Class III obesity and its relationship with the nutritional status of vitamin A in pre- and postoperative gastric bypass

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.

Micronutrients in Pregnancy after Bariatric Surgery: A Narrative Review

Bariatric surgery is increasingly used in women of childbearing age due to the rising prevalence of obesity and the effectiveness and availability of this treatment. Pregnancy in women with previous bariatric surgery deserves special attention. Weight loss induced by surgery reduces the risks that obesity poses to pregnancy. But on the other hand, decreased intake and malabsorption may increase the risk of malnutrition and micronutrient deficiency and negatively affect maternal and foetal health. The aim of this narrative review is to provide an updated analysis of the impact of different bariatric surgery techniques on mineral and micronutrient nutritional status during pregnancy and the possible effect on maternal-foetal health.

Micronutrient Deficiency Pre- and Post-bariatric Metabolic Surgery in Latin America: a Systematic Review

BACKGROUND

Persons submitted to bariatric metabolic surgery present micronutrient deficiency before and after surgery, due to the lack of proper supplementation. The aim of this study is to establish the prevalence of micronutrient deficiency in people before and after bariatric metabolic surgery in Latin America.

METHODS

This review was conducted in accordance with the 2020 PRISMA Guidelines.

RESULTS

Twenty-seven studies and 2135 participants were included. The highest prevalence of deficiency before surgery was reported for vitamin D (74%), zinc (71%), and hemoglobin (62%); after surgery, they were vitamin A (90.6%), vitamin D (90%), and zinc (68%).

CONCLUSIONS

There is a high prevalence of micronutrient deficiency before and after bariatric metabolic surgery from Latin American persons; the micronutrients with the highest deficiency prevalence were vitamin D before and vitamin A after bariatric metabolic surgery.

Effects of Post-operative Nutritional Disorders Following Bariatric Surgery on Health Care Cost and Use

PURPOSE

Risk of nutritional disorders (NDs) in bariatric surgical patients has led to guideline recommendations for pre- and post-operative nutrient deficiency screening. The aim of this study was to identify baseline factors associated with incident NDs and, in addition, to explore possible differences in health care spending and use between patients with and without incident NDs following bariatric surgery.

MATERIALS AND METHODS

Using data linked with a state-wide bariatric surgical registry and a state-wide claims database, subjects who underwent bariatric surgery between July 1, 2013, and December 31, 2015, were identified. Incident NDs and health care cost and use outcomes following 1 year from surgery were extracted from the claims data. Logistic regression was used to identify baseline factors associated with incident NDs. Zero-inflated negative binomial regression and generalized linear regression were used to estimate health care cost and use outcomes.

RESULTS

A total of 3535 patients who underwent bariatric surgery were identified. Of these patients, those without continuous health insurance enrollment (n=1880), having prevalent (pre-surgery) NDs (n=461), and missing baseline BMI (n=41) were excluded. Of patients analyzed (n=1153), about 30% had incident NDs, with a mean (SD) age and BMI at surgery of 46 (12) years and 48 (9.2) kg/m², respectively. Patients with one incident ND had higher total health care spending (coefficient=$41118, p-value<0.01) and ED visits (IRR=1.86, p-value<0.01).

CONCLUSION

Those without pre-operative NDs may have a higher chance of having NDs post-operatively. Taking multivitamins and continues monitoring are necessary to prevent any negative outcomes related to post-operative NDs.

Clinical Practice Guidelines for Childbearing Female Candidates for Bariatric Surgery, Pregnancy, and Post-partum Management After Bariatric Surgery

Emerging evidence suggests that bariatric surgery improves pregnancy outcomes of women with obesity by reducing the rates of gestational diabetes, pregnancy-induced hypertension, and macrosomia. However, it is associated with an increased risk of a small-for-gestational-age fetus and prematurity. Based on the work of a multidisciplinary task force, we propose clinical practice recommendations for pregnancy management following bariatric surgery. They are derived from a comprehensive review of the literature, existing guidelines, and expert opinion covering the preferred type of surgery for women of childbearing age, timing between surgery and pregnancy, contraception, systematic nutritional support and management of nutritional deficiencies, screening and management of gestational diabetes, weight gain during pregnancy, gastric banding management, surgical emergencies, obstetrical management, and specific care in the postpartum period and for newborns.

Vitamin A Deficiency in Patients Undergoing Sleeve Gastrectomy and Gastric Bypass: A 2-Year, Single-Center Review

Introduction: Vitamin A deficiency (VAD) is an underreported micronutrient deficiency after bariatric surgery (BS). Objectives: The goal of this study was to characterize VAD prevalence in patients undergoing malabsorptive and restrictive procedures up to 2 years postoperatively. Methods: Primary sleeve gastrectomy (SG; n = 322) and gastric bypass (GB; n = 249) patients were reviewed. Levels for overall VAD (oVAD; retinol <39 mcg/dL) and moderate VAD (mVAD; retinol <30 mcg/dL) were reported preoperatively and 6, 12, and 24 months postoperatively. Differences in demographic, surgical, and postoperative data were tested between these groups. Settings: Single-center academic institution. Results: Serum retinol levels were documented for 56%, 74%, 61%, and 37% of patients for listed time points. Baseline retinol inversely correlated to preop body mass index (BMI) (R = -0.15, P = .007). Both oVAD and mVAD peaked 6 months postoperatively (33% vs. 15%, P < .005; 12% vs. 4%, P = .0004, respectively). oVAD remained elevated at 24 months (22% vs. 15%, P = .03). Compared to SG, oVAD was higher following GB at 6 months (39% vs. 28%, P = .001) and 12 months (26% vs. 17%, P = .04), and mVAD was greater with GB at 6 months (18% vs. 6%, P < .0005). African American patients had higher oVAD/mVAD preoperatively (26% vs. 13%, P = .02; 13% vs. 3%, P = .001, respectively) and at 6 months (19% vs. 10%, P = .04). Prior mild VAD (retinol 1.05-1.35 μM) was significantly associated with mVAD up to 12 months postoperatively. Conclusions: Although higher following LRYGB, VAD is prevalent following both malabsorptive and restrictive procedures. Preoperative serum retinol is inversely correlated to increasing BMI, and African American race and mild VAD are associated with moderate VAD.

Does Bariatric Surgery Cause Vitamin A, B1, C or E Deficiency? A Systematic Review

BACKGROUND

The restrictive and/or malabsorptive nature of bariatric surgery may increase the risk for micronutrient deficiencies. This systematic review aimed to identify and critique the evidence for vitamin A, B1, C or E deficiencies associated with bariatric surgery.

METHODS

This review utilised PRISMA and MOOSE frameworks with NHMRC evidence hierarchy and the American Dietetic Association bias tool to assess the quality of articles.

RESULTS

Twenty-one articles were included and once critiqued all studies were of level IV grade and neutral or negative in quality. The relevance of measuring micronutrient supplementation and inflammatory markers for validity of serum vitamins is absent within the literature.

CONCLUSIONS

Future research is needed to investigate the risk of deficiency for these procedures with focus on confounders to serum micronutrients.

Overfed but undernourished: recognizing nutritional inadequacies/deficiencies in patients with overweight or obesity

Overweight and obesity are highly prevalent throughout the world and can adversely affect the nutritional status of individuals. Studies have shown that many people with obesity have inadequate intake of iron, calcium, magnesium, zinc, copper, folate and vitamins A and B₁₂, likely as a result of poor diet quality. Nutritional inadequacies or deficiencies may also occur due to altered pharmacokinetics in the individual with obesity and due to interactions in those with overweight or obesity with various pharmaceuticals. However, it has been demonstrated that the adult population in the United States as a whole is deficient in certain micronutrients as a result of the availability and overconsumption of high-calorie, low-nutrient processed foods. Poor nutrition may contribute to the development of certain chronic conditions, such as type 2 diabetes, which is already more prevalent in those with obesity. Clinicians need to be aware of these gaps, particularly in those individuals with obesity who are undergoing bariatric surgery or taking pharmaceutical products long term to facilitate weight loss. Patients with overweight or obesity likely struggle to achieve a balanced diet and may benefit from consultation with a dietitian. Along with providing recommendations for healthy eating and exercise, supplementation with specific micronutrients or multivitamins should be considered for individuals at the highest risk for or with established deficiencies. Further research is needed to understand the factors underlying nutritional inadequacies in individuals with overweight or obesity, as well as the outcomes of treatment strategies employed to address them.

Vitamin A and micronutrient deficiencies post-bariatric surgery: aetiology, complications and management in a complex multiparous pregnancy

Adequate vitamin A is essential for healthy pregnancy, but high levels may be teratogenic. We present a patient who underwent bariatric surgery, prior to child bearing, and suffered maternal and foetal complications during eleven pregnancies, possibly associated with vitamin A deficiency, amongst multiple micronutrient deficiencies and risk factors including smoking and obesity. Maternal complications included visual disturbance, night blindness and recurrent infections. Recurrent foetal pulmonary hypoplasia and microphthalmia led to foetal and neonatal loss, not previously described in the medical literature. Current guidance on vitamin A deficiency in pregnancy is focused on developing countries where aetiology of vitamin A deficiency is different to that of women in developed countries. We describe nutritional management of the micronutritient deficiencies, focusing on vitamin A, during her last pregnancy. The need for specific antenatal nutritional guidance for pregnant women post-bariatric surgery is becoming more urgent as more mothers and offspring will be affected.

Roux-en-Y Gastric Bypass Aggravates Vitamin A Deficiency in the Mother-Child Group

OBJECTIVE

The objectives of this study are to compare the nutritional status of vitamin A in women who previously underwent Roux-en-Y gastric bypass (RYGB) who became pregnant or did not, in the same period after surgery, and to assess its effects on mother and child health.

METHODOLOGY

A retrospective longitudinal study conducted with women who previously underwent RYGB, paired by age and BMI measured before surgery, divided into group 1 (G1) comprising 77 women who did not become pregnant and group 2 (G2) with 39 women in their third gestational trimester. Both groups were assessed before surgery (T0) and in the same interval after surgery: less than or equal to 1 year (T1) or over 1 year (T2), during a maximum of 2 years. Serum concentrations of retinol and β-carotene, night blindness (NB), and gestational and neonatal complications were investigated [urinary tract infection, iron deficiency anemia, hypertensive syndrome of pregnancy, dumping syndrome, birth weight, gestational age at birth (GAB), and correlation between weight and GAB]. Data were analyzed by the Statistical Package for Social Sciences 21.0 (p < 0.05).

RESULTS

RYGB reduced the serum levels of retinol and β-carotene, especially before the first postsurgical year. When associated with pregnancy, inadequacy rate was 55% higher in T1 and T2. Comparing G1 to G2, we noted that pregnancy in women undergoing RYGB can contribute to increased inadequacy of retinol and β-carotene, reaching a higher percentage of women with NB after 1 postsurgical year. High prevalence of pregnancy/neonatal complications was found in T1 and T2. NB was correlated with inadequacy of β-carotene.

CONCLUSION

Pregnancy after RYGB aggravates vitamin A deficiency, increases the percentage of NB cases, and can contribute to pregnancy and neonatal complications even in 1 postsurgical year.

Disturbed Vitamin A Metabolism in Non-Alcoholic Fatty Liver Disease (NAFLD)

Vitamin A is required for important physiological processes, including embryogenesis, vision, cell proliferation and differentiation, immune regulation, and glucose and lipid metabolism. Many of vitamin A’s functions are executed through retinoic acids that activate transcriptional networks controlled by retinoic acid receptors (RARs) and retinoid X receptors (RXRs).The liver plays a central role in vitamin A metabolism: (1) it produces bile supporting efficient intestinal absorption of fat-soluble nutrients like vitamin A; (2) it produces retinol binding protein 4 (RBP4) that distributes vitamin A, as retinol, to peripheral tissues; and (3) it harbors the largest body supply of vitamin A, mostly as retinyl esters, in hepatic stellate cells (HSCs). In times of inadequate dietary intake, the liver maintains stable circulating retinol levels of approximately 2 μmol/L, sufficient to provide the body with this vitamin for months. Liver diseases, in particular those leading to fibrosis and cirrhosis, are associated with impaired vitamin A homeostasis and may lead to vitamin A deficiency. Liver injury triggers HSCs to transdifferentiate to myofibroblasts that produce excessive amounts of extracellular matrix, leading to fibrosis. HSCs lose the retinyl ester stores in this process, ultimately leading to vitamin A deficiency. Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and is a spectrum of conditions ranging from benign hepatic steatosis to non-alcoholic steatohepatitis (NASH); it may progress to cirrhosis and liver cancer. NASH is projected to be the main cause of liver failure in the near future. Retinoic acids are key regulators of glucose and lipid metabolism in the liver and adipose tissue, but it is unknown whether impaired vitamin A homeostasis contributes to or suppresses the development of NAFLD. A genetic variant of patatin-like phospholipase domain-containing 3 (PNPLA3-I148M) is the most prominent heritable factor associated with NAFLD. Interestingly, PNPLA3 harbors retinyl ester hydrolase activity and PNPLA3-I148M is associated with low serum retinol level, but enhanced retinyl esters in the liver of NAFLD patients. Low circulating retinol in NAFLD may therefore not reflect true “vitamin A deficiency”, but rather disturbed vitamin A metabolism. Here, we summarize current knowledge about vitamin A metabolism in NAFLD and its putative role in the progression of liver disease, as well as the therapeutic potential of vitamin A metabolites.

Serum levels of vitamin A, visual function and ocular surface after bariatric surgery

BACKGROUND

- Bariatric surgery is the most effective treatment for severe obesity, but the surgery increases the risk of developing nutritional deficiencies, such as vitamin A deficiency. In human metabolism, vitamin A plays a role in vision.

OBJECTIVE

- To evaluate serum vitamin A, visual function and ocular surface of patients undergoing bariatric surgery.

METHODS

- A cross-sectional and analytical study was conduced with 28 patients undergoing bariatric surgery for at least 6 months. Ophthalmologic evaluation was done through color vision test, contrast sensitivity test, ocular surface tests and confocal microscopy, as well as vitamin A serum measurement.

RESULTS

- Vertical sleeve gastrectomy was performed in seven (25.0%) patients and Roux -en-Y gastric by-pass in 21 (75.0%). Mean serum vitamin A level was 1.7±0.5 µmoL/L. Most patients (60.7%) had symptoms of dry eye. Five (17.9%) patients had contrast sensitivity impairment and 18 (64.3%) color vision changes. In the group of patients undergoing Roux -en-Y gastric by-pass , mean vitamin A levels were 1.8±0.6 µmoL/L, whereas they were 1.7±0.5 µmoL/L in patients submitted to the restrictive technique vertical sleeve gastrectomy . The analysis of the influence of serum levels of vitamin A in the visual function and ocular surface was performed by Pearson correlation test and there was no significant correlation between any of the variables and vitamin A.

CONCLUSION

- There was no influence of the bariatric surgery technique used on serum vitamin A levels, on the visual function or on the ocular surface. Moreover, there was no correlation between serum levels of vitamin A and the visual function or the ocular surface changes.

Post-Bariatric Body Contouring

BACKGROUND

The "epidemic" of obesity has recently been accompanied by a new "epidemic" of massive weight loss. The demand for post-bariatric contouring is rising and, as such, it is extremely important for plastic surgeons to be well versed in the treatment of these patients. Unfortunately, the problem is not solely surgical.

OBJECTIVES

The aim of this article is to understand the nutritional and psychological complications that can occur in patients following massive weight loss, to understand the anatomic deformities in massive weight loss as a means to correct those deformities surgically, and to understand the complications from post-bariatric contouring procedures in an effort to avoid them.

METHODS

This article discusses the nutritional and psychological considerations in the massive weight loss patient, anatomical considerations in this patient group, and the surgical techniques designed to address these anatomic concerns. Important pertinent studies are reviewed and discussed.

RESULTS

Anatomical changes are encountered in each region of the body: there are surgical options available to correct them, although potential complications are associated with these surgical procedures. These surgical options are reviewed as well as the risk and benefits associated with them.

CONCLUSIONS

There are many problems that need to be addressed in the massive weight loss patient prior to embarking on surgical treatment. Additionally, surgery on massive weight loss patients has unique considerations that distinguish these operations from those performed on the non-bariatric population.

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.

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.

Pharmacotherapy prevention and management of nutritional deficiencies post Roux-en-Y gastric bypass

Roux-en-Y gastric bypass is the most commonly performed bariatric procedure. It is associated with nutritional deficiencies due to gastric reduction, intestinal bypass, reduced caloric intake, avoidance of nutrient-rich foods, noncompliance with supplementation and poor food tolerability. Although there are multiple publications on this topic, there is a lack of consistent guidance for the healthcare practitioner caring for the bariatric patient. This article will encompass literature reviewing the pharmacotherapy approach to prevention and management of nutritional deficiencies since the American Society of Metabolic and Bariatric Surgery guidelines were published in 2008.

Oxidative stress markers in adults 2 years after Roux-en-Y gastric bypass

INTRODUCTION

Obesity is a chronic disease associated with oxidative stress. Bariatric surgery for the treatment of obesity may affect biomarkers of oxidative stress.

OBJECTIVES

The aim of the present study was to evaluate the effect of Roux-en-Y gastric bypass (RYGB) on blood markers of oxidative stress, such as vitamins C and E, β-carotene, reduced glutathione (GSH), catalase (CAT), ferric reducing antioxidant potential (FRAP), and thiobarbituric acid-reactive substances (TBARS).

METHODS

A prospective controlled clinical trial was carried out. The participants were distributed into two groups: a control group (n=35), which was evaluated once, and a bariatric group (n=35), which was evaluated at baseline as well as 6, 12, and 24 months after surgery.

RESULTS

After surgery, the BMI decreased from 47.05±1.46 to 30.53±1.14 kg/m (P<0.001), but 25.7% of the participants regained weight after 24 months. In relation to the baseline, postsurgery reductions were found in vitamin C (31.9±4.6%, P<0.001), β-carotene (360.7±368.3%, P<0.001), vitamin E (22.8±4.1%, P<0.001), GSH (6.6±5.2%, P=0.090), CAT (12.7±5.6%, P=0.029), and FRAP (1.2±3.8%, P=0.085) 2 years after RYGB. TBARS levels decreased after 12 months (71.6±2.9%, P<0.001) in relation to the baseline but increased by 195.0±28.2% between the 12th and the 24th month (P<0.001).

CONCLUSION

The present findings show that oxidative stress returned 2 years after RYGB. Concentrations of vitamin C, β-carotene, GSH, CAT, and FRAP were decreased, whereas the concentration of TBARS decreased in the first year but increased in the following year, which may be partly explained by the imbalance between antioxidants and pro-oxidants.

Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery

The development of these updated guidelines was commissioned by the AACE, TOS, and ASMBS Board of Directors and adheres to the AACE 2010 protocol for standardized production of clinical practice guidelines (CPG). Each recommendation was re-evaluated and updated based on the evidence and subjective factors per protocol. Examples of expanded topics in this update include: the roles of sleeve gastrectomy, bariatric surgery in patients with type-2 diabetes, bariatric surgery for patients with mild obesity, copper deficiency, informed consent, and behavioral issues. There are 74 recommendations (of which 56 are revised and 2 are new) in this 2013 update, compared with 164 original recommendations in 2008. There are 403 citations, of which 33 (8.2%) are EL 1, 131 (32.5%) are EL 2, 170 (42.2%) are EL 3, and 69 (17.1%) are EL 4. There is a relatively high proportion (40.4%) of strong (EL 1 and 2) studies, compared with only 16.5% in the 2008 AACE-TOS-ASMBS CPG. These updated guidelines reflect recent additions to the evidence base. Bariatric surgery remains a safe and effective intervention for select patients with obesity. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic & Bariatric Surgery

The development of these updated guidelines was commissioned by the AACE, TOS, and ASMBS Board of Directors and adheres to the AACE 2010 protocol for standardized production of clinical practice guidelines (CPG). Each recommendation was re-evaluated and updated based on the evidence and subjective factors per protocol. Examples of expanded topics in this update include: the roles of sleeve gastrectomy, bariatric surgery in patients with type-2 diabetes, bariatric surgery for patients with mild obesity, copper deficiency, informed consent, and behavioral issues. There are 74 recommendations (of which 56 are revised and 2 are new) in this 2013 update, compared with 164 original recommendations in 2008. There are 403 citations, of which 33 (8.2%) are EL 1, 131 (32.5%) are EL 2, 170 (42.2%) are EL 3, and 69 (17.1%) are EL 4. There is a relatively high proportion (40.4%) of strong (EL 1 and 2) studies, compared with only 16.5% in the 2008 AACE-TOS-ASMBS CPG. These updated guidelines reflect recent additions to the evidence base. Bariatric surgery remains a safe and effective intervention for select patients with obesity. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic & Bariatric Surgery

The development of these updated guidelines was commissioned by the AACE, TOS, and ASMBS Board of Directors and adheres to the AACE 2010 protocol for standardized production of clinical practice guidelines (CPG). Each recommendation was re-evaluated and updated based on the evidence and subjective factors per protocol. Examples of expanded topics in this update include: the roles of sleeve gastrectomy, bariatric surgery in patients with type-2 diabetes, bariatric surgery for patients with mild obesity, copper deficiency, informed consent, and behavioral issues. There are 74 recommendations (of which 56 are revised and 2 are new) in this 2013 update, compared with 164 original recommendations in 2008. There are 403 citations, of which 33 (8.2%) are EL 1, 131 (32.5%) are EL 2, 170 (42.2%) are EL 3, and 69 (17.1%) are EL 4. There is a relatively high proportion (40.4%) of strong (EL 1 and 2) studies, compared with only 16.5% in the 2008 AACE-TOS-ASMBS CPG. These updated guidelines reflect recent additions to the evidence base. Bariatric surgery remains a safe and effective intervention for select patients with obesity. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Dietary assessment of adolescents undergoing laparoscopic Roux-en-Y gastric bypass surgery: macro- and micronutrient, fiber, and supplement intake

BACKGROUND

Extremely obese adolescents are increasingly undergoing bariatric procedures, which restrict dietary intake. However, as yet, no data are available describing the change in caloric density or composition of the adolescent bariatric patient's diet pre- and postoperatively. Our objective was to assess the 1-year change in the dietary composition of adolescents undergoing bariatric surgery at a tertiary care children's hospital.

METHODS

A total of 27 subjects (67% female, 77% white, age 16.7 ± 1.4 yr, baseline body mass index 60.1 ± 14.1 kg/m(2)) were prospectively enrolled into an observational cohort study 1 month before undergoing laparoscopic Roux-en-Y gastric bypass from August 2005 to March 2008. The 3-day dietary intake was recorded at baseline (n = 24) and 2 weeks (n = 16), 3 months (n = 11), and 1 year (n = 9) postoperatively. The dietary record data were verified by structured interview and compared with the Dietary Reference Intake values for ages 14-18 years.

RESULTS

By 1 year after surgery, the mean caloric intake, adjusted for body mass index was 1015 ± 182 kcal/d, a 35% reduction from baseline. The proportion of fat, protein, and carbohydrate intake did not differ from baseline. However, the protein intake was lower than recommended postoperatively. The calcium and fiber intake was also persistently lower than recommended. Calcium and vitamin B(12) supplementation increased the likelihood of meeting the daily minimal recommendations (P ≤ .02).

CONCLUSION

At 1 year after Roux-en-Y gastric bypass, the adolescents' caloric intake remained restricted, with satisfactory macronutrient composition but a lower than desirable intake of calcium, fiber, and protein.

Subclinical vitamin A deficiency does not increase development of tumors in irradiated or unirradiated lungs

Cancer patients often have subclinical vitamin A deficiencies and low vitamin A lung levels. Previous studies showed that subclinical vitamin A deficiency increased the severity of pneumonitis induced by whole-lung irradiation in rats. Many studies have shown that lung irradiation increases the number of lung tumors developing from intravenously injected tumor cells in mice. We examined the impact of vitamin A deficiency on the development of lung metastases from a highly metastatic syngeneic rat rhabdomyosarcoma in normal rats and rats receiving prior lung irradiation. Weanling female WAGrijY rats were randomized to receive either a diet lacking both vitamin A and beta-carotene or a control diet. After five weeks, the deficient diet significantly decreased levels of retinol in the lung and liver but not in the serum, modeling the tissue and blood levels seen in prior studies of patients with subclinical vitamin A inadequacy. The vitamin A-deficient diet did not alter the number of lung tumors developing from intravenously injected tumor cells in unirradiated rats. Whole-lung irradiation produced dose-dependent increases in the number of lung tumors developing from tumor cells injected intravenously one or 29 d after irradiation. Vitamin A deficiency did not alter these dose-response curves, indicating that the more intense radiation-induced pneumonitis seen previously in vitamin A-deficient rats did not alter the enhancement of metastases produced by whole-lung irradiation. Moreover, inadequate vitamin A intake did not influence the growth of tumors implanted subcutaneously or increase the number or size of the spontaneous lung metastases developing from these subcutaneous tumors. Thus, although low vitamin A status influences the development of lung injury and is considered a possible modifiable risk factor increasing risk of primary cancer, it did not affect the growth of subcutaneous tumors or increase the development of artificial or spontaneous lung metastases in this rat model.

Relation between glucose levels, high-sensitivity C-reactive protein (hs-CRP), body mass index (BMI) and serum and dietary retinol in elderly in population-based study

The aim of this study was to evaluate the relationships between fasting glucose levels, hs-CRP, BMI and serum retinol and diet in elderly people. For this study, a cross-sectional, epidemiological, population-based format was adopted. One hundred and sixty-three individuals between 60 and 90 years of age participated; the participants were from different socioeconomic and health backgrounds, except for the individuals diagnosed with diabetes. Most subjects had serum concentrations in the reference ranges for all variables. There was not a significant relationship between fasting glucose and serum retinol or diet. There was a significant correlation between hs-CRP and BMI (r=0.22, p=0.0082) and hs-CRP and total calorie intake (p=0.0091), which reinforces the notion that an increased intake of calories results in being overweight and/or obese. Considering the importance of vitamin A in various physiological processes, more studies on these relationships are necessary to establish a recommendation of vitamin A for the treatment and prevention of changes in fasting glucose and obesity in the elderly population.

Origins of and recognition of micronutrient deficiencies after gastric bypass surgery

Roux-en-Y gastric bypass surgery remains the major surgical option for individuals with medically complicated obesity. The importance of preoperative evaluation to permit identification of micronutrient deficiencies is being re-evaluated. The risk of complications related to pregnancy after gastric bypass supports careful follow-up. Micronutrient deficiencies are common in postoperative gastric bypass patients, despite the suggested use of routine vitamin and mineral supplements after surgery. Copper deficiency must be considered as an origin for visual disorders after gastric bypass. Vitamin D deficiency with metabolic bone disease remains common after gastric bypass and the results suggest that the present postoperative supplements of calcium and vitamin D are inadequate. Major nutritional complications of bariatric surgery are occurring more than 20 years after surgery. There is no evidence for intestinal adaptation as there remains decreased intestinal absorption of iron up to 18 months after gastric bypass surgery. This article supports ongoing examination of nutritional complications after gastric bypass surgery and supports the notion that the daily doses of micronutrient supplements, such as vitamin D, may need to be revised.

Micronutrient deficiencies after bariatric surgery

It has been estimated that approximately 220,000 people with morbid obesity underwent bariatric surgery in 2008. Modification of the gastrointestinal tract affects absorption and health care professionals counseling bariatric patients need to be aware of possible micronutrient deficiencies and their symptoms. A systematic review of several databases and bariatric surgery center websites on the Internet was conducted from January 1980 to July 2009 to identify literature related to micronutrient deficiencies occurring after bariatric surgery. Keywords used individually or in combination were bariatric surgery, obesity, vitamin/mineral deficiencies, altered gastrointestinal function, nutrient absorption, nutrient supplementation, and metabolic complications, and were variously combined in the search list. Based on this review, all patients scheduled for bariatric surgery should receive daily multivitamin and multitrace mineral supplements. The literature suggests that bariatric surgery patients are at risk for deficiency of the following nutrients after surgery: vitamins B(12), B(1), C, folate, A, D, and K, along with the trace minerals iron, selenium, zinc, and copper. Over-the-counter multivitamin and mineral supplements do not provide adequate amounts of certain nutrients such as vitamin B(12), iron, or fat-soluble vitamins and patients will require additional doses of prophylactic supplementation life-long to maintain optimal micronutrient status. In addition, preconception care for adequate prenatal supplementation is critical for pregnant women who have undergone bariatric surgery, as iron, vitamin A, vitamin B(12), vitamin K, and folate deficiencies are associated with maternal and fetal complications, including severe anemia, congenital abnormalities, low birth weight, and failure to thrive. All bariatric surgery patients would be best served by receiving regular monitoring of serum nutrient levels starting at 3 mo after surgery and periodically thereafter.

Incidence of low vitamin A levels and ocular symptoms after Roux-en-Y gastric bypass

BACKGROUND

Previous reports have demonstrated a significant incidence of fat-soluble vitamin deficiency after bariatric surgery. The purpose of the present study was to determine the incidence of vitamin A deficiency after Roux-en-Y gastric bypass and to correlate the laboratory findings with ocular symptoms potentially related to vitamin A deficiency.

METHODS

All patients who had undergone Roux-en-Y gastric bypass were invited to participate in a nutritional screening. The patients completed a detailed survey concerning ocular symptoms and had their vitamin A level evaluated.

RESULTS

A low vitamin A level was identified in 7 (11%) of 64 RYBG patients. Ocular xerosis was present in 18 patients (27%), with night vision changes reported in 45 (68%). Visual disturbances were present in 7 patients (11%) found to have low vitamin A levels, with hypovitaminosis A present in 22% of patients with xerosis (P <.05).

CONCLUSION

Low vitamin A levels and frequent ocular complaints that might be associated with decreased vitamin A are common findings in the post-RYBG patient population. Additional study is needed to assess the role of routine vitamin A screening and replacement in the postbariatric surgery patient.

Nutritional deficiencies in obesity and after bariatric surgery

The presence of nutritional deficiencies in overweight and obesity may seem paradoxical in light of excess caloric intake, but several micronutrient deficiencies appear to be higher in prevalence in overweight and obese adults and children. Causes are multifactorial and include decreased consumption of fruits and vegetables, increased intake of high-calorie, but nutritionally poor-quality foods, and increased adiposity, which may influence the storage and availability of some nutrients. As the obesity epidemic continues unabated and the popularity of bariatric surgery rises for severely obese adults and adolescents, medical practitioners must be aware of pre-existing nutritional deficiencies in overweight and obese patients and appropriately recognize and treat common and rare nutritional deficiencies that may arise or worsen following bariatric surgery. This article reviews current knowledge of nutritional deficits in obese and overweight individuals and those that commonly present after bariatric surgery and summarizes current recommendations for screening and supplementation.

Plasma turnover of 3,4-didehydroretinol (vitamin A2) increases in vitamin A-deficient rats fed low versus high dietary fat

Relationships between increased adiposity and fat-soluble vitamin storage and metabolism are poorly understood. To examine these associations, 6% or 21% dietary fat was fed to rats for 11 weeks and tissue vitamin A storage determined. Two levels of supplemental vitamin A were administered. At the end of the tenth week, 3,4-didehydroretinol (DR) was administered orally, and its kinetics were followed for 1 week in serum and tissues. Model-based compartmental analysis was applied to these data. Kidney total retinol (R) concentrations were elevated in rats fed 6% compared with 21% dietary fat (n = 24/group). The fractional transfer coefficient (FTC) describing the movement of tracer from plasma to extravascular stores was two times higher in the 6% compared with the 21% fat group. Consistent with the elevated renal R in 6% fat fed rats, there was a 2-fold increase in the FTC representing tracer distribution from plasma to kidney in the 6% compared with 21% fat group. Taken together with a fat main effect on renal vitamin A, our data support the evidence that faster turnover of kidney R may help set the mechanism governing vitamin A tissue distribution during deficiency. Rats fed 21% versus 6% dietary fat conserved hepatic R more efficiently.