Razzaghy-Azar Maryam, Nourbakhsh Mitra, Pourmoteabed Abdolreza, Nourbakhsh Mona, Ilbeigi Davod, Khosravi Mohsen
Metabolic Disorders Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, 1411715851 Tehran, Iran.
H. Aliasghar Hospital, Iran University of Medical Sciences, 1449614535 Tehran, Iran.
J Clin Med. 2016 Jun 23;5(7):61. doi: 10.3390/jcm5070061.
Ghrelin is a 28-amino acid peptide with an orexigenic property, which is predominantly produced by the stomach. Acylated ghrelin is the active form of this hormone. Obestatin is a 23-amino acid peptide which is produced by post-translational modification of a protein precursor that also produces ghrelin. Obestatin has the opposite effect of ghrelin on food intake. The aim of this study was to evaluate acylated ghrelin and obestatin levels and their ratio in obese and normal-weight children and adolescents, and their association with metabolic syndrome (MetS) parameters.
Serum acyl-ghrelin, obestatin, leptin, insulin, fasting plasma glucose (FPG), lipid profile, and malondialdehyde (MDA) were evaluated in 73 children and adolescents (42 obese and 31 control). Insulin resistance was calculated by a homeostasis model assessment of insulin resistance (HOMA-IR). MetS was determined according to IDF criteria.
Acyl-ghrelin levels were significantly lower in obese subjects compared to the control group and lower in obese children with MetS compared to obese subjects without MetS. Obestatin was significantly higher in obese subjects compared to that of the control, but it did not differ significantly among those with or without MetS. Acyl-ghrelin to obestatin ratio was significantly lower in obese subjects compared to that in normal subjects. Acyl-ghrelin showed significant negative and obestatin showed significant positive correlations with body mass index (BMI), BMI Z-score, leptin, insulin, and HOMA-IR. Acyl-ghrelin had a significant negative correlation with MDA as an index of oxidative stress.
Ghrelin is decreased and obestatin is elevated in obesity. Both of these hormones are associated with insulin resistance, and ghrelin is associated with oxidative stress. The balance between ghrelin and obestatin seems to be disturbed in obesity.
胃饥饿素是一种具有促食欲特性的28个氨基酸的肽，主要由胃产生。酰基化胃饥饿素是这种激素的活性形式。肥胖抑制素是一种23个氨基酸的肽，由一种也产生胃饥饿素的蛋白质前体经翻译后修饰产生。肥胖抑制素对食物摄入的作用与胃饥饿素相反。本研究的目的是评估肥胖和正常体重儿童及青少年中酰基化胃饥饿素和肥胖抑制素的水平及其比值，以及它们与代谢综合征（MetS）参数的关联。
对73名儿童和青少年（42名肥胖者和31名对照者）进行血清酰基化胃饥饿素、肥胖抑制素、瘦素、胰岛素、空腹血糖（FPG）、血脂谱和丙二醛（MDA）评估。通过胰岛素抵抗稳态模型评估（HOMA-IR）计算胰岛素抵抗。根据国际糖尿病联盟（IDF）标准确定代谢综合征。
与对照组相比，肥胖受试者的酰基化胃饥饿素水平显著降低，与无MetS的肥胖受试者相比，患有MetS的肥胖儿童的酰基化胃饥饿素水平更低。与对照组相比，肥胖受试者的肥胖抑制素水平显著更高，但在有或无MetS的受试者中差异不显著。与正常受试者相比，肥胖受试者的酰基化胃饥饿素与肥胖抑制素比值显著更低。酰基化胃饥饿素与体重指数（BMI）、BMI Z评分、瘦素、胰岛素和HOMA-IR呈显著负相关，肥胖抑制素与上述指标呈显著正相关。酰基化胃饥饿素与作为氧化应激指标的MDA呈显著负相关。
肥胖时胃饥饿素降低，肥胖抑制素升高。这两种激素均与胰岛素抵抗有关，且胃饥饿素与氧化应激有关。肥胖时胃饥饿素和肥胖抑制素之间的平衡似乎受到干扰。
