Effects of short-term energy restriction on liver lipid content and inflammatory status in severely obese adults: Results of a randomized controlled trial using 2 dietary approaches.

Short-term very-low-energy diets (VLEDs) are used in clinical practice prior to bariatric surgery, but regimens vary and outcomes of a short intervention are unclear. We examined the effect of 2 VLEDs, a food-based diet (FD) and a meal-replacement plan (MRP; LighterLife UK Limited, Harlow, UK), over the course of 2 weeks in a randomized controlled trial. We collected clinical and anthropometric data, fasting blood samples, and dietary evaluation questionnaires. Surgeons took liver biopsies and made a visual assessment of the liver. We enrolled 60 participants of whom 54 completed the study (FD, n = 26; MRP, n = 28). Baseline demographic features, reported energy intake, dietary evaluation and liver histology were similar in the 2 groups. Both diets induced significant weight loss. Perceived difficulty of surgery correlated significantly with the degree of steatosis on histology. There were reductions in the circulating inflammatory mediators C-reactive protein, fetuin-A and interleukin-6 between baseline (pre-diet) and post-diet. The diets achieved similar weight loss and reduction in inflammatory biomarkers. There were no significant differences in perceived operative difficulty or between patients' evaluation of diet satisfaction, ease of use or hunger frequency. Non-alcoholic fatty liver disease histology assessments post-diet were also not significantly different between diets. The results of this study show the effectiveness of short-term VLEDs and energy restriction, irrespective of macronutrient composition, although the small sample size precluded detection of subtle differences between interventions.

Retrospective analysis of abnormal 24-h urinary free catecholamine concentration in screening for phaeochromocytoma.

BACKGROUND: Patients with hypertension often have increased 24-h excretion of urinary free catecholamines (UFCA) compared with normotensive patients, but the extent to which beta-blockade and other antihypertensive agents affect 24-h UFCA concentrations remains unclear. Consequently, many patients with slightly elevated 24-h UFCA concentrations are not adequately investigated for the presence of phaeochromocytoma. METHOD: We undertook a retrospective study on patients with at least one abnormal 24-h urinary collection of adrenaline (Adr), noradrenaline (NA) or dopamine (DA) between July 1997 and December 1999 to assess these issues. RESULTS: Of the 168 patients identified with raised 24-h UFCA concentrations, 106 with hospital notes were audited. Of the 46 patients whose values were more than twice the upper reference limit, 24 had their result confirmed with a repeat sample and only 10 underwent computed tomography or m-iodobenzylguanidine scanning. Two patients of these 10 had a phaeochromocytoma. We observed that hypertension correlated with significantly increased NA excretion compared with normotensive patients (median value 490+/-222 nmol per 24 h versus 304+/-229 nmol per 24 h, P<0.005). Patients on beta-blockers showed a trend towards significantly increased NA excretion (P=0.08). CONCLUSIONS: Many patients with abnormal 24-h UFCA excretion are not thoroughly investigated for the presence of phaeochromocytoma. NA concentration is significantly raised above the reference limit for patients with hypertension, and the use of beta-blockers showed a trend towards a further elevation in NA concentrations. Care must therefore be taken when interpreting abnormal NA concentrations in patients with hypertension or in those taking beta-blockers.

Pre-operative dietary restriction for patients undergoing bariatric surgery in the UK: observational study of current practice and dietary effects.

BACKGROUND: Bariatric surgery is effective at achieving weight loss in the severely obese, with the majority of procedures performed laparoscopically. A short-term pre-operative energy restrictive diet is widely adopted to enable surgery by reducing liver size and improving liver flexibility. However, the dietary approach is not standardised. This observational study reports on pre-operative restrictive diets in use across bariatric services in the UK. METHODS: Between September and November 2012, information was collected from bariatric services on current or past pre-operative diets, and any research providing evidence for the use or modification of their diets. RESULTS: Around one third of bariatric services (28) in the UK responded, with a total of 49 diets in current use. Types of diet include low energy, low carbohydrate and liquid, with 59 % offering low energy/low carbohydrate food-based, 21 % milk/yoghurt, 18 % meal replacement (liquid) and 2 % clear liquid. Diet duration varies between 7 and 42 days. Limited anecdotal evidence was provided by services evaluating the pre-operative diet, and its alternative approaches, with dietary choice primarily clinician-led. CONCLUSIONS: This study has highlighted variability and lack of consensus in the form of pre-bariatric surgery diet used across different centres. Further research comparing outcomes for alternative diets would support best practice in the future.