Effect of low protein intake on acute exacerbations in mild to moderate chronic obstructive pulmonary disease: data from the 2007–2012 KNHANES

Background Several researchers have reported that the amount of protein intake is associated with lung function and airflow obstruction. However, few studies have investigated the effect of low protein intake on acute exacerbations of chronic obstructive pulmonary disease. This study aimed to investigate the effect of low protein intake on exacerbations in mild to moderate chronic obstructive pulmonary disease. Methods We used data obtained from the Korean National Health and Nutrition Examination Survey (KNHANES) between 2007 and 2012, linked to the National Health Insurance claims data. The clinical outcomes and the rate of exacerbation were retrospectively compared between the low protein intake group and the non-low protein intake group which was stratified by quartile categories of protein intake in 2,069 patients with mild to moderate chronic obstructive pulmonary disease. Results The low protein intake group was significantly associated with older age, women, never smoker, low household income, and low education level, compared with the non-low protein intake group. The low protein intake group was significantly associated with increased hospitalization (18.0% vs. 10.5%, P<0.001) and emergency department utilization (1.6±1.0 vs. 1.1±0.4, P=0.033) compared with the non-low protein intake group. In multivariate analysis, the low protein intake group was associated with hospitalization (odds ratio 1.46; 95% CI, 1.09-1.96; P=0.012). The multiple linear regression analysis revealed that the amount of protein intake was associated with FVC % predicted (β=0.048, P<0.001) and FEV1% predicted (β=0.022, P=0.015). Conclusions Low protein intake was associated with an increased risk of exacerbations in mild to moderate chronic obstructive pulmonary disease. The data are available at the KNHANES website (https://knhanes.cdc.go.kr).