Moreover, in a cross-sectional study of patients with COPD,C-reactive protein levels were found to be significantly higher in patients with a lowBMI (≤21 kg/m2) than in those with a normal-to-high BMI (>21kg/m2), and an elevated C-reactive protein level was considered to be anindicator of malnutrition in patients with COPD (23). This evidence concerns the gene CRP and nutritional deficiency disease.