key: cord-1006238-u8i838br authors: Tamara, Alice; Tahapary, Dicky L. title: Obesity as a predictor for a poor prognosis of COVID-19: A systematic review date: 2020-05-12 journal: Diabetes Metab Syndr DOI: 10.1016/j.dsx.2020.05.020 sha: 1b161e722691a1c1ef7ddd4592160bca72a4f2fd doc_id: 1006238 cord_uid: u8i838br BACKGROUND AND AIMS: COVID-19 is an emerging pandemic due to droplet infection of 2019-novel coronavirus (2019-nCoV). Due to its rapid transmission and high case-fatality rate, recognition of its risk and prognostic factor is important. Obesity has been associated with impaired immune system, increasing the susceptibility for 2019-nCoV infection. We aimed to study the impact of obesity to the prognosis and disease severity of COVID-19. METHODS: A systematic search and handsearching was conducted in four databases: Cochrane, MEDLINE, EMBASE, and PubMed. The identified articles were screened using the chosen eligibility criteria. We obtained three retrospective cohort studies (Wu J et al., Lighter J et al., and Simonnet A et al.) to be critically appraised using Newcastle Ottawa Scale. RESULTS: The findings of all included studies were consistent in stating the contribution of obesity as a risk factor to increase the requirement for advanced medical care. Study with the highest quality, Simonnet A et al., reported an increase need of invasive mechanical ventilation in COVID-19 patients with body mass index higher than 35 kg/m(2), OR: 7.36 (1.63–33.14; p = 0.021). This is associated with a higher mortality rate in obese population infected with COVID-19. CONCLUSION: Obesity is an independent risk and prognostic factor for the disease severity and the requirement of advanced medical care in COVID-19. This systematic review highlights a particularly vulnerable group – obese, and emphasises on the importance of treatment aggression and disease prevention in this population group. high case-fatality rate, recognition of its risk and prognostic factor is important. 33 Obesity has been associated with impaired immune system, increasing the 34 susceptibility for 2019-nCoV infection. We aimed to study the impact of obesity to 35 the prognosis and disease severity of COVID-19. 36 Coronavirus disease-2019 / COVID-19 is a new emerging pandemic. Its rapid 56 transmission, progressivity and high case fatality rate had affected global social 57 welfare and economy [2] . Per 25 April 2020, the total confirmed coronavirus cases 58 globally reached 2,902,708 along with 202,179 death [1] . 59 The prognosis of COVID-19 has been consistently reported to worsen in 60 advanced age [3, 4] and with the presence of other comorbidities, such as 61 hypertension, cardiovascular diseases, diabetes mellitus, and pulmonary diseases 62 [3-6]. Nevertheless, the growing rate of hospitalization in younger population has 63 been reported and associated with obesity [7,8], a condition of having excessive 64 adipose tissue. The growing prevalence of obesity globally have risen the concern 65 on its additional impact to worsen this pandemic [11] . 66 Obesity has been associated with a condition of chronic inflammation and 67 Hence, we aim to investigate the impact of obesity to the requirement of 75 advanced medical treatment in positively-identified COVID-19 patients, with the 76 hypothesis of obesity being a poor prognostic factor for COVID-19. Data from each study was extracted in a standardised form, compiling study citations, 100 baseline characteristics of the included subjects, appropriate intervention, and the 101 study findings. Study citations included the name of the first author, year of 102 publication, and title of the study. Meanwhile, characteristics of each study refered to Two independent reviewers conducted the quality assessment of the studies (AT and 112 DLT). The included studies were critically appraised using Newcastle Ottawa Quality 113 Assessment Scale (NOS). Any discrepancies of NOS score between reviewers were 114 discussed until it reached a conclusion. High-quality studies were defined as studies 115 fulfilling NOS score of minimum 7. 116 Data was synthesised based on a minimum of three different and high-quality 117 studies with consistent finding. The obtained data was analysed considering the 118 method of variable analysis used, study size, odds/hazard ratio, along with its 119 confidence interval. 120 Literature searching performed using keywords as listed in Table 1 yielded several 123 studies. Out of 573 articles identified, 18 articles were retrieved after title and 124 abstract screening. After the exclusion of duplicates, five studies were assessed in 125 full-text. Three studies remained after full-text screening using eligibility criteria, 126 which were studies by Wu J et al. [17], Lighter J et al. [18] , and Simonnet A et al. [19]. The exclusion of the remaining two studies was due to the usage of language 128 other than English/Indonesian and investigation on other types of coronaviruses. 129 The flow of our study selection is presented according to PRISMA Statement ( Figure 130 1). 131 The summary of baseline study characteristics is presented in stratified their study subjects by their age, dividing them into less than 60 years and 145 over 60 years age-groups. Compared to normo-and over-weight groups, the rate of 146 hospitalization increased 2.0 (1.6-2.6; p<0.0001) and 2.2 (1.7-2.9; p<0.0001) times 147 in younger patient group with obesity grade I and II, respectively. Moreover, 148 younger group patients with obesity grade I and II had an increased likelihood to 149 receive critical care 1.8 (1.2-2.7; p<0.006) and 3.6 (2.5-5.3; p<0.0001) times 150 respectively, compared to normoweight and overweight groups [18] . Study by Wu J In the aspect of sample size, study by Lighter J et al. was very precise with 173 their findings statistically [18] . Meanwhile, study by Simonnet A, the highest quality considered obesity not as an independent risk factor for COVID-19 disease severity 187 [17] as the statistical significance was completely attenuated in the multivariate 188 Article with the highest quality was written by Simonnet et al [19] . Although The limitations of this study arise from the exclusion of articles written in 231 languages other than English and Indonesian and unexplored grey literatures. We 232 also failed to assess the baseline characteristics and variable analysis of Lighter J 233 article. Moreover, this systematic review could not be proceeded to a quantitative 234 analysis (meta-analysis) due to the heterogenous use of variable analysis. Thus, we 235 recommended future studies to adjust comorbidities to their risk ratio presentation 236 to clearly portray the effect of obesity to the disease severity of COVID-19. 237 Taken together, this is the first systematic review to proclaim obesity as an 238 independent risk and prognostic factor for the requirement of advanced medical 239 treatment due to COVID-19. Hence, the results from this study are important in the 240 aspect of treatment aggression and disease prevention. Obese patients with COVID-241 19 should be treated as a higher risk population. In the aspect of prevention, while 242 staying home has been campaigned globally to reduce COVID-19 rapid transmission, 243 in long term, it may simultaneously increase the susceptibility of people to develop This systematic review was funded by the Universitas Indonesia's research grant. 249 The authors declare that the research was conducted in the absence of any 250 commercial or financial relationships that could be construed as a potential conflict 251 of interest. PubMed ((covid-19 or coronavirus or 2019-ncov or sars-cov-2 or cov-19) and (comorbid* or obes* or overweight or high bmi or unhealthy weight)) and (hospital?action or admission or hospital stay or care episode or mortality or morbidity) 208 Handsearching "obesity" AND "COVID-19" 13 Table 3 . Quality assessment of the included studies using Newcastle Ottawa Scale Wu J et al. [17] **** --*** 7 Lighter J et al. [18] **** *-*** 8 Simonnet A et al. [19] **** ** ** Coronavirus update (live): 2,902,708 Cases and 202,179 deaths 261 from COVID-19 virus pandemic Three Emerging Coronaviruses in Two Decades: The Story of SARS Baseline characteristics and outcomes of 1591 patients infected With SARS-267 CoV-2 admitted to ICUs of the Lombardy region, Italy Clinical course and outcomes of 271 critically ill patients with SARS-CoV-2 pneumonia in Wuhan, China: a single-272 centered, retrospective, observational study Does comorbidity increase the risk of patients 274 with COVID-19: evidence from meta-analysis Obesity in patients younger than 60 years is a risk factor for Covid-19 hospital 319 admission High prevalence of obesity in severe acute respiratory syndrome coronavirus-2 322 SARS-CoV-2) requiring invasive mechanical ventilation A crucial role of 326 angiotensin converting enzyme 2 (ACE2) in SARS coronavirus-induced lung 327 injury Two things about COVID-19 329 might need attention Reduction of total lung capacity in obese men: comparison of total 332 intrathoracic and gas volumes The authors declare no conflict of interest.