Energy and protein intake and its relationship with pulmonary function in chronic obstructive pulmonary disease (COPD) patients

Chronic Obstructive Pulmonary Disease (COPD) is a public health problem worldwide. Increased energy and protein needs, decreased energy and protein intake are common in COPD patients. Adequate intake is essential to improve pulmonary function and immune system, prevention of weight loss and maintaining muscle mass and strength. Assessment of energy and protein intake and its relationship with pulmonary function in COPD patients was performed in this study. The study group included 63 COPD patients. For all subjects, evaluation of energy and protein intake by Food Frequency Questionnaire (FFQ) and 24-hour recall, spirometry for measuring pulmonary function and determining disease severity were performed. The subjects were divided into three groups based on disease severity according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages. Relationship between energy and protein intake with pulmonary function was assessed. Energy and protein intake were lower than the calculated energy and protein demand for all groups. Significant relationship was found between the amount of protein intake extrapolated from food frequency questionnaire with Forced Vital Capacity (FVC) (r=0.2, P=0.02) and Vital Capacity (VC) (r=0.3, P=0.008). The results of the study suggest that accurate evaluation of protein and energy intake and requirements should be included in the goals of medical treatment of COPD patients.