Gastric bypass is not associated with protein malnutrition in morbidly obese patients

Protein malnutrition after Roux-en-Y gastric bypass: a challenging case and scoping review of the literature

Although protein malnutrition (PM) is often reported after highly malabsorptive procedures, its exact incidence and mechanisms after Roux-en-Y gastric bypass (RYGB) are poorly understood. The aim of this study was to present a challenging clinical case of PM after RYGB and conduct a scoping review of the literature. Among the 18 studies with 3015 RYGB patients included in the review, the median incidence of PM was 1.7% (range, 0%-8.9%), and it was diagnosed 12 to 120 months after RYGB. The most common cause is insufficient oral intake of protein; however, in cases of persistent hypoalbuminemia, a thorough diagnostic workup needs to be performed. Risk factors for PM after RYGB include specific triggering events such as intractable vomiting and dysphagia, and a total alimentary limb length less than 250 to 300 cm.

PBPK modeling of CYP3A and P-gp substrates to predict drug-drug interactions in patients undergoing Roux-en-Y gastric bypass surgery

Roux-en-Y gastric bypass surgery (RYGBS) is an effective surgical intervention to reduce mortality in morbidly obese patients. Following RYGBS, the disposition of drugs may be affected by anatomical alterations and changes in intestinal and hepatic drug metabolizing enzyme activity. The aim of this study was to better understand the drug-drug interaction (DDI) potential of CYP3A and P-gp inhibitors. The impacts of RYGBS on the absorption and metabolism of midazolam, acetaminophen, digoxin, and their major metabolites were simulated using physiologically-based pharmacokinetic (PBPK) modeling. PBPK models for verapamil and posaconazole were built to evaluate CYP3A- and P-gp-mediated DDIs pre- and post-RYGBS. The simulations suggest that for highly soluble drugs, such as verapamil, the predicted bioavailability was comparable pre- and post-RYGBS. For verapamil inhibition, RYGBS did not affect the fold-change of the predicted inhibited-to-control plasma AUC ratio or predicted inhibited-to-control peak plasma concentration ratio for either midazolam or digoxin. In contrast, the predicted bioavailability of posaconazole, a poorly soluble drug, decreased from 12% pre-RYGBS to 5% post-RYGBS. Compared to control, the predicted posaconazole-inhibited midazolam plasma AUC increased by 2.0-fold pre-RYGBS, but only increased by 1.6-fold post-RYGBS. A similar trend was predicted for pre- and post-RYGBS inhibited-to-control midazolam peak plasma concentration ratios (2.0- and 1.6-fold, respectively) following posaconazole inhibition. Absorption of highly soluble drugs was more rapid post-RYGBS, resulting in higher predicted midazolam peak plasma concentrations, which was further increased following inhibition by verapamil or posaconazole. To reduce the risk of a drug-drug interaction in patients post-RYGBS, the dose or frequency of object drugs may need to be decreased when administered with highly soluble inhibitor drugs, especially if toxicities are associated with plasma peak concentrations.

Weight Regain After Bariatric Surgery-A Multicentre Study of 9617 Patients from Indian Bariatric Surgery Outcome Reporting Group

BACKGROUND

There is little robust data on weight regain (WR) after bariatric surgery making it difficult to counsel patients regarding long-term outcomes of different bariatric procedures. The purpose of this study was to see WR in medium and long term after SG, RYGB, and OAGB in Indian population.

METHODS

In a multicentre study, data on preoperative and postoperative weights over 5 years were collected. Multiple definitions were applied to find the proportion of patients with significant WR increase of 25% of lost weight from nadir (definition 1), weight gain of > 10 kg from nadir (definition 2), and BMI gain of > 5 kg/m² from nadir (definition 3). The proportion of those with significant WR was compared across sub-groups.

RESULTS

A total of 9617 patients were included. Median WR at 5 years was 14.1% of lost weight, 1.92 kg/m², and 5 kg. Significant WR using definition 1 was 35.1%, 14.6%, and 3% after sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and mini-one anastomosis gastric bypass (OAGB) respectively. Severe albumin deficiency was highest in OAGB (5.9%) patients followed by SG (2.9%) and RYGB (2.2%) at 5 years(p = 0.023). Haemoglobin levels < 10 g/dL were seen in 8.2%, 9.0%, and 13.9% of SG, RYGB, and OAGB patients respectively (p = 0.041).

CONCLUSIONS

In the first comparative study of WR, OAGB had lesser WR in comparison to SG and RYGB but had the most impact on Hb and albumin levels in the long term. Definition selection for reporting WR has a significant impact on the results. There is a need for standardising the reporting of WR in bariatric literature.

Effect of Protein Intake on the Protein Status and Lean Mass of Post-Bariatric Surgery Patients: a Systematic Review

BACKGROUND

Post-bariatric surgery may compromise nutritional status due to energy and protein intake restriction.

METHODS

Systematic review was performed to synthesize evidence on the amount of protein intake and its association with lean mass and serum proteins during at least 6 months following Roux-en-Y gastric bypass or sleeve gastrectomy.

RESULTS

Twelve studies (n = 739) were identified in the search. Protein intake below 60 g/day and significant lean mass loss were observed in majority of these studies. Of the four studies that measured association between protein intake and lean mass retention, only two supported this hypothesis.

CONCLUSION

There is insufficient evidence of the effect of dietary protein on serum protein levels. Further studies are needed to better estimate the protein intake that supports a healthy nutritional status in this population.

Psychopharmacology and Bariatric Surgery

Currently, it has been demonstrated that psychotropic drugs, particularly antidepressants, are frequently prescribed for patients who seek bariatric surgery. Many bariatric surgery patients have a history of a mood disorder. Unlike medications for diabetes, hypertension or hyperlipidemia, which are generally reduced and at times discontinued, postsurgery antidepressants use is only slightly reduced. The Roux-en-Y procedure is most frequently associated with alteration in drug exposure. Medication disintegration, dissolution, absorption, metabolism and excretion have been found to be altered in postbariatric patients, although data are sparse at this time. This paper will review the current evidence regarding the effect of bariatric surgery on drug treatment including mechanism of interference as well as the extent of changes identified to date. Data will be presented as controlled trials followed by case series and reports.

Differences in Weight Loss and Gut Hormones: Rouen-Y Gastric Bypass and Sleeve Gastrectomy Surgery

Bariatric surgery is arguably the most effective therapy for weight loss, and Rouen-Y gastric bypass (RYGB) is considered the "gold-standard" procedure. However, sleeve gastrectomy (SG) surgery has become more prevalent in recent years and it is unclear if weight loss differences occur between these procedures. Herein, we discuss evidence from randomized clinical trials comparing the effectiveness of RYGB and SG on weight loss. Moreover, we highlight gut hormones (e.g., GLP-1, ghrelin, bile acids, etc.) as potentially important mechanisms that contribute to the durability of decreased appetite and opposed fat storage following RYGB and SG. Collectively, although a subtle (∼ 3-5 kg) weight loss difference may exist in favor of RYGB up to 3 years post-operation, it appears that RYGB and SG induce comparable weight loss and changes in gut physiology that parallel reduced disease risk. These findings are clinically relevant for optimizing treatment strategies that combat obesity-related diabetes and cardiovascular disease.

Proteomic analysis in type 2 diabetes patients before and after a very low calorie diet reveals potential disease state and intervention specific biomarkers

Very low calorie diets (VLCD) with and without exercise programs lead to major metabolic improvements in obese type 2 diabetes patients. The mechanisms underlying these improvements have so far not been elucidated fully. To further investigate the mechanisms of a VLCD with or without exercise and to uncover possible biomarkers associated with these interventions, blood samples were collected from 27 obese type 2 diabetes patients before and after a 16-week VLCD (Modifast ∼450 kcal/day). Thirteen of these patients followed an exercise program in addition to the VCLD. Plasma was obtained from 27 lean and 27 obese controls as well. Proteomic analysis was performed using mass spectrometry (MS) and targeted multiple reaction monitoring (MRM) and a large scale isobaric tags for relative and absolute quantitation (iTRAQ) approach. After the 16-week VLCD, there was a significant decrease in body weight and HbA1c in all patients, without differences between the two intervention groups. Targeted MRM analysis revealed differences in several proteins, which could be divided in diabetes-associated (fibrinogen, transthyretin), obesity-associated (complement C3), and diet-associated markers (apolipoproteins, especially apolipoprotein A-IV). To further investigate the effects of exercise, large scale iTRAQ analysis was performed. However, no proteins were found showing an exercise effect. Thus, in this study, specific proteins were found to be differentially expressed in type 2 diabetes patients versus controls and before and after a VLCD. These proteins are potential disease state and intervention specific biomarkers.

Trial Registration

Controlled-Trials.com ISRCTN76920690

Dietary protein intake and bariatric surgery patients: a review

Bariatric surgery, a highly successful treatment for obesity, requires adherence to special dietary recommendations to insure the achievement of weight loss goals and weight maintenance. Postoperative consumption of protein is linked to satiety induction, nutritional status, and weight loss. Hence, we conducted an extensive literature review to identify studies focused on the following: protein and nutritional status; recommendations for dietary protein intake; the effects of protein-rich diets; and associations between dietary protein intake and satiety, weight loss, and body composition. We found that there have been few studies on protein intake recommendations for bariatric patients. Dietary protein ingestion among this population tends to be inadequate, potentially leading to a loss of lean body mass, reduced metabolic rates, and physiological damage. Conversely, a protein-rich diet can lead to increased satiety, enhanced weight loss, and improved body composition. The quality and composition of protein sources are also very important, particularly with respect to the quantity of leucine, which helps to maintain muscle mass, and thus is particularly important for this patient group. Randomized studies among bariatric surgery patient populations are necessary to establish the exact quantity of protein that should be prescribed to maintain their nutritional status.

Effect of weight loss after gastric bypass surgery on thyroid function in euthyroid people with morbid obesity

Obesity is positively associated with serum thyrotropin (TSH) concentrations at the high end of the normal range. The relationship between weight loss and thyroid function is less clear and studies to date have yielded inconsistent results. Our aim was to describe changes in thyroid function in obese people in relation to durable and significant weight loss after Roux-en-Y gastric bypass (RYGB) surgery. We recorded percentage of excess weight loss (% EWL), serum TSH and free thyroxine (fT4) before and median 4.5, 15 and 24 months after RYGB in 55 euthyroid patients with morbid obesity ranging in age from 18 to 64 years in a retrospective cohort analysis in a university hospital in Greater Manchester. Mean ± standard error preoperative weight was 135.13 ± 4.23 kg and BMI 48.08 ± 1.58 kg m(-2) . Patients attained nadir %EWL of 68% by median 15 months after RYGB. TSH was 2.00 ± 0.14 mU L(-1) at baseline and 2.02 ± 0.22 mU L(-1) at 24 months after RYGB (non-significant). Baseline fT4 was 13.46 ± 0.28 pmol L(-1) , and increased significantly to 15.14 ± 0.55 pmol L(-1) at 24 months (P < 0.004). In conclusion, we report that weight loss after RYGB was accompanied by significant increase in serum fT4 but no change in TSH concentrations. Further study to elucidate the effect of significant weight loss on the thyroid axis is required.

Pregnancy after laparoscopic bariatric surgery: comparative study of adjustable gastric banding and Roux-en-Y gastric bypass

BACKGROUND

Approximately 80% of patients undergoing bariatric surgery are women, and about one half of these are of reproductive age. The purpose of the present study was to compare laparoscopic adjustable gastric banding (LAGB) and laparoscopic Roux-en-Y gastric bypass (LRYGB) in a series of morbidly obese women with respect to maternal and neonatal outcomes at a university hospital in France.

METHODS

From January 2004 to December 2008, the data from women who had undergone LAGB or LRYGB at our center and were pregnant were collected, including age, parity, gravidity, weight, body mass index (BMI) before surgery and at scheduled intervals after surgery (1, 3, 6, 12, and 18 mo and yearly thereafter), interval from surgery to conception, weight and BMI at conception, weight and weight gain during pregnancy, weight and BMI at 2 weeks after pregnancy, complications during pregnancy, gestational age, method of delivery, fetal birth weight, and fetal outcome.

RESULTS

There were 42 pregnancies in 36 women, 22 in women who had undergone LAGB and 20 who had undergone LRYGB. The LAGB and LRYGB groups were comparable for all analyzed variables, except that the preoperative weight and BMI were greater in the LRYGB group. No differences in weight or BMI were found at conception or after pregnancy. No difference was found between the 2 groups in terms of obstetric complications or neonatal outcomes. A high frequency of cesarean deliveries was necessary in both groups.

CONCLUSIONS

The results of the present study have shown that no significant difference exists in the obstetric and birth outcomes between women who have undergone LRYGB and those who have undergone LAGB.

Bariatric surgery for type 2 diabetes: weighing the impact for obese patients

Obesity is a potent risk factor for the development and progression of type 2 diabetes, and weight loss is a key component of diabetes management. Bariatric surgery results in significant weight loss and remission of diabetes in most patients. After surgery, glycemic control is restored by a combination of enforced caloric restriction, enhanced insulin sensitivity, and increased insulin secretion.

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.

Protein intake, body composition, and protein status following bariatric surgery

BACKGROUND

Daily protein intake recommendations have recently been proposed for the bariatric patient. We aimed to evaluate the accomplishment of these recommendations, and the influence of protein intake (PI) on fat free mass (FFM) and protein status changes following bariatric surgery.

METHODS

We examined 101 consecutive patients undergoing laparoscopic Roux-in-Y gastric gypass (LGBP) or laparoscopic sleeve gastrectomy (LSG). Based on 3-day food records, PI from food and supplements were quantified at 4, 8, and 12 months after surgery. The association between PI and body composition (bioelectrical impedance), plasma albumin and pre-albumin was evaluated at all study time points.

RESULTS

A PI <60 g/day was present respectively in 45%, 35%, and 37% of the cohort at 4, 8, and 12 months after surgery (p < 0.001 relative to baseline). Despite our universal recommendation of protein supplementation, supplements were taken only by 63.4, 50.5, and 33.7% of the participants at 4, 8, and 12 months. However, protein supplementation was effective in helping patients to achieve the daily protein intake goal. In linear regression analysis, male gender and weight loss, but not PI, were significantly associated with loss of FFM (p < 0.001). No significant correlation between PI and plasma albumin or pre-albumin was found.

CONCLUSIONS

Our study underscores the value of protein supplementation for the achievement of the recommended daily protein intake in the bariatric patient. However, our data does not help to define a PI goal as critical in determining the FFM and protein status changes following LGBP or LSG.

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.

Long-term nutritional outcome after gastric bypass

BACKGROUND

Weight loss and nutritional status 5 or more years after Roux-en-Y gastric bypass was prospectively documented. The hypothesis was that even after clinical adaptation, imbalances might still occur.

METHODS

Seventy-five consecutive patients (age 49.3 +/- 10.6 years, 89.3% females) were recruited 83.4 +/- 14.3 months after the intervention. Weight loss and nutritional abnormalities were registered.

RESULTS

Body mass index (BMI) was 56.5 +/- 10.0 preoperatively, 29.4 +/- 6. 2 by 24 months and 34.4 +/- 14.6 when last seen. Major current deficit occurred for magnesium (32.1% of the patients), hemoglobin (50.8%), iron (29.8%), ferritin (36.0%), zinc (40.5%), vitamin B(12) (61.8%), vitamin D(3) (60.5%), and beta-carotene (56.8%). Low preoperative measurements had already been unveiled for iron, transferrin, zinc, and vitamin B(12). Total drug consumption tended to decrease after operation, and present findings correlated with excess weight loss (EWL). Also presence of diabetes and BMI value were predictors of long-term EWL, along with biochemical profile by 2 years. Multivitamin supplementation and gastrointestinal complaints partially correlated with nutritional results.

CONCLUSIONS

(1) Good initial weight loss with moderate late regain, anemia, and multiple nutrient deficits was the common pattern. (2) Massive weight loss, frequent vomiting, dumping syndrome, and women in reproductive age were risk factors for hemoglobin or vitamin deficits, whereas superobesity, diabetes, and use of multiple drugs were associated with EWL result. (3) Most laboratory tests became stable by 2 years and along with BMI correlated with late EWL. (4) Two-year nutritional investigation is especially recommended because of its long-term predictive value.