Pasadena / California - Morbid obesity with a body mass index (BMI) of over 40 kg / m2 increases the risk of dying of COVID-19 after an infection with SARS-CoV-2, even in otherwise physically healthy younger men. This is shown by the analysis of a California health insurer in the Annals of Internal Medicine (2020; DOI: 10.7326 / M20-3742).

The US is one of the countries with the highest percentage of obese people in its population. According to official statistics, 42% of adults have a BMI of over 30 kg / m2, which marks the limit of obesity.

Among the 6,916 COVID-19 patients at Kaiser Permanente Southern California, the region's largest health insurer, one in two was obese. Almost every tenth person with a BMI of 40 kg / m2 or higher even had morbid obesity, which is classified as an acute health risk.
In morbid obesity, the masses of fat on the chest lead to an impairment of breathing, which among other things favors the development of pneumonia. In addition, there is usually a fatty degeneration of the internal organs, including the heart muscle, which further reduces the immune system in the event of illness.

The fatty tissue in the abdominal area is also biologically active. There is an increased release of hormones, which are held responsible for the health disorders that occur more frequently in obese people than in other people.

Those insured with COVID-19 from Kaiser-Permanente suffered more often from comorbidities such as high blood pressure (24%), hyperlipidemia (23%), diabetes (20%) and asthma (18%), which (apart from asthma) unite favor a severe course of COVID-19.
However, these comorbidities do not explain the increased risk of death in extremely obese patients, which Sara Tartof and employees of Kaiser Permanente in Pasadena have determined.
Even after considering other risk factors, insured persons with a BMI of 40 to 44 kg / m2 had an almost 3-fold higher risk of dying from COVID-19 than members of normal weight (risk ratio 2.68; 95% confidence interval: 1, 43 to 5.04). With a BMI of 45 kg / m2 or more, the risk ratio increased to 4.18 (2.12 to 8.26).
Morbid obesity was the most important risk factor, along with older people (risk ratio up to 43.21 in the over 80-year-old group) and an organ transplant (risk ratio 6.54).
Interestingly, the increased risk of death from COVID-19 due to morbid obesity was limited to “younger” men. In the age group under 60 years, a BMI of 40 to 44 kg / m2 was associated with a risk ratio of 17.14 (3.37 to 87.27). With a BMI of over 45, the risk ratio was 12.35 (2.28 to 66.77).
For the entire group of men, Tartof determined a risk ratio of 4.81 (2.15 to 10.78) for a BMI of 40 to 44 kg / m2 and of 10.04 (4.01 to 25.09) for a BMI of 45 kg / m2 or more.
The wide 95% confidence intervals show that the analysis has reached its limits. It remains unclear why women and older men do not have an increased risk of death regardless of other risk factors.