Body-mass index COVID-19 severity: A systematic review of systematic reviews

OBJECTIVES: Conflicting studies have resulted in several systematic reviews and meta-analyses on the relationship between COVID-19 and body mass index (BMI). METHODS: This systematic review of systematic reviews followed an umbrella review design, and preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines; Medical literature analysis and retrieval system online (MEDLINE) and SCOPUS databases were searched for systematic reviews on the topic. A predefined screening and selection procedure was done for the retrieved results based on the population, intervention/interest, comparator, outcome, study (PICOS) framework. RESULTS: The search strategy yielded 6334 citations. With the predefined selection and screening process, 23 systematic reviews were retrieved for inclusion in the present study. Twenty-three (n = 23) systematic reviews met the inclusion criteria. As expected, there was overlap across the reviews in the included primary studies. Available evidence suggests that Class III obesity (morbid obesity) is strongly associated with increased mortality risk in patients with Covid-19. It is difficult to draw a firm conclusion about Class I and Class II obesity due to conflicting outcomes of metanalyses. Increased obesity was consistently associated with increased risk of invasive mechanical ventilation (IMV) in all the reviews with low to moderate heterogeneity. CONCLUSIONS: Available evidence suggests that Class III obesity (morbid obesity) is strongly associated with increased mortality risk in patients with Covid-19. Increased BMI is positively associated with the risk of IMV and the severity of COVID- care.