Relationship between BODE index, quality of life and inflammatory cytokines in COPD patients

Recently a multidimensional grading system based on the body mass index (B), degree of airflow obstruction (O), dyspnea (D) and exercise capacity (E) - the BODE index - has begun to be used increasingly for the evaluation of chronic obstructive pulmonary disease (COPD) patients. The aim of our study was to investigate the relationship between the BODE index and disease duration, annual exacerbation and hospitalization rates, health related quality of life and systemic inflammatory markers like C-reactive protein (CRP), tumor necrosis factor (TNF)-α and interleukin (IL)-8.

In 88 stable COPD patients we evaluated the body-mass index, pulmonary function tests, Modified Medical Research Council dyspnea scale and six-minute walk test (6 MWT). BODE scores were determined. Disease duration, number of exacerbations and hospitalization in the previous year were recorded. We also performed arterial blood gases analysis, administered the St. George's Respiratory Questionnaire (SGRQ) and measured serum levels of CRP, TNF-α, IL-8.

According to BODE score 52% of patients were BODE 1, 21% BODE 2, 15% BODE 3 and 12% were BODE 4. There was a significant relationship between BODE index and COPD stage as classified according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) (p < 0.001). Correlations between BODE score and disease duration (p = 0.011), number of exacerbations (p < 0.001) and hospitalizations (p < 0.001) in the last year were also observed. SGRQ symptom, activity, emotion scores and total scores were found to be significantly correlated to BODE (p < 0.001). Serum CRP levels and BODE were also correlated (p = 0.014); however, no correlation was found between serum levels of TNF-α and IL-8 and BODE.

As the BODE index shows a strong correlation with various prognostic and follow up parameters of COPD and systemic inflammation, its use should be considered for the evaluation of COPD patients.