Effects of Gastric Sleeve Surgery in the Serum Levels of GH, IGF-1 and IGF-binding Protein 2 in Morbidly Obese Patients

Abstract

Background Bariatric or weight loss surgery is an effective treatment for severe obesity. Reduced calorie intake or malabsorption are not the only mechanism, alterations in the activity of certain hormones and neurotransmitters are also the contributory mechanisms. In this study, we investigated the levels of GH, IGF-1 and IGF-binding protein (IGFBP-2) after bariatric surgery in obese individuals.Method Plasma GH, IGF-1 and IGFBP-2 levels were measured by ELISA in 33 obese (BMI >38.3) healthy male subjects age ranged from 25 to 50 years before and six months after gastric sleeve surgery. Plasma glucose, BMI, insulin, HOMA-IR and lipid profile were also investigated.Results Systemic GH (from 12.32±1.3 to 50.97±0.339 ρg/mL, P<0.001) and IGFBP-2 (51.86±11.21 to 68.81±13.36 ρg/mL, P<0.001) levels were elevated after bariatric surgery. However there was no change in IGF-1 levels. BMI (from 52.18±9.86 Kg/m2 to 40.11±8.92 Kg/m2, P<0.001), insulin (19.35±0.304 mIU/L to 8.80±0.181 mIU/L, P<0.001) and Homeostatic model assessment- Insulin resistance (HOMA-IR) index was also reduced from 6.48+0.164 to 2.52 ± 0.061 (p<0.001) were also reduced 6 months after bariatric surgery. Cholesterol, high density lipoproteins (HDL), and low density lipoproteins (LDL) levels were increased after surgery (4.26±0.027 to 5.12±0.026 mmol/L and 0.90±0.007 to 1.55±0.011 mmol/L and 2.62±0.02 to 2.98±0.022 mmol/L, P<0.001) respectively. There was no correlation between GH, IGF-1, IGFBP-2and insulin and lipid parameters.Conclusions Our study suggests that improved circulating GH and IGFBP-2 levels associated with increased levels cholesterol and triglycerides may be an endocrine response to mediate beneficial effects of bariatric surgery.