key: cord-0954438-m57iabd3 authors: Parikh, Raj; Garcia, Michael A.; Rajendran, Iniya; Johnson, Shelsey; Mesfin, Nathan; Weinberg, Janice; Reardon, Christine C. title: ICU outcomes in Covid-19 patients with obesity date: 2020-11-11 journal: Ther Adv Respir Dis DOI: 10.1177/1753466620971146 sha: 347447e35803a493ab7a1a7f2b58bff9a1ce7849 doc_id: 954438 cord_uid: m57iabd3 The reviews of this paper are available via the supplemental material section. To the Editor: Obesity is a risk factor for severe pulmonary disease due to viral infections such as H1N1 influenza, but few studies have assessed the impact of obesity in Coronavirus disease 2019 (Covid-19). [1] [2] [3] [4] [5] International reports suggest an increased risk of severe Covid-19 disease with poorer outcomes correlating with higher body mass index (BMI). 6, 7 The high prevalence of obesity in the United States (US) emphasizes the importance of characterizing this association. 8 This study explores the clinical relationship between obesity and Covid-19 in intensive care unit (ICU) patients admitted to a tertiary hospital. We conducted a retrospective cohort study of adult patients with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who were consecutively admitted to the ICU from 1 March 2020 to 1 May 2020. The study was approved by the Institutional Review Board of Boston Medical Center. Data was extracted manually from electronic medical records by a quality-controlled protocol. Obesity was defined as BMI ⩾30. Primary outcomes included in-hospital mortality and need for invasive mechanical ventilation (IMV). Secondary outcomes were length of stay (LOS), ICU LOS, need for continuous renal replacement therapy (CRRT), and advanced acute respiratory distress syndrome (ARDS) therapies, including prone-positioning, neuromuscular blockade, and pulmonary vasodilators. Our institution recommended against the routine use of non-invasive ventilation. We compared characteristics of patients with Covid-19 stratified by BMI into two groups: obese versus non-obese. Categorical variables are reported as counts and percentages. Normally distributed continuous variables are reported as mean and standard deviation (SD). Non-normally distributed variables are reported as median and interquartile ranges (IQR). Logistic regression and Cox proportional-hazards analysis measured outcomes. For both methods, three models were examined: unadjusted, adjusted for demographic imbalances, and adjusted for demographic and comorbidity differences. Variables considered for adjustment were chosen based on clinical relevance and imbalances between groups evaluated at the p < 0.1 level. 9,10 Statistical analysis was performed using SAS v9.4 with p < 0.05 considered statistically significant, unless otherwise specified. The demographics, clinical characteristics, therapies, and outcomes of 160 Covid-19 patients admitted to our ICU are summarized in Table 1 . Obesity was present in 83 patients (52%) with mean age of 56.5 years and 55.4% (46 patients) male. The differences included older mean age (64.5 years) and higher percentage of men (76.6%) in the non-obese group. The most common comorbidities were hypertension and diabetes mellitus. There was a higher prevalence of asthma (17 patients;20.5%) and obstructive sleep apnea (19 patients;22.9%) within the obese population. At initial admission, higher median values of procalcitonin, ferritin, and D-dimer and decreased lymphocytes were seen in the nonobese patients compared with obese patients. There were no significant differences between groups in regards to therapies received including immunotherapy, self-proning, and vasopressors. Table 1 shows the outcomes of in-hospital mortality, LOS, ICU LOS, need for and duration of IMV, positive end expiratory pressure (PEEP), advanced ARDS therapies, and CRRT frequency and duration. The obese and non-obese groups had 61.5% and 44.2% of patients, respectively, on IMV (p = 0.0285). Obese patients had a higher median peak PEEP (14 mmHg) compared with non-obese patients (10 mmHg; p = 0.0223). Table 2 shows the unadjusted and adjusted odds for primary and secondary outcomes. In the unadjusted analysis, the obese group had twice the odds for IMV compared with the non-obese group (p = 0.0285). In adjusted models, the odds ratio (OR) indicated increased risk of obesity for IMV but was no longer statistically significant. The adjusted OR implied an increased risk within the obese group for developing the other primary and secondary outcomes without statistical significance. This study revealed that obese patients had twice the odds of requiring IMV compared with nonobese individuals infected with SARS-CoV-2. This association was attenuated following adjustment for sociodemographic and comorbid characteristics. There was no significant difference in in-hospital mortality and the secondary outcomes although there was a trend towards increased odds of worse outcomes in the obese population. We found that at baseline, non-obese patients presented with elevated levels of inflammatory markers and decreased lymphocytes. Our investigation is one of the few studies to focus on obesity outcomes in ICU Covid-19 patients. We examined this population to expand on the established literature linking obesity to SARS-CoV-2. 6,7,11-13 Lighter et al.'s analysis of Covid-19 patients found that severe obesity had increased odds for ICU admission. 11 Our findings suggest that, once in the ICU, the clinical trajectory for obese patients continues to differ from the nonobese population. Obese patients more frequently require IMV and a high-PEEP strategy. Optimizing levels of PEEP is a well-documented approach for ARDS especially in obese patients. 14, 15 Our findings that obese patients required higher levels of This analysis included one healthcare system, therefore limiting the generalizability. The sample size was too small to show a statistically significant impact of obesity in the presence of risk factors such as age and male sex. 9,10 The limited sample size precluded further stratification of patients by obesity class. Laboratory studies and ventilator parameters were not performed or recorded in all of the patients thereby insufficiently representing their clinical role and contributing to residual confounding. However, despite these limitations, our study provides an in-depth evaluation of obesity within Covid-19 disease, focusing on primary and secondary outcomes that characterize severity of illness. The epidemiologic and clinical data included in the investigation assesses multiple confounders while evaluating the study outcomes. The association between obesity and Covid-19 in ICU patients is an important finding in the US where obesity prevalence is over 40%. 8 In reflecting on this relationship, we emphasize the need for larger-scale investigations that can closely examine the underlying mechanisms behind Covid-19 severity and patients with obesity. 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Epub ahead of print Obesity and mortality among patients diagnosed with Covid-19: results from an integrated health care organization High positive end expiratory pressure is associated with improved survival in obese patients with acute respiratory distress syndrome COVID-19 ventilatory phenotypes and obesity: is there a relationship? Obesity. Epub ahead of print 8 Risk of Covid-19 for patients with obesity RP was the lead and corresponding author who constructed the study design, coordinated analysis of the data, and was the primary writer of the manuscript.MAG, IR, SJ, NM assisted RP in his tasks as lead, corresponding author as stated above. JW analyzed and interpreted the patient data CCR was a major contributor in regards to providing guidance and advice to the lead author while also helping interpret data and put together the final manuscript. The datasets generated and/or analysed during the current study are not publicly available due to personalized/individualized data but are available from the corresponding author on reasonable request. The authors declare that there is no conflict of interest. This study involved human participants and human data; informed consent was waived as part of the IRB approval for the study The authors received no financial support for the research, authorship, and/or publication of this article. Raj Parikh https://orcid.org/0000-0002-0975-3047 The reviews of this paper are available via the supplemental material section.