Hospital of Chengdu University of Traditional Chinese Medicine, No. 39 Shi-er-qiao Road, Jinniu District, Chengdu, 610075, Sichuan, China.
Ya'an Polytechnic College, No. 130 Yucai Road, Yucheng District, Yaan, 625000, Sichuan, China.
Sci Rep. 2022 Feb 17;12(1):2679. doi: 10.1038/s41598-022-06636-3.
Ghrelin is the only known orexigenic gut hormone, and its synthesis, secretion and degradation are affected by different metabolic statuses. This meta-analysis aimed to investigate the potential differences in plasma acyl ghrelin (AG) and des-acyl ghrelin (DAG) concentrations between normal weight and obese adults. Systematic literature searches of PubMed, Embase and Web of Science through October 2021 were conducted for articles reporting AG or DAG levels in obesity and normal weight, and 34 studies with 1863 participants who met the eligibility criteria were identified. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated to evaluate group differences in circulating AG and DAG levels. Pooled effect size showed significantly lower levels of baseline AG (SMD: - 0.85; 95% CI: - 1.13 to - 0.57; P < 0.001) and DAG (SMD: - 1.06; 95% CI: - 1.43 to - 0.69; P < 0.001) in obese groups compared with healthy controls, and similar results were observed when subgroup analyses were stratified by the assay technique or storage procedure. Postprandial AG levels in obese subjects were significantly lower than those in controls when stratified by different time points (SMD : - 0.85, 95% CI: - 1.18 to - 0.53, P < 0.001; SMD : - 1.00, 95% CI: - 1.37 to - 0.63, P < 0.001; SMD : - 1.21, 95% CI: - 1.59 to - 0.83, P < 0.001). In healthy subjects, a postprandial decline in AG was observed at 120 min (SMD: - 0.42; 95% CI: - 0.77 to - 0.06; P = 0.021) but not in obese subjects (SMD: - 0.28; 95% CI: - 0.60 to 0.03; P = 0.074). The mean change in AG concentration was similar in both the obese and lean health groups at each time point (ΔSMD: 0.31, 95% CI: - 0.35 to 0.97, P = 0.359; ΔSMD: 0.17, 95% CI: - 0.12 to 0.46, P = 0.246; ΔSMD: 0.21, 95% CI: - 0.13 to 0.54, P = 0.224). This meta-analysis strengthens the clinical evidence supporting the following: lower baseline levels of circulating AG and DAG in obese individuals; declines in postprandial circulating AG levels, both for the healthy and obese individuals; a shorter duration of AG suppression in obese subjects after meal intake. These conclusions have significance for follow-up studies to elucidate the role of various ghrelin forms in energy homeostasis.
胃饥饿素是唯一已知的促食欲肠激素，其合成、分泌和降解受不同代谢状态的影响。本荟萃分析旨在研究正常体重和肥胖成年人之间血浆酰基胃饥饿素（AG）和去酰基胃饥饿素（DAG）浓度的潜在差异。通过系统检索PubMed、Embase 和 Web of Science，截至 2021 年 10 月，对报道肥胖和正常体重人群中 AG 或 DAG 水平的文章进行了检索，确定了 34 项符合入选标准的研究，共纳入 1863 名参与者。计算标准化均数差（SMD）及其 95%置信区间（CI），以评估循环 AG 和 DAG 水平的组间差异。合并效应大小显示肥胖组基线 AG（SMD：-0.85；95%CI：-1.13 至-0.57；P<0.001）和 DAG（SMD：-1.06；95%CI：-1.43 至-0.69；P<0.001）水平显著低于健康对照组，并且当按检测技术或储存程序进行亚组分析时，观察到了类似的结果。当按不同时间点分层时，肥胖受试者的餐后 AG 水平明显低于对照组（SMD：-0.85；95%CI：-1.18 至-0.53；P<0.001；SMD：-1.00；95%CI：-1.37 至-0.63；P<0.001；SMD：-1.21；95%CI：-1.59 至-0.83；P<0.001）。在健康受试者中，AG 在 120 分钟时出现餐后下降（SMD：-0.42；95%CI：-0.77 至-0.06；P=0.021），但在肥胖受试者中未出现（SMD：-0.28；95%CI：-0.60 至 0.03；P=0.074）。在每个时间点，肥胖和健康的受试者中 AG 浓度的平均变化相似（ΔSMD：0.31；95%CI：-0.35 至 0.97；P=0.359；ΔSMD：0.17；95%CI：-0.12 至 0.46；P=0.246；ΔSMD：0.21；95%CI：-0.13 至 0.54；P=0.224）。本荟萃分析进一步证实了以下结论：肥胖个体的循环 AG 和 DAG 基础水平较低；健康和肥胖个体的餐后循环 AG 水平下降；肥胖个体餐后 AG 抑制持续时间较短。这些结论对后续研究具有重要意义，有助于阐明各种胃饥饿素形式在能量平衡中的作用。
