Correlation of Self-Reported Breathlessness with Post Exercise Dyspnea in Obesity

Michael Agustin,John Unterborn,Augustine Andoh-Duku,Hong Chang

doi:10.4236/ojrd.2017.74015

Abstract

Background: Dyspnea in obesity is common and dyspnea questionnaires are mostly validated for chronic respiratory diseases. The study aims to assess how modified Medical Research Council (mMRC) dyspnea scale correlates with post exercise dyspnea Borg scale in 6-minute walk test of the obese population. Methods: We performed a retrospective observational study on 342 obese patients with 6 MWT tests from February 2008 to November 2014 at a single tertiary hospital. Linear regression analysis was used to assess the relationship between mMRC and Borg dyspnea score. Fractional polynomial regression was used to analyze the relationship of mMRC and Borg scores with BMI. Results: MMRC dyspnea score was a strong predictor of post exercise dyspnea Borg score in the obese population in a univariate regression model (coefficient = 0.764, p ≤ 0.001). When adjusted to age, BMI, 6 MWT distance and PFT parameters in a multivariate regression model, the relationship remained statistically significant (coefficient = 0.587, p ≤ 0.001). The relationship was stronger in obese group with no airflow obstruction. Conclusion: In obese population, pre-exercise mMRC dyspnea score correlates significantly with post exercise dyspnea Borg score regardless of airflow obstruction. This is the first validity study regarding mMRC scale in assessing dyspnea in the obese population.

Highlights

The study aims to assess how modified Medical Research Council dyspnea scale correlates with post exercise dyspnea Borg scale in 6-minute walk test of the obese population
Our study demonstrates a strong correlation between pre-exercise modified Medical Research Council (mMRC) scores and post exercise Borg dyspnea scores after 6 minute walk test (6 MWT)
Our study demonstrated a stronger correlation of mMRC and Borg scores in obese patients without airflow obstruction

Summary

Introduction

Reduced expiratory reserve volume (ERV), functional residual capacity (FRC) and total lung capacity (TLC) are most frequent observed in the obese pulmonary function tests (PFTs) [2] These are generally related mechanical effect of adipose tissue in chest wall, which reduces total respiratory compliance [2] [4] [5]. The study aims to assess how modified Medical Research Council (mMRC) dyspnea scale correlates with post exercise dyspnea Borg scale in 6-minute walk test of the obese population. Results: MMRC dyspnea score was a strong predictor of post exercise dyspnea Borg score in the obese population in a univariate regression model (coefficient = 0.764, p ≤ 0.001). Conclusion: In obese population, pre-exercise mMRC dyspnea score correlates significantly with post exercise dyspnea Borg score regardless of airflow obstruction. This is the first validity study regarding mMRC scale in assessing dyspnea in the obese population

Objectives

Methods

Conclusion