The effect of Roux-en-Y gastric bypass on zinc nutritional status

Changes in Nutritional Outcomes After Roux-en-Y Gastric Bypass: A Systematic Review and Meta-Analysis

BACKGROUND

Bariatric surgery (BS) is the most effective treatment for severe obesity and it has beneficial effects on glycemic control and metabolism outcomes. However, the effects of BS on nutritional outcomes are controversial. Therefore, we aimed to evaluate the changes in several nutritional outcomes after Roux-en-Y gastric bypass (RYGB).

METHODS

A comprehensive search was performed using the following databases: PubMed, Embase, Web of Science, Cochrane Library, WanFang and Chinese National Knowledge Infrastructure. The following outcomes were evaluated: vitamin A, 25-hydroxyvitamin D [25(OH)D], calcium, phosphorus, parathormone (PTH), iron, ferritin, vitamin B12, folate, and zinc. The pooled outcomes were expressed as standard mean difference (SMD) and 95% confidence interval (CI) using a random effects model.

RESULTS

Fifty-six studies including 5645 individuals with obesity met the inclusion criteria. Serum 25(OH)D (SMD = 0.78, 95%CI 0.38 to 1.20, P < 0.001), phosphorus (SMD = 0.48, 95%CI 0.22 to 0.74, P < 0.001), PTH (SMD = 0.35, 95%CI 0.11 to 0.59, P = 0.005), vitamin B12 (SMD = 1.11, 95%CI 0.41 to 1.80, P = 0.002), and folate (SMD = 1.53, 95%CI 0.77 to 2.28, P < 0.001) significantly increased after RYGB compared with the baseline. Serum ferritin (SMD =  - 1.67, 95%CI - 2.57 to - 0.77, P < 0.001), vitamin A (SMD =  - 0.64, 95%CI - 0.99 to - 0.29, P < 0.001), and plasma zinc (SMD =  - 0.58, 95%CI - 1.09 to - 0.06, P = 0.027) significantly decreased after RYGB. No significant changes in serum calcium (SMD =  - 0.14, 95%CI - 0.40 to 0.11, P = 0.219) and iron (SMD = 0.26, 95%CI - 0.11 to 0.64, P = 0.165) were observed after RYGB.

CONCLUSIONS

Despite the increased levels of 25(OH)D, phosphorus, vitamin B12 and folate, this meta-analysis revealed the unfavorable nutritional consequences after RYGB.

A Literature Review of Taste Change and Zinc Deficiency After Bariatric Surgery: Could There Be a Causal Link?

In this review, we collated evidence relating to taste change and zinc deficiency in relation to bariatric surgery (BS) and effects of zinc replacement on taste perception and speculate on the possible role of zinc deficiency to induce taste change after BS. A literature search was conducted (33 studies, N = 3264). We showed that taste change and zinc deficiency are frequent complications after BS, which both typically occurred at 6 months post-surgery. Our analysis did not support a causal link between the two, but similar onset of incidences indirectly indicates a link. Supplementation with 45-50 mg of zinc sulphate, higher than current recommendation, was effective in improving taste. Further studies are required to establish the causal link between the two in the context of BS.

Micronutrient status in bariatric surgery patients receiving postoperative supplementation per guidelines: Insights from a systematic review and meta-analysis of longitudinal studies

The micronutrient status and optimal monitoring schedule after bariatric surgery have not been sufficiently assessed. This systematic review and meta-analysis investigated the longitudinal changes in micronutrient status after bariatric surgery. PubMed, EMBASE, and Cochrane Library were searched for articles that measured preoperative and postoperative serum micronutrient levels in patients undergoing Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Among guideline-adherent studies, the longitudinal changes in micronutrient status were investigated using weighted mean difference (WMD) using a random-effects model. Among the 82 included studies, the guideline adherence rates for micronutrient supplementation after bariatric surgery did not exceed 20%. In patients supplemented per guidelines, vitamin A significantly decreased after RYGB by -7.54 (95% confidence interval [CI], -10.16 to -4.92) μg/dl at 12-23 months, vitamin E decreased after RYGB by -2.35 (95% CI, -3.65 to -1.05) μg/dl at ≥24 months, and ferritin by -54.93 (95% CI, -77.19 to -32.67] μg/L at ≥24 months after SG, compared with baseline, with moderate level of evidence. Significant decreases in micronutrient levels at certain follow-up intervals in studies with supplementation per guidelines need to be considered to establish a post-bariatric micronutrient monitoring schedule for timely detection and management of micronutrient deficiencies.

The role of laparoscopic sleeve gastrectomy on inflammatory parameters in morbidly obese patients

BACKGROUND

Obesity is an excessive increase in body fat mass and triggers chronic inflammation which causes increased fat accumulation in the visceral fat tissue. The aim of this study was to analyze serum zinc (Zn), Zn-alpha 2 glycoprotein (ZAG), peroxisome proliferator-activated receptor-γ (PPAR-γ) and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) levels in morbidly obese patients before and after laparoscopic sleeve gastrectomy (LSG) and determine the association between alteration in body mass index (BMI), the % Excess Weight Loss (% EWL) and the biochemical parameters.

METHODS

Thirty healthy individuals as a control group and 30 morbidly obese patients who had undergone LSG were enrolled in this study. Routine anthropometric and laboratory biochemical parameters in venous blood samples of groups at baseline and 1 and 12 months after LSG were recorded.

RESULTS

Significant weight loss was achieved at 1 and 12 months after LSG. At baseline serum ZAG and PPAR-γ levels were lower, while NF-кB levels were higher in morbidly obese patients compared with the control group. Serum ZAG and PPAR-γ levels increased while NF-кB levels decreased 1 month and 12 months after LSG. Decreased %EWL was negatively correlated with changes in NF-кB, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), fasting plasma glucose and insulin at 12 months after LSG in morbidly obese patients. However, %EWL was positively correlated with changes in ZAG.

CONCLUSIONS

Obesity was associated with down-regulated serum ZAG and PPAR-γ levels while up-regulated serum NF-кB. Our findings suggest that LSG ameliorates upregulating PPAR-γ expression, thereby inhibiting NF-κB-mediated inflammation by weight loss.

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.

Zinc Deficiency after Gastric Bypass for Morbid Obesity: a Systematic Review

Up to 50% of patients have zinc deficiency before bariatric surgery. Roux-en-Y gastric bypass (RYGB) is the commonest bariatric procedure worldwide. It can further exacerbate zinc deficiency by reducing intake as well as absorption. The British Obesity and Metabolic Surgery Society, therefore, recommends that zinc level should be monitored routinely following gastric bypass. However, the American guidance does not recommend such monitoring for all RYGB patients and reserves it for patients with 'specific findings'. This review concludes that clinically relevant Zn deficiency is rare after RYGB. Routine monitoring of zinc levels is hence unnecessary for asymptomatic patients after RYGB and should be reserved for patients with skin lesions, hair loss, pica, dysgeusia, hypogonadism or erectile dysfunction in male patients, and unexplained iron deficiency anaemia.

Skin changes after bariatric surgery

Today, obesity is considered an epidemic all over the world and it is recognized as one of the major public health problems. Bariatric surgery is considered an appropriate therapeutic option for obesity with progressively increasing demands. The changes resulting from massive weight loss after bariatric surgery are related to numerous complications. This article will present the dermatological alterations that can be found after bariatric surgery. They will be subdivided into dermatoses that are secondary to metabolic and nutritional disorders, those derived from cutaneous structural modifications after major weight loss and the influence the latter may have in improving of certain dermatoses.

Nutrition and metabolic support recommendations for the bariatric patient

Managing the metabolic needs of the patient with obesity is a challenge unto itself without the added demands of accounting for an altered gastrointestinal tract. Nevertheless, with about 200,000 bariatric procedures being performed annually in the United States, clinicians must be prepared to manage the critically ill bariatric surgery patient. This article reviews the recent literature relating to nutrient needs and metabolic support for the bariatric patient. Bariatric patients are at risk for several micronutrient deficiencies, including vitamins D and B₁₂, calcium, and iron; some bariatric procedures affect macronutrient needs as well. Literature on nutrition support guidelines for the bariatric population is limited. However, with an understanding of the anatomical and physiological effects of bariatric surgery, recent guidelines for critically ill patients with obesity can be applied to the bariatric surgery population. The unique needs of the bariatric population, such as susceptibility to micronutrient deficiencies and specialized access routes, must be considered to provide safe and efficacious nutrition support. Further research is necessary to develop specific nutrition support recommendations for the bariatric population.

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.

Zinc-deficiency acrodermatitis in a patient with chronic alcoholism and gastric bypass: a case report

Acquired adult-onset zinc deficiency is occasionally reported in patients with malnutrition states, such as alcoholism, or malabsorptive states, such as post-bariatric surgery. The defining symptoms of hypozincemia include a classic triad of necrolytic dermatitis, diffuse alopecia, and diarrhea. We report a case of zinc deficiency in a 39-year-old man with history of gastric bypass surgery and alcoholism. For this patient, severe hypozincemia confirmed acrodermatitis, and zinc supplementation was met with gradual improvement.

Zinc: The Metal of Life

The importance of zinc was 1st reported for Aspergillus niger. It took over 75 y to realize that zinc is also an essential trace element for rats, and an additional 30 y went by before it was recognized that this was also true for humans. The adult body contains about 2 to 3 g of zinc. Zinc is found in organs, tissues, bones, fluids, and cells. It is essential for many physiological functions and plays a significant role in a number of enzyme actions in the living systems. Bioinformatics estimates report that 10% of the human proteome contains zinc-binding sites. Based on its role in such a plethora of cellular components, zinc has diverse biological functions from enzymatic catalysis to playing a crucial role in cellular neuronal systems. Thus, based on the various published studies and reports, it is pertinent to state that zinc is one of the most important essential trace metals in human nutrition and lifestyle. Its deficiency may severely affect the homeostasis of a biological system. This review compiles the role of zinc in prophylaxis/therapeutics and provides current information about its effect on living beings.

Acrodermatitis due to zinc deficiency after combined vertical gastroplasty with jejunoileal bypass: case report

CONTEXT

Nutritional complications may occur after bariatric surgery, due to restriction of food intake and impaired digestion or absorption of nutrients.

CASE REPORT

After undergoing vertical gastroplasty and jejunoileal bypass, a female patient presented marked weight loss and protein deficiency. Seven months after the bariatric surgery, she presented dermatological features compatible with acrodermatitis enteropathica, as seen from the plasma zinc levels, which were below the reference values (34.4 mg%). The skin lesions improved significantly after 1,000 mg/day of zinc sulfate supplementation for one week.

CONCLUSIONS

The patient's evolution shows that the multidisciplinary team involved in surgical treatment of obesity should take nutritional deficiencies into consideration in the differential diagnosis of skin diseases, in order to institute early treatment.

Zinc absorption and zinc status are reduced after Roux-en-Y gastric bypass: a randomized study using 2 supplements

BACKGROUND

Micronutrient deficiencies are common in patients undergoing gastric bypass. The effect of this type of surgery on zinc absorption and zinc status is not well known.

OBJECTIVE

The objective was to evaluate the effects of Roux-en-Y gastric bypass (RYGBP) on zinc status and zinc absorption at different stages after surgery. We hypothesized that zinc status would be significantly impaired after surgery and that this impairment would be less severe in subjects receiving increased supplemental zinc. We also hypothesized that zinc absorption would be lower after surgery.

DESIGN

Anthropometric and body-composition variables and dietary and biochemical indexes of zinc status and zinc absorption were determined in 67 severe and morbidly obese women [mean (±SD) age: 36.9 ± 9.8 y; BMI (in kg/m(2)): 45.2 ± 4.7] who underwent RYGBP. The subjects were randomly assigned to 1 of 2 vitamin-mineral supplementation groups. Measurements were made before and 6, 12, and 18 mo after surgery. Fifty-six subjects completed the 18-mo follow-up.

RESULTS

Mean plasma zinc, erythrocyte membrane alkaline phosphatase activity, and the size of the rapidly exchangeable zinc pool decreased after RYGBP. Percentage zinc absorption decreased significantly from 32.3% to 13.6% at 6 mo after RYGBP and to 21% at 18 mo after surgery. No effect of supplement type was observed.

CONCLUSIONS

Zinc status is impaired after RYGBP, despite the finding that dietary plus supplemental zinc doubled recommended zinc intakes in healthy persons. Zinc absorption capacity is significantly reduced soon after RYGBP, with no major changes until 18 mo after surgery.

Zinc deficiency: a frequent and underestimated complication after bariatric surgery

BACKGROUND

Although zinc deficiency is common after bariatric surgery, its incidence is underestimated. The objective was to monitor zinc and nutritional status before and 6, 12 and 24 months (M6, M12 and M24) after gastric bypass (Roux-en-Y gastric bypass), sleeve gastrectomy and biliopancreatic diversion with duodenal switch (DS) in patients receiving systematised nutritional care.

METHODS

Data for 324 morbidly obese patients (mean body mass index 46.2 ± 7.3 kg/m(2)) were reviewed retrospectively. The follow-up period was 6 months for 272 patients, 12 months for 175, and 24 months for 70. Anthropometric, dietary and serum albumin, prealbumin, zinc, iron and transferrin saturation measures were determined at each timepoint.

RESULTS

Nine percent of patients had zinc deficiency pre-operatively. Zinc deficiency was present in 42.5% of the population at M12 and then remained stable. Zinc deficiency was significantly more frequent after DS, with a prevalence of 91.7% at M12. Between M0 and M6, variation in plasma prealbumin, surgery type and zinc supplementation explained 27.2% of the variance in plasma zinc concentration. Surgery type explained 22.1% of this variance between M0 and M24. Mean supplemental zinc intake was low (22 mg/day). The percentage of patients taking zinc supplementation at M6, M12 and M24 was 8.9%, 20.6% and 29%, respectively.

CONCLUSIONS

Reduced protein intake, impaired zinc absorption and worsening compensatory mechanisms contribute to zinc deficiency. The mechanisms involved differ according to the type of surgery and time since surgery. Zinc supplementation is necessary early after bariatric surgery, but this requirement is often underestimated or is inadequate.

Managing medical and surgical disorders after divided Roux-en-Y gastric bypass surgery

The National Longitudinal Study of Adolescent Health and the National Health and Nutrition Examination Survey reported that over 40% of the US population is overweight. The average weight loss attained by medical management programs is neither sufficient nor durable enough to treat medically complicated obesity. An estimated 220,000 bariatric procedures are performed yearly in the USA and Canada. The divided Roux-en-Y gastric bypass (RYGB) is performed most commonly in these countries and is considered the gold standard bariatric surgical procedure. The complexity of RYGB means that serious and potentially preventable perioperative complications can occur. RYGB alters the normal anatomy and physiology of the upper gut, which has predictable adverse effects and potential complications. Patients seek advice and care for symptoms that develop or persist after RYGB; although some symptoms are expected and predictable, others are complications that may or may not require active medical or surgical intervention. Physicians should be able to predict and manage most postoperative medical and nutritional disorders related to RYGB and should be prepared to assess patients for potential referral for surgical intervention or revision.

Fewer nutrient deficiencies after laparoscopic sleeve gastrectomy (LSG) than after laparoscopic Roux-Y-gastric bypass (LRYGB)-a prospective study

BACKGROUND

Deficiencies in micronutrients after bariatric operations are frequent, despite routine supplementation. Main outcome measures were pre- and postoperative frequency of nutrient deficiencies and success rate of their treatment.

METHODS

Between 5/2004 and 12/2006, 136 patients (m:f = 0:4) with an average body mass index of 45 (35-58) kg/m(2) and age of 53 (21-66) years were prospectively analysed. Laparoscopic Roux-Y-gastric bypass (LRYGB) was performed in 86 patients and laparoscopic sleeve gastrectomy (LSG) was performed in 50 patients. The patients were examined before surgery as well as 3, 6, 12, 24, 30, and 36 months postoperatively using a standard protocol including laboratory tests. The mean follow-up time was 24.4 (12-40) months; the follow-up rate was 100%.

RESULTS

Prior to surgery, 57% of the patients had at least one deficiency, 23% of whom had vitamin D(3) deficiency. Frequent postoperative deficiencies after LSG were zinc, vitamin D(3), folic acid, iron, and vitamin B(12); after LRYGB, vitamin B(12), vitamin D(3), zinc, and secondary hyperparathyroidism. No vitamin B(1) or B(6) deficiencies were found. Calcium levels were normal in all patients. Treatment of the deficiencies was mostly successful.

CONCLUSION

Preoperatively, 57% of morbidly obese patients already had a deficiency. Postoperatively, significantly more vitamin B(12) and vitamin D deficiencies and hyperparathyroidism were found in patients who had undergone LRYGB. After LSG, folate deficiency was more frequent (but not significantly so). Calcium levels were normal in all patients; therefore, parathyroid hormone and vitamin D(3) levels are more sensitive markers for early detection of disorders of calcium metabolism. Iron deficiency anaemia is most efficiently treated by IV therapy.