The relationship between inflammatory markers and disability in chronic obstructive pulmonary disease (COPD)

Abstract

Aims: To examine relationships between markers of systemic inflammation and functional status in patients with chronic obstructive pulmonary disease (COPD).

Methods: 41 COPD patients were stratified using the Medical Research Council (MRC) dyspnoea scale. Six-minute walking distance (6MWD), Quadriceps (% body weight) (QBW), St George's Hospital Respiratory Questionnaire (SGRQ), London Chest Activity of Daily Living Scale (LCADL), C-reactive protein (CRP), interleukin 6 (IL6), tumour necrosis factor alpha, and neopterin were measured. Relationships between variables and differences in inflammatory markers between MRC categories were tested.

Results: Inflammation increased with MRC grade and was significantly different across grades; CRP (p=0.002) and IL6 (p=0.04). Relationships were evident between CRP, 6MWD, LCADL and SGRQ, r=-0.47, 0.50, 0.43 (all p<0.01) respectively, and between IL6, QBW and LCADL, rho=-0.36, 0.51 (p<0.05).

Conclusions: Measures of systemic inflammation, and in particular CRP, may prove to be useful markers in the assessment of COPD severity in primary care.