) suffer from an increased risk of cardiovascular disease, stroke, venous thromboembolism and all-cause mortality. Objectives: Because weight loss by bariatric surgery reduces cardiovascular and all-cause mortality, we hypothesized that the plasmatic clotting system might be involved in cardiovascular risk. Patients/Methods: Thirty-six MO patients [mean age 42 (±13) years; 29 female) were investigated before and 2 years after bariatric surgery. Thrombin generation was measured with a commercially available assay (Technothrombin-TGA,Technoclone). Metabolic parameters and parameters of the hemostatic system, such as tissue factor (TF), TF pathway inhibitor (TFPI), plasminogen activator inhibitor-1 (PAI-1) and prothrombinfragment 1.2 (F1.2), were determined. To investigate associations of changing parameters, deltas were calculated. Results: Metabolic parameters improved with a mean weight loss of 41 (±19) kg. Postoperatively, the lag phase was significantly extended compared with preoperative values [median (25th-75th percentile), 7 (4-12) vs. 12 (7-19) min, P = 0.005]. Peak thrombin decreased after weight loss from 345 (232-455) to 282 (111-388) nM (P = 0.015) and the area under the curve from 3962 (3432-5023) to 3227 (2202-4030) nM thrombin (P < 0.001). TF, PAI-1 and F1.2 significantly decreased after weight loss. Analyses of the deltas showed a significant correlation between peak thrombin and total cholesterol (r = 0.50), triglycerides (r = 0.46) and HbA1c (r = 0.55). Moreover, an inverse correlation was found between insulin resistance and the lag phase (r = )0.46). Conclusion: Thrombin generation, a marker of the overall coagulation potential, decreased significantly with weight reduction. This might, at least in part, explain the decreased risk of cardiovascular disease after bariatric surgery.

Our data show a high prevalence of micronutrient deficiency in patients with morbid obesity preoperatively and emphasize the importance of exact preoperative evaluation and adequate substitution as well as postoperative surveillance.

In morbidly obese adults reducing their weight by bariatric surgery, fasting PYY levels increased and GLP-1 concentrations decreased independently of each other. Therefore, the relationship between PYY and GLP-1 seems more complicated than might be anticipated from animal and in vitro studies.

KRZYZANOWSKA,KATARZYNA, FRIEDRICH MITTERMAYER, WALTER KRUGLUGER, HANS PETER KOPP, AND GUNTRAM SCHERNTHANER. Increase in visfatin after weight loss induced by gastroplastic surgery. Obesity. 2006;14:1886 -1889. Objective: The recently described adipokine visfatin is produced in visceral fat and has been suggested to influence insulin resistance. To investigate whether visfatin concentrations are related to changes in body weight, this adipokine was measured in insulin-resistant severely obese patients before and after gastroplastic surgery. Research Methods and Procedures: Visfatin, interleukin-6, high-sensitivity C-reactive protein, homeostasis model assessment of insulin resistance (HOMA-IR), and other clinical parameters were assessed in 36 severely obese subjects (28 female; mean age, 43 years) with a median BMI of 44.3 kg/m 2 (95% confidence interval, 43.3 to 48.1 kg/m 2 ). Results: After surgery, BMI decreased to a median of 31.9 kg/m 2 (30.1 to 35.1 kg/m 2 ) (p Ͻ 0.0001). Median visfatin concentrations increased significantly after weight loss [70.9 ng/mL (61.4 to 75.6 ng/mL) vs. 86.4 ng/mL (79.4 to 89.8 ng/mL); p Ͻ 0.0005]. This increase correlated with the decrease of insulin and HOMA-IR and was associated with a reduction in plasma interleukin-6 and high-sensitivity C-reactive protein concentrations. Discussion: Massive weight loss after gastroplastic surgery is accompanied by an increase in circulating concentrations of the novel adipokine visfatin. This increase correlates with the decrease in plasma insulin concentrations and HOMA-IR.

In contrast to previous weight loss studies involving gastric banding, ghrelin levels decreased and obestatin levels remained stable after massive weight loss in long-term follow-up. The favorable gastrointestinal hormone profiles observed are likely to contribute to the long-term weight loss success rate attributed to RYGB.