The severity of Covid-19 disease varies. The spectrum ranges from mild forms with no or mild symptoms to life-threatening courses with lung and circulatory failure. The occurrence of symptoms of pneumonia, such as shortness of breath or the need for oxygen therapy or intubation, distinguishes severe from mild disease courses. Which factors lead to a severe course with pneumonia is not yet fully understood.
Analysis of protective and harmful factors
The online study Life & Covid examined the influence of various lifestyle factors on the severity of Covid 19 disease. In particular, the four possibly protective factors of regular exercise, healthy eating habits, restful sleep and frequent contact with children and thus also with respiratory viruses were investigated. Overweight / obesity, unfavorable fat distribution, smoking, and regular alcohol consumption were analyzed as four potentially harmful lifestyle factors.
In addition to these eight lifestyle factors and the severity of the disease, the Life & Covid study also collected demographic data as well as information on previous illnesses and medication. 204 Covid-19 patients, mainly treated on an outpatient basis, diagnosed with a nasopharynx swab or a retrospective antibody test, participated in the online survey from May to July 2020.
Double the incidence of pneumonia in overweight and obese people
Results of the Life & Covid study show an association between overweight / obesity and severe Covid-19 courses. Pneumonia symptoms were about twice as common in overweight and obese patients than in those of normal weight. In addition, an increased rate of oxygen therapy or intubation could be observed in persons with overweight / obesity. This association exists not only in the case of obesity (Body Mass Index (BMI) of 30 kg/m² or higher), but already in overweight persons with a BMI of 25 kg/m² or higher. A potential link between overweight/obesity and severe disease progression is the fatty tissue. The decisive factor could possibly be signal substances such as the hormone leptin, which is produced in greater quantities as fat mass increases. Leptin can reduce a certain defense mechanism against viral infections, which also seems to play a role against SARS-Covid-2. However, further research is necessary to demonstrate this association between fatty tissue and severe courses of Covid-19.
For the other seven potentially protective or harmful lifestyle factors investigated, no association with disease severity could be identified. This does not mean, however, that they are not relevant in the context of Covid-19. Instead, it is quite possible that their effects were rather too slight to be captured within the framework of the Life & Covid study.