Influence of gastric bypass on nutrient intake and oral drug disposition

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Is bariatric surgery effective in reducing comorbidities and drug costs?: Letter to the editor

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The relevance of dietary protein after bariatric surgery: what do we know?

PURPOSE OF REVIEW: The growing obesity epidemic is associated with an increased demand for bariatric surgery with Roux-en-Y Gastric Bypass and Sleeve Gastrectomy as the most widely performed procedures. Despite beneficial consequences, nutritional complications may arise because of anatomical and physiological changes of the gastrointestinal tract. The purpose of this review is to provide an update of the recent additions to our understanding of the impact of bariatric surgery on the intake, digestion and absorption of dietary protein. RECENT FINDINGS: After bariatric surgery, protein intake is compromised because of reduced gastric capacity and aversion for certain foods. A minority of patients reaches the recommended protein intake of minimal 60 g per day, which results in the loss of fat-free mass rather than the desired loss of fat mass. Despite inadequate protein intake, protein digestion and absorption do not seem to be impaired suggesting that other mechanisms could counteract the reduced secretion of digestive enzymes and their delayed inlet. SUMMARY: After bariatric surgery, protein supplementation or diet enrichment could attribute to achieve the minimal recommended protein intake and benefit the amount and composition of postoperative weight loss.status: publishe

Ijzer, essentieel voor een goede gezondheid

Ijzer is essentieel voor ons lichaam. Zonder ijzer is zuurstoftransport doorheen ons lichaam niet mogelijk. We halen ijzer uit de voeding in de vorm van haemijzer en non-haemijzer. Beide vormen worden voornamelijk opgenomen ter hoogte van het duodenum. De opname kan beïnvloed worden door tal van factoren. Een ijzertekort zal onder meer de ijzeropname stimuleren. Een belangrijk hormoon dat bij dit proces is betrokken, is hepcidine. Kinderen, adolescenten, zwangere vrouwen en premenopauzale vrouwen hebben een verhoogd risico op een ijzertekort. Ook pathologische aandoeningen kunnen meespelen, zoals gastro-intestinale bloedingen en bariatrische chirurgie. Een ijzerdeficiëntie kan aanleiding geven tot een anemie. Vandaar het belang om voldoende ijzer op te nemen via de voeding en mogelijke oorzaken van een ijzerdeficiëntie tijdig te voorkomen of te behandelen.status: publishe

Iron Deficiency After Roux-en-Y Gastric Bypass: Insufficient Iron Absorption from Oral Iron Supplements

Roux-en-Y gastric bypass (RYGB) may reduce the absorption of iron, but the extent to which this absorption is impeded is largely unknown. First, we determined the prevalence of iron deficiency following RYGB and explored the risk factors for its development. Second, we examined to what extent oral iron supplements are absorbed after RYGB.status: publishe

Barriers in the approach of obese patients undergoing bariatric surgery in Flemish hospitals

BACKGROUND: Bariatric 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. METHODS: Semi-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. RESULTS: In 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. CONCLUSIONS: Strategies 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.status: publishe

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

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Drug disposition before and after gastric bypass: fenofibrate and posaconazole

Roux-en-Y gastric bypass (RYGB) alters the anatomical structure of the gastrointestinal tract, which can result in alterations in drug disposition. The aim of the present study was to evaluate the oral disposition of two compounds belonging to the Biopharmaceutical Classification System Class II - fenofibrate (bile salt-dependent solubility) and posaconazole (gastric pH-dependent dissolution) - before and after RYGB in the same individuals.status: publishe

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

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.status: publishe

Predicting iron absorption from an effervescent iron supplement in obese patients before and after Roux-en-Y gastric bypass: a preliminary study

BACKGROUND & AIMS: Oral iron absorption is hampered in obese and bariatric patients, especially after Roux-en-Y gastric bypass (RYGB). As a result, iron deficiency, which is common in both patient groups, can be difficult to treat by oral supplements, often necessitating a switch to parenteral administration. The aim of this study was to find possible predictors of the extent of absorption of an effervescent iron gluconate oral supplement, which enables to pre-emptively identify those patients in which oral supplementation is likely to fail. METHODS: The pharmacokinetic properties of 695 mg effervescent iron gluconate (80 mg Fe2+) were assessed in 13 obese patients (female = 10; mean age ± SD: 45.2 ± 12.5years) pre- and six months post-RYGB by measuring serum iron concentrations during 24 hours and by calculating the adjusted for baseline AUC0-24h, Cmax and Tmax. A multivariate regression analysis was performed to investigate the effect of hepcidin concentration, iron and hematologic indices, personal and anthropometric characteristics on iron absorption. Subsequently, Receiver Operating Characteristic (ROC) curves were used to propose the cut-off value for hepcidin concentrations above which obese patients are unlikely to benefit from oral iron supplementation. Data are expressed as mean ± SD. RESULTS: Low iron status persisted after surgery as there was no significant difference observed in TSAT (17.3 ± 5.2 vs. 20.2 ± 6.6%), ferritin (91.8 ± 68.6 vs. 136.2 ± 176.9 μg/L) and hepcidin concentration (32.0 ± 30.1 vs. 28.3 ± 21.3 ng/mL) after RYGB. The absorption of effervescent iron gluconate was similar pre- and post-RYGB [AUC0-24h,pre-RYGB: 28.6 ± 10.8 μg/dL*h; AUC0-24h,post-RYGB: 27.5 ± 9.11 μg/dL*h (P = 0.84)]. Post-RYGB, iron AUC0-24h showed a strong negative correlation with both hepcidin concentrations and TSAT (R=-0.51; P = 0.08 and R=-0.81; P = 0.001), respectively. Pre-RYGB, there was a clear trend for the same negative correlations for hepcidin concentrations and TSAT (R=-0.47; P = 0.11 ;R=-0.41; P = 0.16), respectively. Taking pre-and post-RYGB data together, the negative correlations were confirmed for hepcidin concentrations and TSAT (R=-0.54; P = 0.004; R=-0.60; P = 0.001), respectively. The AUCROC = 0.87 (95%CI 0.71; 1.00) showed an optimal sensitivity/specificity cut-off at hepcidin concentrations of 26.8 ng/mL. CONCLUSIONS: The iron AUC0-24h showed a negative correlation with the hepcidin concentration and TSAT of obese patients, in particular post-RYGB. Therefore, our data support the use of hepcidin concentration and TSAT to distinguish potential responders from non-responders for iron supplementation particularly post-RYGB. Additionally, this study showed that the pharmacokinetic properties of iron gluconate from an effervescent tablet were unaffected by RYGB-surgery.status: publishe