Quadriceps muscle atrophy and inflammatory markers in COPD patients

Abstract BackgroundCOPD (chronic obstructive pulmonary disease) is a systemic chronic inflammatory disease manifested by increased proinflammatory protein and cytokine levels. In this study, we aimed to investigate whether there is any correlation between systemic inflammatory mediators (CRP, ESR, PCT, IL-6, IL-1β, and TNF-α) and quadriceps muscle atrophy in patients with COPD.MethodsThe study group included forty patients with consecutive COPD followed at the Outpatient Pulmonology Unit of Imam Reza Hospital, Tabriz, Iran. Depth of quadriceps muscle was measured by B-mode ultrasonography using an 8 MHz 5.6 cm linear transducer array. Serum levels of CRP, PCT, IL-1β, IL-6 and TNF-α and the ESR were also measured. All patients were evaluated in three stages; the first day of mechanical ventilator admission, 48 hours later and at the seventh day.ResultsThe results showed that the depth of quadriceps muscle on the seventh day after mechanical ventilator admission was significantly lower than of the first day (P = 0.0008). Statistical analysis showed a significant difference between the level of all systemic biomarkers on day 1 and day 7 (P < 0.05). The correlation study showed the significant negative associations between systemic inflammation markers and depth of quadriceps muscle. We found that the increased level of systemic inflammation biomarkers such as ESR, CRP and PCT were associated with reduced quadriceps depth in COPD patients. Moreover, evaluation of proinflammatory cytokines in COPD patients showed that the elevated IL-1β, IL-6, and TNF-α levels were associated with quadriceps atrophy. ConclusionThe main finding of this study is the positive correlation of systemic biomarkers of inflammation with quadriceps muscle atrophy in COPD patients over 7 days of mechanical ventilator admission.