Plasma Ghrelin Modulation in Gastric Band Operation and Sleeve Gastrectomy

Gastric band operation and sleeve gastrectomy are increasingly popular bariatric surgeries for weight loss. The purpose of this study is to investigate the changes in plasma ghrelin levels and hypothalamic ghrelin receptor expression with weight loss achieved through these surgeries. Twenty-four high fat diet-induced obese rats were used to investigate the effects of gastric band and sleeve operation on Body Mass Index, fat mass, plasma ghrelin levels, and hypothalamic growth hormone secretagogue receptor 1a (GHS-R 1a) protein expression in hypothalamus. In comparison, data of patients who received laparoscopic adjustable gastric banding (LAGB) and laparoscopic sleeve gastrectomy (LSG) in our hospital in 2005 were also summarized. Body weights and fat mass decreased significantly in rats that received operation. Plasma ghrelin concentrations in the sleeve group were 0.4-fold of control rats and about 2-fold of control in the gastric band group. GHS-R1a protein expression in hypothalamus was 1.5-fold in the sleeve group compared with control group, while it was only 0.9-fold in the gastric band group. Clinical data showed that patients in the LSG group lost 60% excess body weights in 2 years follow-up. After operation, fasting plasma ghrelin concentrations in LAGB was significantly higher than the LSG group. Both LAGB and LSG can decrease patients' excess body weights and fat mass. Plasma ghrelin levels are down-regulated with LSG operation but up-regulated with LAGB operation. Hypothalamic GHS-R1a expression is elevated in sleeve gastrectomy.