Obesity pandemic during COVID-19 outbreak: Narrative review and future considerations

Abstract

The high prevalence of obesity and obesity-related comorbidities has reached pandemic proportions, particularly in Western countries. Obesity increases the risk to develop several chronic noncommunicable disease, ultimately contributing to reduced survival. Recently, obesity has been recognized as major risk factor for coronavirus disease-19 (COVID-19)-related prognosis, contributing to worse outcomes in those with established COVID-19. Particularly, obesity has been associated with higher hospitalization rates in acute or intensive care and greater risk for invasive mechanical ventilation than lean people. Obesity is characterized by metabolic impairments and chronic low-grade systemic inflammation that causes a pro-inflammatory microenvironment, further aggravating the cytokine production and risk of cytokine storm response during Sars-Cov2 sepsis or other secondary infections. Moreover, the metabolic dysregulations are closely related to an impaired immune system and altered response to viral infection that can ultimately lead to a greater susceptibility to infections, longer viral shedding and greater duration of illness and severity of the disease. In individuals with obesity, maintaining a healthy diet, remaining physically active and reducing sedentary behaviors are particularly important during COVID-19-related quarantine to reduce metabolic and immune impairments. Moreover, such stategies are of utmost importance to reduce the risk for sarcopenia and sarcopenic obesity, and to prevent a reduction and potentially even increase cardiorespiratory fitness, a well-known independent risk factor for cardiovascular and metabolic diseases and recently found to be a risk factor also for hospitalizations secondary to COVID-19. Such lifestyle strategies may ultimately reduce morbility and mortality in patients with infectious disease, especially in those with concomitant obesity. The aim of this review is to discuss how obesity might increase the risk of COVID-19 and potentially affect its prognosis once COVID-19 is diagnosed. We therefore advocate for implementation of strategies aimed at preventing obesity in the first place, but also to minimize the metabolic anomalies that may lead to a compromized immune response and chronic low-grade systemic inflammation, especially in patients with COVID-19.

Keywords: COVID-19; Immune system; Low-grade inflammation; Obesity; Pandemic; Sars-CoV-2.

Graphical abstract

Fig. 1

Weekly updated Data from COVID-NET [16] as of December 31, 2020, a) prevalence of medical conditions in hospitalized patients; b) focus on the most prevalent (>30%) conditions (same data showed in a).