients with documented height and weight to estimate the body mass index (BMI) were included. Obesity was classified patients according to the World Health Organization recommendations.

Interventions and main outcome measures

The primary outcome was survival time up to two years after ICU admission. The effect of obesity on time to death was assessed using a Cox proportional hazards model. Confounders were acute illness severity, sex, frailty, hospital type and jurisdiction for all patients.

Results

We examined 2,931 patients; the median BMI was 30.2 (IQR 25.6-36.0) kg/m2. Patients with a BMI ≥30 kg/m2 were younger (median [IQR] age 57.7 [46.2-69.0] vs. 63.0 [50.0-73.6]; p < 0.001) than those with a BMI <30 kg/m2. Most patients (76.6%; 2,244/2,931) were discharged alive after ICU admission. The mortality at two years was highest for BMI categories <18.5 kg/m2 (35.4%) and 18.5-24.9 kg/m2 (31.1%), while lowest for BMI ≥40 kg/m2 (14.5%). After adjusting for confounders and with BMI 18.5-24.9 kg/m2 category as a reference, only the BMI ≥40 kg/m2 category patients had improved survival up to 2 years (hazard ratio = 0.51; 95%CI: 0.34-0.76).

Conclusions

The obesity paradox appears to exist beyond hospital discharge in critically ill patients with COVID-19 admitted in Australian and New Zealand ICUs. A BMI ≥40 kg/m2 was associated with a higher survival time of up to two years.

Secondary analysis of potential associations between oral health and infection-related parameters in patients with severe heart failure-results of a German cohort

OBJECTIVES

Aim of this retrospective cohort study was to evaluate whether oral health parameters would be associated with infection-related parameters and overall survival of patients with severe heart failure (HF).

METHODS

Patients with severe HF, heart transplantation (HTx) and left-ventricular assist device (LVAD), which underwent a full oral examination between 2017 and 2018 were included. Infection-related and survival data were assessed from the patient´s medical records. The oral examination included: remaining teeth, caries and periodontal condition, including periodontal probing depth (PPD), clinical attachment loss (CAL), bleeding on probing (BOP), and diagnosis (staging/grading). In addition, the periodontal inflamed surface area (PISA) was determined. Statistical analysis included Chi-square, Fisher´s exact and Mann-Whitney-U test, as well as a logistic regression, considering age, gender, body-mass-index (BMI), diabetes and several oral health parameters with regard to overall survival and infections at heart/driveline.

RESULTS

329 patients (HTx: 34%, LVAD: 38.9%, HF: 27.1%), were included. Patients had on average 18.96 ± 8.90 remaining teeth, whereby the majority had a periodontitis stage III or IV (88.7%) and a grade B (80.5%). Higher BOP was associated with infections at heart/driveline (p = 0.04) and outside the heart (p < 0.01) during follow-up. Increased PISA was significantly associated with bacterial infections outside the heart (p < 0.01) and sepsis (p = 0.02). Only BMI of 25 or higher correlated with an increased risk of infections at heart/driveline in regression analysis (OR 3.063, CI95 1.158-8.101, p = 0.02), while no associations between oral health parameters and infections at heart/driveline or overall survival were confirmed.

CONCLUSIONS

In patients with severe HF, periodontal inflammation might be associated with infection-related parameters. Improved dental care, especially including periodontal therapy and maintenance might be favourable to support prevention of infections in patients with severe HF.

Associations between body mass index and all-cause mortality: A systematic review and meta-analysis

Fasting insulin and c-reactive protein confound the association between mortality and body mass index. An increase in fat mass may mediate the associations between hyperinsulinemia, hyperinflammation, and mortality. The objective of this study was to describe the "average" associations between body mass index and the risk of mortality and to explore how adjusting for fasting insulin and markers of inflammation might modify the association of BMI with mortality. MEDLINE and EMBASE were searched for studies published in 2020. Studies with adult participants where BMI and vital status was assessed were included. BMI was required to be categorized into groups or parametrized as non-first order polynomials or splines. All-cause mortality was regressed against mean BMI squared within seven broad clinical populations. Study was modeled as a random intercept. β coefficients and 95% confidence intervals are reported along with estimates of mortality risk by BMIs of 20, 30, and 40 kg/m2 . Bubble plots with regression lines are drawn, showing the associations between mortality and BMI. Splines results were summarized. There were 154 included studies with 6,685,979 participants. Only five (3.2%) studies adjusted for a marker of inflammation, and no studies adjusted for fasting insulin. There were significant associations between higher BMIs and lower mortality risk in cardiovascular (unadjusted β -0.829 [95% CI -1.313, -0.345] and adjusted β -0.746 [95% CI -1.471, -0.021]), Covid-19 (unadjusted β -0.333 [95% CI -0.650, -0.015]), critically ill (adjusted β -0.550 [95% CI -1.091, -0.010]), and surgical (unadjusted β -0.415 [95% CI -0.824, -0.006]) populations. The associations for general, cancer, and non-communicable disease populations were not significant. Heterogeneity was very large (I2  ≥ 97%). The role of obesity as a driver of excess mortality should be critically re-examined, in parallel with increased efforts to determine the harms of hyperinsulinemia and chronic inflammation.

Potential therapeutic implications of calcitriol administration and weight reduction on CD4 T cell dysregulation and renin angiotensin system-associated acute lung injury in septic obese mice

This study investigated the effects of weight reduction and/or calcitriol administration on regulating CD4 T cell subsets and renin-angiotensin system (RAS)-associated acute lung injury (ALI) in obese mice with sepsis. Half of the mice were fed a high-fat diet for 16 weeks, half of them had high-fat diet for 12 weeks then were transferred to a low-energy diet for 4 weeks. After feeding the respective diets, cecal ligation and puncture (CLP) were performed to induce sepsis. There were four sepsis groups: OSS group, obese mice injected with saline; OSD group, obese mice given calcitriol; WSS group, mice with weight reduction and saline; WSD group, mice with weight reduction and calcitriol. Mice were sacrificed after CLP. The findings showed that CD4 T subsets distribution did not differ among the experimental groups. Calcitriol-treated groups had higher RAS-associated AT2R, MasR, ACE2, and angiopoietin 1-7 (Ang(1-7)) levels in the lungs. Also, higher tight junction proteins were noted 12 h after CLP. At 24 h post-CLP, weight reduction and/or calcitriol treatment reduced plasma inflammatory mediator production. Calcitriol-treated groups had higher CD4/CD8, T helper (Th)1/Th2 and lower Th17/regulatory T (Treg) ratios than the groups without calcitriol. In the lungs, calcitriol-treated groups had lower AT1R levels, whereas the RAS anti-inflammatory protein levels were higher than those groups without calcitriol. Lower injury scores were also noted at this time point. These findings suggested weight reduction decreased systemic inflammation. However, calcitriol administration produced a more-balanced Th/Treg distribution, upregulated the RAS anti-inflammatory pathway, and attenuated ALI in septic obese mice.

Management of patients on antithrombotic therapy with severe infections: a joint clinical consensus statement of the ESC Working Group on Thrombosis, the ESC Working Group on Atherosclerosis and Vascular Biology, and the International Society on Thrombosis and Haemostasis

Patients with severe infections and a pre-existing indication for antithrombotic therapy, i.e. antiplatelet agents, anticoagulant drugs, or their combinations, require integrated clinical counselling among coagulation, infectious disease, and cardiology specialists, due to sepsis-induced coagulopathy that frequently occurs. Bacterial and viral pathogens constitute an increasing threat to global public health, especially for patients with ongoing antithrombotic treatment who have a high risk of thrombotic recurrences and high susceptibility to severe infections with increased morbidity and mortality. Similarly, sepsis survivors are at increased risk for major vascular events. Coagulopathy, which often complicates severe infections, is associated with a high mortality and obligates clinicians to adjust antithrombotic drug type and dosing to avoid bleeding while preventing thrombotic complications. This clinical consensus statement reviews the best available evidence to provide expert opinion and statements on the management of patients hospitalized for severe bacterial or viral infections with a pre-existing indication for antithrombotic therapy (single or combined), in whom sepsis-induced coagulopathy is often observed. Balancing the risk of thrombosis and bleeding in these patients and preventing infections with vaccines, if available, are crucial to prevent events or improve outcomes and prognosis.

Diabetes associates with mortality in critically ill patients with SARS-CoV-2 pneumonia: No diabetes paradox in COVID-19

Background

Diabetes mellitus (DM) is not associated with increased mortality in critically ill patients, a phenomenon known as the "diabetes paradox". However, DM is a risk factor for increased mortality in patients with COVID-19. This study aims to investigate the association of DM and stress-induced hyperglycemia at intensive care unit (ICU) with mortality in this population.

Methods

This is a retrospective study. Electronic medical records from patients admitted from March 2020 to September 2020 were reviewed. Primary outcome was mortality. Secondary outcomes were ICU and hospital mortality and stay, and need for mechanical ventilation and renal replacement therapy.

Results

187 patients were included. Overall mortality was 43.2%, higher in patients with DM (55.7% vs. 34%; p = 0.007), even after adjustment for age, hypertension, and disease severity. When patients were separated into groups, named normoglycemia (without DM and glycemia ≤140 mg/dL), stress-induced hyperglycemia (without DM and glycemia >140 mg/dL), and DM (previous diagnosis or HbA1c ≥ 6.5%), the mortality rate was 25.8%, 37.3%, and 55.7%, respectively (p = 0.021). Mortality was higher in patients with higher glycemic variability. No statistical difference related to secondary outcomes was observed.

Conclusions

DM, hyperglycemia, and glycemic variability associated with increased mortality in critically ill patients with severe COVID-19, but did not increase the rates of other clinical outcomes. More than stress-induced hyperglycemia, DM was associated with mortality.

Effect of neonatal and adult sepsis on inflammation-related diseases in multiple physiological systems: a Mendelian randomization study

Background

Long-term impact of sepsis on whole body systems is not well investigated. The aim of the study was to explore the potential association of neonatal/adult sepsis with several inflammation-related diseases in multiple physiological systems.

Methods

Instrumental variables for neonatal and adult sepsis were collected from the public genome-wide association studies, which must satisfy the correlation, exclusivity and independence assumptions. Mendelian randomization methods (including random-effect inverse-variance weighted, MR-PRESSO, weighted median and MR-Egger) were used to determine the genetic association of neonatal/adult sepsis with asthma, allergy, rheumatoid arthritis, body mass index/obesity, type 1/type 2 diabetes and intelligence/dementia. Sensitivity analyses were conducted to assess heterogeneity and horizontal pleiotropy. The study was performed by TwoSampleMR in R software.

Results

The inverse-variance weighted method reported that neonatal sepsis was related to the decreased level of body mass index (OR = 0.988, 95%CI = 0.980 ~ 0.997, P = 0.007), and adult sepsis was related to the decreased risk of obesity (OR = 0.785, 95%CI = 0.655 ~ 0.940, P = 0.009). These results were supported by the other Mendelian randomization methods. In addition, the study did not find any association of neonatal/adult sepsis with the other inflammation-related diseases. No heterogeneity and horizontal pleiotropy were found using sensitivity analyses.

Conclusion

Sepsis had the potential to reduce the risk of obesity or body mass index level at a genetic level, both in neonates and in adults.

Obesity Paradox and Functional Outcomes in Sepsis: A Multicenter Prospective Study

OBJECTIVES

In Asian populations, the correlation between sepsis outcomes and body mass is unclear. A multicenter, prospective, observational study conducted between September 2019 and December 2020 evaluated obesity's effects on sepsis outcomes in a national cohort.

SETTING

Nineteen tertiary referral hospitals or university-affiliated hospitals in South Korea.

PATIENTS

Adult patients with sepsis ( n = 6,424) were classified into obese ( n = 1,335) and nonobese groups ( n = 5,089).

MEASUREMENTS AND RESULTS

Obese and nonobese patients were propensity score-matched in a ratio of 1:1. Inhospital mortality was the primary outcome. After propensity score matching, the nonobese group had higher hospital mortality than the obese group (25.3% vs 36.7%; p < 0.001). The obese group had a higher home discharge rate (70.3% vs 65.2%; p < 0.001) and lower median Clinical Frailty Scale (CFS) (4 vs 5; p = 0.007) at discharge than the nonobese group, whereas the proportion of frail patients at discharge (CFS ≥ 5) was significantly higher in the nonobese group (48.7% vs 54.7%; p = 0.011). Patients were divided into four groups according to the World Health Organization body mass index (BMI) classification and performed additional analyses. The adjusted odds ratio of hospital mortality and frailty at discharge for underweight, overweight, and obese patients relative to normal BMI was 1.25 ( p = 0.004), 0.58 ( p < 0.001), and 0.70 ( p = 0.047) and 1.53 ( p < 0.001), 0.80 ( p = 0.095), and 0.60 ( p = 0.022), respectively.

CONCLUSIONS

Obesity is associated with higher hospital survival and functional outcomes at discharge in Asian patients with sepsis.

Characterization of Mortality by Sepsis Source in Patients Admitted to the Surgical Intensive Care Unit

INTRODUCTION

The impact of infectious source on sepsis outcomes for surgical patients is unclear. The objective of this study was to evaluate the association between sepsis sources and cumulative 90-d mortality in patients admitted to the surgical intensive care unit (SICU) with sepsis.

METHODS

All patients admitted to the SICU at an academic institution who met sepsis criteria (2014-2019, n = 1296) were retrospectively reviewed. Classification of source was accomplished through a chart review and included respiratory (RT, n = 144), intra-abdominal (IA, n = 859), skin and soft tissue (SST, n = 215), and urologic (UR, n = 78). Demographics, comorbidities, and clinical presentation were compared. Outcomes included 90-d mortality, respiratory and renal failure, length of stay, and discharge disposition. Cox-proportional regression was used to model predictors of mortality; P < 0.05 was significant.

RESULTS

Patients with SST were younger, more likely to be diabetic and obese, but had the lowest total comorbidities. Median admission sequential organ failure assessment scores were highest for IA and STT and lowest in urologic infections. Cumulative 90-d mortality was highest for IA and RT (35% and 33%, respectively) and lowest for SST (20%) and UR (8%) (P < 0.005). Compared to the other categories, UR infections had the lowest SICU length of stay and the highest discharge-to-home (57%, P < 0.0005). Urologic infections remained an independent negative predictor of 90-d mortality (odds ratio 0.14, 95% confidence interval: 0.1-0.4), after controlling for sequential organ failure assessment.

CONCLUSIONS

Urologic infections remained an independent negative predictor of 90-d mortality when compared to other sources of sepsis. Characterization of sepsis source revealed distinct populations and clinical courses, highlighting the importance of understanding different sepsis phenotypes.

Adipose Tissue Remodeling in Pathophysiology

Rather than serving as a mere onlooker, adipose tissue is a complex endocrine organ and active participant in disease initiation and progression. Disruptions of biological processes operating within adipose can disturb healthy systemic physiology, the sequelae of which include metabolic disorders such as obesity and type 2 diabetes. A burgeoning interest in the field of adipose research has allowed for the elucidation of regulatory networks underlying both adipose tissue function and dysfunction. Despite this progress, few diseases are treated by targeting maladaptation in the adipose, an oft-overlooked organ. In this review, we elaborate on the distinct subtypes of adipocytes, their developmental origins and secretory roles, and the dynamic interplay at work within the tissue itself. Central to this discussion is the relationship between adipose and disease states, including obesity, cachexia, and infectious diseases, as we aim to leverage our wealth of knowledge for the development of novel and targeted therapeutics.

MDCT-findings in patients with non-occlusive mesenteric ischemia (NOMI): influence of vasoconstrictor agents

OBJECTIVES

To evaluate the influence of vasoconstrictor agents (VCAs) on signs of vasoconstriction and bowel ischemia on MDCT detected in patients with non-occlusive mesenteric ischemia (NOMI).

METHODS

This 8-year single-center retrospective study consecutively included all patients with histopathologically proven NOMI who underwent MDCT ≤ 48 h prior to surgical bowel resection. Two blinded radiologists jointly reviewed each examination for signs of bowel ischemia, abdominal organ infarct, mesenteric vessel size and regularity, and ancillary vascular findings. VCA administration (length and dosage), clinical and biochemical data, risk factors, and outcomes were retrieved from patients' medical records. Subgroup comparisons were performed.

RESULTS

Ninety patients were included (59 males, mean age 65 years); 40 (44.4%) had received VCAs before MDCT. Overall mortality was 32% (n = 29), with no significant difference between the two groups. In patients treated with VCAs, the calibre of the superior mesenteric artery (SMA) was smaller (p = 0.032), and vasoconstriction of its branches tended to be more important (p = 0.096) than in patients not treated with VCAs. The presence and extent of bowel ischemia did not significantly correlate with VCA administration, but abdominal organ infarcts tended to be more frequent (p = 0.005) and involved more organs (p = 0.088). The VCA group had lower mean arterial pressure (p = 0.006) and lower hemoglobin levels (p < 0.001). Several biomarkers of organ failure and inflammation, differed significantly with VCA use, proving worse clinical condition.

CONCLUSIONS

MDCT demonstrates more severe SMA vasoconstriction and tends to show increased abdominal organ infarcts after VCA administration in NOMI patients compared to NOMI patients not treated with VCAs.

KEY POINTS

• In critically ill patients with NOMI, MDCT demonstrates VCA support via increased vasoconstriction of the main SMA and its branches. • VCA administration in NOMI patients tends to contribute to the development of organ infarcts, as shown on MDCT. • An important degree of vasoconstriction in NOMI patients may indicate insufficient resuscitation and, thus, help clinicians in further patient management.

Association between low body temperature on admission and in-hospital mortality according to body mass index categories of patients with sepsis

Hypothermia has been shown to be associated with a high mortality rate among patients with sepsis. However, the relationship between hypothermia and body mass index (BMI) with respect to mortality remains to be elucidated. We conducted this study to assess the association between hypothermia and survival outcomes of patients with sepsis according to BMI categories. This secondary analysis of a prospective cohort study enrolled 1184 patients (aged ≥ 16 years) with sepsis hospitalized in 59 intensive care units in Japan. Patients were divided into 3 BMI categories (<18.5 [low], 18.5-24.9 [normal], >24.9 [high] kg/m2) and 2 body temperature (36 °C and ≥ 36 °C) groups. The primary outcome was in-hospital mortality rate. Associations between hypothermia and BMI categories with respect to in-hospital mortality were evaluated using multivariate logistic regression analysis. Of the 1089 patients, 223, 612, and 254 had low, normal, and high BMI values, respectively. Patients with body temperature < 36 °C (hypothermia) had a higher in-hospital mortality rate than that had by those without hypothermia in the normal BMI group (25/63, 39.7% vs. 107/549, 19.5%); however, this was not true for patients in the low or high BMI groups. A significant interaction was observed between hypothermia and normal BMI for in-hospital mortality (odds ratio, 1.56; 95% confidence interval, 1.00-3.41; P value for interaction = .04); however, such an interaction was not found between hypothermia and low or high BMIs. Patients with sepsis and hypothermia in the normal BMI subgroup may have a higher mortality risk than that of those in the low or high BMI subgroups and, therefore, require more attention.

Nutritional risk, not obesity, is associated with mortality in critically ill COVID-19 patients

Background

Despite the identification of obesity as a risk factor for higher rates of hospital and Intensive Care Unit (ICU) admissions and complications due to COVID-19, the association between obesity and mortality in critically ill COVID-19 patients remains controversial, and the nutritional risk is little considered. Hence, our study sought to evaluate the association between obesity, nutritional risk, and mortality in critically ill patients diagnosed with COVID-19.

Methods

Retrospective study were condutcted including adult critically ill COVID-19 patients admitted to an ICU between April 2020 and March 2021. Clinical and laboratory data were collected from electronic medical records. Obesity was classified by body mass index ≥ 30 kg/m^2. A mNUTRIC score of ≥ 5 indicated high nutritional risk. Multiple Cox Regression was used to estimate the association between mNUTRIC, obesity, and mortality.

Results

From 71 patients aged 59 (± 15) years, 71.8 % were male. The frequencies of obesity (58.7 %) and death (49.3 %) were high, but obesity was not associated with mortality. Based on mNUTRIC, 85.9 % of patients were at high nutritional risk, presenting a higher frequency of mortality than patients at low nutritional risk (50.8 % vs 40.0 %; p = 0.014). Multiple Cox Regression showed that for each unit increase in mNUTRIC score the probability of death almost doubled, regardless of the presence of obesity (HR = 1.74; p < 0.001).

Conclusions

A higher nutritional risk was positively associated with mortality in critically ill COVID-19 patients, regardless of obesity, showing the importance of early identification of nutritional risk for appropriate nutritional interventions in this population.

A nomogram to predict prolonged stay of obesity patients with sepsis in ICU: Relevancy for predictive, personalized, preventive, and participatory healthcare strategies

Objective

In an era of increasingly expensive intensive care costs, it is essential to evaluate early whether the length of stay (LOS) in the intensive care unit (ICU) of obesity patients with sepsis will be prolonged. On the one hand, it can reduce costs; on the other hand, it can reduce nosocomial infection. Therefore, this study aimed to verify whether ICU prolonged LOS was significantly associated with poor prognosis poor in obesity patients with sepsis and develop a simple prediction model to personalize the risk of ICU prolonged LOS for obesity patients with sepsis.

Method

In total, 14,483 patients from the eICU Collaborative Research Database were randomized to the training set (3,606 patients) and validation set (1,600 patients). The potential predictors of ICU prolonged LOS among various factors were identified using logistic regression analysis. For internal and external validation, a nomogram was developed and performed.

Results

ICU prolonged LOS was defined as the third quartile of ICU LOS or more for all sepsis patients and demonstrated to be significantly associated with the mortality in ICU by logistic regression analysis. When entering the ICU, seven independent risk factors were identified: maximum white blood cell, minimum white blood cell, use of ventilation, Glasgow Coma Scale, minimum albumin, maximum respiratory rate, and minimum red blood cell distribution width. In the internal validation set, the area under the curve was 0.73, while in the external validation set, it was 0.78. The calibration curves showed that this model predicted probability due to actually observed probability. Furthermore, the decision curve analysis and clinical impact curve showed that the nomogram had a high clinical net benefit.

Conclusion

In obesity patients with sepsis, we created a novel nomogram to predict the risk of ICU prolonged LOS. This prediction model is accurate and reliable, and it can assist patients and clinicians in determining prognosis and making clinical decisions.

Mortality risk in patients with underweight or obesity with peripheral artery disease: a meta-analysis including 5,735,578 individuals

OBJECTIVES

The "obesity paradox" - in which patients with obesity exhibit superior survival than normal-weight counterparts - has been reported for several diseases. However, obesity is a well-known risk factor for cardiovascular disease, and whether the obesity paradox is present in peripheral artery disease (PAD) is unknown.

METHODS

A comprehensive search for studies that reported mortality in patients with PAD grouped by BMI identified 12 studies. We compared the survival of underweight patients with those who were not underweight, and patients with obesity against those without. Underweight was defined by a BMI value of <18.5 kg/m² in most studies and obesity by BMI ≥ 30 kg/m². Subgroup analyses were performed according to length of follow-up, presentation of PAD, and mode of revascularization. Meta-regression analyses were conducted, with covariates including age, sex, presence of coronary artery disease (CAD) and diabetes mellitus (DM).

RESULTS

The mortality risk of underweight patients with PAD was significantly higher compared to those who are not underweight (HR 1.72, 95% CI 1.38-2.14; I² = 84.2%). In contrast, the mortality risk of patients with obesity with PAD was significantly lower than those without (HR 0.78, 95% CI 0.62-0.97; I² = 89.8%). These findings remained consistent regardless of the presentation of PAD, revascularization, age, sex, or presence of CAD. The risk of death in the short-term of underweight patients (HR 1.50, 95% CI 0.47-4.72) and patients with obesity (HR 0.86, 95% CI 0.66-1.13) were not significantly different from their counterparts. The meta-regression showed that of the association between obesity and better survival was more pronounced in studies with a greater proportion of patients with concomitant CAD (regression coefficient -0.029, 95% CI -0.054 to -0.004).

CONCLUSIONS

In patients with PAD, mortality is higher among underweight patients and lower among patients with obesity. The mechanisms underlying the obesity paradox in patients with PAD remain to be elucidated, and further evidence is required to guide optimal weight control strategies in these patients.

A Dose Response Association Between Body Mass Index and Mortality in Patients with Peripheral Artery Disease: A Meta-analysis Including 5 729 272 Individuals

OBJECTIVE

Obesity is a significant risk factor for atherosclerotic cardiovascular disease; however, the "obesity paradox", in which obese patients enjoy superior survival, has been observed in various cardiovascular conditions. Whether this phenomenon exists for peripheral artery disease (PAD) remains uncertain. The goal of this study was to evaluate the relationship between body mass index (BMI) and mortality in patients with PAD.

METHODS

A comprehensive literature search identified seven eligible cohort studies that reported the association between BMI and all cause mortality in patients with PAD. A dose response meta-analysis was done for all cause mortality, short term (30 day or in hospital) mortality and long term mortality. The dose response association between BMI and mortality was also assessed in patients who received endovascular therapy (EVT).

RESULTS

The non-linear dose response analysis showed that higher BMI values were associated with a lower mortality risk from the range between 15 kg/m² to approximately 33 - 34 kg/m². The risk of mortality increased slightly thereafter. This relationship was consistent with that of long term mortality but was not apparent in short term mortality. A U shaped relationship was also observed between BMI and mortality in patients who received EVT with the lowest mortality observed at around 30 kg/m².

CONCLUSION

The obesity paradox was evident in the analysis of long term survival among patients with PAD, with the lowest mortality rates observed in obese patients. However, this association was not observed for short term or in hospital mortality.

The fatter, the better in old age: the current understanding of a difficult relationship

PURPOSE OF REVIEW

Obesity has shown a protective effect on mortality in older adults, also known as the obesity paradox, but there are still controversies about this relationship.

RECENT FINDINGS

Recent studies have shown a J or U-shaped relationship between BMI and mortality, wherein an optimal range is described between 22 and 37 kg/m2 depending on the condition. Many mechanisms can explain this protective effect of higher BMI, fat/muscle mass storage, more aggressive treatment in obese individuals, loss of bone mineral content and selection bias. However, BMI must be used with caution due to its limitations to determine body composition and fat distribution.

SUMMARY

Although BMI is an easy tool to evaluate obesity, its protective effect may be present to certain extend, from normal range to class I obesity (BMI 30-34.9 kg/m2), but then it becomes detrimental. Skeletal muscle mass and muscle function associated with adipose tissue assessment can add valuable information in the risk stratification. Further studies should be performed prospectively, adjust BMI for cofounding variable and consider other elderly subpopulations. To promote healthy ageing, excessive fat mass should be avoided and maintenance or improvement of skeletal muscle mass and muscle function should be stimulated in older adults.

Underweight but not overweight is associated with excess mortality in septic ICU patients

Background

Higher survival has been shown for overweight septic patients compared with normal or underweight patients in the past. This study aimed at investigating the management and outcome of septic ICU patients in different body mass index (BMI) categories in a large multicenter database.

Methods

In total, 16,612 patients of the eICU collaborative research database were included. Baseline characteristics and data on organ support were documented. Multilevel logistic regression analysis was performed to fit three sequential regression models for the binary primary outcome (ICU mortality) to evaluate the impact of the BMI categories: underweight (<18.5 kg/m²), normal weight (18.5 to < 25 kg/m²), overweight (25 to < 30 kg/m²) and obesity (≥ 30 kg/m²). Data were adjusted for patient level characteristics (model 2) as well as management strategies (model 3).

Results

Management strategies were similar across BMI categories. Underweight patients evidenced higher rates of ICU mortality. This finding persisted after adjusting in model 2 (aOR 1.54, 95% CI 1.15–2.06; p = 0.004) and model 3 (aOR 1.57, 95%CI 1.16–2.12; p = 0.003). No differences were found regarding ICU mortality between normal and overweight patients (aOR 0.93, 95%CI 0.81–1.06; p = 0.29). Obese patients evidenced a lower risk of ICU mortality compared to normal weight, a finding which persisted across all models (model 2: aOR 0.83, 95%CI 0.69–0.99; p = 0.04; model 3: aOR 0.82, 95%CI 0.68–0.98; p = 0.03). The protective effect of obesity and the negative effect of underweight were significant in individuals > 65 years only.

Conclusion

In this cohort, underweight was associated with a worse outcome, whereas obese patients evidenced lower mortality. Our analysis thus supports the thesis of the obesity paradox.

Reconciling the obesity paradox: Obese patients suffer the highest critical illness associated mortality rates

The obesity paradox refers to the observation that obese patients admitted to intensive care units (ICU) have lower case fatality as compared to healthy weight patients. However, selection bias could explain the apparent paradox. Our objective was to assess whether obese people have a different overall burden of critical illness associated mortality. A retrospective population-based cohort study was conducted in North Brisbane ICUs during 2017-2019. Patients were classified as underweight, healthy weight, overweight, and obese according to BMIs <18.5, 18.5-24.9, 25-29.9, and ≥ 30 kg/m², respectively. ICU admission incidence rates were 245.6, 138.2, 178.9, and 421.9 per 100,000 population; 90-day all cause case fatalities were 24.0%, 17.0%, 18.1%, and 16.0%; and critical illness associated mortality rates were 58.8, 23.4, 32.4, and 67.7 per 100,000 population among underweight, healthy weight, overweight, and obese patients, respectively. As compared to patients of healthy weight, those who were underweight (relative risk; RR 2.51; 95% CI, 1.79-3.44), overweight (RR 1.38; 95% CI, 1.16-1.65), and obese (RR 2.89; 2.43-3.43) were each at significantly higher risk for critical illness associated mortality. While obese patients have lower case fatality they are at much higher risk for ICU admission and as result suffer the highest burden of critical illness associated mortality in our region.

Relationship Between Body Mass Index and Survival Among Critically Ill Patients With Cirrhosis

BACKGROUND

Obesity paradox is a phenomenon in which obesity increases the risk of obesity-related chronic diseases but paradoxically is associated with improved survival among obese patients with these diagnoses.

OBJECTIVES

The aim of this study was to explore the obesity paradox among critically ill patients with cirrhosis admitted to the Intensive Care Unit.

METHODS

A retrospective cohort of 1,143 consecutive patients with cirrhosis admitted to the ICU between January of 2006 and December of 2015 was analyzed. Primary outcome of interest was in-hospital mortality with secondary end points including ICU and short-term mortality at 30 days post ICU admission.

RESULTS

Logistic regression with generalized additive models was used, controlling for clinically relevant and statistically significant factors to determine the adjusted relationship between body mass index (BMI) and ICU, post-ICU in-hospital, and 30 day mortality following ICU discharge. ICU and hospital length of stay was similar across all BMI classes. Adjusted ICU mortality was also similar when stratified by BMI. However, a significant reduction in post-ICU hospital mortality was observed in class I and II obese patients with cirrhosis (BMI 30-39.9 kg/m²) compared to normal BMI (OR = 0.41; 95% CI, 0.20 to 0.83; P = 0.014). Similarly, overweight (BMI 25-29.9 kg/m²) and class I and II obese patients with cirrhosis had significantly lower 30-day mortality following ICU discharge (OR = 0.52, 95% CI 0.31 to 0.87; P = 0.014; OR = 0.50, 95% CI 0.29 to 0.86; P = 0.012, respectively) compared to those with normal BMI.

CONCLUSION

The signal of obesity paradox is suggested among critically ill patients with cirrhosis.

Intravenous calcitriol administration regulates the renin-angiotensin system and attenuates acute lung injury in obese mice complicated with polymicrobial sepsis

Calcitriol, an active form of vitamin D, has immunomodulatory and anti-inflammatory properties. Vitamin D levels have inverse correlation with sepsis outcomes and obesity may aggravate the severity of the diseases. This study administered calcitriol to investigate its impact on sepsis-induced acute lung injury (ALI) in obese mice. Mice were fed a high-fat diet to induce obesity and were randomly assigned to control or sepsis groups, which were intravenously administered either saline (SS) or calcitriol (SD). Sepsis was induced by cecal ligation and puncture (CLP). Saline or calcitriol was injected 1 h after CLP via tail vein. Mice were sacrificed at either 12 or 24 h post-CLP and survival rates were observed. The results demonstrated that sepsis caused upregulation of inflammatory mediators and downregulation of renin-angiotensin system (RAS)-associated gene expressions in the lungs of obese mice. Cluster of differentiation 68 (CD68) expression and myeloperoxidase (MPO) activities also increased. Calcitriol treatment lowered expressions of blood and lung inflammatory mediators at 12 and/or 24 h after CLP. The RAS-proinflammatory-associated angiotensin type 1 receptor (AT1R) was lower while anti-inflammatory Mas receptor and AT2R expressions were higher at 12 h after CLP than those in the SS group. In addition, the SD group exhibited lower CD68 expression and MPO activity. Lower lung injury scores and higher survival rates were also noted in the SD group. The findings suggest that calcitriol treatment after sepsis induction upregulated RAS-associated anti-inflammatory pathway and decreased immune cell infiltration, which may have alleviated the severity of ALI of obese mice.

Scrutinizing Mechanisms of the 'Obesity Paradox in Sepsis': Obesity Is Accompanied by Diminished Formation of Neutrophil Extracellular Traps (NETs) Due to Restricted Neutrophil-Platelet Interactions

Systemic inflammation is a detrimental condition associated with high mortality. However, obese individuals seem to have higher chances of surviving sepsis. To elucidate what immunological differences exist between obese and lean individuals we studied the course of endotoxemia in mice fed high-fat diet (HFD) and ob/ob animals. Intravital microscopy revealed that neutrophil extracellular trap (NET) formation in liver vasculature is negligible in obese mice in sharp contrast to their lean counterparts (ND). Unlike in lean individuals, neutrophil influx is not driven by leptin or interleukin 33 (IL-33), nor occurs via a chemokine receptor CXCR2. In obese mice less platelets interact with neutrophils forming less aggregates. Platelets transfer from ND to HFD mice partially restores NET formation, and even further so upon P-selectin blockage on them. The study reveals that in obesity the overexaggerated inflammation and NET formation are limited during sepsis due to dysfunctional platelets suggesting their targeting as a therapeutic tool in systemic inflammation.

Relationship Between Obesity and Ventilator-Associated Pneumonia: A Post Hoc Analysis of the NUTRIREA2 Trial

BACKGROUND

Patients with obesity are at higher risk for community-acquired and nosocomial infections. However, no study has specifically evaluated the relationship between obesity and ventilator-associated pneumonia (VAP).

RESEARCH QUESTION

Is obesity associated with an increased incidence of VAP?

STUDY DESIGN AND METHODS

This study was a post hoc analysis of the Impact of Early Enteral vs Parenteral Nutrition on Mortality in Patients Requiring Mechanical Ventilation and Catecholamines (NUTRIREA2) open-label, randomized controlled trial performed in 44 French ICUs. Adults receiving invasive mechanical ventilation and vasopressor support for shock and parenteral nutrition or enteral nutrition were included. Obesity was defined as BMI ≥ 30 kg/m² at ICU admission. VAP diagnosis was adjudicated by an independent blinded committee, based on all available clinical, radiologic, and microbiologic data. Only first VAP episodes were taken into account. Incidence of VAP was analyzed by using the Fine and Gray model, with extubation and death as competing risks.

RESULTS

A total of 699 (30%) of the 2,325 included patients had obesity; 224 first VAP episodes were diagnosed (60 and 164 in obese and nonobese groups, respectively). The incidence of VAP at day 28 was 8.6% vs 10.1% in the two groups (hazard ratio, 0.85; 95% CI 0.63-1.14; P = .26). After adjustment on sex, McCabe score, age, antiulcer treatment, and Sequential Organ Failure Assessment at randomization, the incidence of VAP remained nonsignificant between obese and nonobese patients (hazard ratio, 0.893; 95% CI, 0.66-1.2; P = .46). Although no significant difference was found in duration of mechanical ventilation and ICU length of stay, 90-day mortality was significantly lower in obese than in nonobese patients (272 of 692 [39.3%] patients vs 718 of 1,605 [44.7%]; P = .02). In a subgroup of patients (n = 123) with available pepsin and alpha-amylase measurements, no significant difference was found in rate of abundant microaspiration of gastric contents, or oropharyngeal secretions between obese and nonobese patients.

INTERPRETATION

Our results suggest that obesity has no significant impact on the incidence of VAP.