Table 1.
Studies supporting the theory of “obesity-paradox”.
| No. | Authors | Study design No. of Participants Country |
Diagnosis of COVID-19 | Measure of Obesity | Outcomes | Results/Conclusions |
|---|---|---|---|---|---|---|
| 1. | Cummings et al. [31] | Prospective observational cohort study (n = 257) in New York-USA | RT-PCR | Obesity (BMI > 30 kg/m2) Severe obesity (BMI > 40 kg/m2) |
Mortality-in hospital | The results of the study did not identify morbid obesity with a BMI ≥ 40 as an independent risk factor for mortality in COVID-19 disease. |
| 2. | Busetto et al. [32] | Retrospective cohort study (n = 92) in Italy | RT-PCR | Normal weight (<25 kg/m2) Overweight (from 25 to <30 kg/m2) Obesity (≥30 kg/m2) |
ICU admission IMV |
A protective effect of obesity (obesity paradox) or other factors not related to BMI can explain the lack of worsening of the severity of the disease. |
| 3. | Goyal et al. [33] | Retrospective cohort study (n = 1687) in New York- USA | RT-PCR | Underweight (<18.5 kg/m2) Normal (18.5 to 24.9 kg/m2) Overweight (25.0 to 29.9 kg/m2) Mild to moderate obesity (30.0 to 39.9 kg/m2) Morbid obesity (≥40.0 kg/m2) |
In-hospital mortality | The study concluded that obesity was not an independent risk factor for in-hospital mortality, providing insights regarding a plausible obesity paradox in COVID-19. |
| 4. | Biscarini et al. [34] | Retrospective cohort study (n = 427) in Italy | RT-PCR | Obesity (BMI ≥ 30 kg/m2) | ICU admission Mortality in ICU Mortality |
The obesity does not interfere with survival rate or hospitalization length. |
| 5. | Dana et al. [35] | Prospective study (n = 226) in France | RT-PCR | Underweight (<18.5 kg/m2) Normal (18.5 to 24.9 kg/m2) Overweight (25.0 to 29.9 kg/m2) Mild to moderate obesity (30.0 to 39.9 kg/m2) Morbid obesity (≥40.0 kg/m2) |
In-hospital mortality | Interestingly, the mortality rate was lower in those with moderate obesity and overweight compared to those with normal weight and severe obesity, challenging the paradox of obesity. |
| 6. | Kaeuffer et al. [32] | Prospective study (n = 1045) in France | RT-PCR | Normal weight (<25 kg/m2) Overweight (from 25 to <30 kg/m2) Obesity (≥30 kg/m2) |
In-hospital morality | It has been demonstrated that the factors associated with an increased risk of death were the age, male sex, and immunosuppression and not the obesity. |
| 7. | Kim et al. [36] | Retrospective study (n = 10,861) in New York USA | RT-PCR | Underweight (<18.5 kg/m2) normal weight (18.5 to 24.9 kg/m2) Overweight (25.0 to 29.9 kg/m2) Class I (30.0 to 34.9 kg/m2) Class II (35 to 39.9 kg/m2) Class III (≥40.0 kg/m2) |
IMV In-hospital morality |
Once intubated there are no statistical differences in death rate between obese patients and normal weight individuals. |
| 8. | Yoshida et al. [37] | Retrospective study (n = 776) in New Orleans-USA | RT-PCR | Morbid obesity (BMI ≥ 40 kg/m2) | ICU admission IMV Mortality |
No association between obesity and death was found in the non-Black group of patients. |
| 9. | Kim et al. [38] | Multi-site, geographically retrospective study (n = 2491) in USA | RT-PCR | Obesity BMI ≥ 30 kg/m2 Severe obesity BMI ≥ 40 kg/m2 |
ICU admission In-hospital morality |
Despite the higher prevalent of obesity in the study, there was found only an increased risk for ICU admission, but not for death. |
| 10. | Mankowski et al. [39] | Retrospective study (n = 309) in New Orleans-USA | RT-PCR | Obesity (BMI ≥ 30 kg/m2) | IMV In-Hospital Mortality |
Even though obese patients required more invasive mechanical ventilation, there was no difference in risk of in-hospital mortality. |