Plain language summary
A novel coronavirus named SARS-CoV-2, causing COVID-19, emerged in late 2019. The prognosis of COVID-19 has been consistently reported to worsen with older age, male sex and comorbidities. The aim of this study was to quantify the association between overweight or obesity and COVID-19-related hospitalisations and death, and to assess the magnitude of the association and the potential dose–response relationships. This study is a systematic review and meta-analysis of 208 studies. A total of 3 550 977 participants from over 32 countries were included in this study. Results indicate that being overweight increases the risk of COVID-19-related hospitalisations but not death while obesity and extreme obesity increase the risk of both COVID-19-related hospitalisations and death. In addition, there was a linear dose–response association between obesity categories and COVID-19 outcomes. However, the strength of the association has weakened over time following the pattern of the first wave of COVID-19. Authors conclude that their findings suggest the importance of increased vigilance towards people with excess adiposity. Some preventative measures for this vulnerable group include prompt access to COVID-19 testing and healthcare, as well as prioritisation for COVID-19 vaccination.
Objective: To quantify the current weight of evidence of the association between overweight and obesity as risk factors for COVID-19-related hospitalisations (including hospital admission, intensive care unit admission, invasive mechanical ventilation) and death, and to assess the magnitude of the association and the potential dose-response relationships. Design: PubMed, Embase, Cochrane, Web of Sciences, WHO COVID-19 database and Google Scholar were used to identify articles published up to 20 July 2021. Peer-reviewed studies reporting adjusted estimates of the association between overweight or obesity and COVID-19 outcomes were included. Three authors reviewed the articles and agreed. The quality of eligible studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. Random-effects meta-analysis was used to estimate the combined effects. Results: A total of 208 studies with 3 550 997 participants from over 32 countries were included in this meta-analysis. Being overweight was associated with an increased risk of COVID-19-related hospitalisations (OR 1.19, 95% CI 1.12 to 1.28, n=21 studies), but not death (OR 1.02, 95% CI 0.92 to 1.13, n=21). However, patients with obesity were at increased risk of both COVID-19-related hospitalisations (OR 1.72, 95% CI 1.62 to 1.84, n=58) and death (OR 1.25, 95% CI 1.19 to 1.32, n=77). Similarly, patients with extreme obesity were at increased risk of COVID-19-related hospitalisations (OR 2.53, 95% CI 1.67 to 3.84, n=12) and death (OR 2.06, 95% CI 1.76 to 3.00, n=19). There was a linear dose-response relationship between these obesity categories and COVID-19 outcomes, but the strength of the association has decreased over time. Conclusion: Being overweight increases the risk of COVID-19-related hospitalisations but not death, while obesity and extreme obesity increase the risk of both COVID-19-related hospitalisations and death. These findings suggest that prompt access to COVID-19 care, prioritisation for COVID-19 vaccination and other preventive measures are warranted for this vulnerable group.