Hypothalamic Function Before and After Bariatric Surgery

Inclusion criteria

• Patients aged 35-65 years;
• BMI > 40 kg/m2;
• BMI > 35 and <40 kg/m2 with co-morbidity, which is expected to improve after surgically-induced weight loss;
• A history of longstanding obesity (>5 years);
• Proven failed attempts to lose weight in a conventional way, or primarily successful weight loss with eventual weight regain;
• Intention to adhere to a postoperative follow-up programme.

Exclusion criteria

• BMI> 50 or body weight > 150 kg (because it is impossible to safely put people above this weight on a standard table for MRI);
• Subjects with disease related obesity, i.e. Cushing or medication related obesity;
• Use of medication known to affect glucose or lipid metabolism (i.e. prednisone)
• Monogenetic diabetes: MODY, Mitochondrial diabetes;
• LADA (adult-onset latent autoimmune diabetes); detected by c-peptide measurement on screening.
• Impaired renal function (serum creatinine > 176 μmol/L);
• Leg ulcers, gangrene.
• Any genetic or psychiatric disease (e.g. fragile X syndrome, major depression) affecting the brain
• Any significant chronic disease
• Renal or hepatic disease
• Pregnancy
• Recent weight changes or attempts to loose weight (> 3 kg weight gain or loss, within the last 3 months)
• Aerobic exercise more that 3 times 60 minutes a week
• Alcohol consumption of more than 28 units per week at present or in the past
• Recent blood donation (within the last 2 months)
• Recent participation in other research projects (within the last 3 months), participation in 2 or more projects in one year
• Contra-indications to operative procedures as regular in bariatric surgery
• Contra-indications to MRI scanning