The largest study to date of US hospital admissions for COVID-19 reveals that obesity and age are the largest factors in whether a person had to be admitted to a hospital.
The study, consisting of 4,103 patient records of those who tested positive for the virus between March 1st and April 2nd, revealed that "The chronic condition with the strongest association with critical illness was obesity, with a substantially higher odds ratio than any cardiovascular or pulmonary disease," according to Christopher M. Petrilli of NYU's Grossman School and lead author of the paper "Factors associated with hospitalization and critical illness among 4,103 patients with Covid-19 disease in New York City," printed April 11th on the medRxiv pre-print server, according to ZD.net, which notes that the paper has not undergone peer-review.
Obesity was defined as a body mass index (BMI) of 30 or greater.
Of the 4,103 patients in the study, 1,999 required hospital admission and 650 either required intensive care, mechanical ventilation, were discharged to hospice and/or died.
"We find particularly strong associations of older age, obesity, heart failure and chronic kidney disease with hospitalization risk, with much less influence of race, smoking status, chronic pulmonary disease and other forms of heart disease."
The study is "the largest case series from the United States to date," according to Petrilli and colleagues , who sought to understand "which patients are most at risk for hospitalization is crucial for many reasons."
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 30th 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 United States much higher than affected countries like South Korea and China, our outcomes — economic- and health-wise — could be much worse." -ZD.net
The authors point out that obesity "is well-recognized to be a pro-inflammatory condition," while COVID-19 triggers an inflammatory immune response.
"Hyperinflammatory states are well described in severe sepsis," they write, "however, the degree to which Covid-19 related inflammation is similar to or different than that typically found in sepsis is unknown." They also note that COVID-19 patients have displayed blood clotting, or "hypercoaguability" which presents as thrombosis or embolisms.
The authors suggest future studies to determine what role inflammation plays, writing "We did not have inflammatory markers available for non-hospitalized patients; it is possible that these would have been strong predictors for hospitalization risk as well if available."
Of note, Chinese researchers studying 577 COVID-19 patients at one hospital found that older patients with inflammation were most likely to die of the disease after 12 days (study here).
In a nutshell, they found that those over 60-years-old with a CRP (C-Reactive protein, an inflammation marker) over 34 mg/L had a 33.2% chance of dying within 12 days of admission to the hospital.
In short, older, obese people with inflammatory conditions appear to be the least likely to survive COVID-19.