Effects of weight loss after bariatric surgery for morbid obesity on vascular endothelial growth factor-A, adipocytokines, and insulin.

BACKGROUND: Adipocytes regulate blood vessel formation, and in turn endothelial cells promote preadipocyte differentiation through the expression of proangiogenic factors, such as vascular endothelial growth factor (VEGF)-A. Some adipocytokines and hormones also have an effect on vascular development. OBJECTIVES: Our objectives were to analyze the relationship between weight and circulating VEGF-A in morbidly obese subjects before and after bariatric surgery, and investigate the relationship between circulating VEGF-A and certain adipocytokines and hormones regulating adipocytes. METHODS: A total of 45 morbidly obese women and nine lean females were included in the study. Patients underwent bariatric surgery: vertical banded gastroplasty (n=17), gastric bypass (n=17), and biliopancreatic diversion (n=11). Serum samples for VEGF-A, adiponectin, leptin, ghrelin, and insulin were obtained preoperatively and 9-12 months after surgery. RESULTS: Obese patients showed significantly higher VEGF-A levels than controls (306.3+/-170.3 vs. 187.6+/-91.9 pg/ml; P=0.04), decreasing to 246.1+/-160.4 after surgery (P<0.001), with no differences among surgical procedures. In controls there was an inverse correlation between VEGF-A and ghrelin (r=-0.85; P<.01), but not in obese patients. Leptin and insulin concentrations were increased in obese patients, with a significant decrease shown after weight loss with surgery. Conversely, adiponectin concentrations were lower in obese patients, with a significant increase shown after weight loss with surgery. Ghrelin was higher in controls than obese patients, decreasing after gastric bypass and biliopancreatic diversion, but not after vertical banded gastroplasty. CONCLUSION: Serum VEGF-A levels are significantly higher in obese patients than in lean controls, decreasing after weight loss with bariatric surgery, behaving similarly to other hormones related to adipose mass like leptin and insulin.

Peptide YY secretion in morbidly obese patients before and after vertical banded gastroplasty.

BACKGROUND: The Peptide YY (PYY) secretion pattern was assessed in morbidly obese (MO) patients before and after vertical banded gastroplasty (VBG). METHODS: 12 MO patients (10 women, 2 men) age 29-62 years, BMI 50.7 +/- 9.6 kg/m2, treated with a VBG were studied. Before surgery, blood samples were taken in basal conditions of fasting and 10, 15, 20, 30 and 60 min after the ingestion of a semiliquid test meal. This was repeated in the same patients 6 and 12 months after VBG. Blood samples were also taken from 6 healthy non-obese subjects as controls. PYY plasma concentration was measured by radioimmunoassay with I125. RESULTS: There were statistically significant differences between the preoperative PYY concentration in MO patients compared to controls. After a VBG, PYY concentration varied significantly compared to the preoperative levels. There was no significant difference between the PYY concentrations in the MO patients after VBG and the controls. CONCLUSION: PYY concentration is lower in MO patients compared with non-obese. After VBG, PYY concentration gradually rises to the control levels.