Garcia Jose M, Iyer Dinakar, Poston Walker S C, Marcelli Marco, Reeves Rebecca, Foreyt John, Balasubramanyam Ashok
Translational Metabolism Unit, Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX 77030, USA.
Obesity (Silver Spring). 2006 Oct;14(10):1716-23. doi: 10.1038/oby.2006.197.
Ghrelin is postulated to be an orexigenic signal that promotes weight regain after weight loss (WL). However, it is not known whether this putative effect of ghrelin is sustained after weight stabilization. The objective of this study was to investigate the relationship of plasma ghrelin concentrations to active WL and weight maintenance in obese subjects.
This study was a randomized clinical trial, with a 12-month follow-up period. Obese Mexican-American women matched for age and BMI were randomized to a 12-month WL program (n = 25) or no intervention (controls, n = 23). Interventions included diet, exercise, and orlistat. Body weight and fasting ghrelin, leptin, insulin, and glucose concentrations were measured at baseline and 6 and 12 months.
The WL group lost 8.5% of body weight after 6 months and maintained the new weight for the next 6 months. Ghrelin concentrations increased significantly at 6 months but returned to baseline at 12 months. Baseline ghrelin concentrations were directly related to the degree of WL achieved after 12 months. Controls experienced no change in BMI or ghrelin levels. There were no associations between plasma ghrelin and leptin or insulin concentrations.
Consistent with previous results, ghrelin rises in response to WL, perhaps as a counterregulatory mechanism. However, the present results indicate that ghrelin concentrations return to baseline with sustained weight maintenance, suggesting that its effects are unlikely to regulate long-term energy balance. Baseline ghrelin concentrations are related to the degree of WL that can be achieved by active weight reduction.
胃饥饿素被认为是一种促食欲信号，可促进体重减轻（WL）后体重反弹。然而，胃饥饿素的这种假定作用在体重稳定后是否持续尚不清楚。本研究的目的是调查肥胖受试者血浆胃饥饿素浓度与主动体重减轻和体重维持之间的关系。
本研究是一项随机临床试验，随访期为12个月。将年龄和体重指数相匹配的肥胖墨西哥裔美国女性随机分为12个月的体重减轻计划组（n = 25）或无干预组（对照组，n = 23）。干预措施包括饮食、运动和奥利司他。在基线、6个月和12个月时测量体重以及空腹胃饥饿素、瘦素、胰岛素和葡萄糖浓度。
体重减轻组在6个月后体重减轻了8.5%，并在接下来的6个月维持了新体重。胃饥饿素浓度在6个月时显著升高，但在12个月时恢复到基线水平。基线胃饥饿素浓度与12个月后实现的体重减轻程度直接相关。对照组的体重指数和胃饥饿素水平没有变化。血浆胃饥饿素与瘦素或胰岛素浓度之间没有关联。
与先前的结果一致，胃饥饿素会因体重减轻而升高，这可能是一种反调节机制。然而，目前的结果表明，随着体重的持续维持，胃饥饿素浓度会恢复到基线水平，这表明其作用不太可能调节长期能量平衡。基线胃饥饿素浓度与通过主动减重可实现的体重减轻程度有关。
