Table 1.
Clinical Studies Investigating the Association Between Obesity and Disease Severity in COVID-19 Patients.
| Reference | Study Design | Predictor | Outcome | Effect |
|---|---|---|---|---|
| Anderson et al., 2020 [29] | Retrospective cohort study (n = 2466) |
BMI categories: underweight (BMI < 18.5), normal weight (BMI ≥ 18.5 to <25), overweight (BMI ≥ 25 to <30), class 1 obesity (BMI ≥ 30 to <35), class 2 obesity (BMI ≥ 35 to <40), and class 3 obesity (≥ 40) | Intubation death |
Patients younger than 65 with obesity were at higher risk for intubation or death, with the highest risk among those with class 3 obesity (BMI ≥ 40). |
| Battisti et al., 2020 [43] | Cohort study (n = 441) |
VAT/SAT ratio | ICU admission | VAT/SAT was associated with increased risk of ICU admission. |
| Chandarana et al., 2020 [42] |
Retrospective study (n = 51) | VAT, SAT, TAT, VAT/TAT and BMI | Hospi- talization |
Higher VAT and VAT/TAT in hospitalized patients. |
| Deng et al., 2020 [30] |
Retrospective cohort study (n = 65) |
BMI, subcutaneous fat thickness, epicardial fat and visceral fat | Disease severity | High BMI was a risk factor for severe COVID-19. |
| Frank et al., 2020 [25] | Retrospective cohort study (n = 305) |
BMI categories: BMI < 25, BMI ≥ 25 to < 30, BMI ≥ 30 to < 35, and BMI ≥ 35 |
Intubation, death |
BMI ≥ 30 was associated with an increased risk of intubation or death. |
| Hernàndez- Galdamez et al., 2020 [38] |
Cross-sectional study (n = 212,802) | Obesity (not specified) | Hospi- talization ICU admission Intubation death |
Obesity was associated with an increased risk of hospitalization, ICU admission, intubation and death. |
| Kalligeros et al., 2020 [31] | Retrospective cohort study (n = 103) |
BMI categories: BMI < 25, BMI ≥ 25 to <30, BMI ≥ 30 to <35, BMI ≥ 35 |
ICU admission, IMV |
Severe obesity (BMI ≥ 35) was positively associated with ICU admission. Obesity (BMI ≥ 30 to <35) and severe obesity (BMI ≥ 35) were positively associated with the use of IMV. |
| Kim et al., 2020 [26] | Retrospective cohort study (n = 10,861) |
BMI categories: underweight (BMI < 18.5), normal weight (BMI ≥ 18.5 to <25), overweight (BMI ≥ 25 to < 30), obesity class Ⅰ (BMI ≥ 30 to < 35), obesity class Ⅱ (BMI ≥ 35 to <40), and obesity class Ⅲ (BMI ≥ 40) |
IMV, death |
Categories: overweight, obesity class Ⅰ, Ⅱ and Ⅲ were associated with increased risk of requiring IMV. Underweight and obesity classes Ⅱ and Ⅲ were associated with increased risk of death. |
| Mash et al., 2021 [32] | Descriptive observational cross-sectional study (n = 1376) |
BMI categories: normal (BMI ≥ 18.5 to <25), overweight/obese (BMI ≥ 25) |
Death | Overweight/obesity (BMI ≥ 25) was significantly linked with mortality. |
| Nakeshbandi et al., 2020 [24] |
Retrospective cohort study (n = 504) |
BMI categories: normal (BMI ≥ 18.5 to <25), overweight (BMI ≥ 25 to <30), and obese (BMI ≥ 30) |
Mortality, intubation |
Patients with overweight and obesity were at increased risk for mortality and intubation. |
| Palaiodimos et al., 2020 [27] |
Retrospective cohort study (n = 200) |
BMI categories: BMI < 25, BMI ≥ 25 to <35, BMI ≥ 35 |
In-hospital mortality, Worse in-hospital outcomes |
Severe obesity (BMI ≥ 35) was associated with higher in-hospital mortality and worse in-hospital outcomes. |
| Parra- Bracamonte et al., 2020 [39] |
Cross-sectional study (n = 331,298) |
Obesity (not specified) | Death | Obesity was associated with higher risk of mortality. |
| Pediconi et al., 2020 [44] | Retrospective cohort study (n = 62) |
VAT score (overweight: VAT area 100–129 cm2 or VAT score 1. Obesity: VAT area ≥ 130 cm2 or VAT score 2) | ICU admission | VAT score was the best ICU admission predictor. |
| Peña et al., 2020 [40] | Cross-sectional study (n = 323,671) |
Obesity (not specified) | Death | Obesity was a major risk factor for mortality. |
| Randhawa et al., 2021 [33] | Retrospective cohort study (n = 302) |
BMI categories: normal weight (BMI < 30), obesity BMI ≥ 30) | Compli- cations |
Patients with obesity were more likely to suffer severe complications. |
| Rao et al., 2020 [28] | Retrospective cohort study (n = 240) |
BMI (overweight, BMI > 28) | In-hospital death, Disease severity |
Being overweight was related to COVID-19 severity but not to in-hospital death. |
| Salinas Aguirre et al., 2021 [41] | Cross-sectional study (n = 17,479) |
Obesity (not specified) | Death | Obesity was associated with mortality. |
| Simonnet et al., 2020 [34] | Retrospective cohort study (n = 124) |
BMI categories: lean (BMI ≥ 18.5 to <25), overweight (BMI ≥ 25 to < 30), moderate obesity (BMI ≥ 30 to < 35) and severe obesity (BMI ≥ 35) | Need for IMV | Need for IMV was associated with BMI. |
| Suleyman et al., 2020 [35] | Case series (n = 463) |
BMI categories: severe obesity (BMI ≥ 40) | ICU admission | Severe obesity was independently associated with ICU admission. |
| van Zelst et al., 2020 [37] |
Prospective observational cohort study (n = 166) |
BMI Abdominal adiposity (waist-to-hip-ratio) |
Unfavorable outcome | Abdominal adiposity and BMI were associated with an increased risk for unfavorable outcome (respiratory support of 3 L/min, intubation, ICU admission). |
| Watanabe et al., 2020 [45] | Retrospective cohort study (n = 150) | TAT VAT |
ICU admission | TAT and VAT had a univariate association with ICU admission. |
| Zhu et al., 2020 [36] | Retrospective cohort study (n = 489,769) |
BMI, categories: normal weight (BMI ≥ 18.5 to <25), overweight (BMI ≥ 25.0 to <30), and obese (BMI ≥ 30); waist circumference and waist-to-hip ratio |
Hospi- talization with ‘severe COVID-19′ |
BMI, waist circumference and waist-to-hip ratio were positively associated with the risk of severe COVID-19. |
Abbreviations: VAT = visceral adipose tissue; SAT = subcutaneous adipose tissue; TAT = total adipose tissue; BMI = body mass index (kg/m2); IMV = invasive mechanical ventilation; ICU = intensive care unit.