Influence of diet and supplements on iron status after gastric bypass surgery

Dietary supplements and bariatric surgery

Bariatric surgery or weight loss surgery has been in practice for achieving significant weight loss in patients who have failed to achieve weight loss after pharmacological interventions. The rising cases of obesity are a triggering factor for more bariatric surgeries worldwide. Interestingly, sustained weight loss achieved post-bariatric surgery offers metabolic advantages, and patients show improved glucose and lipid metabolisms. Bariatric surgery is directly linked to higher incidences of vitamin, mineral, and trace element deficiencies, thus making patients susceptible to anemia, osteoporosis, and cardiomyopathy. Reduced nutrient absorption capacity, dietary changes, dietary restriction, and altered gastrointestinal tract morphology are some reasons for nutritional deficiency observed in post-bariatric surgery procedures. Micro-and-macronutrient deficiency observed in patients during the postoperative phase requires continuous monitoring of nutritional parameters. Therefore, adequate multivitamin and mineral supplements become essential to prevent/overcome micronutrient deficiencies. Bariatric surgery also raises the risk of small for gestational age (SGA) babies. Hence, a 12 - 24 months gap is recommended between bariatric surgery and pregnancy to achieve desired weight loss targets. The topic of this review is the impact of bariatric surgery procedures on vitamin and mineral absorption and the role of dietary supplements in maintaining a healthy nutritional balance during the postoperative phase.

Macro- and Micro-nutrient Intake Adequacy in Gastric Bypass Patients after 24 Months: a Cross-sectional Study

Decreased food intake is an effective mechanism for gastric bypass surgery (GBS) for successful weight loss. This cross-sectional study aimed to assess dietary intake, micro-and macro-nutrients in the patients undergoing GBS and determine the possible associations with weight changes. We assessed anthropometric indices and food intake at 24 month-post gastric bypass surgery. Dietary data was evaluated using three-day food records. After the 24 months of surgery, among 35 patients (mean age: 43.5 ± 11.2 years; 82.85% females), with the mean body mass index (BMI) of 30.5 ± 4.5 kg/m², 17 cases were < 50% of their excess weight. The average daily calorie intake was 1,733 ± 630 kcal, with 14.88% of calories from protein. Consumption amounts of protein (0.82 ± 0.27 g/kg of the current weight), as well as fiber, and some micro-nutrients (vitamin B9, E, K, B5, and D3) were lower than recommended amounts. Patients were classified into three groups based on their success in weight loss after surgery. Calorie intake was not significantly different between groups, but successful groups consumed considerably more protein and less carbohydrate than the unsuccessful group (p < 0.05). Based on our findings, the patients undergoing GBS had inadequate macro- and micro-nutrient intake after 24 months. However, protein intake can affect patients' success in achieving better weight loss. Long-term cohort and clinical studies need to be conducted to comprehend this process further.

Evaluation of Dietary Assessment Tools Used in Bariatric Population

Severe obesity is associated with major health issues and bariatric surgery is still the only treatment to offer significant and durable weight loss. Assessment of dietary intakes is an important component of the bariatric surgery process. Objective: To document the dietary assessment tools that have been used with patients targeted for bariatric surgery and patients who had bariatric surgery and explore the extent to which these tools have been validated. Methods: A literature search was conducted to identify studies that used a dietary assessment tool with patients targeted for bariatric surgery or who had bariatric surgery. Results: 108 studies were included. Among all studies included, 27 used a dietary assessment tool that had been validated either as part of the study per se (n = 11) or in a previous study (n = 16). Every tool validated per se in the cited studies was validated among a bariatric population, while none of the tools validated in previous studies were validated in this population. Conclusion: Few studies in bariatric populations used a dietary assessment tool that had been validated in this population. Additional studies are needed to develop valid and robust dietary assessment tools to improve the quality of nutritional studies among bariatric patients.

Iron Deficiency in Obesity and after Bariatric Surgery

Iron deficiency (ID) is particularly frequent in obese patients due to increased circulating levels of acute-phase reactant hepcidin and adiposity-associated inflammation. Inflammation in obese subjects is closely related to ID. It induces reduced iron absorption correlated to the inhibition of duodenal ferroportin expression, parallel to the increased concentrations of hepcidin. Obese subjects often get decreased inflammatory response after bariatric surgery, accompanied by decreased serum hepcidin and therefore improved iron absorption. Bariatric surgery can induce the mitigation or resolution of obesity-associated complications, such as hypertension, insulin resistance, diabetes mellitus, and hyperlipidemia, adjusting many parameters in the metabolism. However, gastric bypass surgery and sleeve gastrectomy can induce malabsorption and may accentuate ID. The present review explores the burden and characteristics of ID and anemia in obese patients after bariatric surgery, accounting for gastric bypass technique (Roux-en-Y gastric bypass-RYGB) and sleeve gastrectomy (SG). After bariatric surgery, obese subjects' iron status should be monitored, and they should be motivated to use adequate and recommended iron supplementation.

Nutrient Intake and Deficiency of Patients 1 Year After Bariatric Surgery: Tehran Obesity Treatment Study (TOTS)

PURPOSE

This study aimed at assessing nutrient adequacy after 1 year in patients who had undergone gastric bypass (GB) surgery or sleeve gastrectomy (SG) and to investigate the association of nutrient adequacy with anthropometric indices.

METHODS

A total of 180 severely obese patients (BMI ≥ 35 kg/m²) were selected among the participants of Tehran Obesity Treatment Study. Nutritional assessments were performed over 3 days of 24-h dietary recall. To evaluate the nutrient adequacy ratio (NAR), the subject's nutrient intake was divided by the dietary reference intakes. The mean adequacy ratio (MAR) was also determined as the sum of NARs divided by the number of involved nutrients (n = 11).

RESULTS

The mean age of SG (67%) and GB (32%) patients was 39.2 ± 12 and 41.4 ± 10 years, respectively. SG patients had more postoperative fat-free mass (52.0 ± 12 kg) than GB patients (49.7 ± 8 kg) (P < 0.05). The most common postoperative serum nutrient deficiencies were related to vitamin B12 (30%), ferritin (19%), and 25-hydroxyvitamin D (16.2%). Moreover, high inadequacy of protein (> 80%) and total fat (> 70%) intake was reported. The MAR score showed that almost 45% of the patients had possibly adequate intakes of some nutrients. The adequacy of nutrients was positively associated with fat-free mass (β = 8.67, P < 0.05).

CONCLUSION

These findings revealed that patients had inadequate nutrient intakes 1 year after bariatric surgery, which was accompanied by serum nutritional deficiencies. Compared to GB patients, SG patients had a better body composition. Overall, compliance of patients with dietary guidelines and supplementations needs to be carefully monitored in the postoperative period.

Recommendations Based on Evidence by the Andalusian Group for Nutrition Reflection and Investigation (GARIN) for the Pre- and Postoperative Management of Patients Undergoing Obesity Surgery

In order to develop evidence-based recommendations and expert consensus for nutrition management of patients undergoing bariatric surgery and postoperative follow-up, we conducted a systematic literature search using PRISMA methodology plus critical appraisal following the SIGN and AGREE-II procedures. The results were discussed among all members of the GARIN group, and all members answered a Likert scale questionnaire to assess the degree of support for every recommendation. Patients undergoing bariatric surgery should be screened preoperatively for some micronutrient deficiencies and treated accordingly. A VLCD (Very Low-Calorie Diet) should be used for 4-8 weeks prior to surgery. Postoperatively, a liquid diet should be maintained for a month, followed by a semi-solid diet also for one month. Protein requirements (1-1.5 g/kg) should be estimated using adjusted weight. Systematic use of specific multivitamin supplements is encouraged. Calcium citrate and vitamin D supplements should be used at higher doses than are currently recommended. The use of proton-pump inhibitors should be individualised, and vitamin B12 and iron should be supplemented in case of deficit. All patients, especially pregnant women, teenagers, and elderly patients require a multidisciplinary approach and specialised follow-up. These recommendations and suggestions regarding nutrition management when undergoing bariatric surgery and postoperative follow-up have direct clinical applicability.

Feasibility of Mass-Spectrometry to Lower Cost and Blood Volume Requirements for Assessment of B Vitamins in Patients Undergoing Bariatric Surgery

Bariatric surgery induces deficiencies in a combination of B vitamins. However, high costs and a large blood volume requirement are barriers to routine screening. We adapted and validated a method coupling tandem mass spectrometry (MS/MS) with high-performance liquid chromatography (HPLC) to facilitate cost-effective analysis for simultaneous detection of B vitamins in low volumes of plasma. Based on existing methods, pooled plasma was extracted using hexane and acetonitrile and seven B vitamin analytes were separated using HPLC. Detection was performed with an Agilent 6460 triple quadrupole tandem mass spectrometer (MS/MS) using electrospray ionization in the positive ion mode. We evaluated linearity, recovery, precision, and limit of detection, as well as costs of the assay. We evaluated seven B vitamins from plasma; five (riboflavin, nicotinamide, pantothenic acid, pyridoxine, and biotin) were detected and quantified with precision and linearity. Recovery ranged from 63 to 81% for each of the vitamins, except for nicotinamide—the recovery of which was suppressed to 40%, due to plasma matrix effects. We demonstrated the feasibility of the HPLC–MS/MS method for use in patients who undergo bariatric surgery by analyzing pooled plasma from patients with a lower cost and blood volume than had we sent the samples to a commercial laboratory. It is advantageous and feasible, in terms of low cost and blood volume requirement, to simultaneously measure plasma concentrations of B vitamins using HPLC–MS/MS. With further improvements, the method may enable personalized nutritional assessment for the nutritionally compromised, bariatric surgery population.

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.

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.

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.

Perspectives in obesity and pregnancy

Obesity is currently recognized as a health epidemic worldwide. Its prevalence has doubled in the last three decades. Obesity is a complex clinical picture associated with physical, physiologic, hormonal, genetic, cultural, socioeconomic and environmental factors. The rate of obesity is also increasing in the pregnant women population. Maternal obesity is associated with less than optimal obstetrical, fetal and neonatal outcomes. It is also associated with significant adverse long-term effects on both obese parturients and the infants born from obese women. A number of guidelines have been published to educate health care workers and the general population in an attempt to develop effective interventions on a large scale to prevent obesity. These guidelines are multiple, confusing and inconsistent. There are no standard recommendations regarding gestational weight gaining goals, nutrients and additional elements necessary for certain obese women who have been treated with bariatric surgical procedures, screening for metabolic diseases such as diabetes, additional preventive health care services indicated for obese women in the pregnancy planning stages, during prenatal care, in the immediate post-partum period and as a long-term approach for health preservation. In 2013, the American Medical Association supported by several US national medical specialty organizations published Resolution 420 (A-13) recognizing obesity as a disease state with multiple pathophysiological aspects requiring a range of interventions to improve its prevention and treatment. The goal of this decision was to encourage a broader spectrum of health care benefits insurance coverage for the prevention and treatment of obesity. There are a number of myths and misconceptions associated with obesity. These perspectives present our views and clinical experience with a partial review of recent bibliography addressing the associations between obese reproductive age women and their risks during pregnancy.