# Evaluating the Effect of Body Mass Index on Procalcitonin Level in Patients with Pneumonia: A Retrospective Cross-Sectional Study

## TL;DR

This study found that higher body mass index is linked to lower procalcitonin levels in pneumonia patients, which could affect diagnosis and treatment.

## Contribution

The study demonstrates a significant relationship between BMI and procalcitonin levels in hospitalized pneumonia patients.

## Key findings

- Higher BMI patients had significantly lower procalcitonin levels compared to those with lower BMI.
- BMI significantly influences procalcitonin levels in both floor and MICU pneumonia patients.
- Adjusting procalcitonin reference ranges for BMI may improve diagnostic accuracy in pneumonia.

## Abstract

What are the main findings?

Body mass index (BMI) has a statistically significant effect on serum procalcitonin (PCT) levels in hospitalized patients with pneumonia.

Higher BMI patients exhibited significantly lower PCT levels compared to patients with lower BMI.

What is the implication of the main finding?

The findings suggest that individuals with higher BMI might exhibit either a less robust immune response or increased PCT clearance.

Consideration of BMI-adjusted PCT reference ranges could enhance diagnostic accuracy, though further research is needed to validate this approach.

Procalcitonin (PCT) is commonly used to evaluate the etiology and severity of pneumonia. PCT has been shown to be elevated at baseline in patients with obesity. The aim of this study is to determine if body mass index (BMI) has an influence on admission PCT level in patients admitted to the hospital with a diagnosis of pneumonia. We conducted a retrospective cohort study that encompassed patient visits to a tertiary care center from 2014 until September 2023. A total of 18,652 patients presented to the emergency department with a diagnosis of pneumonia. A total of 3659 were admitted to the floor, and 2246 were admitted to the MICU. Patients were grouped based on admission BMI into five categories. The Kruskal–Wallis test performed on patients admitted to the floor revealed a statistically significant difference in PCT levels among groups of different BMIs (H = 34.97, df = 4, p < 0.001). In patients admitted to the MICU, the Kruskal–Wallis test revealed a significant difference in PCT levels among groups of different BMIs (H = 32.92, df = 4, p < 0.001). BMI has a statistically significant effect on PCT in patients admitted to the hospital with pneumonia. Patients with higher BMI may exhibit less robust PCT levels, which may impact management decisions.