Applied Nutrition and Dietetics, Department of Public Health, 'Federico II' University of Naples Medical School, Naples, Italy.
Respiratory Medicine and Pulmonary Rehabilitation Section, Clinic Center, Private Hospital, Naples, Italy.
Eur J Clin Nutr. 2017 Nov;71(11):1336-1340. doi: 10.1038/ejcn.2017.147. Epub 2017 Sep 13.
BACKGROUND/OBJECTIVES: Although loss of fat-free mass (FFM) and reduced muscle strength are highly prevalent in chronic obstructive pulmonary disease (COPD), only few data are available on the relationships of handgrip strength (HGS) and respiratory muscle strength with body composition in such disease. In particular, we aimed to assess whether raw bioelectrical impedance (BIA) variables were independent predictors of muscle strength in COPD patients, possibly more significant than anthropometric variables and BIA-based estimates of FFM.
SUBJECTS/METHODS: Two hundred and thirty-seven COPD patients (161 males and 76 females) underwent respiratory, anthropometric, BIA, HGS and respiratory muscle strength (maximum inspiratory or expiratory pressure=MIP and MEP) measurements. Bioimpedance index (BI index=height square/whole-body impedance) and phase angle (PhA) were considered as raw BIA variables. FFM was estimated using three disease-specific BIA equations.
In COPD patients a stronger correlation was observed between HGS and PhA compared to the ones with anthropometric variables or FFM estimates. Multiple regression analysis showed that combining BI index and PhA (plus age in male patients) accounted for 50.2% and 42.6% of the variance in HGS in male and female patients, respectively. Similarly, BI index and PhA emerged as predictors of both MIP and MEP in males, while in females MIP was related only to PhA and MEP only to BI index.
Raw BIA variables are independent and valuable predictors of HGS and respiratory muscle strength in COPD patients. BI index and PhA could provide useful information for evaluating body composition and better assessing muscle strength and physical fitness in COPD.
背景/目的：尽管在慢性阻塞性肺疾病（COPD）患者中，体脂肪量（FFM）减少和肌肉力量减弱的情况非常普遍，但关于此类疾病中手握力（HGS）和呼吸肌力量与身体成分的关系，仅有少数数据。特别是，我们旨在评估原始生物电阻抗（BIA）变量是否可作为 COPD 患者肌肉力量的独立预测因子，其意义可能比人体测量变量和基于 BIA 的 FFM 估计更重要。
受试者/方法：237 名 COPD 患者（161 名男性和 76 名女性）接受了呼吸、人体测量、BIA、HGS 和呼吸肌力量（最大吸气或呼气压力=MIP 和 MEP）测量。生物阻抗指数（BI 指数=身高平方/全身阻抗）和相位角（PhA）被视为原始 BIA 变量。使用三种疾病特异性 BIA 方程来估计 FFM。
在 COPD 患者中，HGS 与 PhA 的相关性比与人体测量变量或 FFM 估计值的相关性更强。多元回归分析显示，在男性和女性患者中，BI 指数和 PhA（加男性患者的年龄）联合可解释 HGS 变异的 50.2%和 42.6%。同样，BI 指数和 PhA 是男性 MIP 和 MEP 的预测因子，而在女性中，MIP 仅与 PhA 相关，MEP 仅与 BI 指数相关。
原始 BIA 变量是 COPD 患者 HGS 和呼吸肌力量的独立且有价值的预测因子。BI 指数和 PhA 可提供有关身体成分的有用信息，并能更好地评估 COPD 患者的肌肉力量和体能。
