Alicia Molina López

Background Most relative weight-loss metrics follow the formula “Weight loss(%) = 100 · (Initial BMI - Final BMI) / (Initial BMI-a),” where a is the reference point that defines the metric. The percentage of total weight loss (%TWL, a = 0) and percentage of excess weight loss (%EWL, a = 25) are influenced by a patient’s initial weight. Recently, the percentage of alterable weight loss metric (%AWL, a = 13) has been reported to produce initial-weight-independent outcomes. Objectives This study aimed to replicate the methodology used for %AWL determination in a Mediterranean cohort of bariatric patients. Settings Multicenter study in 10 large hospitals in Spain. Methods Two large prospective databases were retrospectively searched for all primary laparoscopic gastric bypass patients with 2 years of follow-up. Outcomes at nadir were expressed and analyzed with 26 different metrics (a from 0 to 25), looking for the metric whose outcomes produced (1) the lowest coefficient of variation, (2) no differences between initially lighter and heavier patients, and (3) no correlation with patients’ initial BMI. Results A cohort of 1793 patients was stratified into 4 gender-age groups: younger women (YW, n = 733), older women (OW, n = 674), younger men (YM, n = 197), and older men (OM, n = 189). The calculations suggested an optimal reference point of 18 kg/m², defining a new metric (percentage of Mediterranean alterable weight loss, %MAWL). When %TWL, %EWL, %AWL, and %MAWL were tested on the whole sample, only %MAWL produced initial-weight-independent results. Conclusions In our Mediterranean cohort of patients, a reference point of 18 (and not 13) yielded initial-weight-independent outcomes.

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in Western countries. Both iron and lipid metabolism seem to be involved in its pathogenesis. We aimed to assess the relationship between levels of hepcidin, the master iron-regulatory protein, in plasma and the presence of NAFLD in morbidly obese (MO) patients, and to investigate the association between the hepatic expression of the main iron and lipid metabolism -related genes. Enzyme-linked immunosorbent assay was used to measure plasma hepcidin levels in 49 normal-weight control women, 23 MO women with normal liver (NL) histology and 46 MO women with NAFLD. The mRNA expression of hepcidin, the main iron metabolism-related genes, and the main lipid-metabolism genes was quantified by qRT-PCR in liver biopsies from members of the MO group undergoing bariatric surgery. Circulating hepcidin levels were significantly greater in MO than in normal-weight control women. However, there were no significant differences between MO women with NL and those with NAFLD. PCR analysis showed increased expression of hepcidin, FPN1, TfR1 and TfR2 in the liver of MO NAFLD women compared to those with NL. Moreover, a positive association of hepatic hepcidin mRNA expression and the iron metabolism-related genes was found with some key genes involved in the lipid metabolism. These findings suggest that circulating hepcidin levels are associated with obesity but not with the presence of NAFLD. However, the hepatic expression of hepcidin and the iron metabolism-related genes seem to play a role in regulating lipid metabolism pathways in liver, which has implications for NAFLD pathogenesis.

Laparoscopic sleeve gastrectomy is one of the most common techniques in bariatric surgery, but there is no consensus on the optimal distance from the pylorus to start the gastric transection. The aim of this study is to determine the differences in gastric emptying, gastric distension and metabolic response between two starting distances.

The measurement of weight loss after bariatric surgery is under constant review in order to obtain the ideal standard for reporting weight loss. Several formulas have been proposed for this purpose. Our goal is to analyse weight loss after sleeve gastrectomy, with or without antrum preservation through different measurement formulas. A prospective randomised study of 60 patients (30 patients with initial section at 3 cm from pylorus and 30 patients at 8 cm from the pylorus). We calculate the following variables at 3, 6 and 12 months from surgery: BMI, excess weight loss (%EWL), percentage of excess of BMI loss (%PEBMIL), expected BMI, % PEBMIL corrected by EBMI and percentage of total weight loss (%TWL). Weight evolution is similar in both groups, reaching a mean BMI of 33.62 ± 4.35 and 34.48 ± 4.23 kg/m² respectively 12 months after surgery, closer to expected BMI. TWL follows the same trend, with losses exceeding 30%, although 3 cm group is above the tables of percentiles made with our series. Regarding PEBMIL, the 3 cm group reaches 67.8% classified as excellent, while 8 cm group reaches 62.8% classified as a good result. EWL situates the best results for 3 cm group. Group 3 cm obtained a lower percentage of suboptimal results using EWL. %TWL places the 3 cm group in higher percentile than 8 cm group. Through EBMI, both groups are equally effective. It is necessary to have standardised dynamic tables for each surgical technique, becoming essential elements to measure weight loss after surgery.

Metabolic surgery can modulate weight as well as food intake and basal energy expenditure. In this study, we evaluate the effectiveness of duodenal exclusion by analysing anthropometric results, intake variations, food behaviour and calorimetric parameters. This is an experimental study with 8-week-old Sprague-Dawley male rats. The sequences used are as follows: Cafeteria diet for 3 weeks, followed by surgery and sacrifice at 4 weeks. Four experimental groups are as follows: two non-obese groups (n = 15; surgery = 10, sham = 5) and two obese groups by cafeteria diet (n = 15; surgery = 10, sham = 5). Surgery performed was duodenal exclusion with physical barrier. Weight, intake, glycaemia and basal energy expenditure by indirect calorimetry were monitored before and after surgery. Weight changes in groups that underwent intervention were significant. The reduction in calorie consumption after surgery was significant in the obese intervention group despite an increased standard feed consumption (161 ± 11 vs 139 ± 13 Kcal/day, p p Duodeno-jejunal tube placement stops weight gain in obese and non-obese animals. In obese animals, there is an important qualitative change in appetite towards standard feed with a significant decrease in caloric intake. In non-obese animals, changes in quantitative intake are transient. This surgery decreases basal energy expenditure in obese animals. This may be attributed to an enhanced thermogenic effect of food and a slowing in the animal’s weight gain.