The COVID-19 disease is caused by the new coronavirus SARS-CoV-2, which is characterized by a wide and variable clinical spectrum ranging from asymptomatic to fatal infection (5). The identification of risk factors at the time of diagnosis has allowed risk stratification and the establishment of appropriate management. Several risk factors have been described for the development of severe disease and mortality from COVID-19 (6), among them being obesity, which is identified as an independent risk condition and is also a predisposing agent for entities such as hypertension and diabetes (5), increasing the possibility of adverse outcomes.
Obesity is a public health problem worldwide, and the global prevalence has been estimated at 1.9 billion adults, of which 39% are overweight and 13% are obese, with an annual increase in people with this diagnosis, constituting an epidemic worldwide (13). In Colombia, according to the National Health Survey, 55.9% of the population is overweight and obese (14). This is a metabolic disease characterized by increased fat tissue, insulin resistance, elevated glucose, alteration of adipokines and chronic inflammation (15); alterations can predispose individuals to infections, and SARS-CoV-2 is no exception. A study using data from the UK Biobank (n = 285,817) showed that being overweight increases the risk of infection by this virus by 44% (RR = 1.44; CI 1.09–1.92; p = 0.01), and for obesity it almost doubles this value (RR = 1.97; 95% CI 1.46–2.65) (16).
In our study, the average age of patients with SARS-CoV-2 infection was 48 years, similar to that reported in Wuhan (22), Germany and Switzerland (23) cohorts and lower than that reported in a New York series (22). Regarding gender, a greater proportion was observed in men, 53%, which was lower than in the New York (21) and Wuhan (22) areas. A total of 25.65% of the cohort had a lower percentage of obesity than the reference series (24), similar to that in Switzerland (25). The prevalence of arterial hypertension was found to be significantly associated with an increase in BMI, and there was also a high use of ARA 2 in our population, which is of vital importance when considering risk factors for mortality from SARS-CoV-2 (22).
In terms of clinical presentation, dyspnea was the most significant, occurring in a higher proportion in the obese population (7), while in previous series, cough and fever have been the predominant symptoms (10). However, this observation could be related to lower oxygen saturation and PAFI on admission in these patients, which are parameters associated with greater severity, a situation that has been described in previous studies by an OR of 2.31 (95% CI of 1.3–4.12) (23).
Obesity has been documented to increase the risk of being hospitalized. In our study, 39% of patients admitted to the ICU were overweight, and 34% were obese. This result is slightly lower than that reported in the New York City cohort, in whom 42.7% of those hospitalized had obesity. In this regard, different publications have found an OR of 2.13 (95 CI, 1.74–2.60; p < 0.0001) for hospitalization in obese patients (26). Other analyses published to date describe that this pathology increases the risk of being admitted to the ICU by 68% (OR = 1.68%; 95% CI, 1.46–2.08; p < 0.0001) (23); in our case the higher the BMI, the greater the need for hospitalization in the ICU and overall stay in hospitalization.
At the beginning of this pandemic, the documentation of acute kidney injury secondary to SARS-CoV-2 infection was widely variable (33). However, it began to consolidate as a common outcome in several case series with high dialysis requirements, predominantly in populations outside of China and in patients hospitalized in the intensive care unit (33). However, there is insufficient information on the development of this BMI-guided outcome. In our sample of patients, a higher prevalence of renal failure with a requirement for replacement therapy was evidenced in patients with a higher BMI (P 0.009).
Reports of small samples have associated obesity with an increased risk of requiring IMV. One of the first reports in this regard was a study carried out in the city of Seattle in critical patients, which reported that 85% of obese patients required MV. Other studies have shown an increased risk for MV of 66% (OR = 1.66%; 95% CI, 1.38–1.99; p < 0.0001) (10, 23, 24), and in our study, 75% of the patients on MV were overweight or obese, with a higher proportion having higher BMI; thus, 12.1% of the participants with normal weight required MV versus 43.8% of those with BMI 40 kg/m2.
In relation to prognosis, the association described between SARS-CoV-2 infection and obesity is complex, and some reports have documented an increase in hospital mortality by up to 48% (OR = 1.48%; 95% CI, 1.22–1.80; p < 0.0001) (21, 27, 29, 30, 31). Our report does not allow us to determine such an association, since the differences found were not statistically significant.
Obesity represents a risk for severe presentation of the disease and its adverse outcomes, which has been aggravated by measures implemented to combat the pandemic, with a collateral effect of generating favorable conditions to enhance weight gain; strategies such as “stay at home” have increased sedentary lifestyles and unhealthy eating, which translates into an increase in the population BMI (31) for some sites, increasing the risk of these two entities.