Higher BMI tied to increased severity of respiratory infection: JAMA

A higher BMI is among the most important risk factors for several non-communicable diseases. It has also been linked to the severity of COVID-19. More data is necessary on the association of high BMI with the severity of COVID-19.

Considering the above background, researchers investigated the associations between BMI and hospitalization risk and death due to COVID-19, lower respiratory tract infections (LRTIs), and upper respiratory tract infections (URTIs).

Here are the main points of the study:

A total of 476,176 participants were included. The median age was 58, 54% were women, and 94% were white. The mean BMI was 27.4.

• There were a total of 476,176 participants in the study.
• There were 54 % females and 94 % white, with a mean age of 58.
• The follow-up duration was 11.8 years (mean).
• The hazard ratios per 10-unit higher BMI for severe COVID-19, severe lower respiratory tract infections or LRTI and severe upper respiratory tract infections were 2.26, 1.74 and 1.37, respectively.
• The severity of illness is highest in those with a BMI of 35-60. The HR for COVID, LRTI and URTI was 2.38, 1.91 and 1.40, respectively.
• Out of 20,302 participants (hospitalized or died), 1,296 had COVID, 17,085 had an LRTI, and 1,504 had a URTI
• The incidence rates of severe COVID ranged from 1.2 per 1,000 person-year (BMI less than 25 ) up to 5.8 per 1,000 person-years (BMI of 35-60).

Based on the findings of our study, a 10-unit higher BMI double the risk of severe COVID-19.

Previous studies have also shown that obesity increases the frequency of upper and lower respiratory tract infections compared to normal body weight.

Obesity is also tied to symptoms like orthopnea, dyspnea, and wheezing.

Our study has addressed the importance of approaches to reduce obesity. Individuals with a high BMI should have an awareness of vaccination programs targeting respiratory infections.

The authors used data from the prospective U.K. Biobank cohort for this study. They excluded participants with prevalent chronic respiratory diseases, previous hospitalization for infectious respiratory infections, and missing or extreme values for critical variables.

Further reading:

Bohrmann B et al. Body Mass Index and Risk of Hospitalization or Death Due to Lower or Upper Respiratory Tract Infection. JAMA. 2023;329(17):1512–1514. doi:10.1001/jama.2023.2619