The obesity paradox for survivors of critically ill patients

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 and overweight are common among hospitalized patients and are associated with specific causes of admission to an internal medicine department: a cross-sectional study

PURPOSE

Data on the prevalence of obesity among hospitalized patients are limited. Our objective was to capture the rates of overweight and obesity among people admitted to an internal medicine department and to explore a potential association between body mass index (BMI) and causes of hospitalization.

METHODS

Demographic and anthropometric parameters and cause of admission were recorded in all patients admitted to our department over a 30-day period.

RESULTS

One hundred and eighteen patients with a mean age of 71.84 years and a mean BMI of 26.85 kg/m2 were included in the analysis. Among study participants, 53.25% were living with overweight and obesity. Patients admitted for hepatobiliary disease had a higher BMI compared to those admitted for other diseases of the gastrointestinal tract (P < 0.001).

CONCLUSIONS

More than half of patients admitted to an internal medicine department live with obesity or overweight, the specific reasons for admission being associated with a higher BMI.

Increased red cell distribution width predicts mortality in COVID-19 patients admitted to a Dutch intensive care unit

BACKGROUND

Abnormal red blood cell distribution width (RDW) is associated with poor cardiovascular, respiratory, and coronavirus disease 2019 (COVID-19) outcomes. However, whether RDW provides prognostic insights regarding COVID-19 patients admitted to the intensive care unit (ICU) was unknown. Here, we retrospectively investigated the association of RDW with 30-day and 90- day mortalities, duration of mechanical ventilation, and length of ICU and hospital stay in patients with COVID-19.

METHODS

This study included 321 patients with COVID-19 aged >18 years who were admitted to the ICU between March 2020 and July 2022. The outcomes were mortality, duration of mechanical ventilation, and length of stay. RDW >14.5% was assessed in blood samples within 24 hours of admission.

RESULTS

The mortality rate was 30.5%. Multivariable Cox regression analysis showed an association between increased RDW and 30-day mortality (hazard ratio [HR], 3.64; 95% CI, 1.54-8.65), 90-day mortality (HR, 3.66; 95% CI, 1.59-8.40), and shorter duration of invasive ventilation (2.7 ventilator-free days, P=0.033).

CONCLUSIONS

Increased RDW in COVID-19 patients at ICU admission was associated with increased 30-day and 90-day mortalities, and shorter duration of invasive ventilation. Thus, RDW can be used as a surrogate biomarker for clinical outcomes in COVID-19 patients admitted to the ICU.

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.

Joint effect of atrial fibrillation and obesity on mortality in critically ill patients

BACKGROUND

The interplay between atrial fibrillation (AF) and obesity on mortality in critically ill patients warrants detailed exploration, given their individual impacts on patient prognosis. This study aimed to assess the associations between AF, obesity, and 1-year mortality in a critically ill population.

METHODS

Utilizing data from the Medical Information Mart for Intensive Care (MIMIC)-IV database, we conducted a retrospective analysis of adult patients admitted to the intensive care unit. The primary endpoint was 1-year mortality, analyzed through Cox regression with hazard ratio (HR) and Kaplan-Meier survival methods.

RESULTS

The study included 25,654 patients (median age 67.0 years, 40.6% female), with 39.0% having AF and 36.1% being obese. Multivariate COX regression analysis revealed that AF was associated with a 14.7% increase in the risk of 1-year mortality (p < 0.001), while obesity was linked to a 13.9% reduction in mortality risk (p < 0.001). The protective effect of obesity on mortality was similar in patients with (HR = 0.85) and without AF (HR = 0.86). AF led to a slightly higher risk of mortality in patients without obesity (HR = 1.16) compared to those with obesity (HR = 1.13). Kaplan-Meier survival curves highlighted that non-obese patients with AF had the lowest survival rate, whereas the highest survival was observed in obese patients without AF.

CONCLUSIONS

AF significantly increased 1-year mortality risk in critically ill patients, whereas obesity was associated with a decreased mortality risk. The most adverse survival outcomes were identified in non-obese patients with AF.

Adaptive Metabolic Responses Facilitate Blood-Brain Barrier Repair in Ischemic Stroke via BHB-Mediated Epigenetic Modification of ZO-1 Expression

Adaptive metabolic responses and innate metabolites hold promising therapeutic potential for stroke, while targeted interventions require a thorough understanding of underlying mechanisms. Adiposity is a noted modifiable metabolic risk factor for stroke, and recent research suggests that it benefits neurological rehabilitation. During the early phase of experimental stroke, the lipidomic results showed that fat depots underwent pronounced lipolysis and released fatty acids (FAs) that feed into consequent hepatic FA oxidation and ketogenesis. Systemic supplementation with the predominant ketone beta-hydroxybutyrate (BHB) is found to exert discernible effects on preserving blood-brain barrier (BBB) integrity and facilitating neuroinflammation resolution. Meanwhile, blocking FAO-ketogenesis processes by administration of CPT1α antagonist or shRNA targeting HMGCS2 exacerbated endothelial damage and aggravated stroke severity, whereas BHB supplementation blunted these injuries. Mechanistically, it is unveiled that BHB infusion is taken up by monocarboxylic acid transporter 1 (MCT1) specifically expressed in cerebral endothelium and upregulated the expression of tight junction protein ZO-1 by enhancing local β-hydroxybutyrylation of H3K9 at the promoter of TJP1 gene. Conclusively, an adaptive metabolic mechanism is elucidated by which acute lipolysis stimulates FAO-ketogenesis processes to restore BBB integrity after stroke. Ketogenesis functions as an early metabolic responder to restrain stroke progression, providing novel prospectives for clinical translation.

Impact of obesity on intensive care unit outcomes in older patients with critical illness: A cohort study

BACKGROUND

Although the paradoxical association between obesity and improved survival has been reported in a variety of clinical settings, its applicability to intensive care unit (ICU) outcomes in older critically ill patients remains unclear. We sought to examine the association between obesity and 30-day mortality and other adverse outcomes in this population.

METHODS

We analyzed data of older patients (≥ 60 years) in the eICU Collaborative Research Database. Body mass index (BMI) was stratified according to the World Health Organization obesity classification. Logistic regression model was used to estimate adjusted odds ratios (ORs), and cubic spline curve was used to explore the nonlinear association between BMI and 30-day ICU outcomes. Stratified analysis and sensitivity analysis were also performed.

RESULTS

Compared with class I obesity, under- and normal-weight were associated with higher all-cause, cardiovascular and noncardiovascular mortality, and class III obesity was associated with greater all-cause and cardiovascular mortality (OR, 1.18 [95% CI, 1.06-1.32], 1.28 [1.08-1.51]). Obesity classes II and III were associated with higher composite all-cause mortality, mechanical ventilation, or vasoactive drug usage risks (OR, 1.12 [95% CI, 1.04-1.20], 1.33 [1.24-1.43]). Mechanical ventilation was strongly positively associated with BMI. A significant BMI-by-sex interaction was observed for cardiovascular mortality, such that the association between severe obesity and mortality was more pronounced among older men than older women.

CONCLUSIONS

The obesity paradox does not appear to apply to short-term ICU outcomes in older patients with critical illness, mainly due to increased all-cause and cardiovascular mortality in severely obese patients, particularly in men.

The association between triglyceride glucose-body mass index and all-cause mortality in critically ill patients with atrial fibrillation: a retrospective study from MIMIC-IV database

BACKGROUND

The TyG-BMI index, which is a reliable indicator of insulin resistance (IR), has been found to have a significant correlation with the occurrence of cardiovascular events. However, there still lacks study on the TyG-BMI index and prognosis in patients with atrial fibrillation (AF). The objective of the present study was to evaluate the relationship between TyG-BMI index at admission to ICU and all-cause mortality in critically ill patients with AF.

METHODS

The patient's data were extracted from Medical Information Mart for Intensive Care IV(MIMIC-IV) database. All patients were divided into four groups according to TyG-BMI index. Outcomes include primary and secondary endpoints, with the primary endpoint being the 30-day and 365-day all-cause mortality and the secondary endpoint being the 90-day and 180-day all-cause mortality. TyG-BMI index was quartile and Kaplan-Meier curve was used to compare the outcome of each group. Cox proportional-hazards regression model and restricted cubic splines (RCS) were conducted to assess the relationship between TyG-BMI index and outcomes.

RESULTS

Out of a total of 2509 participants, the average age was 73.26 ± 11.87 years, with 1555 (62.0%) being males. Patients with lower level of TyG-BMI had higher risk of 30-day, 90-day, 180-day and 365-day all-cause mortality, according to the Kaplan-Meier curves (log-rank P < 0.001). In addition, cox proportional-hazards regression analysis revealed that the risk of 30-day, 90-day, 180-day and 365-day all-cause mortality was significantly higher in the lowest quartile of TyG-BMI. Meanwhile, the RCS analysis indicated that L-typed relationships between TyG-BMI index and all-cause mortality, with inflection points at 223.60 for 30-day and 255.02 for 365-day all-cause mortality, respectively. Compared to patients with TyG-BMI levels below the inflection points, those with higher levels had a 1.8% lower risk for 30-day all-cause mortality (hazard ratio [HR] 0.982, 95% confidence interval [CI] 0.9676-0.988) and 1.1% lower risk for 365-day all-cause mortality (HR 0.989, 95% CI 0.986-0.991).

CONCLUSION

In critically ill patients with AF, a lower TyG-BMI level is significantly associated with a higher risk of 30-day, 90-day, 180-day and 365-day all-cause mortality. TyG-BMI index could be used as a valid indicator for grading and treating patients with AF in the ICU.

Prolonged intensive care: muscular functional, and nutritional insights from the COVID-19 pandemic

During the coronavirus disease 2019 (COVID-19) pandemic, clinical staff learned how to manage patients enduring extended stays in an intensive care unit (ICU). COVID-19 patients requiring critical care in an ICU face a high risk of experiencing prolonged intensive care (PIC). The use of invasive mechanical ventilation in individuals with severe acute respiratory distress syndrome can cause numerous complications that influence both short-term and long-term morbidity and mortality. Those risks underscore the importance of proactively addressing functional complications. Mitigating secondary complications unrelated to the primary pathology of admission is imperative in minimizing the risk of PIC. Therefore, incorporating strategies to do that into daily ICU practice for both COVID-19 patients and those critically ill from other conditions is significantly important.

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.

Elevated MMP-8 levels, inversely associated with BMI, predict mortality in mechanically ventilated patients: an observational multicenter study

BACKGROUND

The present study aimed to investigate the correlation between weight status and mortality in mechanically ventilated patients and explore the potential mediators.

METHODS

Three medical centers encompassing 3301 critically ill patients receiving mechanical ventilation were assembled for retrospective analysis to compare mortality across various weight categories of patients using machine learning algorithms. Bioinformatics analysis identified genes exhibiting differential expression among distinct weight categories. A prospective study was then conducted on a distinct cohort of 50 healthy individuals and 193 other mechanically ventilated patients. The expression levels of the genes identified through bioinformatics analysis were quantified through enzyme-linked immunosorbent assay (ELISA).

RESULTS

The retrospective analysis revealed that overweight individuals had a lower mortality rate than underweight individuals, and body mass index (BMI) was an independent protective factor. Bioinformatics analysis identified matrix metalloproteinase 8 (MMP-8) as a differentially expressed gene between overweight and underweight populations. The results of further prospective studies showed that overweight patients had significantly lower MMP-8 levels than underweight patients ((3.717 (2.628, 4.191) vs. 2.763 (1.923, 3.753), ng/ml, P = 0.002). High MMP-8 levels were associated with increased mortality risk (OR = 4.249, P = 0.005), indicating that elevated level of MMP-8 predicts the mortality risk of underweight patients receiving mechanical ventilation.

CONCLUSIONS

This study provides evidence for a protective effect of obesity in mechanically ventilated patients and highlights the potential role of MMP-8 level as a biomarker for predicting mortality risk in this population.

Association of obesity paradox with prognosis of veno-venous-extracorporeal membrane oxygenation in patients with coronavirus disease 2019

Aim

Although the obesity paradox is known for various diseases, including cancer and acute respiratory distress syndrome, little is known about veno-venous extracorporeal membrane oxygenation (VV-ECMO) in patients with coronavirus disease 2019 (COVID-19). In this study, we aimed to investigate the association between body mass index (BMI) and prognosis in critical patients with COVID-19 requiring VV-ECMO.

Methods

We conducted a retrospective observational single-center study at Yokohama City University Civic General Medical Center between March 2020 and October 2021. Participants were patients with COVID-19 who required VV-ECMO. They were classified into two groups: BMI ≤30 kg/m² and >30 kg/m².

Results

In total, 23 patients were included in the analysis, with a median BMI of 28.7 kg/m². Overall, 22 patients were successfully weaned from the ECMO. When comparing the two groups, there was a trend toward fewer days from onset to ECMO induction in the BMI >30 kg/m² group. Moreover, the two groups had a similar prognosis. There were no statistically significant differences in the number of days from onset to hospitalization or the duration of ECMO induction between the groups.

Conclusion

VV-ECMO induction for patients with COVID-19 may lead to earlier indications in patients with BMI >30 kg/m² than in those with BMI ≤30 kg/m².

Impact of obesity on all-cause and cause-specific mortality among critically ill men and women: a cohort study on the eICU database

Background

The effect of obesity on intensive care unit outcomes among critically ill patients and whether there are sex differences have not been well investigated. We sought to determine the association between obesity and 30-day all-cause and cause-specific mortality among critically ill men and women.

Methods

Adult participants who had body mass index (BMI) measurements were included from the eICU database. Participants were divided into six groups according to BMI (kg/m²) categories (underweight, <18.5; normal weight, 18.5-24.9; overweight, 25-29.9; class I obesity, 30-34.9; class II obesity, 35-39.9; class III obesity, ≥40). A multivariable adjusted logistic model was conducted with odds ratios (ORs) and 95% confidence intervals (CIs). A cubic spline curve based on the generalized additive model was used to represent the nonlinear association. Stratified analysis and sensitivity analysis were also performed.

Results

A total of 160,940 individuals were included in the analysis. Compared with the class I obesity category, the underweight and normal weight categories had higher all-cause mortality, and the multivariable adjusted ORs were 1.62 (95% CI: 1.48-1.77) and 1.20 (95% CI: 1.13-1.27) for the general population, 1.76 (95% CI: 1.54-2.01) and 1.22 (95% CI: 1.13-1.32) for men, and 1.51 (95% CI: 1.33-1.71) and 1.16 (95% CI: 1.06-1.27) for women, respectively. Accordingly, multivariable adjusted ORs for the class III obesity category were 1.14 (95% CI: 1.05-1.24) for the general population, 1.18 (95% CI: 1.05-1.33) for men, and 1.10 (95% CI: 0.98-1.23) for women. With cubic spline curves, the association between BMI and all-cause mortality was U-shaped or reverse J-shaped. Similar findings were observed for cause-specific mortality, with the underweight category associated with a higher risk of mortality. Class III obesity increased the risk of cardiovascular death among men (OR 1.51; 95% CI: 1.23-1.84) and increased the risk of other-cause death among women (OR 1.33; 95% CI: 1.10-1.61).

Conclusion

The obesity paradox appears to be suitable for all-cause and cause-specific mortality among critically ill men and women. However, the protective effect of obesity cannot be extended to severely obese individuals. The association between BMI and cardiovascular mortality was sex-specific and was more pronounced among men than among women. Graphical abstract.

The "obesity paradox" in patients with atrial fibrillation: Insights from the Gulf SAFE registry

BACKGROUND

The prognostic impact of obesity on patients with atrial fibrillation (AF) remains under-evaluated and controversial.

METHODS

Patients with AF from the Gulf Survey of Atrial Fibrillation Events (Gulf SAFE) registry were included, who were recruited from six countries in the Middle East Gulf region and followed for 12 months. A multivariable model was established to investigate the association of obesity with clinical outcomes, including stroke or systemic embolism (SE), bleeding, admission for heart failure (HF) or AF, all-cause mortality, and a composite outcome. Restricted cubic splines were depicted to illustrate the relationship between body mass index (BMI) and outcomes. Sensitivity analysis was also conducted.

RESULTS

A total of 1,804 patients with AF and recorded BMI entered the final analysis (mean age 56.2 ± 16.1 years, 47.0% female); 559 (31.0%) were obese (BMI over 30 kg/m2). In multivariable analysis, obesity was associated with reduced risks of stroke/systematic embolism [adjusted odds ratio (aOR) 0.40, 95% confidence interval (CI), 0.18-0.89], bleeding [aOR 0.44, 95%CI, 0.26-0.74], HF admission (aOR 0.61, 95%CI, 0.41-0.90) and the composite outcome (aOR 0.65, 95%CI, 0.50-0.84). As a continuous variable, higher BMI was associated with lower risks for stroke/SE, bleeding, HF admission, all-cause mortality, and the composite outcome as demonstrated by the accumulated incidence of events and restricted cubic splines. This "protective effect" of obesity was more prominent in some subgroups of patients.

CONCLUSION

Among patients with AF, obesity and higher BMI were associated with a more favorable prognosis in the Gulf SAFE registry. The underlying mechanisms for this obesity "paradox" merit further exploration.