Effect of body mass index on prognosis of patients with acute exacerbation of chronic obstructive pulmonary disease / 中国中西医结合急救杂志

ABSTRACT

Objective To investigate the effect of body mass index (BMI) on the clinical efficacy and prognosis of patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD), and to provide evidence for the use of BMI in predicting their disease situation and prognosis.Methods Eighty patients with AECOPD admitted to the Department of Respiration of the Fourth Central Hospital of Tianjin from October 2014 to October 2015 were enrolled, and they were divided into low BMI group (BMI < 18.5 kg/m2) and normal BMI group (BMI 18.5 - 24.9 kg/m2) by difference in BMI. The differences in body height, body weight, blood gas analysis indexes [arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2)], lung function indexes [the percentage of the first second forced vital capacity/predicted value (FEV1%), the ratio of the first second forced vital capacity/forced vital capacity (FEV1/FVC)], hospitalization time, recurrence time and smoking index were compared between the two groups, the correlations between BMI and the indexes of blood gas analysis, pulmonary function, hospitalization time, recurrence time and smoking index in low BMI group were analyzed.Results The BMI (kg/m2 21.09±2.03 vs. 16.39±1.26), PaO2 [mmHg (1 mmHg = 0.133 kPa) 63.59±4.95 vs. 56.54±3.23], FEV1% [(64.18±3.82)% vs. (59.82±5.73)%] and FEV1/FVC (63.83±3.20 vs. 59.28±3.63) in normal BMI group were all significantly higher than those in the low BMI group, PaCO2 in normal BMI group was significantly lower than that in the low BMI group (mmHg 57.05±5.25 vs. 63.70±7.29). The results indicated that the patients in low BMI group had severer hypoxia and carbon dioxide retention than those in normal BMI group, and the lung function was also worse than that in the normal BMI group; the hospitalization time of normal BMI group was shorter than that of low BMI group (days 11.70±2.36 vs. 15.25±2.80), and the recurrence time in normal BMI group was obviously longer than that of low BMI group (days 93.78±57.85 vs. 48.58±17.85), smoking index in normal BMI group was markedly lower than that of low BMI group (year·branch 2550.0±917.6 vs. 3652.5±1015.8), the differences were statistically significant (allP < 0.05). The linear correlation analyses showed that BMI in low BMI group was positively correlated with PaO2, FEV1% and recurrence time (r = 0.557, 0.507, 0.455,P = 0.000, 0.000, 0.003), and was negatively correlated with PaCO2, hospitalization time and smoking index (r = -0.670, -0.405, -0.440,P = 0.009, 0.000, 0.005), and had no significant correlation with FEV1/FVC (r = 0.061,P = 0.707).Conclusion BMI is an important index for evaluating the severity and prognosis of patients with AECOPD.