Increased body mass index linked to greater short- and long-term survival in sepsis patients: A retrospective analysis of a large clinical database

Pronounced effects of the sepsis-obesity paradox in elderly and male individuals without septic shock and the role of immune-inflammatory status: an analysis of MIMIC-IV data

BACKGROUND

Obesity has been shown to reduce short-term mortality in sepsis patients, but the main subgroups and its role in immune-related inflammatory status require further research. The aim of this study was to identify the primary beneficiaries of the sepsis-obesity paradox and to investigate the involvement of immune-inflammatory status.

METHODS

In this study, we analyzed data from 6602 sepsis patients from the MIMIC-IV database. Body mass index (BMI) was divided into quartiles, and mortality rates were assessed for each interval. Logistic trend tests and subgroup and restricted cubic spline (RCS) analyses were performed. Blood biochemical indicators were compared across different BMI ranges and between survivors and non-survivors. The receiver operating characteristic (ROC) curve for 28-day mortality was also evaluated.

RESULTS

The 28-day mortality of sepsis patients followed a U-shaped pattern with increasing BMI. Trend analysis confirmed that BMI was a significant risk factor for 28-day mortality (p < 0.05). Subgroup analysis revealed an interactive effect of BMI on 28-day mortality in elderly (≥ 65 years old), male, and non-septic shock individuals (p < 0.05). A higher BMI was associated with an increased lymphocyte proportion and decreased neutrophil proportion, neutrophil-to-lymphocyte ratio (NLR), and systemic immune-inflammation index (SII) (p < 0.05). Compared with survivors, non-survivors had lower lymphocyte proportions and higher neutrophil proportions, NLRs, and SIIs. ROC analysis revealed that the lymphocyte and neutrophil proportions, NLR, and SII had predictive value for 28-day mortality. Subgroup and RCS analyses revealed that increased BMI was associated with reduced 28-day mortality in sepsis patients, mainly in elderly, male, and septic shock individuals, with protective BMIs ranging from 27.8 ~ 41.7 kg/cm2, 28.4 ~ 37.7 kg/cm2, and > 28.6 kg/cm2, respectively.

CONCLUSIONS

The sepsis-obesity paradox significantly affects elderly (≥ 65 years old), male, and non-septic shock individuals, displaying a U-shaped pattern for 28-day mortality. BMI may mediate this phenomenon by influencing the body's immune-inflammatory status.

The Association Between Body Mass Index and 28-day Mortality in Patients With Sepsis: A Retrospective Cohort Study

BackgroundSepsis is a severe clinical syndrome with high morbidity and mortality in intensive care units (ICUs). Body Mass Index (BMI) shows a rising trend of obese patients being admitted to ICUs. The relationship between BMI and the clinical outcome of sepsis remains highly debated.MethodsThe data used in this study were sourced from the Intensive Care Information Center IV (MIMIC-IV) database. Baseline information extracted within 24 hours of ICU admission was categorized according to World Health Organization (WHO)'s BMI classifications. A multivariate Cox regression model and curve fitting assessed the independent correlation between BMI and the primary outcome.ResultsA total of 7836 patients were included in the study and categorized into five groups based on BMI. The overall 28-day mortality rate was 21.94% (1719/7836). Class I obesity (17.14%) and class II/III obesity (13.49%) individuals tended to be younger and male. Compared to patients with normal BMI (32.55%), those with low BMI (5.79%) had a 47% increased risk of 28-day mortality (HR 1.47, 95% CI 1.16-1.85, P = 0.0013), while class II/III obesity patients had a 17% lower 28-day mortality rate (HR 0.83, 95% CI 0.71-0.97, P = 0.0218). Curve fitting revealed a nonlinear relationship between BMI and 28-day mortality. The Kaplan-Meier survival analysis highlighted variations in survival rates across the five groups (P = 0.0123), with underweight patients exhibiting poorer survival outcomes.ConclusionIn sepsis patients, a low BMI is related to higher 28-day mortality compared to those with a normal BMI. Conversely, patients with a BMI≥35 kg/m2 have significantly reduced mortality risks.

Obesity as a Risk Factor in Pediatric Sepsis: A Retrospective Comparative Study Under the Phoenix Definition

Background: The relationship between sepsis outcomes and obesity has attracted significant interest in the medical community. However, this association has not been tested under Phoenix criteria, which represent the new pediatric sepsis definition, defining sepsis as life-threatening organ dysfunction in the setting of infection. Methods: A single-center, observational, retrospective study of pediatric sepsis patients from January 2014 to December 2019. The PICU was located within a tertiary pediatric center in the United States. Children more than one month old, but less than 18 years old, with a diagnosis of sepsis were included. Results: Six hundred and twenty-seven patients with a diagnosis of sepsis based on the Sepsis-2 definition were identified. Within the cohort, 554 patients met the definition of sepsis under the Phoenix criteria. Patients were classified based on the body habitus as underweight, normal, overweight, and obese. Obese patients had significantly higher mortality compared to the normal weight group (p = 0.033). More renal dysfunction was also seen in the obesity group (p = 0.0007). No difference in the frequency of identified Gram-positive, Gram-negative bacterial, viral, or fungal sepsis was observed between normal-weight and obese patients. Conclusions: In our cohort of pediatric sepsis, obesity was significantly associated with a higher degree of organ dysfunction and mortality. However, no difference in the incidence of identified bacterial, fungal, or viral sepsis was observed.

Impact of underweight status on mortality in sepsis patients: a meta-analysis

Objective

The evidence regarding the impact of underweight status on clinical outcomes in patients with sepsis are still scarce and controversial. We aimed at conducting a meta-analysis to evaluate the potential associations between underweight and the mortality rate among sepsis patients.

Methods

A comprehensive electronic search was performed in PubMed, Cochrane Library, Embase, and Web of Science databases. Odds ratios (ORs) or mean differences and 95% confidence intervals (CIs) were calculated using RevMan 5.3.

Results

A total of 58,348 patients (normal weight group: 49,084 patients; underweight group: 9,264 patients) from 23 studies were included in this meta-analysis. The results indicated that the in-hospital mortality (OR, 1.28; 95% CI, 1.21, 1.35; heterogeneity: I 2 = 21%, P = 0.21), 28-day mortality (OR, 1.54; 95% CI, 1.26, 1.88; heterogeneity: I 2 = 74%, P < 0.0001) and 1-year mortality (OR, 1.78; 95% CI, 1.58, 2.00; heterogeneity: I 2 = 41%, P = 0.17) of underweight patients were significantly higher than those of normal weight patients. However, there was no significant difference in length of hospital stay or intensive care unit length of stay between underweight patients and normal-weight patients.

Conclusion

Underweight is associated with increased mortality in patients with sepsis. Physicians should pay more attention to the management of underweight sepsis patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=631417, identifier CRD42025631417.

Gram-Negative Bloodstream Infections in a Medical Intensive Care Unit: Epidemiology, Antibiotic Susceptibilities, and Risk Factors for in-Hospital Death

Purpose

Gram-negative bloodstream infection (GNBI) poses a serious threat to critically ill patients. This retrospective study aimed to uncover drug resistance of pathogens and the GNBI effect on in-hospital death and distinguish death risk factors in a medical intensive care unit (ICU).

Patients and Methods

A retrospective study of all GNBI patients in the medical ICU of the Third Xiangya Hospital over 9 nine years was conducted. Blood samples were performed by a BACTEC 9240 system, MALDI-TOF MS, Bruker and Vitek-2 system. Logistic regression was used for analyzing risk factors for death.

Results

Seventy-five episodes of GNBI developed in 68 (1.4%) out of 4954 patients over a span of 9 years. The most frequently isolated bacterium was Klebsiella pneumoniae, with the lungs as the predominant source of GNBI. The resistance rate of Gram-negative bacteria to polymyxin B was 11.6% after excluding those intrinsically resistant non-fermentative bacteria. All Enterobacter spp. were susceptible to ceftazidime/avibactam. Thirty-three (48.5%) patients underwent inappropriate empirical antibiotic treatment and 48 (70.6%) patients died during the hospitalization. Multivariate logistic regression analysis identified that lymphocyte count at GNBI onset ≤0.5×109/L, invasive mechanical ventilation, and septic shock were related to in-hospital death. Body mass index ≥23 and appropriate empirical antibiotic use after GNBI were negatively associated with in-hospital death.

Conclusion

GNBI was a frequent complication among patients in the medical ICU. This study underscored the presence of diverse factors that either heightened or attenuated the risk of in-hospital death.

Correlation between body mass index and gender-specific 28-day mortality in patients with sepsis: a retrospective cohort study

Objective

To investigate the potential correlation between body mass index (BMI) and the 28-day mortality rate among sepsis patients and the gender difference in this association.

Design

The current research was a retrospective cohort study.

Participants

A total of 14,883 male and female cohorts of sepsis patients were included in the Medical Information Mart for Intensive Care IV (MIMIC-IV V2.2) database. Patients in each gender cohort were further classified as underweight, normal weight, overweight, or obese according to BMI and the World Health Organization (WHO) BMI categories.

Outcomes

The 28-day mortality from the date of ICU hospitalization was the primary outcome measure.

Results

The BMI and 28-day mortality exhibited an L-shaped relationship (p for nonlinearity <0.001) with significant gender-specific differences. Subgroup analysis revealed different association patterns between the male and female cohorts. Specifically, BMI and mortality exhibited a U-shaped curve relationship among the males (p for nonlinearity <0.001) and an L-shaped relationship among the females (p for nonlinearity = 0.045).

Conclusion

This study proposes a link between extreme BMI and 28-day mortality in patients with sepsis. Underweight patients have an increased risk of mortality; however, this risk decreases in overweight and obese patients. Upon stratifying by sex, a U-shaped pattern was observed, indicating an association between BMI and 28-day mortality in males, while an L-shaped pattern emerged in females.

Impact of obesity on outcomes of patients with acute respiratory distress syndrome: a retrospective analysis of a large clinical database

OBJECTIVE

To evaluate the link between obesity and mortality in patients with acute respiratory distress syndrome (ARDS).

METHODS

We performed a retrospective cohort study of a large clinical database. A Cox proportional hazards regression model was used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for the relationship between body mass index (BMI) and mortality. The primary endpoint was 30-day death rate and the secondary endpoints were 90-day and 1‑year mortality.

RESULTS

Overall, 418 patients with ARDS were enrolled in the study, including 185 women and 233 men (age: 70.7 ± 44.1 years; BMI: 28.7 ± 8.1 kg/m2). Compared with patients with normal weight, obese patients were younger (60.1 ± 13.7, p = 0.003) and a higher percentage of these patients were women (51.3% vs. 49.0%, p = 0.001). The HRs (95% CI) of 30-day mortality in the underweight, overweight, and obese populations were 1.82 (0.85, 3.90), 0.59 (0.29, 1.20), and 3.85 (1.73, 8.57), respectively, after adjustment for other confounding factors. A similar pattern was also seen for death after 90 days and after 1 year. A U-shaped association between BMI and 30-day mortality was discovered by curve fitting.

CONCLUSION

Obesity had a significant impact on the short- and long-term mortality in patients with ARDS. There was a U-shaped relationship between BMI and mortality, while a higher BMI was associated with an increased risk of death in patients with ARDS.

Association of body mass index and bloodstream infections in patients on extracorporeal membrane oxygenation: a single-centre, retrospective, cohort study

BACKGROUND

Obesity is associated with poor clinical outcomes in critically ill patients. However, under some clinical conditions, obesity has protective effects. Bloodstream infections (BSI) are among the most common nosocomial infections associated with extracorporeal membrane oxygenation (ECMO). BSI during ECMO is associated with higher mortality rates and poorer clinical outcomes.

AIM

To analyse whether body mass index (BMI) is associated with BSI during ECMO or with in-hospital mortality.

METHODS

All adult patients who had received ECMO support for >48 h were included in the analysis. The analysis of total duration of ECMO support, in-hospital mortality and BSI was stratified by BMI category. The Cox proportional hazards model was used to compare the risk of BSI among BMI categories.

FINDINGS

In total, 473 patients were enrolled in the study. The average age was 56.5 years and 65.3% were men. The total duration of ECMO was approximately 11.8 days, with a mortality rate of 47.1%. The incidence rates of BSI and candidaemia were 20.5% and 5.5%, respectively. The underweight group required ECMO for respiratory support, whereas the overweight and obese groups required ECMO for cardiogenic support (P<0.0001). No significant difference in BSI rate was found (P=0.784). However, after adjusting for clinical factors, patients in Group 4 (BMI 25.0-<30.0 kg/m2) exhibited lower mortality compared with patients in Group 2 (normal BMI) (P=0.004).

CONCLUSION

BMI was not associated with risk of BSI, but patients with higher BMI showed lower in-hospital mortality associated with ECMO support.

Association of obesity and mortality in sepsis patients: A meta-analysis from observational evidence

The project aims to investigate the correlation between obesity, overweight, or low body weight and the risk of mortality in sepsis patients. We performed a rigorous and thorough search of major electronic databases, including PubMed, Web of Science, EMBASE, and Cochrane Library, from the inception of these databases up to March 28, 2023. The data were analyzed with Stata software (version 16.0). Twelve studies incorporating 521,207 individuals were enrolled. The results demonstrated that obesity (OR = 0.82; 95% CI: 0.69-0.97; P < 0.001) or overweight (OR = 0.83; 95% CI: 0.73-0.94; P < 0.001) decreased the risk of mortality in sepsis patients. Instead, the reverse phenomena existed in patients with a low weight (OR = 1.43; 95%CI: 1.16-1.76; P = 0.038). There is an "obesity paradox" phenomenon in the mortality of obese and overweight patients with sepsis, but low body weight is an independent risk factor for the mortality of sepsis patients. This study demonstrated that the mortality in sepsis patients and obesity or overweight were negatively correlated, but displayed a significant positive relation to low weight.

Impact of initial fluid resuscitation volume on clinical outcomes in patients with heart failure and septic shock

Background

Fluid resuscitation is a key treatment for sepsis, but limited data exists in patients with existing heart failure (HF) and septic shock. The objective of this study was to determine the impact of initial fluid resuscitation volume on outcomes in HF patients with reduced or mildly reduced left ventricular ejection fraction (LVEF) with septic shock.

Methods

This multicenter, retrospective, cohort study included patients with known HF (LVEF ≤50%) presenting with septic shock. Patients were divided into two groups based on the volume of fluid resuscitation in the first 6 h; <30 mL/kg or ≥30 mL/kg. The primary outcome was a composite of in-hospital mortality or renal replacement therapy (RRT) within 7 days. Secondary outcomes included acute kidney injury (AKI), initiation of mechanical ventilation, and length of stay (LOS). All related data were collected and compared between the two groups. A generalized logistic mixed model was used to assess the association between fluid groups and the primary outcome while adjusting for baseline LVEF, Acute Physiology and Chronic Health Evaluation (APACHE) II score, inappropriate empiric antibiotics, and receipt of corticosteroids.

Results

One hundred and fifty-four patients were included (93 patients in <30 mL/kg group and 61 patients in ≥30 mL/kg group). The median weight-based volume in the first 6 h was 17.7 (12.2-23.0) mL/kg in the <30 mL/kg group vs. 40.5 (34.2-53.1) mL/kg in the ≥30 mL/kg group (P <0.01). No statistical difference was detected in the composite of in-hospital mortality or RRT between the <30 mL/kg group compared to the ≥30 mL/kg group (55.9% vs. 45.9%, P=0.25), respectively. The <30 mL/kg group had a higher incidence of AKI, mechanical ventilation, and longer hospital LOS.

Conclusions

In patients with known reduced or mildly reduced LVEF presenting with septic shock, no difference was detected for in-hospital mortality or RRT in patients who received ≥30 mL/kg of resuscitation fluid compared to less fluid, although this study was underpowered to detect a difference. Importantly, ≥30 mL/kg fluid did not result in a higher need for mechanical ventilation.

Association of body mass index with mortality of sepsis or septic shock: an updated meta-analysis

BACKGROUND

The effects of body mass index (BMI) on mortality of sepsis remain unknown, since previous meta-analyses have reported conflicting results. Several observational studies published recently have provided new evidence. Thus, we performed this updated meta-analysis.

METHODS

PubMed, Embase, Web of Science, and Cochran Library were searched for articles published before February 10, 2023. Observational studies that assessed the association of BMIs with mortality of sepsis patients aged > 18 years were selected. We excluded studies of which data were unavailable for quantitative synthesis. Odds ratios (OR) with 95% confidence interval (CI) were the effect measure, which were combined using fixed-effect or random-effect models. The Newcastle-Ottawa Scale was applied for quality assessment. Subgroups analyses were conducted according to potential confounders.

RESULTS

Fifteen studies (105,159 patients) were included in the overall analysis, which indicated that overweight and obese BMIs were associated with lower mortality (OR: 0.79, 95% CI 0.70-0.88 and OR: 0.74, 95% CI 0.67-0.82, respectively). The association was not significant in patients aged ≤ 50 years (OR: 0.89, 95% CI 0.68-1.14 and OR: 0.77, 95% CI 0.50-1.18, respectively). In addition, the relationship between morbidly obesity and mortality was not significant (OR: 0.91, 95% CI 0.62-1.32).

CONCLUSIONS

Overweight and obese BMIs (25.0-39.9 kg/m²) are associated with reduced mortality of patients with sepsis or septic shock, although such survival advantage was not found in all crowds. Trial registration The protocol of this study was registered in PROSPERO (registration number CRD42023399559).

The PaO2/FiO2 is independently associated with 28-day mortality in patients with sepsis: a retrospective analysis from MIMIC-IV database

BACKGROUND

To clarify the relationship between the PaO₂/FiO₂ and 28-day mortality in patients with sepsis.

METHODS

This was a retrospective cohort study regarding MIMIC-IV database. Nineteen thousand two hundred thirty-three patients with sepsis were included in the final analysis. PaO₂/FiO₂ was exposure variable, 28-day mortality was outcome variable. PaO₂/FiO₂ was log-transformed as LnPaO₂/FiO₂. Binary logistic regression was used to explore the independent effects of LnPaO₂/FiO₂ on 28-day mortality using non-adjusted and multivariate-adjusted models. A generalized additive model (GAM) and smoothed curve fitting was used to investigate the non-linear relationship between LnPaO₂/FiO₂ and 28-day mortality. A two-piecewise linear model was used to calculate the OR and 95% CI on either side of the inflection point.

RESULTS

The relationship between LnPaO₂/FiO₂ and risk of 28-day death in sepsis patients was U-shape. The inflection point of LnPaO₂/FiO₂ was 5.30 (95%CI: 5.21-5.39), which indicated the inflection point of PaO₂/FiO₂ was 200.33 mmHg (95%CI: 183.09 mmHg-219.20 mmHg). On the left of inflection point, LnPaO₂/FiO₂ was negatively correlated with 28-day mortality (OR: 0.37, 95%CI: 0.32-0.43, p < 0.0001). On the right of inflection point, LnPaO₂/FiO₂ was positively correlated with 28-day mortality in patients with sepsis (OR: 1.53, 95%CI: 1.31-1.80, p < 0.0001).

CONCLUSIONS

In patients with sepsis, either a high or low PaO₂/FiO₂ was associated with an increased risk of 28-day mortality. In the range of 183.09 mmHg to 219.20 mmHg, PaO₂/FiO₂ was associated with a lower risk of 28-day death in patients with sepsis.

Association between obesity and short- and medium-term mortality in critically ill patients with atrial fibrillation: a retrospective cohort study

BACKGROUND

There has been controversy about how obesity affects the clinical prognosis for patients with atrial fibrillation (AF), and the relationship between obesity and outcomes in critically ill patients with AF remains unclear. The purpose of this study was to explore the association between obesity and short- and medium-term mortality in critically ill patients with AF.

METHODS

The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was used to conduct a retrospective cohort analysis on 9282 critically ill patients with AF. Patients were categorized into four groups based on their body mass index (BMI) values: underweight, normal-weight, overweight, and obese. The outcomes of this study were 30-day, 90-day, and 1-year all-cause mortality. Cox proportional-hazards models and restricted cubic spline analyses were performed to investigate the association between BMI and mortality.

RESULTS

For 30-day mortality, after adjustment for all confounding factors, the hazard ratio (HR) with 95% confidence interval (CI) for the underweight, overweight, and obese categories were 1.58 (1.21, 2.07), 0.82 (0.72, 0.93), and 0.79 (0.68, 0.91), respectively, compared to the normal-weight category. Using multivariable-adjusted restricted cubic spline analysis, an "L-shaped" correlation was observed between BMI and 30-day mortality. For each 1 kg/m² increase in BMI when BMI was less than 30 kg/m², the risk of 30-day mortality decreased by 6.4% (HR, 95% CI: 0.936 [0.918, 0.954]; P < 0.001); however, this relationship was not present when BMI was greater than or equal to 30 kg/m². Similar results were observed for 90-day and 1-year mortality.

CONCLUSIONS

There was a nonlinear relationship between BMI and all-cause mortality among critically ill patients with AF. All-cause mortality and the BMI were negatively correlated when the BMI was less than 30 kg/m².

Association between obesity and 1-year mortality in septic patients: a retrospective cohort study

OBJECTIVE

Sepsis is a major contributor of intensive care units (ICUs) patient mortality. Prior investigations claimed that obesity enhances overall survival (OS) of septic patients. However, the reported results were inconsistent. This study examined the association between obesity and the 1-year mortality of septic patients.

DESIGN

A retrospective cohort study.

SETTING

The Medical Information Mart for Intensive Care III database.

PARTICIPANTS

3145 septic patients were separated into three distinct cohorts, based on their WHO body mass index (BMI) status.

OUTCOMES

Our primary endpoint was the 1-year mortality from the date of ICU hospitalization.

RESULT

1334 (42.4%) died within 1 year. The 1-year mortality rate was low in obese patients (38.8%), compared with normal (46.9%) and overweight (42.1%) patients. Crude assessment revealed that obese patients experienced reduced 1-year mortality, relative to normal weight patients (HR 0.79, 95% CI 0.69 to 0.9, p<0.001). However, once adjusted for baseline variables and comorbidities, no correlation was found between obesity and the 1-year mortality (HR 0.93, 95% CI 0.81 to 1.06, p=0.28) of septic patients. There was an association among diabetic (HR 0.72, 95% CI 0.56 to 0.93, p=0.012) and hypertensive (HR 0.73, 95% CI 0.58 to 0.92, p=0.008) patients, and among males (HR 0.71, 95% CI 0.59 to 0.86, p<0.001), with obese individuals experiencing the lowest mortality rate. Given these evidences, the interactions between BMI and mortality in diabetic (p=0.031) and hypertensive (p=0.035) patients were significant.

CONCLUSION

In our study, obese diabetic and hypertensive patients associated to less sepsis-related mortality risk, compared with normal weight patients. Further researches were need to validated.

Early predicting 30-day mortality in sepsis in MIMIC-III by an artificial neural networks model

OBJECTIVE

Early identifying sepsis patients who had higher risk of poor prognosis was extremely important. The aim of this study was to develop an artificial neural networks (ANN) model for early predicting clinical outcomes in sepsis.

METHODS

This study was a retrospective design. Sepsis patients from the Medical Information Mart for Intensive Care-III (MIMIC-III) database were enrolled. A predictive model for predicting 30-day morality in sepsis was performed based on the ANN approach.

RESULTS

A total of 2874 patients with sepsis were included and 30-day mortality was 29.8%. The study population was categorized into the training set (n = 1698) and validation set (n = 1176) based on the ratio of 6:4. 11 variables which showed significant differences between survivor group and nonsurvivor group in training set were selected for constructing the ANN model. In training set, the predictive performance based on the area under the receiver-operating characteristic curve (AUC) were 0.873 for ANN model, 0.720 for logistic regression, 0.629 for APACHEII score and 0.619 for SOFA score. In validation set, the AUCs of ANN, logistic regression, APAHCEII score, and SOFA score were 0.811, 0.752, 0.607, and 0.628, respectively.

CONCLUSION

An ANN model for predicting 30-day mortality in sepsis was performed. Our predictive model can be beneficial for early detection of patients with higher risk of poor prognosis.

Current status and trends in researches based on public intensive care databases: A scientometric investigation

Objective

Public intensive care databases cover a wide range of data that are produced in intensive care units (ICUs). Public intensive care databases draw great attention from researchers since they were time-saving and money-saving in obtaining data. This study aimed to explore the current status and trends of publications based on public intensive care databases.

Methods

Articles and reviews based on public intensive care databases, published from 2001 to 2021, were retrieved from the Web of Science Core Collection (WoSCC) for investigation. Scientometric software (CiteSpace and VOSviewer) were used to generate network maps and reveal hot spots of studies based on public intensive care databases.

Results

A total of 456 studies were collected. Zhang Zhongheng from Zhejiang University (China) and Leo Anthony Celi from Massachusetts Institute of Technology (MIT, USA) occupied important positions in studies based on public intensive care databases. Closer cooperation was observed between institutions in the same country. Six Research Topics were concluded through keyword analysis. Result of citation burst indicated that this field was in the stage of rapid development, with more diseases and clinical problems being investigated. Machine learning is still the hot research method in this field.

Conclusions

This is the first time that scientometrics has been used in the investigation of studies based on public intensive databases. Although more and more studies based on public intensive care databases were published, public intensive care databases may not be fully explored. Moreover, it could also help researchers directly perceive the current status and trends in this field. Public intensive care databases could be fully explored with more researchers' knowledge of this field.

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.

Body mass index linked to short-term and long-term all-cause mortality in patients with acute myocardial infarction

PURPOSES OF STUDY

This study aimed to elucidate the relationship between obesity and short-term and long-term mortality in patients with acute myocardial infarction (AMI) by analysing the body mass index (BMI).

STUDY DESIGN

A retrospective cohort study was performed on adult intensive care unit (ICU) patients with AMI in the Medical Information Mart for Intensive Care III database. The WHO BMI classification was used in the study. The Kaplan-Meier curve was used to show the likelihood of survival in patients with AMI. The relationships of the BMI classification with short-term and long-term mortality were assessed using Cox proportional hazard regression models.

RESULTS

This study included 1295 ICU patients with AMI, who were divided into four groups according to the WHO BMI classification. Our results suggest that obese patients with AMI tended to be younger (p<0.001), be men (p=0.001) and have higher blood glucose and creatine kinase (p<0.001) compared with normal weight patients. In the adjusted model, compared with normal weight AMI patients, those who were overweight and obese had lower ICU risks of death HR=0.64 (95% CI 0.46 to 0.89) and 0.55 (0.38 to 0.78), respectively, inhospital risks of death (0.77 (0.56 to 1.09) and 0.61 (0.43 to 0.87)) and long-term risks of death (0.78 0.64 to 0.94) and 0.72 (0.59 to 0.89). On the other hand, underweight patients had higher risks of short-term(ICU or inhospital mortality) and long-term mortality compared with normal weight patients (HR=1.39 (95% CI 0.58 to 3.30), 1.46 (0.62 to 3.42) and 1.99 (1.15 to 3.44), respectively).

CONCLUSIONS

Overweight and obesity were protective factors for the short-term and long-term risks of death in patients with AMI.

Sepsis in a Combined Medical and Surgical High Dependency/Intensive Care Unit in Singapore: A Cohort Study and Survival Analysis

Background

Sepsis is a common indication for intensive care unit (ICU) admission and is associated with significant mortality and morbidity. The aim of our study was to first assess the incidence, severity, short-term and long-term mortality of sepsis in a combined medical and surgical high dependency/ ICU in Singapore, and to identify factors associated with increasing short-term and long-term mortality.

Methods

All admissions from July 1 to December 31, 2017 were retrospectively screened and clinical data were collected. Patients were followed up until 3 years post ICU admission.

Results

Of a total 1526 admissions, 281 had infection at ICU admission, and 254 (16.6%) fulfilled sepsis-3 criteria for sepsis. A total of 141 (9.2%) had septic shock. The 30-day, 1-year, 2-year and 3-year mortality of sepsis patients were 19.3%, 25.2%, 30.3% and 32.3%, respectively. Lung was the most common site of infection. Compared with 30-day sepsis survivors, non-survivors were older (median age 70 vs 63, P <0.001), had higher percentage of lung infection (65.3% vs 36.1%, P <0.05), higher admission Sequential Organ Failure Assessment (SOFA) score (median 9 vs 5, P <0.001), and longer ICU stay (median days: 4 vs 3, P = 0.037). In stepwise Cox regression analysis, lung infection was an independent risk factor for both increasing 30-day and 3-year mortality. Immunocompromised host, increasing age and SOFA score were associated with higher 30-day mortality. Diabetes, admission quick Sequential Organ Failure Assessment (qSOFA) score >1 and unplanned ICU re-admission were associated with increasing 3-year mortality in 30-day survivors.

Conclusion

Our retrospective cohort single center study first reported sepsis admission incidence of 16.6% in a combined medical and surgical high dependency/ICU in Singapore, with significant short-term and long-term mortality. Lung infection was an independent risk factor for both 30-day and 3-year mortality.

Exploring the Obesity Paradox in A Murine Model of Sepsis: Improved Survival Despite Increased Organ Injury in Obese Mice

ABSTRACT

Despite the known deleterious effects of obesity, clinical data indicate that overweight or obese patients experience higher rates of sepsis survival compared to normal and underweight patients; a phenomenon called the obesity paradox. Results from preclinical sepsis studies have not been able to replicate these findings. The objective of this study was to test the existence of the obesity paradox in a murine model of cecal slurry (CS)-induced sepsis with insulin-resistant diet-induced obese mice. Male C57BL/6 mice were provided high-fat (HFD) or low-fat (LFD) diets for 20 weeks. HFD-fed mice experienced higher rates of survival compared to LFD-fed mice after septic challenge induced by CS injection (66% vs. 25%, P = 0.01, survival assessed for 14 days). Despite the survival advantage, HFD-fed mice had higher rates of positive bacterial cultures and increased markers of kidney injury. Circulating levels of IL-6, IL-1β, TNFα, and IL-23 were equivalent 24 h after CS-injection; however, IL-17A was uniquely increased in HFD-fed mice. While LFD-fed mice maintained euglycemia, HFD-fed mice were hyperglycemic 6 and 12 h after CS-injection. Stable isotope resolved metabolomics analysis of liver tissue showed diverging pathways of glucose utilization during sepsis, with LFD-fed mice significantly upregulating glycolytic activity and HFD-fed mice decreasing glucose entry into the TCA cycle. This murine study corroborates clinical data that obesity confers a survival benefit in sepsis, albeit at the expense of more significant organ injury. The mechanisms promoting survival in the obese remain unknown; however, this model appears to be well-poised to begin answering this question. Differences in glucose utilization are a novel target to investigate this paradox.

Association Between Obesity and Lower Short- and Long-Term Mortality in Coronary Care Unit Patients: A Cohort Study of the MIMIC-III Database

INTRODUCTION

Obesity has long been considered an independent risk factor for cardiovascular diseases (CVD), even in the COVID-19 pandemic. However, recent studies have found that a certain degree of obesity may be beneficial for patients who have already suffered from CVD, which is called the "obesity paradox". Our objective was to investigate whether the obesity paradox existed in coronary care unit (CCU) patients and the relationship between body mass index (BMI) and short- and long-term mortality.

METHODS

We performed a cohort analysis of 3,502 adult CCU patients from the Medical Information Mart for Intensive Care III (MIMIC-III) database. The patients were divided into four groups according to the WHO BMI categories. Both multivariable logistic regression and Cox regression were used to reveal the relation between BMI and mortality. Subgroup analyses were performed based on Simplified Acute Physiology Score (SAPS) and age.

RESULTS

After adjusting for confounders, obese patients had 33% and 30% lower mortality risk at 30-day and 1-year (OR 0.67, 95% CI 0.51 to 0.89; HR 0.70, 95% CI 0.59 to 0.83; respectively) compared with normal-weight patients, while the underweight group were opposite, with 141% and 81% higher in short- and long-term (OR 2.41, 95% CI 1.37 to 4.12; HR 1.81, 95% CI 1.34 to 2.46; respectively). Overweight patients did not have a significant survival advantage at 30-day (OR 0.91, 95% CI 0.70 to 1.17), but did have a 22% lower mortality risk at 1-year (HR 0.78; 95% CI 0.67 to 0.91). The results were consistent after being stratified by SAPS and age.

CONCLUSION

Our study supports that obesity improved survival at both 30-day and 1-year after CCU admission, and the obesity paradox existed in CCU patients.

Divergent Sepsis Pathophysiology in Older Adults

Significance: Both incidence and mortality rates of sepsis significantly increase with advanced age, and the majority of sepsis patients are late middle-aged or older. With the proportion of older adults rapidly increasing in developed countries, age-dependent sepsis vulnerability is an urgent medical issue. Due to an increasing life expectancy, postsepsis complications and health care costs are expected to increase as well. Recent Advances: Older patients suffer from higher sepsis incidence and mortality rates, likely resulting from frequent comorbidities, increased coagulation, dysgylcemia, and altered immune responses. Critical Issues: Despite a large number of ongoing clinical and basic research studies, there is currently no effective therapeutic strategy targeting older patients with severe sepsis. The disparity between clinical and basic studies is a problem, and this is largely due to the use of animal models lacking clinical relevance. Although the majority of sepsis cases occur in older adults, most laboratory animals used for sepsis research are very young. Further, despite the wide use of combination fluid and antibiotic treatment in intensive care unit (ICU) patients, most animal research does not include such treatment. Future Directions: Because sepsis is a systemic disease with multiple organ dysfunction, combined therapy approaches, not those targeting single pathways or single organs, are essential. As for preclinical research, it is critical to confirm new findings using aged animal models with clinically relevant ICU-like medical treatments. Antioxid. Redox Signal. 35, 1358-1375.

Sentiment Analysis Based on the Nursing Notes on In-Hospital 28-Day Mortality of Sepsis Patients Utilizing the MIMIC-III Database

In medical visualization, nursing notes contain rich information about a patient's pathological condition. However, they are not widely used in the prediction of clinical outcomes. With advances in the processing of natural language, information begins to be extracted from large-scale unstructured data like nursing notes. This study extracted sentiment information in nursing notes and explored its association with in-hospital 28-day mortality in sepsis patients. The data of patients and nursing notes were extracted from the MIMIC-III database. A COX proportional hazard model was used to analyze the relationship between sentiment scores in nursing notes and in-hospital 28-day mortality. Based on the COX model, the individual prognostic index (PI) was calculated, and then, survival was analyzed. Among eligible 1851 sepsis patients, 580 cases suffered from in-hospital 28-day mortality (dead group), while 1271 survived (survived group). Significant differences were shown between two groups in sentiment polarity, Simplified Acute Physiology Score II (SAPS-II) score, age, and intensive care unit (ICU) type (all P < 0.001). Multivariate COX analysis exhibited that sentiment polarity (HR: 0.499, 95% CI: 0.409-0.610, P < 0.001) and sentiment subjectivity (HR: 0.710, 95% CI: 0.559-0.902, P = 0.005) were inversely associated with in-hospital 28-day mortality, while the SAPS-II score (HR: 1.034, 95% CI: 1.029-1.040, P < 0.001) was positively correlated with in-hospital 28-day mortality. The median death time of patients with PI ≥ 0.561 was significantly earlier than that of patients with PI < 0.561 (13.5 vs. 49.8 days, P < 0.001). In conclusion, sentiments in nursing notes are associated with the in-hospital 28-day mortality and survival of sepsis patients.

A Novel Nomogram for Predicting Survival in Patients with Severe Acute Pancreatitis: An Analysis Based on the Large MIMIC-III Clinical Database

BACKGROUND

Severe acute pancreatitis (SAP) can cause various complications. Septic shock is a relatively common and serious complication that causes uncontrolled systemic inflammatory response syndrome, which is one of the main causes of death. This study aimed to develop a nomogram for predicting the overall survival of SAP patients during the initial 24 hours following admission.

MATERIALS AND METHODS

All the data utilized in this study were obtained from the MIMIC-III (Medical Information Mart for Intensive Care III) database. The data were analyzed using multivariate Cox regression, and the performance of the proposed nomogram was evaluated based on Harrell's concordance index (C-index) and the area under the receiver operating characteristic curve (AUC). The clinical value of the prediction model was tested using decision-curve analysis (DCA). The primary outcomes were 28-day, 60-day, and 90-day mortality rates.

RESULTS

The 850 patients included in the analysis comprised 595 in the training cohort and 255 in the validation cohort. The training cohort consisted of 353 (59.3%) males and 242 (40.7%) females with SAP. Multivariate Cox regression showed that weight, sex, insurance status, explicit sepsis, SAPSII score, Elixhauser score, bilirubin, anion gap, creatinine, hematocrit, hemoglobin, RDW, SPO2, and respiratory rate were independent prognostic factors for the survival of SAP patients admitted to an intensive care unit. The predicted values were compared using C-indexes, calibration plots, integrated discrimination improvement, net reclassification improvement, and DCA.

CONCLUSIONS

We have identified some important demographic and laboratory parameters related to the prognosis of patients with SAP and have used them to establish a more accurate and convenient nomogram for evaluating their 28-day, 60-day, and 90-day mortality rates.

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.

Association between body mass index and short-term mortality in patients with intra-abdominal infections: a retrospective, single-centre cohort study using the Medical Information Mart for Intensive Care database

OBJECTIVES

This study aimed to determine the relationship between the body mass index (BMI) and short-term mortality of patients with intra-abdominal infection (IAI) using the Medical Information Mart for Intensive Care (MIMIC-III) database.

DESIGN

Retrospective cohort study.

SETTING

Adult intensive care units (ICUs) at a tertiary hospital in the USA .

PARTICIPANTS

Adult IAI ICU patients from 2001 to 2012 in the MIMIC-III database.

INTERVENTIONS

In univariate analysis, we compared the differences in the characteristics of patients in each BMI group. Cox regression models were used to evaluate the relationships between BMI and short-term prognosis.

PRIMARY AND SECONDARY OUTCOME MEASURES

90-day survival.

RESULTS

In total, 1161 patients with IAI were included. There were 399 (34.4%) patients with a normal BMI (<25 kg/m²), 357 (30.8%) overweight patients (25-30 kg/m²) and 405 (34.9%) obese patients (>30 kg/m²) who tended to be younger (p<0.001) and had higher Sequential Organ Failure Assessment scores (p<0.05). The mortality of obese patients at 90 days was lower than that of patients with a normal BMI (20.74% vs 23.25%, p<0.05), but their length of stay in the ICU was higher (4.9 days vs 3.6 days, p<0.001); however, their rate of mechanical ventilation utilisation was higher (61.48% vs 56.86%, p<0.05). In the Cox regression model, we also confirmed that BMI was a protective factor in patients with IAIs, and the adjusted mortality rate of patients with a higher BMI was 0.97 times lower than that of patients with a lower BMI (p<0.001, HR=0.97, 95% CI 0.96 to 0.99).

CONCLUSIONS

IAI patients with an overweight or obese status might have lower 90-day mortality than patients with a normal BMI.

Impact of obesity on outcomes in patients with acute respiratory syndrome

Objectives

We assessed the relationship between obesity and all-cause mortality in patients with acute respiratory distress syndrome (ARDS).

Methods

In this retrospective cohort study, patient data were extracted from the eICU Collaborative Research Database and the Medical Information Mart for Intensive Care Database III. Body mass index (BMI) was grouped according to World Health Organization classifications: underweight, normal weight, overweight, obese. Cox regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause mortality related to obesity.

Results

Participants included 185 women and 233 men, mean age 70.7 ± 44.1 years and mean BMI 28.7 ± 8.1 kg/m². Compared with normal weight patients, obese patients tended to be younger (60.1 ± 13.7 years) and included more women (51.3% vs. 49.0%). In the unadjusted model, HRs (95% CIs) of 30-day mortality for underweight, overweight, and obesity were 1.57 (0.76, 3.27), 0.64 (0.39, 1.08), and 4.83 (2.25, 10.35), respectively, compared with those for normal weight. After adjustment, HRs (95% CIs) of 30-day mortality for underweight, overweight, and obesity were 1.82 (0.85, 3.90), 0.59 (0.29, 1.20), and 3.85 (1.73, 8.57), respectively, compared with the reference group; 90-day and 1-year all-cause mortalities showed similar trends.

Conclusions

Obesity was associated with increased all-cause mortality in patients with ARDS.

Body Mass Index Is Associated with the Severity and All-Cause Mortality of Acute Kidney Injury in Critically Ill Patients: An Analysis of a Large Critical Care Database

Background

Acute kidney injury (AKI) is a common clinical syndrome carrying high morbidity and mortality. Body mass index (BMI) is a common health indicator, and a high BMI value-obesity has been shown to be associated with the outcomes of several diseases. However, the relationship between different BMI categories and mortality in all critically ill patients with AKI is unclear and needs further investigation. Therefore, we evaluated the ability of BMI to predict the severity and all-cause mortality of AKI in critically ill patients.

Methods

We extracted clinical data from the MIMIC-III v1.4 database. All adult patients with AKI were initially screened. The baseline data extracted within 24 hours after ICU admission were presented according to WHO BMI categories. Logistic regression models and the Cox proportional hazards models were, respectively, constructed to assess the relationship between BMI and the severity and all-cause mortality of AKI. The generalized additive model (GAM) was used to identify nonlinear relationships as BMI was a continuous variable. The subgroup analyses were performed to further analyze the stability of the association between BMI category and 365-day all-cause mortality of AKI.

Result

A total of 15,174 patients were extracted and were divided into four groups according to BMI. Obese patients were more likely to be young and male. In the fully adjusted logistic regression model, we found that overweight and obesity were significant predictors of AKI stage III (OR, 95 CI: 1.17, 1.05-1.30; 1.32, 1.18-1.47). In the fully adjusted Cox proportional hazards model, overweight and obesity were associated with significantly lower 30-day, 90-day, and 365-day all-cause mortality. The corresponding adjusted HRs (95 CIs) for overweight patients were 0.87 (0.77, 0.99), 0.84 (0.76, 0.93), and 0.80 (0.74, 0.88), and for obese patients, they were 0.87 (0.77, 0.98), 0.79 (0.71, 0.88), and 0.73 (0.66, 0.80), respectively. The subgroup analyses further presented a stable relationship between BMI category and 365-day all-cause mortality.

Conclusions

BMI was independently associated with the severity and all-cause mortality of AKI in critical illness. Overweight and obesity were associated with increased risk of AKI stage III; however, they were predictive of a relatively lower mortality risk in these patients.

Development and Validation of a Sepsis Mortality Risk Score for Sepsis-3 Patients in Intensive Care Unit

Background: Many severity scores are widely used for clinical outcome prediction for critically ill patients in the intensive care unit (ICU). However, for patients identified by sepsis-3 criteria, none of these have been developed. This study aimed to develop and validate a risk stratification score for mortality prediction in sepsis-3 patients. Methods: In this retrospective cohort study, we employed the Medical Information Mart for Intensive Care III (MIMIC III) database for model development and the eICU database for external validation. We identified septic patients by sepsis-3 criteria on day 1 of ICU entry. The Least Absolute Shrinkage and Selection Operator (LASSO) technique was performed to select predictive variables. We also developed a sepsis mortality prediction model and associated risk stratification score. We then compared model discrimination and calibration with other traditional severity scores. Results: For model development, we enrolled a total of 5,443 patients fulfilling the sepsis-3 criteria. The 30-day mortality was 16.7%. With 5,658 septic patients in the validation set, there were 1,135 deaths (mortality 20.1%). The score had good discrimination in development and validation sets (area under curve: 0.789 and 0.765). In the validation set, the calibration slope was 0.862, and the Brier value was 0.140. In the development dataset, the score divided patients according to mortality risk of low (3.2%), moderate (12.4%), high (30.7%), and very high (68.1%). The corresponding mortality in the validation dataset was 2.8, 10.5, 21.1, and 51.2%. As shown by the decision curve analysis, the score always had a positive net benefit. Conclusion: We observed moderate discrimination and calibration for the score termed Sepsis Mortality Risk Score (SMRS), allowing stratification of patients according to mortality risk. However, we still require further modification and external validation.

Association between low body mass index and increased 28-day mortality of severe sepsis in Japanese cohorts

Current research regarding the association between body mass index (BMI) and altered clinical outcomes of sepsis in Asian populations is insufficient. We investigated the association between BMI and clinical outcomes using two Japanese cohorts of severe sepsis (derivation cohort, Chiba University Hospital, n = 614; validation cohort, multicenter cohort, n = 1561). Participants were categorized into the underweight (BMI < 18.5) and non-underweight (BMI ≥ 18.5) groups. The primary outcome was 28-day mortality. Univariate analysis of the derivation cohort indicated increased 28-day mortality trend in the underweight group compared to the non-underweight group (underweight 24.4% [20/82 cases] vs. non-underweight 16.0% [85/532 cases]; p = 0.060). In the primary analysis, multivariate analysis adjusted for baseline imbalance revealed that patients in the underweight group had a significantly increased 28-day mortality compared to those in the non-underweight group (p = 0.031, adjusted odds ratio [OR] 1.91, 95% confidence interval [CI] 1.06–3.46). In a repeated analysis using a multicenter validation cohort (underweight n = 343, non-underweight n = 1218), patients in the underweight group had a significantly increased 28-day mortality compared to those in the non-underweight group (p = 0.045, OR 1.40, 95% CI 1.00–1.97). In conclusion, patients with a BMI < 18.5 had a significantly increased 28-day mortality compared to those with a BMI ≥ 18.5 in Japanese cohorts with severe sepsis.

Association between Body Mass Index and Short-Term Clinical Outcomes in Critically Ill Patients with Sepsis: A Real-World Study

BACKGROUND

Obesity is now recognized as one of the major public health threats, especially for patients with a critical illness. However, studies regarding whether and how body mass index (BMI) affects clinical outcomes in patients with sepsis are still scarce and controversial. The aim of our study was to determine the effect of BMI on critically ill patients with sepsis.

MATERIALS AND METHODS

We performed this study using data from the Medical Information Center for Intensive Care III database. A multivariate Cox regression model was used to assess the independent association of BMI with the primary outcome.

RESULTS

A total of 7,967 patients were enrolled in this study. Firstly, we found that the 28-day mortality was reduced by 22% (HR = 0.78, 95% CI 0.69-0.88) and 13% (HR = 0.87, 95% CI 0.78-0.98) for obese and overweight compared to normal weight, respectively. Subsequently, a U-shaped association of BMI with 28-day mortality was observed in sepsis patients, with the lowest 28-day mortality at the BMI range of 30-40 kg/m2. Finally, significant interactions were observed only for sex (P = 0.0071). Male patients with a BMI of 25-30 kg/m2 (HR = 0.74, 95% CI 0.63-0.86) and 30-40 kg/m2 (HR = 0.63, 95% CI 0.53-0.76) had a significantly lower risk of 28-day mortality.

CONCLUSIONS

A U-shaped association of BMI with 28-day mortality in critically ill sepsis patients was found, with the lowest 28-day mortality at a BMI range of 30-40 kg/m2. Notably, male patients were protected by a higher BMI more effectively than female patients as males had a significantly lower mortality risk.

Is There an Obesity Paradox in Critical Illness? Epidemiologic and Metabolic Considerations

PURPOSE OF REVIEW

Obesity represents a global epidemic with serious implications in public health due to its increasing prevalence and its known association with a high morbidity and mortality burden. However, a growing number of data support a survival benefit of obesity in critical illness. This review summarizes current evidence regarding the obesity paradox in critical illness, discusses methodological issues and metabolic implications, and presents potential pathophysiologic mechanisms.

RECENT FINDINGS

Data from meta-analyses and recent studies corroborate the obesity-related survival benefit in critically ill patients as well as in selected populations such as patients with sepsis and acute respiratory distress syndrome, but not trauma. However, this finding warrants a cautious interpretation due to certain methodological limitations of these studies, such as the retrospective design, possible selection bias, the use of BMI as an obesity index, and inadequate adjustment for confounding variables. Main pathophysiologic mechanisms related to obesity that could explain this phenomenon include higher energy reserves, inflammatory preconditioning, anti-inflammatory immune profile, endotoxin neutralization, adrenal steroid synthesis, renin-angiotensin system activation, cardioprotective metabolic effects, and prevention of muscle wasting. The survival benefit of obesity in critical illness is supported from large meta-analyses and recent studies. Due to important methodological limitations, more prospective studies are needed to further elucidate this finding, while future research should focus on the pathophysiologic role of adipose tissue in critical illness.

Favorable 90-Day Mortality in Obese Caucasian Patients with Septic Shock According to the Sepsis-3 Definition

Septic shock is a frequent life-threatening condition and a leading cause of mortality in intensive care units (ICUs). Previous investigations have reported a potentially protective effect of obesity in septic shock patients. However, prior results have been inconsistent, focused on short-term in-hospital mortality and inadequately adjusted for confounders, and they have rarely applied the currently valid Sepsis-3 definition criteria for septic shock. This investigation examined the effect of obesity on 90-day mortality in patients with septic shock selected from a prospectively enrolled cohort of septic patients. A total of 352 patients who met the Sepsis-3 criteria for septic shock were enrolled in this study. Body-mass index (BMI) was used to divide the cohort into 24% obese (BMI ≥ 30 kg/m²) and 76% non-obese (BMI < 30 kg/m²) patients. Kaplan-Meier survival analysis revealed a significantly lower 90-day mortality (31% vs. 43%; p = 0.0436) in obese patients compared to non-obese patients. Additional analyses of baseline characteristics, disease severity, and microbiological findings outlined further statistically significant differences among the groups. Multivariate Cox regression analysis estimated a significant protective effect of obesity on 90-day mortality after adjustment for confounders. An understanding of the underlying physiologic mechanisms may improve therapeutic strategies and patient prognosis.