People who are very overweight have a drastically increased risk of suffering severe illness or even death if infected. This comes from an analysis of health data from more than 540,000 patients in Great Britain and Finland. While being slightly overweight only increases the risk slightly, it is around three times as high for people with category 3 obesity as for people of normal weight. The study by a group led by Mika Kivimäki from University College London (Great Britain) and Solja Nyberg from the University of Helsinki (Finland) was published in the journal “The Lancet”.
Overweight people were already at increased risk with Covid
The starting point for the study were observations made a few years ago: “Studies during the Covid-19 pandemic showed that overweight people had a higher risk of a severe course of a Sars-Cov-2 infection, which was reflected in increased hospital stays and higher mortality,” writes the team. However, it was not clear weather this also applied to other infectious diseases.The team led by Kivimäki and Nyberg therefore used health data from two Finnish databases and the British “UK Biobank” to investigate the connection between overweight and obesity and a serious course of infections such as hospitalization or even death.
The analysis showed that being slightly overweight increased the risk of severe to fatal infections by 10 (Finland) and 13 percent (Great Britain). For category 1 obesity (body-Mass-Index 30 to 34.9), the risk was already 47 (Finland) and 53 percent (Great Britain) higher than for people of normal weight.Category 3 obesity (body mass index over 40) resulted in a 2.69-fold (Finland) and 3.07-fold (UK) increased risk. Other factors such as gender, age or socioeconomic status had little influence on this result.
Obesity creates favorable conditions for germs
“It is indeed plausible that obesity weakens the ability of the immune system to defend itself against infectious bacteria, viruses, parasites or fungi, which can lead to more severe disease progression,” Kivimäki is quoted as saying in a statement by The Lancet. The reasons could be factors associated with obesity, such as a nutrient-rich habitat that promotes the survival of microorganisms, and also insulin resistance, hyperglycemia and chronic low-grade inflammation. Though, the study authors also wriet that the data shows the connection between obesity and the risk of infection, but not the exact reasons for it.
The researchers transferred the knowledge gained to data from the “Global Burden of Disease” study and were thus able to calculate the risk of severe infection for regions of the world and for individual countries. For the year 2023,they show a connection with obesity for 4,700 of 31,900 deaths after infections in Germany; that was 14.7 percent of these deaths. This puts Germany below the values of the USA (25.7 percent), Spain (21.2 percent), Great Britain (17.4 percent), but significantly above the values of China (9.0 percent) and India (3.8 percent).
The study authors warn that the situation could worsen in the coming years. “As obesity rates are expected to rise worldwide, the number of deaths and hospitalizations due to obesity-related infectious diseases will also increase,” says Nyberg. In order to reduce the risk of serious infections and other health problems associated with obesity, ther is an urgent need for measures that help peopl
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