The obesity paradox: Analysis from the SMAtteo COvid-19 REgistry (SMACORE) cohort

Abstract

Summary Background and aims Obesity has been suggested as a possible risk factor for a more severe course of COVID-19; however, conclusive evidence is lacking and few studies have investigated the role of BMI as a risk factor for admission to intensive care unit (ICU) and mortality. We retrospectively analysed a COVID-19 cohort recruited during the first 40 days of the epidemic in Italy. We examined the association between obesity and 30-day mortality, admission to ICU, mortality and length of hospital stay in patients with COVID-19. Methods and results Demographic, clinical and outcome data were retrospectively analyzed in 331 patients with COVID-19 admitted to hospital between 21 February and 31 March 2020. The predictive effect of obesity on mortality was assessed using a Cox proportional-hazard regression model, its effect on ICU admission and mortality in the ICU using logistic regressions, and its effect on length of hospital stay using a linear regression. Seventy-four of 331 patients had a BMI ≥30 kg/m 2 . Among obese patients, 21 (28.4%) required admission in ICU and 25 died (33.8%). After controlling for sex, age, comorbidities and clinical data, obesity was not significantly associated with mortality, mortality in ICU and length of hospital stay. The effect of obesity on ICU admission remained significant after controlling for sex, age, interstitial lung disease, heart disease and serum C-reactive protein. Conclusions Obese patients with COVID-19 were more likely to be admitted to ICU than non-obese patients. However, there were no significant differences in mortality between the two groups.

Comparing COVID-19 and influenza presentation and trajectory

“…However, due to the high proportion of missing data on BMI among the patients that died and the relatively small sample size, the observed differences warrant further investigations. This obesity paradox has been reported elsewhere (40) and seems to be common between ILIs (41). Several hypothesis have been proposed to explain why obese patients are more affected by COVID-19 without an increased mortality (42).…”

Does there exist an obesity paradox in COVID-19? Insights of the international HOPE-COVID-19-registry

“…However, the risk of death was high in severe obesity with BMI > 40 kg/m 2 [ 30 ]. In another analysis in 331 patients with COVID-19, ICU admission was more revealed in patients with BMI > 30 kg/m 2 , but the obesity was not associated with a high mortality rate [ 12 ]. Additionally, the obesity paradox in COVID-19 was also reported [ 31 ].…”

“…It has been reported that the risk for a severe course of COVID-19 with intensive care unit (ICU) and requiring invasive mechanical ventilation is higher in COVID-19 with concomitant obesity than without [ [7] , [8] , [9] , [10] , [11] ]. On the other hand, the mortality rate in obesity is not higher as compared to non-obese patients in CVOID-19 [ 12 ]. However, data were based on a small number of patients and limited participating centers.…”

Predictors of Worse Prognosis in Young and Middle-Aged Adults Hospitalized with COVID-19 Pneumonia: A Multi-Center Italian Study (COVID-UNDER50)

“…A strong association between obesity and complicated viral infections has been already documented for H1N1 influenza A [ 6 ], as well as for the previous coronaviruses causing widespread infections (SARS, MERS) [ 5 ]. Adipocytes play a relevant role in several physiologic and metabolic processes and an excess in adipose tissue leads to increased levels of adipokines and inflammatory cytokines [ 20 ]. Such subtle, chronic inflammation is thought to cause immune dysfunction, impairing the adaptive immune response to viral infections and favoring the development of immune-mediated diseases.…”