Iron absorption and iron status are reduced after Roux-en-Y gastric bypass

Iron homeostasis in obesity and metabolic and bariatric surgery: a narrative review

Iron deficiency has been recognized as a potentially modifiable nutritional complication of metabolic and bariatric surgery (MBS) since prior to the turn of the century. Despite this, it remains the most common and clinically significant nutritional complication of this surgery with the potential to negate quality of life and the health benefits of surgical weight loss. This narrative review summarizes the current literature regarding iron deficiency as it relates to patients with severe obesity and those who undergo MBS. Advances in the clinical knowledge of iron homeostasis in severe obesity as a chronic disease, current diagnostic criteria for the diagnosis of iron deficiency in this patient population, the significance of preoperative iron deficiency, postoperative iron deficiency, and the status of supplementation and treatment will be reviewed with emphasis on gaps in knowledge and needed areas of further study.

The Role of Dietary Intake in the Weight Loss Outcomes of Roux-en-Y Gastric Bypass and Sleeve Gastrectomy: A Systematic Review and Meta-analysis

The relationship between postoperative dietary intake and weight loss after bariatric surgery remains unclear. We performed a systematic review and meta-analysis of studies published between January 2000 and May 2023, reporting weight loss outcomes, and dietary intake before and after Roux-en-Y gastric bypass and sleeve gastrectomy. A total of 42 studies were included. There was no detectable difference in dietary intake between the two procedures. Roux-en-Y gastric bypass induced an average decrease in energy intake of 886 kcal/day at 12-month post-surgery; however, there was no correlation between daily energy intake and weight loss. These findings show a substantial reduction of energy intake in the first year after bariatric surgery but do not support a link between lower energy intake and greater weight loss.

Bariatric Surgery in Obesity: Metabolic Quality Analysis and Comparison of Surgical Options

Obesity is a constantly growing health problem which reduces quality of life and life expectancy. Bariatric surgery (BS) for obesity is considered when all other conservative treatment modalities have failed. Comparison of the multidisciplinary programs with BS regarding to the weight loss showed that substantial and durable weight reduction have been achieved only with bariatric surgical treatments. Although laparoscopic sleeve gastrectomy is the most popular BS, it has high long-term failure rates, and it is claimed that one of every three patients will undergo another bariatric procedure within a 10-year period. Although BS provides weight loss and improvement of metabolic comorbidities, in long-term follow-up, weight gain is observed in half of the patients, while decrease in bone mass and nutritional deficiencies occur in up to 90%. Moreover, despite significant weight loss, several psychological aspects of patients are worsened in comparison to preoperative levels. Nearly one-fifth of postoperative patients with "Loss-of-eating control" meet food addiction criteria. Therefore, the benefits of weight loss following bariatric procedures alone are still debated in terms of the proinflammatory and metabolic profile of obesity.

Impact on oxidative stress of oral, high-dose, iron supplementation for management of iron deficiency after bariatric surgery, a preliminary study

OBJECTIVES

High-dose oral iron supplementation for patients who develop iron deficiency after bariatric surgery may induce oxidative stress in the gastrointestine. The study's objective was to test this hypothesis by determining the impact of high-dose oral iron on systemic oxidative stress.

METHODS

We used archived plasma samples from a randomized controlled clinical trial (NCT02404012) comparing FeSO4 (195 mg/day, NatureMade®, West Hills, CA) with a heme iron polypeptide (HIP, 60.4 mg/day, Proferrin®, Colorado Biolabs, Lafayette, CO) for 8 weeks. Systemic oxidative stress was measured using malondialdehyde and total antioxidant capacity (MDA, Abcam, ab238537 and TAC, Abcam, ab65329 Cambridge, UK) assays. Data was log-transformed and presented as means and standard deviations; a mixed model was used to determine the effects of time (0, 2, 4, and 8 weeks) and treatment (FeSO4 versus HIP) on oxidative stress.

RESULTS

The FeSO4 (N = 8) and HIP (N = 5) participants were balanced in body mass index (35.0 ± 5.5 kg/m2), race (93 % White), time post-surgery (7.3 ± 3.3 years), as well as serum concentrations of iron (P > 0.05). The FeSO4 group tended to be older (44.3 ± 4.5 years) and they had lower concentrations of serum ferritin (6.5 ± 2.7 µg/mL) than the HIP (38.2 ± 9.3 years, and 12.9 ± 16.8 µg/mL) group (P = 0.080, and P = 0.017 respectively). We observed a larger increase in serum iron in the FeSO4 group during the 8 weeks of Fe supplementation, compared to that in the HIP group (p = 0.004). We observed a decreasing trend in MDA over the 8 weeks (p = 0.080) in the FeSO4 treatment group. There were no significant differences in TAC between and within FeSO4 and HIP groups over the 8 week supplementation period.

CONCLUSIONS

This preliminary study suggests that high-dose oral iron supplementation for iron deficiency does not adversely impact systemic oxidative stress in patients undergoing bariatric surgery.

Change in Mineral Status After Bariatric Surgery: a Meta-analysis

BACKGROUND

The risk of protein and vitamin deficiencies after bariatric surgery has been well studied, but the change in mineral status has not gotten enough attention. This study aimed to perform a meta-analysis regarding the change in mineral levels after bariatric surgery and the prevalence of postoperative mineral deficiency, with subgroup analyses of different surgical procedures, study regions, and follow-up time.

METHODS

CENTRAL, PubMed, and EMBASE were searched for related articles. Meta-analysis, subgroup analysis, and sensitivity analysis were performed if necessary.

RESULTS

A total of 107 articles with 47,432 patients were included. The most severe mineral deficiency after bariatric surgery was iron (20.1%), followed by zinc (18.3%), copper (14.4%), chlorine (12.2%), phosphorus (7.5%), and calcium (7.4%). Serum concentrations of potassium, sodium, selenium, manganese, and molybdenum showed no significant change before and after surgery. Subgroup analyses revealed that SG had fewer deficiencies in serum iron, calcium, zinc, magnesium, phosphorus, copper, and selenium than RYGB. OAGB showed a higher incidence of serum iron and zinc deficiencies than RYGB. Studies conducted in different regions also found various mineral statuses after surgery. Studies with follow-up ≥ 5 years had a lower prevalence of zinc, copper, and selenium deficiencies than follow-up < 5 years.

CONCLUSION

A high deficiency rate of serum iron, zinc, copper, chlorine, phosphorus, and calcium was seen after bariatric surgery. The difference in surgical procedures, study regions, and follow-up time may affect postoperative mineral status; more targeted mineral supplement programs are needed considering these influencing factors.

Gut HIF2α signaling is increased after VSG, and gut activation of HIF2α decreases weight, improves glucose, and increases GLP-1 secretion

Gastric bypass and vertical sleeve gastrectomy (VSG) remain the most potent and durable treatments for obesity and type 2 diabetes but are also associated with iron deficiency. The transcription factor HIF2α, which regulates iron absorption in the duodenum, increases following these surgeries. Increasing iron levels by means of dietary supplementation or hepatic hepcidin knockdown does not undermine the effects of VSG, indicating that metabolic improvements following VSG are not secondary to lower iron levels. Gut-specific deletion of Vhl results in increased constitutive duodenal HIF2α signaling and produces a profound lean, glucose-tolerant phenotype that mimics key effects of VSG. Interestingly, intestinal Vhl deletion also results in increased intestinal secretion of GLP-1, which is essential for these metabolic benefits. These data demonstrate a role for increased duodenal HIF2α signaling in regulating crosstalk between iron-regulatory systems and other aspects of systemic physiology important for metabolic regulation.

Bariatric surgery remains the most potent treatment for obesity and type 2 diabetes but also reduces iron levels. Evers et al. find that the machinery for absorbing iron is activated after VSG. Activation of this machinery recapitulates multiple effects of VSG. These findings may lead to less invasive therapies.

Efficacy and safety of ferric derisomaltose (FDI) compared with iron sucrose (IS) in patients with iron deficiency anemia after bariatric surgery

Purpose

Iron deficiency is common following bariatric surgery, and treatment with intravenous iron is often required. This post hoc analysis of data from two randomized, open-label, multicenter trials evaluated the efficacy and safety of ferric derisomaltose (FDI; formerly iron isomaltoside 1000) versus iron sucrose (IS) over 4 weeks in adults with iron deficiency anemia (IDA) resulting from prior bariatric surgery.

Materials and methods

Data were pooled for participants who received FDI or IS in the PROVIDE or FERWON-IDA trials for the treatment of IDA post bariatric surgery. Efficacy outcomes included changes in hemoglobin (Hb) and iron parameters; safety outcomes included the incidence of adverse drug reactions (ADRs), serious or severe hypersensitivity reactions (HSRs), and hypophosphatemia.

Results

The analysis included 159 patients. Mean (standard deviation) cumulative iron doses were 1199 (± 347) mg for FDI and 937 (± 209) mg for IS. Compared with IS, FDI resulted in a faster and more pronounced Hb response, and a higher proportion of responders (Hb level increase ≥ 2 g/dL from baseline) at all time points. The incidence of ADRs was similar with FDI and IS (15.1% and 18.2%, respectively), with no serious ADRs or serious or severe HSRs reported. The incidence of hypophosphatemia was low and similar in both treatment groups, with no cases of severe hypophosphatemia observed.

Conclusions

In patients with IDA resulting from bariatric surgery, FDI produced a faster and more pronounced Hb response than IS. Both FDI and IS were well tolerated.

Graphical abstract

How Does Fat Mass Change in the First Year After Bariatric Surgery? A Systemic Review and Meta-Analysis

This systematic review and meta-analysis investigated the time-course effect of different type of bariatric surgeries (BS) up to 1 year post-surgery on fat mass (FM) and body fat percentage (BFP) in patients with morbid obesity. We searched PubMed, Scopus, EMBASE, ISI web of science, and Cochrane databases from October 2002 until May 2020 with no restriction in the English language, to find studies examining the effect of BS on FM (kg) and BFP (%) in morbid obese patients. Meta-analysis of 103 studies carried out on data of 18,166 and 14,575 morbid obese patients following BS, showed that BS was associated with a substantial decrease in FM and BFP, respectively, in 1 month (- 8.17 kg [95% CI - 9.07, - 7.27] and - 1.51% [95% CI - 2.56, - 0.46]), 3 months (- 15.75 [95% CI - 17.49, - 14.0] and - 4.90 [95% CI - 5.97, - 3.83]), 6 months (- 22.51 [95% CI - 23.93, - 21.09] and - 8.56% [95% CI - 9.63, - 7.49]), and 12 months (- 29.69 [95% CI - 31.3, - 28.09] and - 13.49% [95% CI - 14.52, - 12.40]) after the surgery. In conclusion, BS was associated with sustained declines in FM and BFP, from 1 to 12 months, with no indication of plateau phase post-surgery post-operatively. The present study emphasizes that post-bariatric care should have more focus on FM loss during 1-year post-surgery to identify the patients at risk for fat loss plateau.

Acquired Refractory Iron Deficiency Anemia

Anemia is a global health problem affecting one-third of the world population, and half of the cases are due to iron deficiency (ID). Iron deficiency anemia (IDA) is the leading cause of disability in several countries. Although multiple mechanisms may coexist, ID and IDA causes can be classified as i) insufficient iron intake for the body requirement, ii) reduced absorption, and iii) blood losses. Oral iron represents the mainstay of IDA treatment. IDA is defined as "refractory" when the hematologic response after 4 to 6 weeks of treatment with oral iron (an increase of >=1 g/dL of Hb) is absent. The cause of iron-refractory anemia is usually acquired and frequently related to gastrointestinal pathologies, although a rare genetic form called iron-refractory iron deficiency anemia (IRIDA) exists. In some pathological circumstances, either genetic or acquired, hepcidin increases, limiting the absorption in the gut, remobilization, and recycling of iron, thereby reducing iron plasma levels. Indeed, conditions with high hepcidin levels are often under-recognized as iron refractory, leading to inappropriate and unsuccessful treatments. This review provides an overview of the iron refractory anemia underlying conditions, from gastrointestinal pathologies to hepcidin dysregulation and iatrogenic or provoked conditions, and the specific diagnostic and treatment approach.

Iron Deficiency - Not Only a Premenopausal Topic After Bariatric Surgery?

Purpose

In our centre, specialized high dose multivitamin supplementation designed to meet the needs of patients after gastric bypass surgery is routinely recommended in the early postoperative period. The aim of the present study was to analyse whether iron supplementation prescribed in clinical practice is sufficient in both sexes and whether multivitamin supplementation standardized for women might potentially lead to iron overload in men.

Materials/Methods

This was a retrospective study covering the period up to 36 months after bariatric surgery. Three groups were compared (men, premenopausal and postmenopausal women). The iron status was evaluated employing serum ferritin concentrations.

Results

A total of 283 patients who had at least one follow-up visit between January 2015 and April 2018 at a specialized academic outpatient centre were included (71 men, 130 premenopausal women, 82 postmenopausal women). Thirty-six months after surgery, 33.3%, 68.4% and 54.5% of the men, pre- and postmenopausal women, respectively, were iron deficient. The preoperative prevalence of excess ferritin levels was 13.7% in premenopausal, 3.0% in postmenopausal women, 5.7% in men and declined in the following months.

Conclusion

Iron deficiency is very common after gastric bypass surgery, and even high dosages of multivitamin and mineral supplements might not be sufficient to prevent the development of iron deficiency. Men, pre- and postmenopausal women differ in their prevalence of iron deficiency which demands adapted iron dosage regimens based on the sex and the age. Iron overload is rare in all observed groups and highest in premenopausal women.

Graphical abstract

Recognizing postoperative nutritional complications of bariatric surgery in the primary care patient: a narrative review

Bariatric surgery is an effective treatment for patients with morbid obesity. However, as safe and common as bariatric procedures have become, multiple complications can still result. These complications vary depending on the type of procedure performed (malabsorptive or restrictive) and are often nutritional derangements from the altered malabsorptive surface of the gastrointestinal tract and decreased capacity of the stomach. Deficiencies in vitamin D after malabsorptive procedures such as the Roux-en-Y gastric bypass can result in subsequent hypocalcemia and bone demineralization, and anemias can also present after surgery from inadequate vitamin B12 and iron absorption. Because of the prevalence of these deficiencies, baseline micronutrient testing and postoperative screening are recommended in many cases. Additionally, supplemental treatment often requires higher doses than those recommended for healthy adults. The purpose of this narrative review is to outline the various nutrient deficiencies that can result from bariatric procedures and report previously-published recommendations for screening and medical treatment of patients with these deficiencies. This review is directed toward primary care practitioners because of their unique position in delivering continuity of care and the frequency with which they will encounter patients who have undergone bariatric surgery and are seeking counseling regarding weight loss modalities.

Systematic review and meta-analysis of perioperative behavioral lifestyle and nutritional interventions in bariatric surgery: a call for better research and reporting

Bariatric surgery is considered the most effective treatment for people with morbid obesity, and certain interventions could enhance its long-term results. We searched MEDLINE, Embase, Web of Science, CENTRAL, and trial registers up to January 1, 2020. Randomized controlled trials, where behavioral lifestyle or nutritional interventions were provided perioperatively were included. Primary outcome was weight change. Two reviewers independently performed each stage of the review. Altogether 6652 references were screened. 31 studies were included for qualitative synthesis and 22 studies for quantitative synthesis. Interventions varied greatly, thus limiting possibility of synthesizing all results. Six groups of interventions were discerned, and we used standardized mean differences for synthesis. Low to very-low certainty evidence suggests that physical activity, nonvitamin nutritional interventions, vitamins, psychotherapy, and counseling but not combined interventions might bring some benefit regarding short-term postsurgery follow-ups (up to 12 mo), but the estimates varied and results were not statistically significant, except for 12 months follow-ups regarding counseling. Psychotherapy and counseling, but not vitamins and combined interventions, may provide some benefit at longer follow-ups (over 12 mo), but the certainty of evidence was low to very-low and statistically significant results were observed in comparisons including data from single studies with small sample sizes only. Included studies expressed an outcome "weight change" using 20 different measures. Misreporting of data and huge variety of outcomes do not benefit systematic analyses and may possibly lead to confusion of both researchers and readers. We suggest that authors follow a predefined set of outcomes when reporting the results of their studies. The initiative to produce "core outcome set" for clinical trials in bariatric surgery trials is currently underway.

Iron, Vitamin B12, Folate and Copper Deficiency After Bariatric Surgery and the Impact on Anaemia: a Systematic Review

Bariatric surgery may increase the risk of iron, vitamin B₁₂, folate and copper deficiencies, which can cause anaemia. This review aims to critique the evidence on the prevalence of these nutritional deficiencies and the impact on anaemia in the first 12 months after surgery. PRISMA and MOOSE frameworks, the NHMRC evidence hierarchy and The Academy of Nutrition and Dietetics bias tool were used to systematically critique current literature. Seventeen studies reported on deficiency prevalence with the majority being of low quality. Important confounders to serum micronutrient levels were not adequately considered. Results on the prevalence of nutritional anaemias were also lacking. Further investigation into the prevalence of iron, vitamin B₁₂, folate and copper deficiency and its impact on anaemia in bariatric surgery is needed.

Is Transdermal Multivitamin Patch Effective in Gastric Bypass Patients?

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (LRYGB) patients are recommended to take multiple oral vitamin supplements daily. Transdermal multivitamin patches are being advertised as an alternative for use in bariatric patients with no data to support their efficacy. The purpose of this study was to evaluate response to daily transdermal use of multivitamin patch after LRYGB and to compare them with a control group of similar patients who used oral supplements.

METHODS

A retrospective review was carried out on patients who had LRYGB at a community hospital from February 2015 to February 2019. Patients who had completed preoperative and annual postoperative bariatric laboratory tests were included. They were divided into patch and pill (control) group.

RESULTS

Seventeen patients were included in the patch and 27 in the pill group. Patients in each group used either patch or pills for 12 months and they were 1 year post LRYGB. Fourteen patients (82.35%) in patch group and 11 patients (40.74%) in pill group had at least 1 deficiency at annual postoperative blood work (P = .0116). Vitamin D deficiency was seen in 81% patients in patch group vs 36% in the pill group (P = .0092). Statistically significant lower postoperative serum concentrations of vitamin D, B1, and B12 were seen in the patch group.

CONCLUSIONS

Multivitamin patch users are more likely to have vitamin D deficiency and lower serum concentration of various vitamins and minerals. Future large studies are needed on the efficacy of multivitamin patches before they can be recommended to bariatric patient population.

High Risk of Hypophosphatemia in Patients with Previous Bariatric Surgery Receiving Ferric Carboxymaltose: A Prospective Cohort Study

BACKGROUND

Iron deficiency is a common finding in patients with previous bariatric surgery, and parenteral supplementation is frequently required. Ferric carboxymaltose (FCM) is among the preferred compounds used but may be associated with new-onset hypophosphatemia. This study was undertaken to study the prevalence of hypophosphatemia following FCM in patients with previous bariatric surgery, a population that may be at particular risk due to highly prevalent secondary hyperparathyroidism.

METHODS

Patients with previous bariatric surgery and iron depletion scheduled for FCM infusion were prospectively studied before and one week after FCM application. The primary endpoint was new-onset hypophosphatemia. Patients were followed until plasma phosphate had normalized without replacement.

RESULTS

Fifty-two patients (40 females) following Roux-en-Y gastric bypass (n = 50) or sleeve gastrectomy (n = 2), with a median age of 46 years (range 22-68) and a BMI of 32.2 kg/m² (27.5-37.3), were analyzed. Fifteen patients (29%) developed new-onset hypophosphatemia, with 11 (21%) requiring oral phosphate supplementation for a median duration of 14 days (14-25). The plasma phosphate decreased by 0.3 mmol/l (-0.5--0.2; p < 0.001) secondary to a 56% increase in the fractional urinary phosphate excretion (p < 0.001). This was associated with a significant increase in serum intact FGF23 (+30%; p < 0.001) and a decrease in serum 1,25(OH)2 vitamin D3 concentrations (-37.6%; p < 0.001).

CONCLUSION

Patients with previous bariatric surgery receiving FCM are at considerable risk of developing significant hypophosphatemia secondary to increased renal phosphate wasting through a mechanism involving FGF23. Monitoring plasma phosphate should be considered following FCM in patients with previous bariatric surgery.

CLINICAL TRIAL REGISTRATION

ISRCTN registry, ISRCTN12291677, https://www.isrctn.com.

High-precision isotopic analysis of serum and whole blood Cu, Fe and Zn to assess possible homeostasis alterations due to bariatric surgery

Bariatric surgery is an effective procedure to achieve weight loss in obese patients. However, homeostasis of essential metals may be disrupted as the main absorption site is bypassed. In this study, we determined Cu, Fe and Zn isotopic compositions in paired serum and whole blood samples of patients who underwent Roux-en-Y gastric bypass (RYGB) surgery for evaluation of longitudinal changes and their potential relation to mineral element concentrations and relevant clinical parameters used for monitoring the patient's condition. Samples from eight patients were collected pre-surgery and at 3, 6 and 12 months post-surgery. Multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS) was used for high-precision isotope ratio measurements. Alterations in metal homeostasis related to bariatric surgery were reflected in the serum and whole blood Cu, Fe and Zn isotopic compositions. The serum and whole blood Cu became isotopically lighter (lower δ⁶⁵Cu values) after bariatric surgery, reaching statistical significance at 6 months post-surgery (p < 0.05). The difference between the serum and the whole blood Zn isotopic composition increased after surgery, reaching significance from 6 months post-surgery onwards (p < 0.05). Those changes in Cu, Fe and Zn isotopic compositions were not accompanied by similar changes in their respective concentrations, making isotopic analysis more sensitive to physiological changes than elemental content. Furthermore, the Zn isotopic composition correlates with blood glycaemic and lipid parameters, while the Fe isotopic composition correlates with glycaemic parameters. Graphical Abstract.

Proceedings of the 2017 ASPEN Research Workshop-Gastric Bypass: Role of the Gut

The goal of the National Institutes of Health-funded American Society for Parenteral and Enteral Nutrition 2017 research workshop (RW) "Gastric Bypass: Role of the Gut" was to focus on the exciting research evaluating gut-derived signals in modulating outcomes after bariatric surgery. Although gastric bypass surgery has undoubted positive effects, the mechanistic basis of improved outcomes cannot be solely explained by caloric restriction. Emerging data suggest that bile acid metabolic pathways, luminal contents, energy balance, gut mucosal integrity, as well as the gut microbiota are significantly modulated after bariatric surgery and may be responsible for the variable outcomes, each of which was rigorously evaluated. The RW served as a timely and novel academic meeting that brought together clinicians and researchers across the scientific spectrum, fostering a unique venue for interdisciplinary collaboration among investigators. It promoted engaging discussion and evolution of new research hypotheses and ideas, driving the development of novel ameliorative, therapeutic, and nonsurgical interventions targeting obesity and its comorbidities. Importantly, a critical evaluation of the current knowledge regarding gut-modulated signaling after bariatric surgery, potential pitfalls, and lacunae were thoroughly addressed.

The incidence of iron deficiency anemia post-Roux-en-Y gastric bypass and sleeve gastrectomy: a systematic review

SETTING

The physiological and anatomical changes that occur as a consequence of bariatric surgery result in macro- and micro-nutritional deficiencies, especially iron deficiency. The reported incidence of iron deficiency and associated anemia after bariatric surgery varies widely across studies.

OBJECTIVES

The aim of this systematic review is to quantify the impact of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on the incidence of iron deficiency.

METHODS

Databases including Ovid Medline, Ovid Embase, Helthstar, Scopus, Cochrane (CDSR), LILACS, and ClinicalKey were searched for original articles with additional snowballing search. Search terms included Obesity, nutrient deficiency, iron deficiency, iron deficiency anemia, bariatric surgery, Roux-en-Y gastric bypass, and sleeve gastrectomy. Original articles reporting the incidence of iron deficiency and anemia pre- and post-RYGB and SG from January 2000 to January 2015 with minimum 1-year follow-up were selected. Data extraction from selected studies was based on protocol-defined criteria.

RESULTS

There were 1133 articles screened and 20 studies were included in the final analysis. The overall incidence of iron deficiency was 15.2% pre-operatively and 16.6% post-operatively. When analyzed by procedure, the incidence of iron deficiency was 12.9% pre-RYGB versus 24.5% post-RYGB and 36.6% pre-SG versus 12.4% post-SG. The incidence of iron deficiency-related anemia was 16.7% post-RYGB and 1.6% post-SG. Risk factors for iron deficiency were premenopausal females, duration of follow-up, and pre-operative iron deficiency. Prophylactic iron supplementation was reported in 16 studies and 2 studies provided therapeutic iron supplementation only for iron-deficient patients. Iron dosage varied from 7 to 80 mg daily across studies.

CONCLUSION

Iron deficiency is frequent in people with obesity and may be exacerbated by bariatric surgery, especially RYGB. Further investigation is warranted to determine appropriate iron supplementation dosages following bariatric surgery. Careful nutritional surveillance is important, especially for premenopausal females and those with pre-existing iron deficiency.

Malnutrition in obesity before and after bariatric surgery

Bariatric surgeries are considered the only effective way of weight loss therapy in morbidly obese patients, i.e. body mass index ≥ 35. However, micronutrient deficiencies and malnutrition are common after most bariatric procedures and thus, pre- and postoperative nutritional assessment and corrections are advised. The present review is presented in an effort to describe in some detail about prevalence, and mechanisms of macro- and micronutrient deficiencies in obese and post-bariatric surgery individuals. We also aimed to summarize the data on screening and supplementation of macro- and micronutrients before and after bariatric surgeries.

Metabolic surgery and iron homeostasis

Iron deficiency and anaemia after metabolic surgery, potentially modifiable nutritional complications, are becoming an increasing cause for concern as prevalence increases with time and there is limited evidence supporting the effectiveness of the current guidelines for prophylactic oral iron supplementation and treatment for deficiency. Abnormalities in iron nutrition predisposing to deficiency are common in severely obese patients, and the low-grade systemic inflammation, also common to these patients, reduces the effectiveness of oral iron supplementation. The surgical procedures result in alterations of foregut anatomy and physiology, which limit iron absorptive capacity and daily food intake. These alterations and the limited effects of oral iron supplementation explain the high prevalence of postoperative iron deficiency and anaemia. This review outlines current mechanisms concerning the pathogenesis of disordered iron nutrition in patients with severe obesity, current gaps in knowledge, and opportunities for quality improvement.

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 AUC_0-24h, C_max and T_max. 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 [AUC_{0-24h,pre-RYGB}: 28.6 ± 10.8 μg/dL*h; AUC_{0-24h,post-RYGB}: 27.5 ± 9.11 μg/dL*h (P = 0.84)]. Post-RYGB, iron AUC_0-24h 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 AUC^ROC = 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 AUC_0-24h 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.

Evolution of 29 Anthropometric, Nutritional, and Cardiometabolic Parameters Among Morbidly Obese Adolescents 2 Years Post Sleeve Gastrectomy

Background

Laparoscopic sleeve gastrectomy (LSG) is a popular treatment for adolescent morbid obesity. Research on LSG outcomes among adolescents assessed a narrow range of anthropometric, nutritional, or cardiometabolic parameters, leading to an incomplete picture of these changes. We examined a wide variety of anthropometric, nutritional, and cardiometabolic parameters among adolescents before and after LSG.

Methods

We retrospectively reviewed medical charts of all obese adolescents who underwent LSG at Hamad Medical Corporation, Qatar, between January 2011 and June 2015 (N = 102). We assessed preoperative levels and postoperative changes in 4 anthropometric, 15 nutritional, and 10 cardiometabolic parameters.

Results

The study sample comprised 79 patients with complete information (36 males, mean age 15.99 ± 1.1 years). At a mean of 24.2 months post-LSG, we observed (1) significantly reduced mean weight and body mass index by 51.82 ± 28.1 kg and 17 ± 6.24 kg/m², respectively; (2) the highest prevalence of post-LSG deficiencies pertained to vitamin D, albumin, and ferritin (89.3, 38, and 33.3%, respectively); (3) low hemoglobin levels (29.3%) only in females; (4) trace elements were not deficient; (4) significant reductions in percentage of adolescents with elevated low-density lipoprotein (from 66.1 to 38.9%), alanine aminotransferase (from 45.3 to 10.9%), and aspartate aminotransferase (from 24.1 to 8.6%) levels; (5) 100% remission of prediabetes cases; and (6) 80% remission of type 2 diabetes cases.

Conclusions

LSG achieved significant weight loss and improvement of cardiometabolic risk factors among adolescents. However, the slight worsening of preexisting nutritional deficiencies warrants careful preoperative surveillance and appropriate postoperative nutritional supplementation.

Comparison of Oral Iron Supplement Formulations for Normalization of Iron Status Following Roux-EN-y Gastric Bypass Surgery: a Randomized Trial

BACKGROUND

The evidence behind recommendations for treatment of iron deficiency (ID) following roux-en-y gastric bypass surgery (RYGB) lacks high quality studies.

SETTING

Academic, United States OBJECTIVE: The objective of the study is to compare the effectiveness of oral iron supplementation using non-heme versus heme iron for treatment of iron deficiency in RYGB patients.

METHODS

In a randomized, single-blind study, women post-RYGB and iron deficient received non-heme iron (FeSO₄, 195 mg/day) or heme iron (heme-iron-polypeptide, HIP, 31.5 to 94.5 mg/day) for 8 weeks. Measures of iron status, including blood concentrations of ferritin, soluble transferrin receptor (sTfR), and hemoglobin, were assessed.

RESULTS

At baseline, the mean ± standard deviation for age, BMI, and years since surgery of the sample was 41.5 ± 6.8 years, 34.4 ± 5.9 kg/m², and 6.9 ± 3.1 years, respectively; and there were no differences between FeSO₄ (N = 6) or HIP (N = 8) groups. Compliance was greater than 94%. The study was stopped early due to statistical and clinical differences between groups. Values before and after FeSO₄ supplementation, expressed as least square means (95% CI) were hemoglobin, 10.8 (9.8, 11.9) to 13.0 (11.9, 14.0) g/dL; sTfR, 2111 (1556, 2864) to 1270 (934, 1737) μg/L; ferritin, 4.9 (3.4, 7.2) to 15.5 (10.6, 22.6) μg/L; and sTfR:ferritin ratio, 542 (273, 1086) to 103 (51, 204); all p < 0.0001. With HIP supplementation, no change was observed in any of the iron status biomarkers (all p > 0.05).

CONCLUSIONS

In accordance with recommendations, oral supplementation using FeSO₄, but not HIP, was efficacious for treatment of iron deficiency after RYGB.

Iron deficiency after bariatric surgery: what is the real problem?

The growing prevalence of obesity explains the rising interest in bariatric surgery. Compared with non-surgical treatment options, bariatric surgery results in greater and sustained improvements in weight loss, obesity associated complications, all-cause mortality and quality of life. These encouraging metabolic and weight effects come with a downside, namely the risk of nutritional deficiencies. Particularly striking is the risk to develop iron deficiency. Postoperatively, the prevalence of iron deficiency varies between 18 and 53 % after Roux-en-Y gastric bypass and between 1 and 54 % after sleeve gastrectomy. Therefore, preventive strategies and effective treatment options for iron deficiency are crucial to successfully manage the iron status of patients after bariatric surgery. With this review, we discuss the risks and the contributing factors of developing iron deficiency after bariatric surgery. Furthermore, we highlight the discrepancy in the diagnosis of iron deficiency, iron deficiency anaemia and anaemia and highlight the evidence supporting the current nutritional recommendations in the field of bariatric research. In conclusion, we advocate for more nutrition-related research in patient populations in order to provide strong evidence-based guidelines after bariatric surgery.

Micronutrient Deficiencies After Bariatric Surgery: An Emphasis on Vitamins and Trace Minerals [Formula: see text]

Obesity has become a worldwide epidemic with a disproportionate increase in grade III obesity. Bariatric surgery offers an attractive option for sustained weight loss compared with traditional methods such as exercise and diet. Micronutrient deficiencies are common and clinically significant after bariatric surgery. These deficiencies are related to a combination of patient and surgical variables. A thorough understanding of specific micronutrient deficiencies is necessary for early recognition and optimal management. The purpose of this review is to describe indications, outcomes, and types of bariatric procedures, risk factors, and mechanisms for micronutrient deficiencies, as well as outline specific vitamin and trace element deficiencies after bariatric surgery.

Does Bariatric Surgery Improve Obesity Associated Comorbid Conditions

Obesity is a constantly growing health problem which reduces quality of life and life expectancy. Bariatric surgery for obesity is taken into account when all other conservative treatment modalities have failed. Comparison of the multidisciplinary programs with bariatric surgery regarding to weight loss showed that substantial and durable weight reduction have been achieved only with bariatric surgical treatments. However, the benefits of weight loss following bariatric procedures are still debated regarding the pro-inflammatory and metabolic profile of obesity.

Anemia and iron deficiency in gastrointestinal and liver conditions

Iron deficiency anemia (IDA) is associated with a number of pathological gastrointestinal conditions other than inflammatory bowel disease, and also with liver disorders. Different factors such as chronic bleeding, malabsorption and inflammation may contribute to IDA. Although patients with symptoms of anemia are frequently referred to gastroenterologists, the approach to diagnosis and selection of treatment as well as follow-up measures is not standardized and suboptimal. Iron deficiency, even without anemia, can substantially impact physical and cognitive function and reduce quality of life. Therefore, regular iron status assessment and awareness of the clinical consequences of impaired iron status are critical. While the range of options for treatment of IDA is increasing due to the availability of effective and well-tolerated parenteral iron preparations, a comprehensive overview of IDA and its therapy in patients with gastrointestinal conditions is currently lacking. Furthermore, definitions and assessment of iron status lack harmonization and there is a paucity of expert guidelines on this topic. This review summarizes current thinking concerning IDA as a common co-morbidity in specific gastrointestinal and liver disorders, and thus encourages a more unified treatment approach to anemia and iron deficiency, while offering gastroenterologists guidance on treatment options for IDA in everyday clinical practice.

Micronutrient Deficiencies in Morbidly Obese Women Prior to Bariatric Surgery

BACKGROUND

Although morbid obesity is related to excess of energy and macronutrient intake, it does not rule out the presence of micronutrient deficiencies. The aim of this study was to evaluate food intake and the prevalence of micronutrient deficiencies in a group of morbidly obese women seeking bariatric surgery.

METHODS

A total of 103 morbidly obese women were studied prior to bariatric surgery. Anthropometry and body composition (dual-energy X-ray absorptiometry, DEXA) were performed on all subjects. Energy and nutrient intake was determined by food frequency questionnaire. Blood tests to assess micronutrients status, including plasma iron, ferritin, transferrin, zinc, copper, calcium, phosphorus, hemoglobin, hematocrit, mean corpuscular volume (MCV), and hair zinc, were performed. Folic acid, vitamin B12, vitamin D, and parathyroid hormone (PTH) were also assessed in 66 subjects.

RESULTS

Mean energy intake was 2801 ± 970 kcal/day. Carbohydrate, protein, and lipid intake represented 55 ± 9.1, 13.9 ± 3.3, and 32.5 ± 8.2% of total energy intake, respectively. Iron, calcium, and vitamin D intake was below the recommended dietary allowance. The prevalence of nutritional deficiencies were as follows: plasma iron 12.6%, ferritin 8.7%, transferrin 14.6%, plasma zinc 2.9%, calcium 3.3%, phosphorus 2.3%, hemoglobin 7.7%, hematocrit 13.6%, MCV 6.8%, and hair zinc 15.7%. In the subsample, 10.6% had a vitamin B12 deficiency, 71.7% showed low concentrations of vitamin D, and 66% had high PTH levels. No folic acid or copper deficiencies were detected.

CONCLUSIONS

Despite high daily energy intake and adequate macronutrient distribution, morbidly obese Chilean women seeking bariatric surgery present with deficient intake of some micronutrients and a high prevalence of micronutrient deficiencies.

Lower hepatic iron storage associated with obesity in mice can be restored by decreasing body fat mass through feeding a low-fat diet

High-fat diet (HFD)-induced obesity has been reported to result in low hepatic iron storage. In the current study, we tested the hypothesis that these obesity-related changes in hepatic iron status could be reversed by decreasing adiposity by feeding a low-fat diet. Five-week-old C57BL/6 mice were assigned to 3 groups: the LL group was fed a control diet for 31 weeks, the HH group was fed a HFD for 31 weeks, and the HL group was fed the HFD for 15 weeks and then switched to the control diet for 16 weeks. The fat mass of the HL group decreased by 3.2 g from the 14th to the 30th weeks. Fat mass was significantly different among the groups (11.4, 15.8, and 37.5 g in the LL, HH, and HL groups, respectively; P< .001). The liver iron concentration of the HL group was similar to that of the LL group, which was about 30% higher than that of the HH group (74.2, 72.7, and 55.7 μg/g in the LL, HL, and HH groups, respectively; P< .05). Duodenal cytochrome b messenger RNA (mRNA) levels were higher in the HL group than in the HH group. Although bone morphogenetic protein 6 (Bmp6) mRNA levels showed no significant differences in the liver, duodenal Bmp6 mRNA levels were significantly lower in the HH group compared with the LL and HL groups. Liver Smad1/5 proteins were differentially activated: the HH group had significantly less phosphorylated Smads than did the LL and HL groups. Our data demonstrate that hepatic iron storage levels are closely related to body adiposity, and reducing body fat mass through feeding a lower-fat diet to HFD-induced obese mice restores liver iron storage.

What do individuals with morbid obesity report as a usual dietary intake? A narrative review of available evidence

BACKGROUND

In several developed countries, as obesity prevalence doubles it has quadrupled for morbid obesity (BMI ≥ 40 kgm^-2). As more individuals with morbid obesity present for weight loss treatment there is a greater need to understand their dietary habits. No reviews were found in the literature, therefore this systematic review aims to identify and describe the existing evidence on the usual dietary intake of individuals with morbid obesity including those from a general population and those seeking treatment such as weight loss surgery.

METHODS

A literature search of ten databases from 1980 to June 2014 was conducted to identify original research of adults with morbid obesity (aged 18-60 years) that reported a usual dietary intake.

RESULTS

Ten studies met all inclusion criteria and reported energy intake, most reported macronutrient composition, two assessed micronutrient intake, and one reported food-based outcomes. Other dietary outcomes were related to surgical intervention. The most plausible energy intake data suggest high intakes, >4000 Kcal/day for those weight stable at the highest levels of morbid obesity (up to BMI 97 kgm^-2). Fat intakes are also high, around 40% of energy intake and up to 57% for some individuals. Suboptimal intakes of iron and calcium are reported.

CONCLUSION

This review draws attention to a limited evidence base, offers preliminary insight suggesting individuals with morbid obesity are prone to consuming poor quality diets similar to those reported for obese populations, and highlights challenges for future research.

Comparing Outcomes of Two Types of Bariatric Surgery in an Adolescent Obese Population: Roux-en-Y Gastric Bypass vs. Sleeve Gastrectomy

BACKGROUND

Obesity is prevalent among adolescents and is associated with serious health consequences. Roux-en-Y Gastric Bypass (RYGB) and Sleeve Gastrectomy (SG) are bariatric procedures that cause significant weight loss in adults and are increasingly being performed in adolescents with morbid obesity. Data comparing outcomes of RYGB vs. SG in this age-group are scarce. This study aims to compare short-term (1-6 months) and longer-term (7-18 months) body mass index (BMI) and biochemical outcomes following RYGB and SG in adolescents/young adults.

METHODS

A retrospective study using data extracted from medical records of patients 16-21 years who underwent RYGB or SG between 2012 and 2014 at a tertiary care academic medical center.

RESULTS

Forty-six patients were included in this study: 24 underwent RYGB and 22 underwent SG. Groups did not differ for baseline age, sex, race, or BMI. BMI reductions were significant at 1-6 months and 7-18 months within groups (p < 0.0001), but did not differ by surgery type (p = 0.65 and 0.09, for 1-6 months and 7-18 months, respectively). Over 7-18 months, within-group improvement in low-density lipoprotein (LDL) (-24 ± 6 in RYGB, p = 0.003, vs. -7 ± 9 mg/dl in SG, p = 0.50) and non-high-density lipoprotein (non-HDL) cholesterol (-23 ± 8 in RYGB, p = 0.02, vs. -12 ± 7 in SG, p = 0.18) appeared to be of greater magnitude following RYGB. However, differences between groups did not reach statistical significance. When divided by non-alcoholic steatohepatitis stages (NASH), patients with Stage II-III NASH had greater reductions in alanine aminotransferase levels vs. those with Stage 0-I NASH (-45 ± 18 vs. -9 ± 3, p = 0.01) after 7-18 months. RYGB and SG groups did not differ for the magnitude of post-surgical changes in liver enzymes.

CONCLUSION

RYGB and SG did not differ for the magnitude of BMI reduction across groups, though changes trended higher following RYGB. Further prospective studies are needed to confirm these findings.

The role of ferric carboxymaltose in the treatment of iron deficiency anemia in patients with gastrointestinal disease

Iron deficiency anemia (IDA) is the most common form of nutritional anemia worldwide. Iron plays a pivotal role in vital functioning of almost every organ system. IDA affects both physical and psychological functioning of humans. Oral iron is considered as first-line therapy for the treatment of IDA due to low cost, good safety profile and ease of administration. However, the absorption of oral iron is affected by several factors and incidence of gastrointestinal side effects can lead to lack of adherence to therapy as well as poor efficacy. This has led to the emergence of intravenous iron therapy which is clearly superior to oral iron with higher increment of hemoglobin levels and rapid replenishment of iron stores. Ferric carboxymaltose (FCM) is a novel non-dextran intravenous iron form which has been approved for use in patients with iron deficiency who have had inadequate response to oral iron therapy, intolerance to oral iron, or nondialysis-dependent chronic kidney disease. The safety and efficacy of using FCM for the treatment of IDA has been demonstrated in several clinical trials. One dose can provide a large amount of iron and has a very short infusion time. It should be considered as first-line therapy in patients with active inflammation like inflammatory bowel disease when gastrointestinal absorption of oral iron may be compromised. It should also be given to patients who have inadequate response to oral iron therapy. It has been shown to be noninferior to other intravenous iron formulations with a good safety profile and produced fewer anaphylactic reactions.

Changes in Hematology and Calcium Metabolism After Gastric Bypass Surgery--a 2-Year Follow-Up Study

BACKGROUND

Concerns regarding nutritional deficiencies have recently emerged after Roux-en-Y gastric bypass (RYGB).

METHODS

A total of 835 subjects underwent RYGB, age 43.3 years, body mass index (BMI) 47.2 kg/m(2). Hematological and calcium metabolic variables were measured before, 6, 12, and 24 months after surgery. Daily supplement of 800 mg calcium, 800 U vitamin D, a multivitamin, and a vitamin B12 injection (1 mg) every third month was recommended. In subjects with low ferritin and decreasing hemoglobin levels, oral, or intravenous iron was administered.

RESULTS

Hemoglobin concentration decreased from before surgery to month 24 for both men (9.3 ± 0.05 vs. 8.3 ± 0.08 mmol/L, p < 0.001) and women (8.4 ± 0.03 vs. 7.7 ± 0.06 mmol/L, p < 0.001). At 24 months, anemia was present in 25.8 % of women and 22.1 % of men. Predictors of anemia in both sexes were baseline hemoglobin (p < 0.001), excessive weight loss in men, and younger age in women (p < 0.001). Plasma ferritin levels decreased in both sexes (p < 0.01), whereas concentrations of folic acid and vitamin B12 increased from before surgery to 24 months after surgery (p < 0.001). Vitamin D increased from baseline to month 24 in both sexes (p < 0.01). In women, PTH increased from baseline to month 24 (p < 0.05) with no changes in calcium or magnesium.

CONCLUSIONS

Supplementation of calcium and vitamin D was sufficient. Iron substitution did not prevent anemia, which especially affected premenopausal women. More attention should be given to iron substitution after RYGB.

An optimized multivitamin supplement lowers the number of vitamin and mineral deficiencies three years after Roux-en-Y gastric bypass: a cohort study

BACKGROUND

Vitamin and mineral deficiencies are common after Roux-en-Y gastric bypass (RYGB) surgery. In particular, inadequate serum concentrations of ferritin and vitamin B12 have been found in 11% and 23% (respectively) of patients using a standard multivitamin supplement (sMVS) 1 year after RYGB.

OBJECTIVE

To evaluate the effectiveness and safety of Weight Loss Surgery (WLS) Forte® (a pharmaceutical-grade, optimized multivitamin supplement) compared with an sMVS and a control group (nonuser) 3 years after RYGB.

SETTING

General hospital specialized in bariatric surgery.

METHODS

A follow-up cohort study of a triple-blind randomized, controlled clinical trial.

RESULTS

At baseline 148 patients were enrolled (74 [50%] in the sMVS group and 74 [50%] in the WLS Forte group). After a mean follow-up of 36 months, 11 (7%) patients were lost to follow-up, of whom 2 were secondary to death. At the end of the study, 11 (17%) patients in the WLS Forte and 17 (24%) in the sMVS group stopped using a supplement. In addition, 64 (47%) patients were using WLS Forte and 45 (33%) patients a sMVS. Patient characteristics and follow-up length were comparable between the groups. Significantly more patients were diagnosed with anemia (16% versus 3% [P = .021]), a ferritin deficiency (14% versus 3% [P = .043]), and a zinc deficiency (8% versus 0% [P = .033]) in the sMVS group compared with WLS Forte. Five patients developed a vitamin B12 deficiency while using WLS Forte, versus 15 of sMVS users (P = .001). No adverse events occurred that were related to supplement use.

CONCLUSION

At 3 years postoperative of RYGB, an optimized multivitamin supplement (WLS Forte) was more effective in reducing anemia and ferritin, vitamin B12, and zinc deficiencies compared with a standard supplement and control.

Management of vitamin K deficiency after biliopancreatic diversion with or without duodenal switch

BACKGROUND

Reduced serum vitamin K levels are frequently observed after biliopancreatic diversion (BPD) and BPD with duodenal switch (BPD/DS). The criteria for treatment are not precisely defined.

OBJECTIVES

To assess the effects of standardized vitamin K supplementation in patients who develop vitamin K deficiency after BPD or BPD/DS.

SETTING

Teaching hospital specializing in bariatric surgery.

METHODS

Serum vitamin K levels, clotting times, and vitamin K-dependent coagulation factors were measured after an overnight fast at baseline and then at 4 days and 1, 4, and 52 weeks after the start of vitamin K supplementation in 10 consecutive patients who had developed severe vitamin K deficiency after BPD or BPD/DS. Vitamin K was administered in a dose of 5 mg/d for 1 week, followed by a maintenance dose of 5 mg once a week.

RESULTS

At baseline, all patients had serum vitamin K1 levels below the limit of detection, but none reported symptoms of easy bleeding. Minor prolongation of the prothrombin time and minimal decreases of some coagulation factors were observed in a minority of patients. During the first week of vitamin K loading, median serum vitamin K1 levels rose into the high normal range. During maintenance treatment, median vitamin K1 levels settled in the low normal range.

CONCLUSION

Vitamin K1 deficiency in patients with BPD or BPD/DS is not commonly associated with bleeding or clinically relevant decreases in coagulation factor activity. We hypothesize that vitamin K2 production in the large intestine is usually sufficient to compensate for vitamin K1 deficiency and to maintain total liver vitamin K stores within the range required for (near) normal coagulation factor production.

Vitamin concentrations 5 years after gastric bypass

BACKGROUND/OBJECTIVES

Few studies have investigated the effects of bariatric surgery on vitamin status in the long term. We examined changes in vitamin status up to 5 years after Roux-en-Y gastric bypass surgery.

SUBJECTS/METHODS

Using a retrospectively maintained database of patients undergoing weight loss surgery, we identified all patients operated with Roux-en-Y gastric bypass at our tertiary care hospital during July 2004-May 2008. Data on vitamin concentrations and patient-reported intake of dietary supplements were collected up to July 2012. Linear mixed models were used to estimate changes in vitamin concentrations during follow-up, adjusting for age and sex. All patients were recommended daily oral multivitamin, calcium/vitamin D and iron supplements and 3-monthly intramuscular B-12 after surgery.

RESULTS

Out of the 443 patients operated with gastric bypass, we included 441 (99.5%) patients with one or more measurements of vitamin concentrations (75.1% women; mean age 41.5 years, mean body mass index 46.1 kg/m(2) at baseline). At 5 years after surgery, the patients' estimated mean vitamin concentrations were either significantly higher (vitamin B-6, folic acid, vitamin B-12, vitamin C and vitamin A) or not significantly different (thiamine, 25-hydroxyvitamin D and lipid-adjusted vitamin E) compared with before surgery. Use of multivitamin, calcium/vitamin D and vitamin B-12 supplements was reported by 1-9% of patients before surgery, 79-84% of patients at 1 year and 52-83% of patients 5 years after surgery.

CONCLUSIONS

In patients who underwent gastric bypass surgery, estimated vitamin concentrations were either significantly increased or unchanged up to 5 years after surgery.

Anemia and the Need for Intravenous Iron Infusion after Roux-en-Y Gastric Bypass

The frequency of anemia, iron deficiency, and the long-term need for IV iron following Roux-en-y gastric bypass (RYGB) surgery has not been well characterized. Three-hundred and nineteen out of 904 consecutive subjects who underwent RYGB at Penn State Hershey Medical Center from 1999 to 2006 met the inclusion criteria for a preoperative complete blood count (CBC) and at least one CBC >6 months following surgery. Cumulative incidence of anemia 7 years post procedure was 58%. Menstruation status and presence of preoperative anemia were predictive of anemia by univariate analysis and multivariable Cox regression (P = 0.0014 and 0.044, respectively). Twenty-seven subjects, primarily premenopausal women, representing 8.5% of the cohort and 22% of the 122 anemic subjects, needed intravenous (IV) iron a mean of 51 months postoperatively for anemia unresponsive or refractory to oral iron. The risk for development of anemia necessitating IV iron therapy following RYGB is highest in menstruating women and continues to increase for many years, even in post-menopausal women. Well-designed prospective studies are needed to identify the incidence of iron deficiency anemia and the patient populations at increased risk for requiring IV iron replacement after RYGB surgery.

Early Endocrine and Metabolic Changes After Bariatric Surgery in Grade III Morbidly Obese Patients: A Randomized Clinical Trial Comparing Sleeve Gastrectomy and Gastric Bypass

BACKGROUND

We compared the early endocrine and metabolic changes associated with sleeve gastrectomy (SG) and gastric bypass (GB) in grade III obese patients.

METHODS

Fifty morbidly obese patients were randomized into two groups on the basis of their position in the queue-group A comprised SG and group B was GB. Comparison between the two groups was based on clinical and laboratory variables such as fasting blood glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), glycated hemoglobin (HbA1c), lipids, albumin, and ferritin. Patients were assessed after 7, 14, 30, 60, and 90 days and additional laboratory tests were done on the 90(th) day.

RESULTS

The following mean values were recorded for groups A and B, respectively: Age (years), 36.4 and 31.1; weight (kg), 123.2 and 128.3; and body mass index (BMI; kg/m(2)), 45.6 and 47.3. In the first postoperative week, group B showed a greater weight loss (P=0.047) that was not observed after 14, 30, 60, and 90 days (P>0.05). Group A had an average excess weight loss of 31.09 kg compared to 32.69 kg in group B (P=0.222). Glycemic control was better in group B (P=0.023), whereas the control of systemic arterial pressure was better in group A (P=0.026). There were no significant differences in early lipid control and micronutrient deficiencies between the two groups.

CONCLUSIONS

SG and GB were equally effective in promoting weight loss after 90 days. However, whereas SG was associated with better early remission rates for hypertension, GB was more effective in fasting blood glucose control but not in HOMA-IR and HbA1c levels. There was no difference in the protein or vitamin deficiencies of the two groups.

Optimization of vitamin suppletion after Roux-en-Y gastric bypass surgery can lower postoperative deficiencies: a randomized controlled trial

Iron, vitamin B12, and folic acid deficiencies are among the most common deficiencies occurring after laparoscopic Roux-en-Y gastric bypass (LRYGB). The present study evaluates the effectiveness of a specially designed multivitamin supplement (WLS Forte, FitForMe, Rotterdam, the Netherlands) specifically developed for LRYGB patients.A triple-blind, randomized, 12-month study was conducted comparing WLS forte with a standard multivitamin supplement (sMVS) containing approximately 100% of the recommended daily allowance (RDA) for iron, vitamin B12, and folic acid. WLS Forte contains vitamin B12 14000% RDA, iron 500% RDA, and folic acid 300% RDA.In total, 148 patients (74 in each group) underwent a LRYGB procedure. Baseline characteristics were similar for both groups. Per protocol analysis demonstrated that sMVS treatment was associated with a decline in ferritin (-24.4 ± 70.1 μg/L) and vitamin B12 (-45.9 ± 150.3 pmol/L) over 12 months, whereas in WLS Forte patients, ferritin remained stable (+3.2 ± 93.2 μg/L) and vitamin B12 increased significantly (+55.1 ± 144.2 pmol/L). The number of patients developing ferritin or vitamin B12 deficiency was significantly lower with WLS Forte compared with sMVS (P < 0.05). Iron deficiency (ID) was reduced by 88% after WLS Forte compared with sMVS. Adverse events related to supplement use did not occur.An optimized multivitamin supplement is safe and reduces the development of iron and vitamin B12 deficiencies after LRYGB.

Patients at risk for trace element deficiencies: bariatric surgery

Obesity is a worldwide epidemic associated with diseases such as diabetes mellitus and cardiovascular disease. Current methods for weight loss are not very effective, particularly for those with morbid obesity. Surgical therapy may be recommended for those with a BMI≥40kg/m(2), or BMI≥35kg/m(2) with co-morbidities. This therapy can produce significant weight loss and improve/resolve co-morbidities including hypertension and hyperlipidemia. Yet successes may be tempered by adverse effects on trace element absorption and status. A PubMed literature search identified studies from January 1980 to February 2013 for inclusion in a meta-analysis. Publications that contained keywords 'bariatric surgery or gastric bypass,' 'trace element or mineral or zinc or iron or copper or iodine or manganese', and 'absorption or status or rate or level' were identified. Inclusion criteria were human markers that reflect changes in trace element status before and after bariatric surgery. The meta-analysis found a decrease in blood copper, zinc, hemoglobin, as well as an increase in iron, regardless of the type of surgery. The pooled effect sizes and 95% confidence intervals were 0.17 and -0.09 to 0.43 for plasma/serum iron (p=0.20); -0.49 and -0.67 to -0.31 for blood hemoglobin (p=0.00); -0.47 and -0.90 to -0.05 for plasma/serum copper (p=0.03); -0.77 and -1.20 to -0.35 for plasma/serum zinc (p=0.00). Differences in levels of these minerals pre- and post-surgery may have been influenced by the time period after surgery, a pre-existing deficiency, type and dose of vitamin-mineral supplements, and malabsorption due to elimination of parts of the gastrointestinal tract.

Review article: The nutritional and pharmacological consequences of obesity surgery

BACKGROUND

Obesity surgery is acknowledged as a highly effective therapy for morbidly obese patients. Beneficial short-term effects on common comorbidities are practically undisputed, but a growing data pool from long-term follow-up reveals increasing evidence of potentially severe nutritional and pharmacological consequences.

AIMS

To assess the prevalence, causes and symptoms of complications after obesity surgery, to elucidate and compare therapy recommendations for macro- and micronutrient deficiencies, and to explore surgically-induced effects on drug absorption and bioavailability, discussing ramifications for long-term therapy and prophylaxis.

METHODS

PubMed, Embase and MEDLINE were searched using terms including, but not limited to, bariatric surgery, gastric bypass, obesity surgery and Roux-en-Y, coupled with secondary search terms, e.g. anaemia, micronutrients, vitamin deficiency, bacterial overgrowth, drug absorption, pharmacokinetics, undernutrition. All studies in English, French or German published January 1980 through March 2014 were included.

RESULTS

Macro- and micronutrient deficiencies are common after obesity surgery. The most critical, depending on surgical technique, are hypoalbuminemia (3-18%) and deficiencies of vitamins B1 (≤49%), B12 (19-35%) and D (25-73%), iron (17-45%) and zinc (12-91%). Many drugs commonly administered to obese patients (e.g. anti-depressants, anti-microbials, metformin) are subject to post-operative and/or PPI-associated changes affecting bioavailability and absorption.

CONCLUSIONS

Complications are associated with pre-operative and/or post-operative malnutrition or procedure-related changes in intake, absorption and drug bioavailability. The high prevalence of nutrient deficiencies after obesity surgery makes life-long nutritional monitoring and supplementation essential. Post-operative changes to drug absorption and bioavailability in bariatric patients cast doubt on the validity of standard drug dosage and administration recommendations.

Iron deficiency after Roux-en-Y gastric bypass: insufficient iron absorption from oral iron supplements

BACKGROUND

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.

METHODS

Monocentric retrospective study in 164 patients (123 females, 41 males; mean age 43 years) who underwent RYGB between January 2006 and November 2010 was done. Pre- and postoperative data on gender, age, BMI, serum levels of iron, ferritin, hemoglobin, vitamin B12, 25-hydroxy vitamin D, and use of proton pump inhibitors and H2 antagonists were collected. Generalized linear mixed models were used for the analysis of the data. In 23 patients who developed iron deficiency after surgery, an oral challenge test with 100 mg FeSO4 · 7H2O was performed.

RESULTS

Following RYGB, 52 (42.3 %) female patients and 9 male (22.0 %) patients developed iron deficiency (serum ferritin concentration ≤ 20 μg/L). The prevalence of iron deficiency was significantly higher in females than males (p = 0.0170). Young age (p = 0.0120), poor preoperative iron status (p = 0.0004), vitamin B12 deficiency (p = 0.0009), and increasing time after surgery (p < 0.0001) were also associated with iron deficiency. In the oral iron challenge test, only one patient out of 23 showed sufficient iron absorption.

CONCLUSIONS

Iron deficiency is extremely frequent after RYGB and is linked with different risk factors. Iron supplementation seems essential, but the effect of oral tablets may be limited as absorption of oral iron supplements is insufficient post-RYGB.

Anthropometric evaluation and micronutrients intake in patients submitted to laparoscopic Roux-en-Y gastric bypass with a postoperative period of ≥ 1 year

BACKGROUND

Bariatric surgery is indicated as the most effective treatment for morbid obesity; the Roux-en-Y gastric bypass (RYGB) is considered the procedure of choice. However, nutritional deficiency may occur in the postoperative period as a result of reduced gastric capacity and change in nutrients absorption in the gastrointestinal tract. The prescription of vitamin and mineral supplementation is a common practice after RYGB; however, it may not be sufficient to prevent micronutrient deficiencies. The aim of this study was to quantify the micronutrient intake in patients undergoing RYGB and verify if the intake of supplementation would be enough to prevent nutritional deficiencies.

METHODS

The study was conducted on 60 patients submitted to RYGB. Anthropometric, analytical, and nutritional intake data were assessed preoperatively and 1 and 2 years postoperatively. The dietary intake was assessed using 24-h food recall; the values of micronutrients evaluated (vitamin B12, folic acid, iron, and calcium) were compared to the dietary reference intakes (DRI).

RESULTS

There were significant differences (p < 0.05) between excess weight loss at the first and second year (69.9 ± 15.3 vs 9.6 ± 62.9 %). In the first and second year after surgery, 93.3 and 94.1 % of the patients, respectively, took the supplements as prescribed. Micronutrient deficiencies were detected in the three evaluation periods. At the first year, there was a significant reduction (p < 0.05) of B12, folic acid, and iron intake.

CONCLUSIONS

Despite taking vitamin and mineral supplementation, micronutrient deficiencies are common after RYGB. In the second year after surgery, micronutrient intake remains below the DRI.