Understanding the Link Between Obesity and Respiratory Infections

Maccioni L, Weber S, Elgizouli M, Stoehlker AS, Geist I, Peter HH, et al. Obesity and risk of respiratory tract infections: results of an infection-diary based cohort study. BMC Public Health. 2018 Feb 20;18(1):271.

Another PUN/DEN for me as I knew there was a link, but couldn’t cite any particular evidence. I knew about various triggers and reasons why it might make a difference, but it was good to look it up. I used a new AI tool I have been trialling called Consensus. Really easy to use and a good free plan. Anyway, this is a brief critique of one of the papers I found.

Recent research has highlighted the connection between obesity and respiratory tract infections (RTIs), revealing how excess body weight may contribute to a higher risk of these infections. RTIs can significantly affect quality of life, lead to high healthcare costs, and result in missed work. Given the rising global obesity rates, understanding how obesity influences RTIs is increasingly important.

The study found that obese individuals were more likely to suffer from a variety of RTIs, including influenza-like illnesses, bronchitis, pneumonia, sinusitis, and rhinitis. The risk was even higher for long-lasting or frequent infections. This suggests that obesity may weaken the body’s immune defenses, making it harder to fight off respiratory pathogens.

Interestingly, the link between obesity and RTIs was stronger in women than in men. Previous studies support this gender difference, indicating that obesity may affect the immune system differently in women, possibly due to variations in immune cells that are more affected by obesity in women than in men.

The study also explored how lifestyle factors like physical activity and diet might influence the obesity-RTI connection. Surprisingly, obese individuals who were more physically active or reported healthier diets had a higher risk of RTIs. This could be due to increased oxidative stress from intense exercise, which may impair immune response, or it might suggest that those who try to lead a healthier lifestyle are more aware of their symptoms. Alternatively, there could be a genetic factor linking obesity and a higher susceptibility to infections.

Despite these findings, the study had some limitations. It relied on self-reported data, which can be inaccurate, and had a disproportionate number of female participants, which might affect how broadly the results apply.

In conclusion, the study supports the idea that obesity increases the risk of frequent and prolonged RTIs, particularly in women. However, the unexpected findings regarding physical activity and diet suggest that more research is needed to fully understand these interactions and how they influence the risk of infection. Future studies should aim to better measure physical activity and dietary habits to clarify these relationships.