Relationship between inflammation and malnutrition in patients with chronic obstructive pulmonary diseases

Objective To study the relationship between inflammation and malnutrition in patients with stable chronic obstructive pulmonary disease (COPD).Methods A total of 85 patients with stable COPD and 30 healthy subjects were recruited .All patients were divided into the lower body mass index (BMI,BMI<18.5 kg/m~2) group and normal BMI (BMI=18.5-23.9 kg/m~2) group.Lung function,arterial blood gall,cell differenti-als in induced sputum,and the levels of serum C-reactive protein (CRP),interleukin-8(IL-8),interleukin-6 (IL-6),interleukin-10 (IL-10),and tumor necrosis factor-α(TNF-α) were determined.Results The levels of total cell count and neutrophils in induced sputum were significantly higher in lower BMI group than in normal BMI group and healthy subjects (P<0.05).The forced expiratory volume in 1 second percentage,forced expiratory volume in 1 second/forced vital capacity,and arterial oxygen tension were significantly lower in lower BMI group than in normal BMI group,and the arterial carbon dioxide tension was significantly higher in lower BMI group than in normal BMI group (P<0.05).The levels of serum CRP,IL-8,IL-6,and TNF-α were significantly higher in lower BMI group than those in normal BMI group and healthy subjects (P<0.05).In lower BMI group,BMI was negatively correlated with total cell count (r=-0.492,P=0.0038) and neutrophils (r=-0.501,P=0.0032) in induced sputum and the levels of serum CRP (r=-0.473,P=0.0083),IL-8(r=-0.382,P=0.0421),IL-6(r=-0.422,P=0.0147),and TNF-α(r=-0.416,P=0.0156),respectively.Conclu-sion Local and systemic inflammatory reaction is responsible for malnutrition associated with COPD. Key words: chronic obstructive pulmonary disease; inflammation; malnutrition; body mass index