Un estudio que acaban de sacar de los ingresados en USA, dice que como factor individual la obesidad es un indicador mayor que cualquier otro de cara a la enfermedad haciendo que esta gente sean los casos usualmente más graves
Results: Among 4,103 Covid-19 patients, 1,999 (48.7%) were hospitalized, of whom 981/1,999 (49.1%) have been discharged home, and 292/1,999 (14.6%) have died or were discharged to hospice. Of 445 patients requiring mechanical ventilation, 162/445 (36.4%) have died. Strongest hospitalization risks were age ≥75 years (OR 66.8, 95% CI, 44.7-102.6), age 65-74 (OR 10.9, 95% CI, 8.35-14.34), BMI>40 (OR 6.2, 95% CI, 4.2-9.3), and heart failure (OR 4.3 95% CI, 1.9-11.2). Strongest critical illness risks were admission oxygen saturation <88% (OR 6.99, 95% CI 4.5-11.0), d-dimer>2500 (OR 6.9, 95% CI, 3.2-15.2), ferritin >2500 (OR 6.9, 95% CI, 3.2-15.2), and C-reactive protein (CRP) >200 (OR 5.78, 95% CI, 2.6-13.8). In the decision tree for admission, the most important features were age >65 and obesity; for critical illness, the most important was SpO2<88, followed by procalcitonin >0.5, troponin <0.1 (protective), age >64 and CRP>200.
https://www.medrxiv.org/content/10.1101/2020.04.08.20057794v1
Obesity, in this case, was measured as weight relative to a person's height. The authors use a metric scale, so a body mass index of 30 and higher is considered obese.
The "decision tree," which is shown in the illustration above, refers to the statistical method they used to analyze the patient data. A decision tree is a way to group members of a sample based on their shared characteristics. "For a given population, the decision tree classification method splits the population into two groups using one feature at a time, starting with the feature that maximizes the split between groups relative to the outcome in question." They keep splitting groups into smaller and smaller groups until they arrive at groups that "[have] similar characteristics and outcomes."
Note that in the decision tree, age is the initial determining factor, at the top of the tree, followed by obesity. Hence, obesity is the most significant "chronic" factor, leaving aside age. The authors had to make decisions about the splits in data at different branching points in the tree. For example, there are two buckets for age just below obesity, one being "Age 20 - 44" and another being "Age>35."
As co-author Leora Horwitz told ZDNet in an email, "the algorithm found age 35 and age group 20-44 as the most important features that increase the information gain the most, respectively."
Bear in mind that age still functions as the biggest overall single determinant. "Age is far and away the strongest risk factor for hospitalization, dwarfing the importance of obesity," Horwitz told ZDNet in email. "Obesity is the most important of the chronic conditions when considering all such conditions simultaneously."
Others have made reference to obesity in conjunction with COVID-19, to a greater or lesser extent, but without the data of the NYU group.
Writing in The Lancet on March 31st, RNA virus researcher Gregory Poland summed-up the conditions aggravating the COVID-19 situation globally: "We have an increasingly older age demographic across virtually all countries, as well as unprecedented rates of obesity, smoking, diabetes, and heart and lung disease, and an ever-growing population of people who are immunocompromised—all comorbidities that lead to significantly higher risks of severe disease and death from coronavirus disease 2019 (COVID-19)."
And Drs. David S. Ludwig and Richard Malley of Boston Children's Hospital wrote in The New York Times on March 30 that Americans' risk from the virus is compounded by the fact that they are generally "too diseased."
"The huge burden of obesity and other chronic conditions among Americans puts most of us at direct risk," they wrote. "In fact, with obesity rates in the US much higher than affected countries like South Korea and China, our outcomes -- economic- and health-wise -- could be much worse."
But what does it mean for obesity to show up as the big deciding factor for hospitalization?
Obesity is generally known to be associated with inflammation. As the NYU authors observe, "Obesity is well-recognized to be a pro-inflammatory condition." They focus on the inflammation aspect because it has been cited in several studies as being a possible factor in COVID-19, in particular, inflammations that seem to be in a hyper-activated state. But it's not entirely clear what role it plays.
Si tu bmi pasa de 29, malo.
