Diagnostic efficiency of CRP and IL-6 in chronic obstructive pulmonary disease complicated with sarcopenia

LI Shengjie; ZHOU Qiaoyun; ZHANG Peng; QI Baolong; WANG Jin

doi:10.3969/j.issn.1002-266X.2026.01.006

Abstract：Objective To observe the diagnostic efficacy of serum C-reactive protein(CRP)and interleukin-6(IL-6)in chronic obstructive pulmonary disease(COPD)complicated with sarcopenia.Methods Totally 130 patients with COPD were divided into two groups based on the presence of sarcopenia:the COPD group(59 cases)and the COPD with sarcopenia group(71 cases).Serum CRP was detected by latex-enhanced immunoturbidimetry in both groups and serum IL-6 by ELISA.The receiver operating characteristic(ROC)curve was drawn to evaluate the diagnostic efficacy of serum CRP and IL-6 levels in COPD complicated with sarcopenia.Results The serum CRP and IL-6 levels in the COPD group were(3.03±2.43)mg/L and(2.44±1.60)pg/mL,respectively,and they were(32.23±25.17)mg/L and(10.24±8.75)pg/mL in the COPD complicated with sarcopenia group,respectively;there were statistically significant differences between these two groups(all P<0.05).The area under the curve of serum CRP level in diagnosing COPD with sarcopenia was 0.944(95%CI:0.900-0.987).When the cut-off value was 10.85 mg/L,the sensitivity and specificity of serum CRP level in diagnosing COPD with sarcopenia were 0.873 and 0.983,respectively.The area under the curve of serum IL-6 level in diagnosing COPD with sarcopenia was 0.816(95%CI:0.743-0.889).When the cut-off value was 6.98 pg/mL,the sensitivity and specificity of serum IL-6 level in diagnosing COPD with sarcopenia were 0.761 and 0.864,respective-ly.The area under the curve of serum CRP combined with IL-6 for the diagnosis of COPD with sarcopenia was 0.952(95%CI:0.913-0.991);the sensitivity and specificity for the diagnosis of COPD with sarcopenia were 0.897 and 0.905,re-spectively.Conclusion Serum CRP and IL-6 levels increase in patients with COPD complicated with sarcopenia;detec-tion of serum CRP and IL-6 levels is helpful in the diagnosis of COPD complicated with sarcopenia and has a high diagnos-tic efficacy.