The role of increased body mass index in outcomes of sepsis: a systematic review and meta-analysis

Abstract

BackgroundThe role of increased body mass index (BMI) in sepsis is controversial. We aimed to evaluate the associations between overweight (25 kg/m2 < BMI ≤ 29.9 kg/m2), obese (30 kg/m2 < BMI ≤ 39.9 kg/m2) and morbidly obese (BMI > 40 kg/m2) BMIs and outcomes in septic patients.MethodsWe searched the PubMed, Embase, Web of Science, Cochrane Library and ClinicalTrials.gov databases for studies published by December 1, 2016. Electronic database searches yielded 3713 articles, eight of which were included in this meta-analysis. Data were independently extracted by two reviewers, and a third reviewer participated in making decisions as needed. We used Review Manager to conduct the analysis, and the outcomes were reported with odds ratios (ORs) or mean differences (MDs). The primary outcome was mortality, and the secondary outcome was length of stay (LOS) in the intensive care unit (ICU) or the hospital.ResultsData from eight studies involving a total of 9696 patients were pooled in our final analysis. Compared with patients with normal BMI (18.5 kg/m2 < BMI ≤ 24.9 kg/m2), patients with BMI ≥ 25 kg/m2 exhibited decreased mortality (OR 0.81; 95% confidence interval (CI), 0.74–0.89, P < 0.0001). In subgroup analysis, compared with normal-weight patients, overweight patients had lower mortality (OR 0.87; 95% CI 0.77–0.97, P = 0.02), whereas obese (OR 0.89, 95% CI 0.72–1.10, P = 0.29) and morbidly obese (OR 0.64, 95% CI 0.38–1.08, P = 0.09) patients did not exhibit significantly reduced mortality.ConclusionsIn sepsis cases, overweight, but not obesity or morbid obesity, was associated with lower mortality. Further prospective studies are needed to clarify this relationship.Electronic supplementary materialThe online version of this article (doi:10.1186/s12871-017-0405-4) contains supplementary material, which is available to authorized users.

The Effects of Obesity on Outcome in Preclinical Animal Models of Infection and Sepsis: A Systematic Review and Meta-Analysis

“…Different from these findings in animal obesity models, two recent systematic reviews of observational clinical studies and a retrospective analysis of a large patient database found that obese body mass indices (BMI) appeared to increase survival in septic patients [13][14][15]. Preclinical and clinical results may differ for several reasons.…”

“…is point is highlighted by conflicting data regarding obesity's effects on mortality in patients with bacterial infection and sepsis or viral influenza, two common reasons for ICU admission. Although several individual studies suggest that obesity worsens or has no impact on survival in patients with sepsis, two recent systematic reviews and meta-analyses both reported that overweight or obese body mass indices (BMIs) were paradoxically associated with improved outcomes in sepsis [11][12][13][14][15]. By contrast, two other systematic reviews and metaanalyses and a retrospective analysis of a large patient database found that for patients with influenza pneumonia, obesity increased the risk of either a combined endpoint of ICU admission and death or death alone [16,17].…”

The Prognostic Factors in Patients With Sepsis After Operation of Gastrointestinal Tumors

“…It was reported that the visceral fat (VAT) accumulation detected by CT scan was a risk factor for poor prognosis of sepsis. Sepsis patients with a high ratio of VAT area to the subcutaneous fat (SAT) area had an increased risk of death and organ damage [17] . In future, more detailed and rigorous studies should be designed to clarify the relationship between sepsis and BMI.…”

Lifestyle Risk Factors, Obesity and Infectious Disease Mortality in the General Population: Linkage Study of 97,844 Adults from England and Scotland

“…12,13 In sepsis cases overweight, but not obesity, was associated with lower risk of mortality. 6 Other cohort data have suggested that overweight and obesity is associated with higher risk of respiratory and skin infections, 14 higher 30 day mortality risk after detection of blood borne bacterial infection, 15 whilst protective against viral and fungal infections. 14 The aim of the present study was to examine associations between multiple lifestyle risk factors, obesity (both from BMI and waist measures) and infectious disease mortality in a large general population cohort.…”