Date Published: July 10, 2017
Publisher: Public Library of Science
Author(s): Li-Wen Lee, Chieh-Mo Lin, Hung-Chou Li, Pei-Lin Hsiao, An-Chi Chung, Chu-Jung Hsieh, Pi-Chi Wu, Shu-Feng Hsu, Stelios Loukides.
Chronic obstructive pulmonary disease (COPD) mainly affects middle-age and elderly adults. It is unclear if the presence of muscle wasting and fat accumulation in patients with COPD is age or disease-related. This study investigated the effect of age and COPD disease severity on body composition with the aim of identifying a biomarker(s) for COPD.
Healthy subjects and patients with COPD of different severity were recruited. Dual-energy X-ray absorptiometry was used to analyze total and segmental body composition. Subjects included in the analysis were classified into four groups: healthy young (aged 20–45 years) (n = 35), healthy old (aged ≥ 60 years) (n = 37), moderate COPD (n = 40), and severe COPD (n = 14).
In healthy old adults, leg and limb lean masses were lower by 10.6% and 8.5%, respectively, compared with healthy young adults (P < 0.05). Appendicular lean outcomes were significantly lower in the moderate COPD compared to the healthy old group and were significant lower in subjects with severe COPD compared to those with moderate COPD. All fat depots were similar for both young and old healthy subjects and subjects with moderate COPD, but significantly decreased in patients with severe COPD. This study examined the changes in total and segmental body composition with aging and COPD severity. It found that aging and COPD altered the body composition differently, and the effect was most pronounced in leg lean mass. Remarkably, differences in appendicular lean masses were seen in mild COPD although no changes in body weight or BMI were apparent compared with healthy young adults. In contrast, fat depot changes were only observed in severe COPD. Aging and COPD processes are multifactorial and additional longitudinal studies are required to explore both the quantitative and qualitative changes in body composition with aging and disease process.
Chronic obstructive pulmonary disease (COPD) is a group of diseases characterized by progressive airflow limitation, airway inflammation and extrapulmonary effects . Evidence of extrapulmonary systemic effects includes muscle wasting, osteoporosis, increased risk of cardiovascular disease, and increased inflammatory markers in the circulation [2, 3]. The prevalence of skeletal muscle wasting and dysfunction is 15% to 40% in patients with COPD, depending on the disease severity, leading to physical disability, exercise intolerance, and deaths [4, 5].
The study recruited 135 male subjects: 35 young healthy adults (aged 20–45 years), 45 old healthy adults (aged ≥ 60 years), 40 moderate COPD patients (GOLD 2), 14 severe COPD patients (GOLD 3), and one very severe COPD (GOLD 4) patients. Of the recruited healthy old subjects, eight (17.8%) were excluded from the study due to abnormal lung function tests (FEV1/FVC < 70%). The one subject with GOLD 4 was also excluded as a single subject was not sufficient for meaningful evaluation. The final analysis included 126 male subjects in four groups: the healthy young (n = 35), healthy old (n = 37), GOLD 2 (n = 40) and GOLD 3 (n = 14) groups. Chronic obstructive pulmonary disease is more commonly found in middle age and older people and is associated with muscle wasting. Age can also impact muscle mass and body composition; hence it is not clear what changes in body composition is associated with COPD or is due to age. The aim of this study was to evaluate the differences in body composition between younger and older healthy subjects and older subjects with and without COPD. In healthy subjects, increasing age was only associated with a decrease in leg lean mass. No difference was observed with respect to arm and trunk lean mass or fat depots. In subjects with GOLD 2, both arm and leg lean mass decreased compared with healthy older subjects and no change was observed in the other variables. Cachexia appears more prevalent in advanced COPD [4, 7], and as expected, subjects with GOLD 3 had significant reduction in all body composition parameters compared with healthy subjects and subjects with GOLD 2, except for percentage body fat and BMD. Our study suggested that age and COPD severity primarily impacted lean variables rather than fat and bone variables. This study examined changes in total and segmental body composition with aging and COPD severity. The results indicate that aging and COPD altered body composition differently,and the effect was most pronounced in leg lean mass. Remarkably, differences in appendicular lean masses were seen in GOLD 2 patients, although no changes in body weight of BMI were apparent compared with healthy young adults. In contrast, fat depot changes were only observed in GOLD 3 patients. Aging and COPD processes are multifactorial and complex and therefore, additional longitudinal studies are required to explore both the quantitative and qualitative changes in body composition with aging and disease process. Source: http://doi.org/10.1371/journal.pone.0180928