Ina Gesquiere

Micronutrient intake, from diet and supplements, and association with status markers in pre- and post-RYGB patients

BACKGROUND & AIMS Roux-en-Y gastric bypass (RYGB) is associated with an increased risk for micronutrient deficiencies. This study aimed to assess total (dietary and supplement) intake and association with iron (including hepcidin), vitamin B12, vitamin C and zinc status markers before and after Roux-en-Y gastric bypass (RYGB). METHODS This prospective study included patients with a planned RYGB in University Hospitals Leuven, Belgium; who were followed until 12 months post-RYGB. Patients completed an estimated dietary record of two non-consecutive days before and 1, 3, 6 and 12 months post-RYGB and supplement/drug use was registered. Associations between total micronutrient intake and status markers were analyzed. RESULTS Fifty-four patients (21 males; mean age: 48.0 [95%CI 46.6; 49.3] years; mean preoperative BMI: 40.4 [95%CI 39.4; 41.4] kg/m2) were included. One month post-RYGB, usual dietary intake of the studied micronutrients was significantly decreased compared to pre-RYGB, but gradually increased until 12 months post-RYGB, remaining below baseline values. By including micronutrient supplement intake, 12 months post-RYGB values were higher than baseline, except for zinc. Hemoglobin, ferritin, vitamin B12 and C-reactive protein serum concentrations were significantly decreased and transferrin saturation and mean corpuscular volume were significantly increased 12 months post-RYGB. Serum hepcidin concentration was significantly decreased 6 months post-RYGB. CONCLUSIONS Medical nutritional therapy is essential following RYGB as dietary intake of iron, vitamin B12, vitamin C, copper and zinc was markedly decreased postoperatively and some patients still had an inadequate total intake one year post-RYGB.

Drug disposition and modelling before and after gastric bypass: immediate and controlled release metoprolol formulations

AIMS The aim of the present study was to evaluate the disposition of metoprolol after oral administration of an immediate and controlled-release formulation before and after Roux-en-Y gastric bypass (RYGB) surgery in the same individuals and to validate a physiologically based pharmacokinetic (PBPK) model for predicting oral bioavailability following RYGB. METHODS A single-dose pharmacokinetic study of metoprolol tartrate 200 mg immediate release and controlled release was performed in 14 volunteers before and 6-8 months after RYGB. The observed data were compared with predicted results from the PBPK modelling and simulation of metoprolol tartrate immediate and controlled-release formulation before and after RYGB. RESULTS After administration of metoprolol immediate and controlled release, no statistically significant difference in the observed area under the curve (AUC(0-24 h)) was shown, although a tendency towards an increased oral exposure could be observed as the AUC(0-24 h) was 32.4% [95% confidence interval (CI) 1.36, 63.5] and 55.9% (95% CI 5.73, 106) higher following RYGB for the immediate and controlled-release formulation, respectively. This could be explained by surgery-related weight loss and a reduced presystemic biotransformation in the proximal gastrointestinal tract. The PBPK values predicted by modelling and simulation were similar to the observed data, confirming its validity. CONCLUSIONS The disposition of metoprolol from an immediate-release and a controlled-release formulation was not significantly altered after RYGB; there was a tendency to an increase, which was also predicted by PBPK modelling and simulation.

Barriers in the Approach of Obese Patients Undergoing Bariatric Surgery in Flemish Hospitals

BackgroundBariatric surgery is associated not only with weight loss and improvement of comorbidities of obesity but also with short and long-term complications. Preoperative screening and lifelong follow-up of these patients are important to optimize the effect of bariatric surgery and minimize complications. The objective of this study was to create an inventory of the current care offered to bariatric patients before and after surgery in Flemish hospitals, Belgium and to identify barriers for optimal care.MethodsSemi-structured interviews with healthcare professionals involved in screening and follow-up of bariatric patients in 12 hospitals in Flanders, Belgium were performed. Interviews were transcribed verbatim and analyzed with NVivo 10.0.ResultsIn each participating hospital, except one, biochemical screening before and after bariatric surgery was performed, but the extent and timing varied between hospitals. In ten hospitals, a standard multivitamin preparation was started in all patients after surgery, but there was a large variation for timing of initiation and duration between hospitals. The interviewees indicated that the knowledge about appropriate dosage and formulation adjustments after surgery was limited. Most of the performed drug adjustments were due to improvement of comorbidities. In 9 out of 12 hospitals, a multidisciplinary team was involved, but the approach varied widely. Only in 3 out of 12 hospitals, eligibility of patients for bariatric surgery was discussed in team meetings.ConclusionsStrategies to implement existing guidelines are required in order to obtain more uniform, interdisciplinary support for bariatric patients, resulting in an increase of efficiency of surgery and improved patient care.

At similar weight loss, dietary composition determines the degree of glycemic improvement in diet-induced obese C57BL/6 mice

Background Achieving weight loss is the cornerstone of the treatment of the metabolic consequences of obesity, in particular of glucose intolerance. Objective To determine whether improvement in glucose control depends on dietary macronutrient composition of the diet at identical weight loss. Materials and methods Twenty-two weeks old diet-induced obese C57BL/6 mice lost weight through caloric restriction on normal chow (R-NC) or high fat diet (R-HF). Control mice were fed normal chow (LEAN) or high fat diet (OBESE) ad libitum. Body weight and composition were assessed after 8 weeks of dietary intervention. Glucose homeostasis was evaluated by intraperitoneal glucose tolerance tests (IPGTT). Epididymal white adipose (eWAT) and hepatic tissues were analyzed by immunohistochemistry and RT-qPCR. Results By 30 weeks of age, the body weight of the mice on R-NC (31.6±1.7g, mean±SEM) and R-HF (32.3±0.9g) was similar to LEAN mice (31.9±1.4g), while OBESE mice weighed 51.7±2.4g. Glucose tolerance in R-NC was better than in LEAN mice (69% AUC IPGTT, P 0.0168) whereas R-HF mice remained significantly less glucose tolerant (125% AUC IPGTT, P 0.0279 vs LEAN), despite identical weight loss. The eWAT pads and adipocyte size were similar in LEAN and R-NC mice, while the eWAT pad size of R-HF was 180% of R-NC (P < 0.0001) and the average adipocyte size of R-HF mice was 134% of R-NC fed mice (P 0.0285). No LEAN or R-NC mice had hepatic steatosis, in contrast to 28.6% of R-HF mice. Compared to OBESE mice, inflammatory markers were lower in eWAT and liver tissue of R-NC, but not in R-HF mice. Measures of visceral adiposity correlated well with glucose tolerance parameters. Conclusions In mice, caloric restriction on a normal chow diet improved glucose tolerance significantly more when identical weight loss was achieved on a high fat diet.

Iron and Bariatric Surgery

This chapter focuses on iron deficiency in obese patients before and after bariatric surgery. Iron deficiency is common in obese patients due to the unbalanced Western affluent diet in combination with the obesity-associated, chronic, low-grade inflammation that induces the production of hepcidin and subsequently inhibits iron absorption and release. Bariatric surgery in these patients creates anatomical changes in the gastrointestinal tract, which influences nutrient intake and absorption, and subsequently the development of nutritional deficiencies (including iron deficiency). There are multiple factors that can contribute to the development of iron deficiency after bariatric surgery: (1) reduction of gastric acid secretion, which is required for the absorption of iron as it transforms the ferric form (Fe 3+ ) to the absorbable ferrous form (Fe 2+ ); (2) diminished intestinal absorption surface, especially bypassing the duodenum and proximal jejunum as the main absorption sites of iron; and (3) reduced nutrient intake, including iron-rich foods, due to increased satiety, reduced hunger, and food intolerances. Furthermore, insufficient supplementation due to nonadherence to a prescribed regimen or inadequate amounts of iron and inadequate nutritional support contribute to the development of iron deficiency. Therefore, preoperative screening and treatment of deficiencies is essential, and lifelong follow-up (including nutritional advice) after bariatric surgery is crucial.

Is Bariatric Surgery Effective in Reducing Comorbidities and Drug Costs?: Letter to the editor

Dear editor, We have read with great interest the article BIs bariatric surgery effective in reducing comorbidities and drug costs? A systematic review and meta-analysis,^ by Lopes and colleagues [1]. Although this study has compiled a lot of studies and included a large number of patients, we have some questions concerning the methodology. The PICO strategy was used to construct the methodology search for this systematic review, and the authors followed the PRISMA guidelines to conduct a literature review. However, we think that if more synonyms of the keywords had been added to the search strategy, the authors would have found and included more articles in this literature review therefore increasing the power of the results they herein present. For example, different terms for drug cost and pharmacoeconomics were implemented, but the term Bmedication cost^was not included. If this term had been added to the strategy search, articles meeting the inclusion criteria, such as BMedication cost is significantly reduced after Roux-en-Y Gastric Bypass in obese patients^ and BShort-term medication cost savings for treating hypertension and diabetes after gastric bypass^ would have also been included in this systematic review and meta-analysis [2, 3]. The results of these two published studies are in line with the other papers discussed in this systematic review. Therefore, we do not believe that including these papers would have changed the overall conclusion of this meta-analysis. However, it would have given a more comprehensive vision of what has already been published. Indeed these two studies have included quite an important number of patients, comparable to that of some of the studies already present in this meta-analysis. Overall, we believe that a more exhaustive search strategy could have yet improved this already extensive paper and strengthen its impact. Yours sincerely.

Do Roux-en-Y gastric bypass patients meet the dietary guidelines?

Background The prevalence of obesity has increased to epidemic proportions and, as a result, the number of bariatric surgeries has increased worldwide. To date, bariatric surgery remains the sole medical intervention that achieves considerable and sustained weight loss. As both obesity and bariatric surgery are associated with nutritional deficiencies, the aim of this study was to evaluate the dietary intake of macroand micronutrients in patients before and after Roux-en-Y gastric bypass (RYGB).