Yang Yi-meng, Sun Tie-ying, Liu Xin-min
Department of Medicine, Peking University First Hospital, Beijing 100034, China.
Chin Med J (Engl). 2006 Apr 20;119(8):628-33.
Leptin is a protein mainly secreted by adipocytes, and the major function of leptin was its role in body weight regulation. It is suggested that increased levels of circulating leptin may contribute to anorexia in pathologic conditions including chronic obstructive pulmonary disease (COPD). Recent studies have provided evidence for a link between leptin and proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha). This study aimed to explore the role of serum leptin in the malnutrition of COPD patients, and to observe the changes of serum leptin levels during acute exacerbation, also to investigate relationship between leptin and TNF-alpha.
Seventy-two COPD patients and 34 control subjects participated in this study. Seventy-two COPD patients were divided into 3 groups: group COPD IA (patients without malnutrition during acute exacerbation, n = 25), group COPD IB (patients without malnutrition during stable disease, n = 29), group COPD II (patients with malnutrition during stable disease, n = 18). To eliminate the effect of sex differences, all patients and controls were male. Body mass index (BMI), percent ideal body weight (IBW%), triceps skin-fold thickness (TSF), mid-upper arm circumference (MAC), mid-upper arm muscle circumference (MAMC), serum leptin and TNF-alpha levels, serum prealbumin (PA), serum transferrin (TF), serum albumin (Alb), total lymphocytes count (TLC), forced expiratory volume in one second (FEV(1)), maximal inspiration pressure (MIP) and maximal expiration pressure (MEP) were measured in all participants. Leptin levels were measured by radioimmunoassay. TNF-alpha levels were measured by ELISA. The between group difference and correlation of these parameters were analyzed.
Serum leptin levels were significantly lower in group COPD II [(4.07 +/- 3.42) ng/ml] than in group COPD IB [(9.72 +/- 6.67) ng/ml] and controls [(8.21 +/- 5.41) ng/ml] (P < 0.05). There was no statistically significant difference in serum leptin levels between group COPD IA [(10.82 +/- 6.40) ng/ml], group COPD IB [(9.72 +/- 6.67) ng/ml] and controls [(8.21 +/- 5.41) ng/ml]. There was no statistically significant difference in serum TNF-alpha levels between group COPD II [(8.03 +/- 3.37) pg/ml], group COPD IA [(8.90 +/- 1.60) pg/ml], and group COPD IB [(7.25 +/- 2.08) pg/ml]. There was no significant correlation between leptin and TNF-alpha in any group.
Leptin was not involved in anorexia and weight loss of COPD patients. There was no statistically significant difference in serum leptin levels between COPD patients during stable stage and acute exacerbation, and there was no significant correlation between TNF-alpha and leptin during the regulation of the energy balance in COPD patients.
瘦素是一种主要由脂肪细胞分泌的蛋白质，其主要功能是在体重调节中发挥作用。有研究表明，在包括慢性阻塞性肺疾病（COPD）在内的病理状态下，循环瘦素水平升高可能导致厌食。最近的研究为瘦素与肿瘤坏死因子-α（TNF-α）等促炎细胞因子之间的联系提供了证据。本研究旨在探讨血清瘦素在COPD患者营养不良中的作用，观察急性加重期血清瘦素水平的变化，并研究瘦素与TNF-α之间的关系。
72例COPD患者和34例对照者参与了本研究。72例COPD患者分为3组：COPD IA组（急性加重期无营养不良患者，n = 25），COPD IB组（稳定期无营养不良患者，n = 29），COPD II组（稳定期有营养不良患者，n = 18）。为消除性别差异的影响，所有患者和对照者均为男性。测量了所有参与者的体重指数（BMI）、理想体重百分比（IBW%）、肱三头肌皮褶厚度（TSF）、上臂中部周长（MAC）、上臂中部肌肉周长（MAMC）、血清瘦素和TNF-α水平、血清前白蛋白（PA）、血清转铁蛋白（TF）、血清白蛋白（Alb）、总淋巴细胞计数（TLC）、一秒用力呼气容积（FEV(1)）、最大吸气压力（MIP）和最大呼气压力（MEP）。瘦素水平采用放射免疫法测定。TNF-α水平采用ELISA法测定。分析了这些参数的组间差异和相关性。
COPD II组血清瘦素水平[(4.07±3.42) ng/ml]显著低于COPD IB组[(9.72±6.67) ng/ml]和对照组[(8.21±5.41) ng/ml]（P < 0.05）。COPD IA组[(10.82±6.40) ng/ml]、COPD IB组[(9.72±6.67) ng/ml]和对照组[(8.21±5.41) ng/ml]之间血清瘦素水平无统计学显著差异。COPD II组[(8.03±3.37) pg/ml]、COPD IA组[(8.90±1.60) pg/ml]和COPD IB组[(7.25±2.08) pg/ml]之间血清TNF-α水平无统计学显著差异。任何一组中瘦素与TNF-α之间均无显著相关性。
瘦素不参与COPD患者的厌食和体重减轻。COPD患者稳定期和急性加重期血清瘦素水平无统计学显著差异，在COPD患者能量平衡调节过程中，TNF-α与瘦素之间无显著相关性。
