The Impact of Plasma Ghrelin Levels On Weight Loss After Gastrectomy.

Ghrelin是生长激素促分泌素受体的内源性配体。它主要在胃中合成，并模拟下丘脑食欲中心。因此，我们测试了胃切除术后血浆ghrelin水平是否与术后体重指数（BMI）降低的百分比相关，以及ghrelin治疗是否改善GH分泌和食欲。我们研究了1995年至2003年在长崎大学医院接受手术的53例患者，年龄38至89岁（平均67岁）。16例患者分别于术前、术后2周、4周采血。术后1年以上34例。测定胃癌行远端或全胃切除术、胰腺癌或胆总管癌行胰十二指肠切除术患者的BMI、血清IGF-I水平、血浆ghrelin和leptin水平。BMI的下降百分比由当前BMI与术前BMI之间的差值计算。结果表明，慢性期胃切除术后，胃体质量指数（BMI）下降率与血浆ghrelin水平呈显著正相关（r=0.734，p<0.001）。相比之下，虽然胰腺切除术后BMI也降低，但血浆ghrelin水平没有变化。与BMI不同，BMI降低%与血浆瘦素水平无关。Ghrelin治疗改善了胃部分切除术患者的GH分泌和食欲，这些结果支持了胃切除术后体重减轻部分由Ghrelin缺乏以及营养吸收缺陷解释的假设。

Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor. It is synthesized predominantly in the stomach and s simulates the hypothalamic appetite center. Therefore, we tested whether plasma ghrelin levels after gastrectomy were correlated with the percentage postoperative reduction in body mass index (BMI), and whether ghrelin treatment improved GH secretion and appetite.We studied 53 patients, aged 38 to 89 years (average 67 years), operated on in Nagasaki University Hospital from 1995 to 2003. 16 patients were sampling their blood at before, 2 weeks and 4 weeks after gastrectomy. 34 patients were more than 1 year after operation. BMI, serum IGF-I levels, plasma ghrelin and leptin levels were measured in patients with distal or total gastrectomy due to gastric cancer, as well as after pancreatico-duodenectomy due to pancreatic cancer or common bile duct cancer. The percentage reduction in BMI was calculated from the difference between the present BMI and the BMI before operation. Furthermore, the patient with distal gastrectomy was treated by ghrelin infusion (2μg/kg) for ten days.Our results showed that % BMI reduction was significantly correlated with plasma ghrelin level after gastrectomy at chronic stage (r=0.734, p<0.001). In contrast, although BMI was also reduced after pancreatico-duodenectomy, plasma ghrelin levels were unchanged. Unlike BMI, % reduction of BMI is not correlated with plasma leptin level. Ghrelin treatment improves GH secretion and appetite in the patient with partial gastrectomy.These results lend support to the hypothesis that post-gastrectomy weight loss is partly explained by ghrelin deficiency as well by defective nutrient absorption.