Abstract
BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) and sarcopenia experience poorer clinical prognosis. Although sedentary behaviour (SB) is common risk factor for COPD, its relationship with sarcopenia in this specific population remains unclear. METHODS: This is a cross-sectional survey of participants aged 40 and above with COPD, involving 27 communities and 2 hospitals' outpatient departments. The definition of sarcopenia was in accordance with the Asian Expert Consensus Criteria for sarcopenia. SB and physical activity (PA) were evaluated using the short form of the international physical activity questionnaires (IPAQ-SF). SB was categorized into 4 categories: less than 4 h/day, 4 to 6 h/day, 6 to 8 h/day, and 8 h or more per day. PA was classified into light-intensity and moderate-to-vigorous intensity physical activity (LPA and MVPA). Multiple logistic regression and restricted cubic spline (RCS) were performed to investigate the rates of association between sarcopenia and SB. Subgroups was analysed by gender. RESULTS: A total of 414 COPD patients with complete information were included in this trial. The overall prevalence of sarcopenia was 22.9%. Participants with sarcopenia had longer of SB (P = 0.008) and less MVPA (P < 0.001) compared to those without sarcopenia. After adjustment for confounders, SB showed a significant association with sarcopenia (adjusted β = 1.47, 95% CI = 1.28-1.68). The participants who spent 6 or more hours on SB had a greater odds ratio for sarcopenia (= 6-8 h: adjusted OR = 2.97, 95% CI = 1.14-7.70; > 8 h: OR = 9.14, 95% CI = 3.59-23.22) than the participants who spent less than 4 h. The results of RCS indicated that when SB exceeded 5.7 h/day, a trend towards a significant increasing prevalence of sarcopenia was observed with increased SB. This trend was also observed across genders, differing only in the threshold values (male: SB = 5.7 h; female: SB = 8.0 h). CONCLUSION: SB was an independent determinant of sarcopenia, independent of MVPA, and the prevalence of sarcopenia increases as SB increases within a certain range. This study advocated for the integration of SB in the self-management strategies for patients with COPD. Regardless of their engagement in MVPA, it was crucial to regulate SB.