ObjectivesRoux-en-Y gastric bypass (RYGB) has greater efficacy for weight loss in obese patients than gastric banding (BAND) surgery. We hypothesise that this may result from different effects on food hedonics via physiological changes secondary to distinct gut anatomy manipulations.DesignWe used functional MRI, eating behaviour and hormonal phenotyping to compare body mass index (BMI)-matched unoperated controls and patients after RYGB and BAND surgery for obesity.ResultsObese patients after RYGB had lower brain-hedonic responses to food than patients after BAND surgery. RYGB patients had lower activation than BAND patients in brain reward systems, particularly to high-calorie foods, including the orbitofrontal cortex, amygdala, caudate nucleus, nucleus accumbens and hippocampus. This was associated with lower palatability and appeal of high-calorie foods and healthier eating behaviour, including less fat intake, in RYGB compared with BAND patients and/or BMI-matched unoperated controls. These differences were not explicable by differences in hunger or psychological traits between the surgical groups, but anorexigenic plasma gut hormones (GLP-1 and PYY), plasma bile acids and symptoms of dumping syndrome were increased in RYGB patients.ConclusionsThe identification of these differences in food hedonic responses as a result of altered gut anatomy/physiology provides a novel explanation for the more favourable long-term weight loss seen after RYGB than after BAND surgery, highlighting the importance of the gut–brain axis in the control of reward-based eating behaviour.

Free cortisol index is a reliable and user-friendly measure of serum free cortisol.

Background: Bile acids (BAs) play an important role in releasing incretin hormones via the enteroendocrine L-cell surface TGR5 receptors. The aim of this study was to investigate the difference in BA concentration at baseline and in response to a meal stimulus between type 2 diabetes mellitus (T2DM) and a matched normoglycaemic group. Materials and methods: A cross-sectional study of 12 patients with known T2DM and 12 matched normoglycaemic controls compared BA fractions after an overnight fast and following a standard meal. Results: The T2DM group had higher baseline glucose (P < 0.001), but baseline total BA, total glycine conjugated BAs (GCBA) and total taurine conjugated BA (TCBA) were similar between both groups. The T2DM group compared to the normoglycaemic group had a higher post-prandial peak change in total BAs 4.28 (3.51-5.38) mmol/L vs. 0.88 (0.60-1.57) mmol/L (P < 0.001) and peak total GCBA 2.77 (1.07-4.19) mmol/L vs. 0.94 (0.34-1.15) mmol/L (P < 0.0001), but similar peak total TCBA 0.36 (0.02-0.76) mmol/L vs. 0.08 (0.04-0.22) mmol/L (P¼0.91). Conclusion: The post-prandial bile acid response is elevated in obese patients with T2DM compared to matched normoglycaemic individuals.

Weight loss following RYGB is associated with an increase in post-prandial plasma BA response due to larger amounts of glycine-conjugated BAs. This suggests up regulation of BA production and conjugation after RYGB.

It is desirable that young women with primary ovarian failure achieve normal peak bone mass to reduce the subsequent risk of osteoporosis, and that there are management strategies to replace bone that is already lost. While estrogen (E 2 ) is generally considered to prevent bone loss by suppressing bone resorption, it is now recognized that estrogen also exerts an anabolic effect on the human skeleton. In this study, we tested whether estrogen could increase bone mass in women with primary ovarian failure. We studied the mechanism underlying this by analyzing biochemical markers of bone turnover and iliac crest biopsy specimens obtained before and 3 years after E 2 replacement. Twenty-one women with Turner's syndrome, aged 20 -40 years, were studied. The T scores of bone mineral density at lumbar spine and proximal femur at baseline were ؊1.4 and -1.1, respectively. Hormone replacement was given as subcutaneous E 2 implants (50 mg every 6 months) with oral medroxy progesterone. Serum E 2 levels increased incrementally from 87.5 pM at baseline to 323, 506, 647, and 713 pM after 6 months and 1, 2, and 3 years of hormone replacement therapy (HRT), respectively. The bone mineral density at the lumbar spine and proximal femur increased after 3 years to T scores of -0.