The association between BMI and metabolically unhealthy status with COVID-19 mortality: Based on 3019 inpatients from Wuhan, China

BACKGROUND AND AIMS: Patients with multiple metabolic diseases are at high risk for the occurrence and death of COVID-19. Little is known about patients with underweight and metabolically healthy obesity. The aim of this study is to evaluate the impact of BMI and COVID-19 mortality in hospitalized patients, and also explore the association in different metabolically healthy (MHS) and unhealthy status (MUS). METHODS AND RESULTS: A retrospective cohort study based on 3019 inpatients from Wuhan was conducted. Included patients were classified into four groups according the BMI level (underweight, normal weight, overweight and obesity), and patients with at least one of the metabolic abnormalities (diabetes, hypertension, dyslipidemia) was defined as MUS. Multiple Cox model was used to calculate the hazard ratio (HR). Compared to patients with normal weight, the HRs of overweight and obesity for COVID-19 mortality were 1.91 (95%CI:1.02–3.58) and 2.54 (95%CI:1.22–5.25) respectively in total patients, and 2.58 (95%CI:1.16–5.75) and 3.89 (95%CI:1.62–9.32) respectively in the elderly. The HR of underweight for COVID-19 mortality was 4.58 (95%CI:1.56–13.48) in the elderly. For different metabolic statuses, both underweight, overweight and obesity had obviously negative association with COVID-19 mortality in total and elderly patients with MUS. However, no significance was found in non-elderly and patients with MHS. CONCLUSION: Not only overweight or obesity, but also underweight can be associated with COVID-9 mortality, especially in the elderly and in patients with MUS. More large-scale studies are needed for patients with underweight and metabolically healthy overweight or obesity.