BACKGROUND: Obese patients are often affected by hypertension, dyslipidaemia, impaired glucose metabolism, and suffer from cardiovascular disease (CVD), related to the characteristic metabolic alterations. AIM OF THE STUDY: To evaluate reduction of risk factors for CVDs in morbid-obese patients (body mass index (BMI)440 kg/m 2 ) after weight loss upon bariatric surgery intervention of biliary-intestinal bypass. SUBJECTS: 45 (17 men, 28 women) morbid-obese patients (age: 19-49 y, BMI440 kg/m 2 ). All patients were selected on the basis of medical history, physical and biochemical evaluation and of psychiatric tests, which were performed on all individuals admitted to our Day Hospital to verify the safety of surgical intervention. MEASUREMENTS: Body weight, body composition (by dual X-ray absorptiometry, DXA), blood pressure, lipid profile, fibrinogen and glucose metabolism were monitored at baseline and 1, 3, 6, 9, 12, 24 and 36 months after surgery. RESULTS: A significant and persistent weight loss was present in all patients at the end of the 3 y follow-up period (Po0.001), with a progressive reduction of total and trunk fat mass as evaluated by means of DXA. Additionally, a parallel significant reduction in systolic (Po0.001) and diastolic (Po0.001) blood pressure was observed. Total and LDL cholesterol were significantly reduced (Po0.001), while HDL showed no modifications; triglycerides declined progressively during the 3 y followup (Po0.001). Fibrinogen decreased from 364.5782.4 to 266.4745.7 mg/dl at the end of the period (Po0.001). Fasting glucose levels and glucose levels 120 min after an oral glucose tolerance test were reduced from 95.1720.3 to 78.679.1 mg/dl (Po0.001) and from 116.9734.7 to 77.6715.5 mg/dl (Po0.001), respectively, at baseline and at the end of the study. Moreover, fasting insulin decreased from 30.0720.4 to 8.672.9 mUI/ml (Po0.001) after 3 y, while insulin levels after (120 min) oral glucose load decreased from 105.5761.5 to 12.076.0 mUI/ml (Po0.001). CONCLUSION: Our results show that biliary-intestinal bypass may represent a valid and alternative therapeutic approach in patients with morbid obesity since it induces a significant and stable reduction of body weight and obesity-related risk factors for CVD.