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Phase angle as an indicator of sarcopenia and malnutrition in patients with chronic obstructive pulmonary disease
Tomoyuki Murakami1, Takeshi Kobayashi2, Hiroto Ono2
1Department of Rehabilitation, Tohoku Medical and Pharmaceutical University Wakabayashi Hospital, 2-29-1, Yamatomachi, Wakabayashi-ku, Sendai 984-8560, Miyagi, Japan; Department of Occupational Health, Tohoku University Graduate School of Medicine, 2-1, Seiryomachi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
Background:
Phase angle (PhA), which is measured using bioelectrical impedance analysis, is an indicator of muscle quality and malnutrition. PhA has been shown to be correlated with sarcopenia and malnutrition; however, studies on patients with chronic obstructive pulmonary disease (COPD) are limited. In this study, we investigated the correlation between PhA and sarcopenia and malnutrition and determined the cutoff values of PhA for those in patients with COPD.
Methods:
This study included 105 male patients with COPD (mean age 75.7 ± 7.7 years, mean forced expiratory volume in 1s % predicted [%FEV1] 57.0 ± 20.1%) and 12 male controls (mean age 74.1 ± 3.8 years) who were outpatients between December 2019 and March 2024. PhA was measured using the InBody S10, and its correlation with sarcopenia and malnutrition was assessed. The cutoff PhA values for sarcopenia and malnutrition were determined using receiver operating characteristic curves.
Results:
The prevalence rates of sarcopenia and malnutrition were 31% and 22%, respectively, in patients with COPD. PhA significantly correlated with sarcopenia- and malnutrition-related indicators. Multivariate logistic regression analysis independently correlated PhA with sarcopenia and malnutrition. The cutoff values of the PhA for sarcopenia and malnutrition were 4.75° (AUC = 0.78, 95% CI = 0.68-0.88) and 4.25° (AUC = 0.75, 95% CI = 0.63-0.86), respectively.
Conclusions:
PhA was significantly correlated with sarcopenia and malnutrition in Japanese patients with COPD and may be a useful diagnostic indicator.
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