Study links obesity to increased risk of severe infections

New research sheds light on the connection between obesity and infectious disease outcomes, suggesting that obesity may contribute to over 10% of deaths related to infections. The study examined medical records of approximately 550,000 adults in Finland and the UK over a period of 14 years, revealing that individuals with obesity had a 70% higher chance of hospitalization or death due to infections.

The participants in Finland averaged 42 years of age, while those in the UK averaged 57. Obesity was classified as having a body mass index (BMI) of 30 or greater. Notably, individuals categorized as having “class 3 obesity” (BMI of 40 or higher) were three times more likely to be hospitalized or die from infections compared to those with a normal BMI, defined as 18.5 to 24.9.

Researchers estimated that in 2018, obesity was linked to about 9% of infectious disease-related deaths, which increased to 15% in 2021 and then settled at 11% this year.

This study indicated that the correlation existed even among obese individuals without diabetes, heart disease, or metabolic disorders. Interestingly, physical activity appeared to have little effect on this relationship.

Published in The Lancet, the study analyzed nearly 925 types of infections, including common ones like influenza and COVID-19, among others. Almost all types showed a connection between obesity and poorer infection outcomes. “Obesity may not make people more susceptible to infections, but it certainly makes recovery more challenging,” explained Professor Mika Kivimäki from the London School of Brain Sciences.

He emphasized that severe infections were notably more frequent among obese individuals. Symptoms most strongly tied to obesity involved skin and soft tissue infections. The findings clearly indicate that obesity compromises the body’s defenses when it comes to fighting infections.

According to the research, addressing obesity could potentially prevent up to 11% of global deaths associated with infectious diseases.

Furthermore, individuals who lost weight after being initially obese saw about a 20% reduction in the risk of serious infections. Dr. Sorja Nyberg from the University of Helsinki pointed out that as global obesity rates rise, so too will the number of deaths and hospitalizations connected to infections linked to obesity. He called for urgent policy changes to ensure access to healthy food and exercise opportunities.

While this research provides an important association between obesity and infection severity, the authors noted some limitations. The study primarily established a correlation rather than a causal link, and there is ongoing discussion about the efficacy of BMI as a measure of obesity. Additionally, this research focused only on adults from Finland and the UK Biobank, which raises questions about its applicability to other populations. The study received funding from several prominent health research organizations.