Ju Chun-Rong, Chen Rong-Chang
State Key Lab of Respiratory Disease, Guangzhou Institute of Respiratory Disease, the First Affiliated Hospital of Guangzhou Medical College, China.
Zhonghua Nei Ke Za Zhi. 2011 Jun;50(6):465-8. doi: 10.3760/cma.j.issn.0578-1426.2011.06.005.
To investigate the prevalence and severity of malnutrition in patients with stable chronic obstructive pulmonary disease (COPD), analyze serum levels of myostatin, tumor necrosis factor alpha (TNFα) and C reactive protein (CRP), and investigate the relationship between serum myostatin and malnutrition in COPD.
Seventy-one patients with stable COPD and 60 age-matched healthy volunteers were recruited in this study. Pulmonary function was tested in all of the subjects and the severity of malnutrition was evaluated by a multiple-parameter malnutritional index (MNI). Based on the MNI scores, patients with COPD were divided into group I (MNI ≥ 5 score) and group II (MNI < 5 score), the former represents the patients with severe or very severe malnutrition while the latter represents the patients with mild or without malnutrition. Serum concentration of myostatin, TNFα and CRP were measured by enzyme-linked immunosorbent assay.
The MNI score was significantly elevated in patients with COPD [(7.75 ± 3.86) score] compared with the controls [(1.13 ± 0.96) score; P < 0.001], and 55 patients (77%) in COPD group I showed MNI ≥ 5 (9.30 ± 3.01) score. Serum myostatin concentration was significantly elevated in COPD group I [(12.18 ± 4.76) µg/L] than in COPD group II [(9.73 ± 2.85) µg/L] and controls [(7.93 ± 2.35) µg/L], with each P < 0.001. Serum TNFα concentration was also significantly elevated in patients with COPD compared with the controls (P < 0.001). Pearson correlation analysis showed that serum myostatin levels were significantly correlated with MNI scores (r = 0.438, P = 0.000) and TNFα levels (r = 0.234, P = 0.041) in COPD group (combined group I and II) while MNI scores were correlated inversely with BMI in COPD group (r = -0.530, P = 0.000). After stratified with subgroups, the correlation between myostatin levels and MNI scores was more significant and the correlation coefficient was higher (r = 0.464, P = 0.000) in COPD group I patients. Moreover, myostatin levels were inversely correlated with BMI (r = -0.287, P = 0.034) and forced expiratory volume in one second of the predicted value (r = -0.264, P = 0.049) in COPD group I patients.
Malnutrition commonly and substantially exists in patients with COPD; serum myostatin concentration is significantly elevated and is correlated with the severity of malnutrition in the patients. The elevation of serum myostatin may contribute to malnutrition in COPD patients.
探讨稳定期慢性阻塞性肺疾病（COPD）患者营养不良的患病率及严重程度，分析血清肌生成抑制素、肿瘤坏死因子α（TNFα）和C反应蛋白（CRP）水平，并研究COPD患者血清肌生成抑制素与营养不良之间的关系。
本研究招募了71例稳定期COPD患者和60例年龄匹配的健康志愿者。对所有受试者进行肺功能测试，并通过多参数营养不良指数（MNI）评估营养不良的严重程度。根据MNI评分，将COPD患者分为I组（MNI≥5分）和II组（MNI<5分），前者代表重度或极重度营养不良患者，后者代表轻度或无营养不良患者。采用酶联免疫吸附测定法检测血清肌生成抑制素、TNFα和CRP浓度。
与对照组[（1.13±0.96）分；P<0.001]相比，COPD患者的MNI评分显著升高[（7.75±3.86）分]，COPD I组中有55例患者（77%）的MNI≥5（9.30±3.01）分。COPD I组的血清肌生成抑制素浓度[（12.18±4.76）μg/L]显著高于COPD II组[（9.73±2.85）μg/L]和对照组[（7.93±2.35）μg/L]，P均<0.001。与对照组相比，COPD患者的血清TNFα浓度也显著升高（P<0.001）。Pearson相关性分析显示，COPD组（I组和II组合并）中血清肌生成抑制素水平与MNI评分（r=0.438，P=0.00）和TNFα水平（r=0.234，P=0.041）显著相关，而COPD组中MNI评分与BMI呈负相关（r=-0.530，P=0.000）。在亚组分层后，COPD I组患者中肌生成抑制素水平与MNI评分之间的相关性更显著，相关系数更高（r=0.464，P=0.000）。此外，COPD I组患者中肌生成抑制素水平与BMI（r=-0.287，P=0.034）和预计值的第一秒用力呼气量（r=-0.264，P=0.049）呈负相关。
COPD患者普遍且严重存在营养不良；血清肌生成抑制素浓度显著升高，且与患者营养不良的严重程度相关。血清肌生成抑制素升高可能导致COPD患者营养不良。
