The worldwide spread of coronavirus disease 2019 (COVID-19) has generated a global health crisis and more than a million deaths so far. Epidemiological and clinical characteristics of COVID-19 are increasingly reported, along with its potential relationship with overweight and/or obesity. Therefore, we aim here to review the current scientific literature on the impact of overweight and/or obesity among hospitalized patients who have developed severe or critical forms of COVID-19. Following PRISMA guidelines, our literature search identified over 300 scientific articles using the keywords “obesity” and “COVID-19”, 22 of which were finally selected for reporting useful information on the association between overweight/obesity and disease severity. In particular, in 11 out of the 14 studies (79%) which evaluated the association between obesity and disease severity providing also a risk estimate (i.e., the odd ratio; OR), the OR value was constantly >2. Although the studies were found to be heterogeneous in terms of design, population, sample size and endpoints, in most cases a significant association was found between obesity and the risk of progressing to severe COVID-19 illness, intensive care unit admission and/or death. We can hence conclude that an increased body mass index shall be considered a negative prognostic factor in patients with COVID-19, and more aggressive prevention or treatment shall hence be reserved to overweight and/or obese patients.
In December 2019 a new virus belonging to the Coronaviridae family has been identified as the responsible pathogen of a new pneumonia-like illness . This novel virus, which has been finally defined severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a zoonotic pathogen originated by spillover from bats in Wuhan, China, from where the infection has then spread all around the world . SARS-CoV-2 belongs to the beta coronavirus subfamily, which is known for other similar viruses responsible of two previous epidemic diseases, i.e., the severe acute respiratory syndrome (SARS) in 2002 and the Middle-East respiratory syndrome (MERS) in 2012, respectively , . SARS-CoV-2 rapidly spread from China, infecting Europe (with the first case in Italy on 28th February 2020), America, Australia and Africa. On the 11th March 2020 the pandemic state has been finally declared by the World Health Organization (WHO) .
SARS-CoV-2 is responsible of an illness that has been defined COVID-19, which is characterized by a heterogeneous spectrum of clinical manifestations, from asymptomatic disease to development of pulmonary involvement (with pneumonia and/or acute respiratory distress syndrome; ARDS), up to systemic dissemination with multiple organ failure and high risk of death . The incubation period is typically comprised between 1 and 14 days. Although respiratory involvement is the most frequent complication in symptomatic people, this frequently needing mechanical ventilation and intensive care unit (ICU) admission, the first set of symptoms may include visual, olfactory, gastrointestinal and skin disturbances, encompassing also fever, headache, dry cough, fatigue, ageusia, anosmia and diarrhea .
The current figures of SARS-CoV-2 infection reveal that the virus has already infected nearly 43 millions of people worldwide, causing over 1.156.000 deaths . Although the virus can virtually infect all individuals, with no clear distinction of sex, age and diseased status, the clinical progression seems to be strongly influenced by a number of demographic and clinical factors, which would need to be accurately and timely identified for providing the most accurate care to the patients according to their health condition and disease state . In particular, the information garnered so far seemingly attests that elderly subjects are more vulnerable to COVID-19, and carry a higher risk of developing severe illness, being admitted to the ICU and dying . Males are also more susceptible than females to progress towards severe COVID-19 illness , but the presence of some associated pathologies can substantially amplify the pathogenic potential of SARS-CoV-2 . Notably, a number of studies have described worse clinical outcomes in COVID-19 patients with hypertension and diabetes , , . These two chronic conditions are associated with endothelial injury and dysfunction, and would hence represent important predisposing factors for increased risk of mortality and morbidity. In a meta-analysis conducted by Li et al., 28.8% of COVID-19 patients in ICU had hypertension, while this proportion was only 14.1% in those not needing ICU care . Similarly, Onder et al. reported an extraordinary prevalence of diabetes, as high as 35.5%, in 355 Italian patients who died for COVID-19 .
It has been now definitely established that SARS-CoV-2 enters the host cell by binding to the transmembrane enzyme angiotensin-converting enzyme 2 protein (ACE2), which is widely expressed in a variety of human tissues. In a recent analysis, Li et al. found that ACE2 is strongly expressed in the adipose tissue, at an even higher extent than in cells of lower respiratory tract . The adipose tissue would hence represent a natural reservoir for SARS-CoV-2 , potentially increasing the overall systemic viral load and thereby the risk of unfavorable clinical progression . On the other hand, it is also widely known that obesity, with excessive visceral fat, is associated with chronic inflammatory conditions and magnified release of pro-inflammatory cytokines into the bloodstream, which might then provide an important milieu for development or amplification of the paradigmatic “cytokine storm” observed in COVID-19 patients with severe illness . Obese subjects have also decreased expiratory reserve volume, functional capacity and respiratory compliance, along with reduced diaphragmatic excursion and impaired pulmonary function in supine position, which would all contribute to make pulmonary ventilation very challenging in COVID-19 patients with severe pulmonary involvement .
These important aspects, combined with recent studies demonstrating that ACE2 is over-expressed in adipocytes, persuaded us to carry out a critical review of the current scientific literature on the impact of overweight and/or obesity among hospitalized patients at risk of developing severe or critical forms of COVID-19 .
To perform our systematic review, we carried out an electronic search in Medline (PubMed interface) and Scopus, using the keywords “COVID-19” OR “SARS-CoV-2” OR “coronavirus 2019” AND “obesity” OR “overweight”, up to 7th July 2020, applying a restriction to articles published in English and in accordance with the Preferred Reporting Items for a Systematic Review and Meta-analysis (PRISMA) guidelines . The reference list of all documents was reviewed for identifying additional potentially eligible studies. The title, abstract and full text of the articles identified according to our search criteria were analyzed by two authors, and were considered eligible for inclusion in this literature review if they were case series (sample size >10) or observational studies reporting clear extractable data on body mass index (BMI) in laboratory-confirmed COVID-19 patients, and compared BMI between patients with severe or non-severe disease or between survivors and non-survivors. Reviews, case reports and other editorial material with no original data were excluded (Figure 1). Disagreement arising during the selection assessment were resolved by discussion and consensus. The data extracted included: authors, year of publication, country, type of study, number of patients, number of obese or overweight subjects, age, sex, BMI cut-off for obesity, outcome (death or severe infection), severe infection criteria (ICU admission, need for invasive mechanical ventilation, presence of at least one respiratory distress such as >30 breaths/min, Sat <93%, FIO2 defined as the ratio of partial pressure of oxygen and fraction of inspired oxygen ≤300 mmHg) and correlations between BMI and disease severity (Table 1).
|Study ID||Country||Type of study||Number of patients COVID-19+||Number of obese or overweight patients||Age||Male/total||BMI cut-off for obesity||Severe infection criteria||Outcomes||Correlations between obesity/overweight and disease severity OR||Conclusions|
|Caussy C. et al.
|France||Cohort prospective||340 (in Lyon ICU)||85||Average age ≥65 years||197/340||BMI >30||Admitted in intensive care unit||Severe disease||OR: 2.05 [1.24, 3.41] P-Value 0.006||Significant association between the prevalence of obesity and severe COVID-19|
|Simonnet A. et al.
|France||Single center, retrospective cohort study||124||BMI>30: 59;
|Median age was 60 years||90/124||Overweight: BMI 25–30;
Obesity: BMI >30;
Severe obesity: BMI ≥35
|Requirement for invasive mechanical ventilation (IMV)||Severe disease||OR for IMV in patients with BMI >35 vs. patients with BMI <25 was 7.36 (1.63–33.14; p=0.02)||Disease severity increased with BMI. Obesity is
a risk factor for SARS-CoV-2 severity
|Kalligeros M. et al.
|USA||Retrospective cohort||103||BMI 25–29.9: 35;
BMI 30–34.9: 22;
BMI ≥35: 27
|Median age was 60 years||63/103||Obesity BMI >30; s
Severe obesity BMI ≥35
|Admitted in intensive care unit (ICU);
Requirement for invasive mechanical ventilation (IMV)
|Severe disease||OR ICU admission: 2.80 (0.75–10.48) P-Value 0.126 if BMI 30–34.9 and OR 3.02 (0.85–10.74) P-Value 0.088 if BMI ≥35
IMV: 4.86 (0.88–26.68) P-Value 0.069 if BMI 30–30.49 and 5.84 (1.12–30.55) P-Value 0.036 if BMI≥35
|Severe obesity (BMI ≥35) was associated with ICU admission, while history of heart disease and obesity (BMI ≥30) were independently associated with the use of IMV|
|Gao F. et al.
|China||Retrospective multicenter cohort study||150||Not specified||Averageage was 48 years||94/150||BMI >25||Presence of at least one respiratory distress (>30 breaths/min, Sat <93%, FIO2<300)||Severe disease||Or: 2.91 (95% CI 1.31–6.47)||Obesity increases the risk of severe illness approximately threefold with a consequent longer hospital stay|
|Petrilli CM. et al.
|USA (New York)||Prospective cohort study||5279||BMI 25.0–29.9:
BMI ≥40 311
|Median age was 54 years old||2615/5279||Obese BMI 30–39.9
Super obese BMI ≥40
|Critical illness (intensive care, mechanical ventilation, discharge to hospice care, or death)||Severe disease||OR 0.73 (0.59–0.90) if BMI 30–39.9
OR 0.87 (0.63–1.22) if BMI ≥40
|The strongest risks for critical illness besides age were associated with heart failure (1.9, 1.4 to 2.5), BMI >40 (1.5, 1.0 to 2.2), and male sex (1.5, 1.3 to 1.8)|
|Cai Q. et al.
|China (Shenzen)||Single center, prospective study||383||Overweight 123; Obese 41||18–62||183/383||Overweight BMI 27-27,9
|Presence of (almost one) respiratory distress (>30 breaths/min), Sat <93%, FIO2<300)||Severe disease||BMI adjusted for age:
BMI 24–27.9: 1.78 (1.00–3.21) P-Value 0.05
BMI >28: 3.35 (1.47–7.63) P-Value 0.004
BMI 24–27.9: 1.84 (0.99–3.43) P-Value 0.05.
BMI >28: 3.40 (1.40–8.26) P-Value 0.007
|Obese patients had increased odds of progressing to severe COVID-19|
|Huang R. et al.
|China (Jiangsubprovince)||Multi-center, retrospective study||202||24||Average age 44 years||116/202||BMI >28||Presence of at least one respiratory distress (>30 breaths/min, Sat <93%, FIO2<300)||Severe disease||Univariate: 6.900 (2.381, 19.997) P-Value <0.001;
Multivariate: 9.219 (2.731, 31.126) P-Value <0.001
|The study provides a comprehensive description of the clinical characteristics of laboratory confirmed cases of COVID-19, and the risk factors for severe COVID-19|
|Palaiodimos L. et al.
|USA (Bronx- New York)||Retrospective study||200||BMI 25–34: 116;
|Median 64 years||98/200||Overweight 25–34;
Increasing oxygen requirement during hospital stay;
|Death and severe disease||BMI ≥35 mortality: OR: 3.78; 95% CI: 1.45–9.83; p=0.006; B
Oxygen requirement in BMI ≥ 35
OR: 3.09; 95% CI: 1.43–6.69; p =0.004;
Intubation: in BMI≥35
OR: 3.87; 95% CI: 1.47–10.18; p=0.006
|BMI ≥ 35 were found to have significant associations with mortality, increase oxygen requirement, intubation|
|Klang E. et al.
|USA (New York)||Retrospective color study||572||240||Average age 64 years||352/572||BMI ≥ 30||Death;
Intubation, mechanical ventilation
|Death and severe disease||Mortality: <50 years-BMI >40 OR 5.1, 95% CI 2.3–11.1;
Mortality>50 years -BMI ≥ 40 OR 1.6, 95% CI 1.2–2.3;
Intubation and mechanical ventilation: BMI ≥ 40 both in the young age group (OR 4.1, 95% CI 2.1–8.2)
OR in the older age group (OR 1.5, 95% CI 1.1–2.1)
|For the younger population, BMI above 40 kg/m2 was independently associated with mortality; for older population, BMI ≥ 40, was also independently associated with mortality; secondary outcome, intubation and mechanical ventilation status was independently
Associated with BMI ≥ 40 both in the young age group and in the older age group
|Buckner FS. et al.
|USA (Seattle)||Retrospective study||105||44||Median 69 years||53/105||BMI >30||Admission to an intensive care unit (ICU) or death, shock and acute respiratory distress syndrome (ARDS)||Death and severe disease||Not specified||Correlation between obesity and severe clinical outcomes|
|Urra JR. et al.
|Spain||Retrospective case-control study||172||17||44–79 years old||104/172||BMI >30||Admission to intensive care unit (ICU)||Severe disease||Univariate OR = 4.72 (95% CI 1.614–13.830), p=0.005||Obesity predict a poor prognosis in patients with covid19 disease.|
|Zachriah P. et al.
|USA (New York)||Retrospective study||50||Obese: 11, overweight: 8||<21 years old||27/50||Obese: BMI at or above the 95th percentile for age/sex; Overweight: BMI between 85 and 95th percentile for age/sex||Requirement for mechanical ventilation||Severe disease||Among patients with non severe-disease 20% were obese. Among patients with severe-disease 67% were obese||Obesity was the most significant factor associated with mechanical ventilation in children 2 years and older|
|Bello-Chavolla OY. et al.
|Mexico||Retrospective study||51633||10708||Averageage 46 years||29.803/51633||Not specified||Death, admission to intensive care unit (ICU), intubation||Death and severe disease||Univariable HR: 1.25 (1.17–1.34, p<0.001)||Confirmed covid-19+ cases with obesity had higher rates for ICU admission, need for intubation and mortality.
Obese mediates 49,5 of the effect of diabetes on COVID-19 lethality.
|Cummings MJ. et al.
|USA (New York)||Prospective observational cohort study||257||Obese 119, super obese 33||Average age 62 years||171/257||Obese: BMI>30 Super obese: BMI>40||Frequency and duration of invasive mechanical ventilation, frequency of vasopressor use and renal replacement therapy, time to in-hospital clinical deterioration following admission||Death and severe disease||Univariable HR for BMI>40 0.76 (0.40–1.47)||46% of critically ill patients had obesity. BMI>40 hasn’t identified as an independent risk factor for mortality. Obesity is associated with mortality in hospital|
|Docherty AB. et al.
|UK||Prospective observational cohort study||20133||1671||Average age 73 years||12068/20133||Not specified||Admission to critical care and mortality in hospital||Death and severe disease||Univariable HR:
0.91 (0.82–1.01,p=0.077); Multivariable HR: 1.33 (1.19–1.49,
|Obesity is associated with mortality in hospital in COVID + patients|
|Dreher M. et al.
|Germany||Cohort retrospective study||50||17||Average age 65 years||33/50||BMI ≥ 30||Presence of al least one respiratory distress symtoms (>30 breaths/min, Sat <93%, FIO2<300)||Severe disease||Among patients with ARDS 46% were obese (vs. 23% in patients without ARDS).Prevalence overweight (38 vs. 19%)||Correlation between obesity and severe clinical outcomes|
|Pettit NN. et al.
|USA (Chicago)||Retrospective cohort study||238||146||Average age 58.5 years||113/238||BMI >30||Death;
|Death and severe disease||Mortality OR: 1.7(1.1–2.8), p=0.016 in multivariable analysis.
Hypoxemia OR: 1.7(1.3–2.1),p<0.0005) in multivariable analysis
|Obesity was identified as a predictor for mortality, as was male gender and older age and older were also risk factors for hypoxemia|
|Hu X. et al.
|China||Single-center, retrospective study||55||55||Averageage 49.2 years||36/55||BMI ≥24||Prolonged hospitalization (more than the median value of the hospitalized days in this population)||Severe disease||BMI HR = 0.83, P for trend = 0.001||BMI and ALT were inversely associated with being discharged from hospital in time, respectively|
|Busetto L. et al.
|Italy||Retrospective cohort||92||Obese: 29
|Averageage 70.5 years||57/92||BMI ≥25||Need for assisted ventilation beyond pure oxygen support (Invasive mechanical ventilation or Non-Invasive ventilation)
SEMI + ICUs vs medical ward
|Severe disease||OR NIV + IMV vs. only oxygen: 4.19 (1.36–12.89) p0.012.
OR SEMI + ICUs vs. medical ward: 11.65 (3.88–34.96) p<0.001
|Patients with overweight and obesity required more frequently assisted ventilation and access to intensive or semi‐intensive care units than normal weight patients|
|Zheng KI. et al.
|China||Prospective study||66||45||18–75 years old.||49/66||BMI>25||Presence of at least one respiratory distress (>30 breaths/min, Sat <93%, FIO2<300)||Severe disease||OR unadjusted: 5.77 (1.19–27.91) P-Value 0.029.
OR adjousted for age and sex: 6.25 (1.23–31.71) P-Value 0.027
OR adjousted for age, sex, smoking, type 2 DM, hypertension, dyslidemia: 6.32 (1.16–34.54) P-Value 0.033
|Compared to those with non-severe COVID-19, patients with severe disease were more obese|
|Goyal P. et al.||USA (New York)||Multi-center, retrospective study||393||136||Median 62.2 years||238/393||BMI >30||Mechanical ventilation||Severe disease||Not specified||43.4% of patients who received invasive mechanical ventilation were obese|
|Lighter J. et al.
|USA (New York)||Retrospective study||3615||BMI 30–34: 96;
|<60 years old
≥60 years old
|Not specified||Obese BMI 30–34; super obese BMI ≥35||ICU admission.||Severe disease||Age ≥60 years: OR 1.1 (95% CI 0.8–1.7) P-Value 0.57 with BMI 30–34
OR 1.5 (95% CI 0.9–2.3) P-Value 0.10 with BMI ≥35.Age <60 years: OR 1.8 (95% CI 1.2–2.7) P-Value 0.006 with BMI 30-34
OR 3.6 (95% CI 2.5–5.3) P-Value <0.0001 with BMI ≥35
|In patients aged <60 years old, obesity appears to be arisk factor for hospital admission and need for critical care|
A total of 22 studies , , , , , , , , , , , , , , , , , , , , ,  were finally selected out of over 300 scientific articles preliminarily identified according to our search criteria (Table 1). The cohorts of patients in these studies were extremely heterogeneous for ethnicity, age, comorbidities, degree of overweight/obesity and clinical outcome, so that performance of a meta-analysis was unfeasible. We decided to not compare all the studies as they were performed with different statistical methods which made impossible combine them and proceed with a statistically relevant analysis. Therefore, we limited our specific analysis to the 14 studies which evaluated the association between obesity and COVID-19 severity and reported a clear risk estimate (i.e., the odds ratio; OR). 11 of such investigations , , , , , , , , , , , , ,  reported an OR value >2 (totaling 2058 total patients, 852 obese), two other studies reported an OR value <1 and the remaining investigation reported an intermediate value (Figure 2).
The death rate as endpoint was evaluated in a limited number of studies. Pettit et al.  reported that obesity (defined as BMI>30 kg/m2) was a significant predictor of death, with an OR of 1.7 (95% CI, 1.1–2.8). These findings were confirmed by Docherty et al. , who prospectively followed-up 20133 patients with COVID-19, and reported 33% increased risk of death in those with unspecified obesity (hazard ratio, 1.33; 95% CI, 1.19–1.49). In the analysis of Klang et al. , BMI >40 kg/m2 was found to be independently associated with mortality, especially in the population aged <50 years (OR, 5.1; 95% CI, 2.3–11.1), whereas this association was found to be less pronounced in older subjects (aged 50 years or older; OR, 1.6; 1.2–2.3). Finally, Palaiodimos et al.  studied 200 COVID-19 patients and also found that a BMI>35 kg/m2 was significantly associated with the risk of death (OR 3.78; 95% CI, 1.15–9.83).
The aim of this article was to review the current scientific literature to identify clinical studies exploring the potential relationship between overweight/obesity and unfavorable COVID-19 progression. Although a broad heterogeneity was found in the investigations in terms of study design (some were prospective, others retrospective), sample size, ethnical origin, definition of overweigh/obesity, presence of co-morbidities and clinical endpoints (Table 1), a significant association between overweight and disease severity can be clearly seen. This would hence represent an important aspect that shall be considered when planning the most suitable preventive and therapeutic measures for managing patients with COVID-19, since overweight/obese patients may be especially vulnerable to the adverse consequences of SARS-CoV-2 infection.
Notably, ACE2 expression is higher in adipose tissue than in lower respiratory tract, and adipocytes shall hence be considered a major target of SARS-CoV-2 infection, as well as potential viral reservoirs , . Obesity is also frequently accompanied by increased circulating levels of pro-inflammatory biomarkers such as interleukin 6 (IL-6) and C-reactive protein (CRP), thus underpinning the potential pro-inflammatory role of adipose tissue, characterized by enhanced expression of cytokines, which could ultimately contribute to induce lymphocytes apoptosis . Interestingly, thrombotic episodes, either localized or disseminated, frequently complicate severe SARS-CoV-2 infections, even in patients undergoing systemic anticoagulation therapy , . Since obesity has been consistently associated with an increased risk of developing venous thromboembolism , the prothrombotic potential of obesity shall be considered another reasonable mechanism to explain unfavorable progression of COVID-19. Finally, obesity is associated with a globally impaired pulmonary function, which may ultimately render overweight or frankly obese COVID-19 patients less responsive to mechanical ventilation used for managing respiratory distress , .
In conclusion, the results of this critical literature review would contribute to confirm that overweight and/or obesity seem to have a substantial impact on the risk of developing severe/critical SARS-COV-2 infections, so that overweight/obese COVID-19 patients shall be targeted with more aggressive preventive or therapeutic measures to prevent unfavorable outcomes. Further studies shall also be planned to investigate the interplay between low BMI and the pathogenesis of COVID-19.
Research funding: None declared.
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
Competing interests: Authors state no conflict of interest.
1. Lippi, G, Sanchis-Gomar, F, Henry, BM. Coronavirus disease 2019 (COVID-19): the portrait of a perfect storm. Ann Transl Med 2020;8:497. https://doi.org/10.21037/atm.2020.03.157. Search in Google Scholar
2. Zhong, NS, Zheng, BJ, Li, YM, Poon, LLM, Xie, ZH, Chan, KH, et al. Epidemiology and cause of severe acute respiratory syndrome (SARS) in Guangdong, People’s Republic of China. Lancet 20032003;362:1353–8. https://doi.org/10.1016/s0140-6736(03)14630-2. Search in Google Scholar
3. Zaki, AM, Van Boheemen, S, Bestebroer, TM, Osterhaus, ADME, Fouchier, RAM. Isolation of a novel coronavirus from a man with pneumonia in Saudi Arabia. N Engl J Med 2012;367:1814–20. https://doi.org/10.1056/nejmoa1211721. Search in Google Scholar
5. Lippi, G, Sanchis-Gomar, F, Henry, BM. COVID-19: unravelling the clinical progression of nature’s virtually perfect biological weapon. Ann Transl Med 2020;8:693. https://doi.org/10.21037/atm-20-3989. Search in Google Scholar
6. Wang, D, Hu, B, Hu, C, Zhu, F, Liu, X, Zhang, J, et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China. J Am Med Assoc 2020;323:1061–9. https://doi.org/10.1001/jama.2020.1585. Search in Google Scholar
7. Center for Systems Science and Engineering (CSSE) at Johns Hopkins University (JHU). COVID 19 Dashboard. Data Available from: https://coronavirus.jhu.edu/map.html [Accessed 26 October 2020]. Search in Google Scholar
9. Grasselli, G, Zangrillo, A, Zanella, A, Antonelli, M, Cabrini, L, Castelli, A, et al. Baseline characteristics and outcomes of 1591 patients infected with SARS-CoV-2 admitted to ICUs of the Lombardy region, Italy. J Am Med Assoc 2020;323:1574–81. https://doi.org/10.1001/jama.2020.5394. Search in Google Scholar
10. Guzik, TJ, Mohiddin, SA, Dimarco, A, Patel, V, Savvatis, K, Marelli-Berg, FM, et al. COVID-19 and the cardiovascular system: implications for risk assessment, diagnosis, and treatment options. Cardiovasc Res 2020;116:1666–87. https://doi.org/10.1093/cvr/cvaa106. Search in Google Scholar
11. Guan, WJ, Ni, ZY, Hu, Y, Liang, WH, Ou, CQ, He, JX, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med 2020;382:1708–20. https://doi.org/10.1056/nejmoa2002032. Search in Google Scholar
12. Guo, T, Fan, Y, Chen, M, Wu, X, Zhang, L, He, T, et al. Cardiovascular implications of fatal outcomes of patients with coronavirus disease 2019 (COVID-19). JAMA Cardiol 2020;5:811–8. https://doi.org/10.1001/jamacardio.2020.1017. Search in Google Scholar
13. Palaiodimos, L, Chamorro-Pareja, N, Karamanis, D, Li, W, Zavras, PD, Mathias, P, et al.. Diabetes is associated with increased risk for in-hospital mortality in patients with COVID-19: a systematic review and meta-analysis comprising 18,506 patients. medRxiv 2020. https://doi.org/10.1101/2020.05.26.20113811. Search in Google Scholar
14. Li, B, Yang, J, Zhao, F, Zhi, L, Wang, X, Liu, L, et al. Prevalence and impact of cardiovascular metabolic diseases on COVID-19 in China. Clin Res Cardiol 2020;109:531–8. https://doi.org/10.1007/s00392-020-01626-9. Search in Google Scholar
15. Onder, G, Rezza, G, Brusaferro, S. Case-fatality rate and characteristics of patients dying in relation to COVID-19 in Italy. J Am Med Assoc 2020;323:1775–6. https://doi.org/10.1001/jama.2020.4683. Search in Google Scholar
16. Li, MY, Li, L, Zhang, Y, Wang, XS. Expression of the SARS-CoV-2 cell receptor gene ACE2 in a wide variety of human tissues. Infect Dis Poverty 2020;9:45. https://doi.org/10.1186/s40249-020-00662-x. Search in Google Scholar
17. Sanchis-Gomar, F, Lavie, CJ, Mehra, MR, Henry, BM, Lippi, G. Obesity and outcomes in COVID-19: when an epidemic and pandemic collide. Mayo Clin Proc 2020;95:1445–53. https://doi.org/10.1016/j.mayocp.2020.05.006. Search in Google Scholar
18. Xu, D, Zhou, F, Sun, W, Chen, L, Lan, L, Li, H, et al.. Relationship between serum SARS-CoV-2 nucleic acid(RNAemia) and organ damage in COVID-19 patients: a cohort study. Clin Infect Dis 2020. https://doi.org/10.1093/cid/ciaa1085. [Epub ahead of print]. Search in Google Scholar
21. Urra, JM, Cabrera, CM, Porras, L, Ròdenas, I. Selective CD8 Cell Reduction by SARS-CoV-2 is Associated with a worse prognosis and systemic inflammation in COVID-19 patients. Clin Immunol 2020;217:108486. https://doi.org/10.1016/j.clim.2020.108486. Search in Google Scholar
22. Moher, D, Liberati, A, Tetzlaff, J, Altman, DG. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. J Clin Epidemiol 2009;62:1006–12. https://doi.org/10.1016/j.jclinepi.2009.06.005. Search in Google Scholar
23. Caussy, C, Pattou, F, Wallet, F, Simon, C, Chalopin, S, Telliam, C, et al. Prevalence of obesity among adult inpatients with COVID-19 in France. Lancet Diabetes Endocrinol 2020;8:562–4. https://doi.org/10.1016/s2213-8587(20)30160-1. Search in Google Scholar
24. Simonnet, A, Chetboun, M, Poissy, J, Raverdy, V, Noulette, J, Duhamel, A, et al. High prevalence of obesity in severe acute respiratory syndrome coronavirus-2 (SARS-CoV- 2) requiring invasive mechanical ventilation. Obesity 2020;28:1195–9. https://doi.org/10.1002/oby.22831. Search in Google Scholar
25. Kalligeros, M, Shehadeh, F, Mylona, EK, Benitez, G, Beckwith, CG, Chan, PA, et al. Association of obesity with disease severity among patients with Coronavirus disease 2019. Obesity 2020;28:1200–4. https://doi.org/10.1002/oby.22859. Search in Google Scholar
26. Gao, F, Zheng, KI, Wang, X-B, Sun, Q-F, Pan, K-H, Wang, T-Y, et al. Obesity is a risk factor for greater COVID-19 severity. Diabetes Care 2020;43:e72–4. https://doi.org/10.2337/dc20-0682. Search in Google Scholar
27. Petrilli, CM, Jones, SA, Yang, J, Rajagopalan, H, O’Donnell, L, Chernyak, Y, et al. Factors associated with hospital admission and critical illness among 5279 people with coronavirus disease 2019 in New York City: prospective cohort study. BMJ 2020;369:m1966. https://doi.org/10.1136/bmj.m1966. Search in Google Scholar
28. Cai, Q, Chen, F, Wang, T, Luo, F, Liu, X, Wu, Q, et al. Obesity and COVID-19 severity in a designated hospital in Shenzen, China. Diabetes Care 2020;43:1392–8. https://doi.org/10.2337/dc20-0576. Search in Google Scholar
29. Huang, R, Zhu, L, Xue, L, Liu, L, Yan, X, Wang, J, et al. Clinical findings of patients with coronavirus disease 2019 in Jiangsub province, China. A retrospective, multi-center study. PLoS Neglected Trop Dis 2020;14:e0008280. https://doi.org/10.1371/journal.pntd.0008280. Search in Google Scholar
30. Palaiodimos, L, Kokkinidis, DG, Li, W, Karamanis, D, Ognibene, J, Arora, S, et al. Severe obesity, increasing age and male sex are independently associated with higher in-hospital mortality in a cohort of patients with COVID-19 in the Bronx, New York. Metabolism 2020;108:154262. https://doi.org/10.1016/j.metabol.2020.154262. Search in Google Scholar
31. Klang, E, Kassim, G, Soffer, S, Freeman, R, Levin, MA, Reich, DL. Severe obesity as an independent risk factor for COVID-19 mortality in hospitalized patients younger than 50. Obesity 2020;28:1595–9. https://doi.org/10.1002/oby.22913. Search in Google Scholar
32. Buckner, FS, McCulloch, DS, Atluri, V, Blain, M, McGuffin, SA, Nalla, AK, et al.. Clinical features and outcomes of 105 hospitalized patients with COVID-19 in Seattle, Washington. Clin Infect Dis 2020. https://doi.org/10.1093/cid/ciaa632. [Epub ahead of print]. Search in Google Scholar
33. Zachriah, P, Johnson, CL, Halabi, KC, Ahn, D, Sen, AI, Fischer, A, et al.. Epidemiology, clinical features, and disease severity in patients with Coronavirus disease 2019 (Covid-19) in a children’s hospital in New York City. JAMA Pediatr 2020. https://doi.org/10.1001/jamapediatrics.2020.2430. [Epub ahead of print]. Search in Google Scholar
34. Bello-Chavolla, OY, Bahena-López, JP, Antonio-Villa, NE, Vargas-Vázquez, A, González-Diaz, A, Márquez-Salinas, A, et al. Predicting mortality due to SARS-Cov-2: a mechanistic score relation obesity and diabetes to COVID-19 outcomes in Mexico. J Clin Endocrinol Metab 2020;105:dgaa346. https://doi.org/10.1210/clinem/dgaa346. Search in Google Scholar
35. Cummings, MJ, Baldwin, MR, Abrams, D, Jacobson, SD, Meyer, BJ, Balough, EM, et al. Epidemiology, clinical course, and outcomes of critically ill adults with COVID-19 in New York City: a prospective cohort study. Lancet 2020;395:1763–70. https://doi.org/10.1016/s0140-6736(20)31189-2. Search in Google Scholar
36. Docherty, AB, Harrison, EM, Green, CA, Hardwick, HE, Pius, R, Norman, L, et al. Features of 20133 UK patients in hospital with covid-19 using the ISARIC WHO clinical characterisation protocol: a prospective observational cohort study. BMJ 2020;369:m1985. https://doi.org/10.1136/bmj.m1985. Search in Google Scholar
37. Dreher, M, Kersten, A, Bickenbach, J, Balfanz, P, Hartmann, B, Cornelissen, C, et al. The characteristics of 50 hospitalized COVID-19 patients with and without ARDS. Dtsch Ärztebl Int 2020;117:271–8. https://doi.org/10.3238/arztebl.2020.0271. Search in Google Scholar
38. Pettit, NN, MacKenzie, EL, Ridgway, JP, Pursell, K, Ash, D, Patel, B, et al.. Obesity is associated with increased risk for mortality among hospitalized patients with COVID-19. Obesity 2020. https://doi.org/10.1002/oby.22941. [Epub ahead of print]. Search in Google Scholar
39. Hu, X, Pan, X, Zhou, W, Gu, X, Shen, F, Yang, B, et al. Clinical epidemiological analyses of overweight/obesity and abnormal liver function contributing to prolonged hospitalization in patients infected with COVID-19. Int J Obes 2020;44:1784–9. https://doi.org/10.1038/s41366-020-0634-3. Search in Google Scholar
40. Busetto, L, Bettini, S, Fabris, R, Serra, R, Dal Pra, C, Maffei, P, et al. Obesity and COVID-19: an Italian snapshot. Obesity 2020;28:1600–5. https://doi.org/10.1002/oby.22918. Search in Google Scholar
41. Zheng, KI, Gao, F, Wang, X-B, Sun, Q-F, Pan, K-H, Wang, T-Y, et al. Letter to the editor: obesity as a risk factor for greater severity of COVID-19 in patients with metabolic associated fatty liver disease. Metabolism 2020;108:154244. https://doi.org/10.1016/j.metabol.2020.154244. Search in Google Scholar
42. Goyal, P, Choi, JJ, Pinheiro, LC, Schenck, EJ, Chen, R, Jabri, A, et al. Clinical characteristics of covid-19 in New York city. N Engl J Med 2020;382:2372–4. https://doi.org/10.1056/nejmc2010419. Search in Google Scholar
43. Lighter, J, Philips, M, Hochman, S, Sterling, S, Johnson, D, Francois, F, et al. Obesity in patients younger than 60 years is a risk factor for Covid-19 hospital admission. Clin Infect Dis 2020;71:896–7. https://doi.org/10.1093/cid/ciaa415. Search in Google Scholar
45. Kruglikov, IL, Scherer, PE. The role of adipocytes and adipocyte like cells in the severity of COVID-19 infections. Obesity 2020;28:1187–90. https://doi.org/10.1002/oby.22856. Search in Google Scholar
46. Klok, FA, Kruip, MJHA, van der Meer, NJM, Arbous, MS, Gommers, DAMPJ, Kant, KM, et al. Incidence of thrombotic complications in critically ill ICU patients with COVID-19. Thromb Res 2020;191:145–7. https://doi.org/10.1016/j.thromres.2020.04.013. Search in Google Scholar
47. Kyriakoulis, KG, Kokkinidis, DG, Kyprianou, IA, Papanastasiou, CA, Archontakis-Barakakis, P, Doundoulakis, I, et al.. Venous thromboembolism in the era of COVID-19. Phlebology 2020 Sep 10. https://doi.org/10.1177/0268355520955083. [Epub ahead of print]. Search in Google Scholar
49. Pelosi, P, Croci, M, Ravagnan, I, Tredici, S, Pedoto, A, Lissoni, A, et al. The effects of body mass on lung volumes, respiratory mechanics, and gas exchange during general anesthesia. Anesth Analg 1998;87:654–60. https://doi.org/10.1213/00000539-199809000-00031. Search in Google Scholar
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