Obesity is quickly becoming an epidemic in the Western world, with the associated health problems raising the costs of healthcare. Obesity is more than just a high body mass index (BMI); it is also paired with high blood pressure, poor cholesterol values and impaired glucose tolerance, collectively known as metabolic syndrome. This combination of factors has a major impact on the immune response of the lungs, a vital organ that distributes oxygen throughout the body via the blood. The lungs also form an important barrier, filtering out harmful substances and organisms that enter the body when inhaled.

White blood cells
Neutrophils (one of two types of white blood cells) play an essential role in helping our body fight infections by attacking and neutralising harmful bacteria. In her study, Ubags found that obesity compromises the effectiveness of these neutrophils. This leads to decreased immune response and triggers an inflammatory response in the lungs. 'This changing immune response makes it more likely for pneumonia to develop into something much worse, like ARDS,' explains Ubags.

Hormones
In addition to altering the way neutrophils function, obesity also influences the hormone leptin, which is released from fatty tissue in much higher quantities in people with obesity. It affects satiety and has a negative impact on the development of pneumonia. 'My research has demonstrated how this mechanism works in obese people with pneumonia. We can use these insights to develop new treatment methods and prevent pneumonia in the future,' says the researcher.

Niki D.J. Ubags received her PhD from Maastricht University on Thursday 24 March for her dissertation entitled, 'Obesity and Pulmonary Host Defense'.