Sarcopenia correlates with systemic inflammation in COPD
Authors Byun MK, Cho EN, Chang J, Ahn CM, Kim HJ
Received 21 December 2016
Accepted for publication 30 January 2017
Published 20 February 2017 Volume 2017:12 Pages 669—675
Checked for plagiarism Yes
Review by Single-blind
Peer reviewers approved by Dr Charles Downs
Peer reviewer comments 2
Editor who approved publication: Dr Richard Russell
Min Kwang Byun,1 Eun Na Cho,1 Joon Chang,2 Chul Min Ahn,1 Hyung Jung Kim1
1Division of Pulmonology, Department of Internal Medicine, Gangnam Severance Hospital, 2Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
Background: Muscle wasting and chronic inflammation are predominant features of patients with COPD. Systemic inflammation is associated with an accelerated decline in lung function. In this study, the prevalence of sarcopenia and the relationships between sarcopenia and systemic inflammations in patients with stable COPD were investigated.
Materials and methods: In a cross-sectional design, muscle strength and muscle mass were measured by handgrip strength (HGS) and bioelectrical impedance analysis in 80 patients with stable COPD. Patients (≥40 years old) diagnosed with COPD were recruited from outpatient clinics, and then COPD stages were classified. Sarcopenia was defined as the presence of both low muscle strength (by HGS) and low muscle mass (skeletal muscle mass index [SMMI]). Levels of circulating inflammatory biomarkers (IL-6 and high-sensitivity TNFα [hsTNFα]) were measured.
Results: Sarcopenia was prevalent in 20 (25%) patients. Patients with sarcopenia were older, had lower body mass index, and a higher percentage of cardiovascular diseases. In addition, they had significantly higher modified Medical Research Council scores and lower 6-minute walk distance than those without sarcopenia. HGS was significantly correlated with age, modified Medical Research Council score, and COPD Assessment Test scores. Both HGS and SMMI had associations with IL-6 and hsTNFα (HGS, r=-0.35, P=0.002; SMMI, r=-0.246, P=0.044) level. In multivariate analysis, old age, lower body mass index, presence of cardiovascular comorbidities, and higher hsTNFα levels were significant determinants for sarcopenia in patients with stable COPD.
Conclusion: Sarcopenia is very common in patients with stable COPD, and is associated with more severe dyspnea-scale scores and lower exercise tolerance. Systemic inflammation could be an important contributor to sarcopenia in the stable COPD population.
Keywords: sarcopenia, muscle wasting, handgrip strength, systemic inflammation, COPD