Comparison of 5% versus 15% sucrose intakes as part of a eucaloric diet in overweight and obese subjects: effects on insulin sensitivity, glucose metabolism, vascular compliance, body composition and lipid profile. A randomised controlled trial.

AIMS: The effect of dietary sucrose on insulin resistance and the pathogenesis of diabetes and vascular disease is unclear. We assessed the effect of 5% versus 15% sucrose intakes as part of a weight maintaining, eucaloric diet in overweight/obese subjects. METHODS: Thirteen subjects took part in a randomised controlled crossover study (M:F 9:4, median age 46 years, range 37-56 years, BMI 31.7±0.9 kg/m(2)). Subjects completed two 6 week dietary periods separated by 4 week washout. Diets were designed to have identical macronutrient profile. Insulin action was assessed using a two-step hyperinsulinaemic euglycaemic clamp; glucose tolerance, vascular compliance, body composition and lipid profiles were also assessed. RESULTS: There was no change in weight or body composition between diets. There was no difference in peripheral glucose utilization or suppression of endogenous glucose production. Fasting glucose was significantly lower after the 5% diet. There was no demonstrated effect on lipid profiles, blood pressure or vascular compliance. CONCLUSION: A low-sucrose diet had no beneficial effect on insulin resistance as measured by the euglycaemic glucose clamp. However, reductions in fasting glucose, one hour insulin and insulin area under the curve with the low sucrose diet on glucose tolerance testing may indicate a beneficial effect and further work is required to determine if this is the case. Clinical Trial Registration number ISRCTN50808730.

All patients with 'idiopathic' hypopituitarism should be screened for hemochromatosis.

Hypopituitarism usually occurs as the result of a pituitary tumour or as a consequence of its treatment. If, however, pituitary imaging is negative then an alternative diagnosis should be sought. Patients are often diagnosed as having idiopathic hypopituitarism when imaging is normal. Our objective is to highlight the importance of screening for hemochromatosis in patients with presumed 'idiopathic' hypopituitarism. Our patients presented initially with biochemical hypopituitarism and, after initial investigation and normal imaging, were labelled as having idiopathic disease. They subsequently developed iron overload in cardiac and hepatic tissue respectively requiring regular venesection to deplete body stores. Genetic analysis revealed homozygosity for the C282Y mutation in our first patient thus explaining his more severe iron overload whereas our second case was a heterozygote for the same mutation, with iron overload confirmed on liver biopsy. We recommend that iron studies are performed in all patients who present with hypopituitarism and normal pituitary imaging. This may lead to reversal of the hypopituitarism and avoid development of any systemic consequences of hemochromatosis.