[Systemic inflammation among stable ex smokers with chronic obstructive pulmonary disease]

Low grade systemic inflammation is commonly observed in chronic obstructive pulmonary disease (COPD).

To evaluate the extent of systemic inflammation in a group of ex-smokers with COPD in stable condition and its relation with pulmonary function and clinical manifestations.

We studied 104 ex-smokers aged 69 ± 8 years (62 males) with mild to very severe COPD and 52 healthy non-smoker subjects aged 66 ± 11 years (13 males) as control group. High sensitivity serum C reactive protein (CRP), interleukin 6 (IL6), fibrinogen (F) and neutrophil count (Nc) were measured. Forced expiratory volume in the first minute (FEV1), inspiratory capacity (IC), arterial blood gases, six minutes walking test, dyspnea and body mass index (BMI) were measured, calculating the BODE index. Health status was assessed using the Saint George Respiratory Questionnaire (SGRQ), the chronic respiratory questionnaire (CRQ), registering the number of acute exacerbations (AE) during the previous year and inhaled steroids use. Systemic inflammation was considered present when levels of CRP or IL6 were above the percentile 95 of controls (7.98 mg/L and 3.42 pg/ml, respectively).

COPD patients had significantly higher CRP and IL6 levels than controls. Their F and Nc levels were within normal limits. Systemic inflammation was present in 56 patients, which had similar disease severity and frequency of inhaled steroid use, compared with patients without inflammation. Patients with systemic inflammation had more AE in the previous year; lower inspiratory capacity, greater dyspnea during the six minutes walk test and worse SGRQ and CRQ scores.

Low-grade systemic inflammation was found in 56 of 104 ex-smokers with COPD. This group showed a greater degree of lung hyperinflation, dyspnea on exercise and poor quality of life.