Dietary Recommendations for Bariatric Patients to Prevent Kidney Stone Formation

Brazilian Guidelines on evaluation and clinical management of Nephrolithiasis: Brazilian Society of Nephrology

The prevalence of nephrolithiasis has been increasing in recent years, affecting appro-ximately 10% and 15% of the population. Kidney stone disease is associated with syste-mic comorbidities such as cardiovascular dis-ease, diabetes mellitus, and obesity. The first Nephrolithiasis Guideline by the Brazilian Society of Nephrology was published in 2002, and since then, the accumulation of new clinical studies and guidelines has justified a review of the subject. This updated document, prepared by the Nephrolithiasis Committee of the Brazilian Society of Nephrology, reflects the advances in the management of patients with kidney stones. The guideline aims to provide recommendations for the diagnosis, prevention, and treatment of nephrolithiasis, based on the best available evidence. Topics covered include clinical evaluation, laboratory and imaging tests, as well as dietary and pharmacological interventions, and follow-up strategies.

The Pandora's Box of Bariatric Surgery: Unveiling the Association with Kidney Stone Risk-A Cross-Sectional Study

BACKGROUND

Metabolic and bariatric surgery is an effective intervention for severe obesity, known for improving comorbidities such as type 2 diabetes, hypertension, and hyperlipidemia. However, its association with kidney stone formation remains uncertain. This study investigates the relationship between bariatric surgery and kidney stone prevalence using data from NHANES 2015-2018.

METHODS

We conducted a cross-sectional analysis of 8,087 participants from NHANES (2015-2018). Bariatric surgery and kidney stone history were self-reported. Logistic regression models adjusted for demographic, clinical, and lifestyle factors were used to evaluate associations. Stratified analyses explored effect modification by subgroups.

RESULTS

Kidney stones were more prevalent among participants with bariatric surgery (26.57%) compared to those without (10.92%, P < 0.001). Bariatric surgery was associated with increased odds of kidney stones in the crude model (OR: 2.95, 95% CI: 1.57-5.55) and adjusted models (OR: 2.69, 95% CI: 1.27-5.70). Subgroup analyses highlighted stronger associations among females and participants with moderate physical activity.

CONCLUSION

Metabolic and bariatric surgery is linked to an elevated risk of kidney stones, influenced by demographic and clinical factors. Personalized counseling on hydration and dietary modifications is essential for mitigating this risk.

Sleeve Gastrectomy and Gastric Bypass Impact in Patient's Metabolic, Gut Microbiome, and Immuno-inflammatory Profiles-A Comparative Study

BACKGROUND

Bariatric surgery is the most long-term effective treatment option for severe obesity. The role of gut microbiome (GM) in either the development of obesity or in response to obesity management strategies has been a matter of debate. This study aims to compare the impact of two of the most popular procedures, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (GB), on metabolic syndrome parameters and gut bacterial microbiome and in systemic immuno-inflammatory response.

METHODS

A prospective observational study enrolled 24 patients with severe obesity, 14 underwent SG and 10 GB. Evaluations before (0 M) and 6 months (6 M) after surgical procedures included clinical and biochemical parameters, expression of 17 immuno-inflammatory genes in peripheral blood leukocytes, and assessment of gut microbiome profile using 16 s rRNA next-generation sequencing approach. Statistical significance was set to a p value < 0.05 with an FDR < 0.1.

RESULTS

A significant and similar decrease in weight-associated parameters and for most metabolic markers was achieved with both surgeries. Considering the gut microbiome in the whole study population, there was an increase in alpha diversity at family-level taxa. Beta diversity between SG and GB at 6 M showed near significant differences (p = 0.042) at genus levels. Analysis of the relative abundance of individual taxonomic groups highlighted differences between pre- and post-surgical treatment and between both approaches, namely, a higher representation of family Enterobacteriaceae and genera Veillonella and Enterobacteriaceae_unclassified after GB. Increased expression of immune-inflammatory genes was observed mainly for SG patients.

CONCLUSIONS

We conclude that SG and GB have similar clinical and metabolic outcomes but different impacts in the gut bacterial microbiome. Results also suggest reactivation of immune response after bariatric surgery.

A Comprehensive Review of Antinutrients in Plant-Based Foods and Their Key Ingredients

In recent years, the growing popularity of vegan and vegetarian diets, along with the rising demand for plant-based foods, has led researchers to concentrate on examining the presence and effects of antinutrients. While there are existing literature reviews focusing on antinutritional compounds, particularly on their reduction, this review aims to provide a comprehensive description of antinutrients for producers, food scientists, professionals, legislators and consumers, emphasising the complexity of the subject and the necessity for diverse approaches while identifying aspects that still require further research. Antinutrients, including protease inhibitors, amylase inhibitors, phytic acid, lectins, saponins, tannins, cyanogenic glycosides, oxalic acid, polyphenols, goitrogens and pyrimidine glycosides, are described, encompassing various aspects such as their structural characteristics, analytical detection methods, distribution, physiological impacts and strategies for mitigation or elimination. Specifically, our review concentrates on assessing the presence of antinutrients in plant-based food products and the primary ingredients, categorised into five distinct groups, cereals, pseudocereals, pulses, seeds and nuts, which are commonly used in their production. Among these categories, legumes are identified as the richest source of anti-nutritional compounds, followed by cereal grains. However, certain pseudocereals, seeds and nuts also demonstrate high levels of specific antinutrients. While antinutrients are generally regarded as harmful to nutrient absorption, recent studies have revealed some potential health benefits associated with them. Therefore, further in vivo research is essential to elucidate the behaviour of antinutritional compounds within the human body. Additionally, there is a significant lack of formal regulations and guidelines regarding antinutrients, and food products currently do not feature labelling related to these compounds.

Integrated Insights into Metabolic and Bariatric Surgery: Improving Life Quality and Reducing Mortality in Obesity

Metabolic and bariatric surgery (MBS) is an effective intervention for patients with severe obesity and metabolic comorbidities, particularly when non-surgical weight loss methods prove insufficient. MBS has shown significant potential for improving quality of life and metabolic health outcomes in individuals with obesity, yet it carries inherent risks. Although these procedures offer a multifaceted approach to obesity treatment and its clinical advantages are well-documented, the limited understanding of its long-term outcomes and the role of multidisciplinary care pose challenges. With an emphasis on quality-of-life enhancements and the handling of postoperative difficulties, the present narrative review seeks to compile the most recent findings on MBS while emphasizing the value of an integrated approach to maximize patient outcomes. Effective MBS and patients' management require a collaborative team approach, involving surgeons, dietitians, psychologists, pharmacists, and other healthcare providers to address not only physiological but also psychosocial patient needs. Comparative studies demonstrate the efficacy of various MBS methods, including Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy that may considerably decrease morbidity and mortality in individuals with obesity. Future studies should target long-term patient treatment, and decision making should be aided by knowledge of obesity, comorbidity recurrence rates, and permanence of benefits.

Bariatric surgery does not affect kidney stone disease

BACKGROUND

numerous epidemiological studies demonstrate the correlation between obesity and urolithiasis. Bariatric surgery is effective in significant weight loss, reducing mortality rates, and lowering the incidence of obesity-related comorbidities. However, it may be associated with long-term complications such as urolithiasis, with an estimated increase of 7.6% in bariatric patients. This study investigates the impact of various bariatric surgical techniques and personal and nutritional habits on post-operative urolithiasis.

MATERIAL AND METHOD

185 patients were prospectively enrolled in the study. All patients underwent nutritional assessment two years after surgery, and urinary stone disease was evaluated through urinalysis. Patients with urinary crystals were subsequently sent to the division of Urology to evaluate the possible presence of urinary stones through an abdominal CT scan.

RESULTS

kidney stone disease was present in 12 female patients (12/ 185 - 6.49%) out of the 25 (12/25-48%) with urinary crystals. Among the various surgical techniques, 8 patients underwent SG, 2 patients each for OAGB and RYGB, without a proven significant correlation. Hypertension, Dyslipidemia, and OSAS were significantly correlated with the incidence of urolithiasis (p-value < 0.05). BMI > 30 kg/m2 was significantly correlated with urinary stone formation (p-value < 0.05).

CONCLUSION

patients undergoing bariatric surgery should receive counseling about the risk of developing urolithiasis (6.49%) independently from the surgical treatment, highlighting the necessity of adhering to nutritional guidelines. Evaluation for urinary stones could be recommended during follow-up, especially for patients with a BMI > 30 kg/m2.

LLL 44 - Module 3: Micronutrients in Chronic disease

Micronutrients (MN), i.e. trace elements and vitamins, are essential organic molecules, which are required in the diet in relatively small amounts in any form of nutrition (oral, enteral, parenteral). The probability of MN depletion or deficiencies should be considered in all chronic illnesses, especially in those that can interfere with intake, digestion, or intestinal absorption. Low socio-economic status and food deprivation are recognized as the most prevalent reasons for MN deficiencies world-wide. Elderly multimorbid patients with multimodal therapy, as well as patients with long-lasting menu restrictions, are at high risk for both disease related malnutrition as well as multiple MN deficiencies, needing careful specific follow-up. The importance of monitoring MN blood levels along with CRP is essential for optimal care. Drug interactions are also highlighted. In patients with chronic conditions depending on medical nutrition therapy, the provision of adequate dietary reference intakes (DRI) of MN doses and monitoring of their adequacy belongs to standard of care.

Study on the mechanism of vitamin E alleviating non-alcoholic fatty liver function based on non-targeted metabolomics analysis in rats

Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome. Vitamin E (VE) has antioxidant properties and can mediate lipid metabolism. Non-targeted metabolomics technology was employed to uncover comprehensively the metabolome of VE in NAFLD rats. NAFLD model was created with a high-fat and high-cholesterol diet (HFD) in rats. NAFLD rats in the VE group were given 75 mg/(kg day) VE. The metabolites in the serum of rats were identified via UPLC and Q-TOF/MS analysis. KEGG was applied for the pathway enrichment. VE improved the liver function, lipid metabolism, and oxidative stress in NAFLD rats induced by HFD. Based on the metabolite profile data, 132 differential metabolites were identified between VE group and the HFD group, mainly including pyridoxamine, betaine, and bretylium. According to the KEGG results, biosynthesis of cofactors was a key metabolic pathway of VE in NAFLD rats. VE can alleviate NAFLD induced by HFD, and the underlying mechanism is associated with the biosynthesis of cofactors, mainly including pyridoxine and betaine.

Identification and validation of the biomarkers related to ferroptosis in calcium oxalate nephrolithiasis

Ferroptosis is a specific type of programmed cell death characterized by iron-dependent lipid peroxidation. Understanding the involvement of ferroptosis in calcium oxalate (CaOx) stone formation may reveal potential targets for this condition. The publicly available dataset GSE73680 was used to identify 61 differentially expressed ferroptosis-related genes (DEFERGs) between normal kidney tissues and Randall's plaques (RPs) from patients with nephrolithiasis through employing weighted gene co-expression network analysis (WGCNA). The findings were validated through in vitro and in vivo experiments using CaOx nephrolithiasis rat models induced by 1% ethylene glycol administration and HK-2 cell models treated with 1 mM oxalate. Through WGCNA and the machine learning algorithm, we identified LAMP2 and MDM4 as the hub DEFERGs. Subsequently, nephrolithiasis samples were classified into cluster 1 and cluster 2 based on the expression of the hub DEFERGs. Validation experiments demonstrated decreased expression of LAMP2 and MDM4 in CaOx nephrolithiasis animal models and cells. Treatment with ferrostatin-1 (Fer-1), a ferroptosis inhibitor, partially reversed oxidative stress and lipid peroxidation in CaOx nephrolithiasis models. Moreover, Fer-1 also reversed the expression changes of LAMP2 and MDM4 in CaOx nephrolithiasis models. Our findings suggest that ferroptosis may be involved in the formation of CaOx kidney stones through the regulation of LAMP2 and MDM4.

Identification of novel inhibitor against human phosphoethanolamine cytidylyltransferase from phytochemicals of Citrus sinensis peel extract by in vitro and in silico approach

Kidney stone is a major global menace that demands research on nonsurgical treatment involving biological compounds for the benefit of the patients. Among the biological extracts, citric acid is traditionally used to dissolve kidney stones. The current research focuses on evaluating the in vitro anti-urolithiatic activity and in silico study of ethanolic extract of Citrus sinensis (ECS) peel against c: phosphoethanolamine cytidylyltransferase (PCYT). The diuretic activity was evaluated using in vitro model against the synthesized calcium oxalate crystals and cytotoxicity study in Madin-Darby canine kidney cell lines. The phytochemicals were identified using gas chromatography-mass spectroscopy. The interaction mechanism was studied using computational docking studies to confirm their involvement in the dissolution of calcium oxalate kidney stones. Further molecular properties, drug-likeness, ADME (absorption, distribution, metabolism, and excretion), and toxicity analysis were followed for the ligands using software tools. 5-Hydroxymethylfurfural, 2,4-di-tert-butylphenol, 2-methoxy-4-vinylphenol, 6-octen-1-ol, 3,7-dimethyl-, acetate (citronellyl acetate), 3',5'-dimethoxyacetophenone, and ethyl alpha-d-glucopyranoside showed good binding affinities against PCYT. Moreover, the docking studies showed the ligand 3',5'-dimethoxyacetophenone has the highest binding energy (-6.68 kcal/mol) for human CTP. The present investigation concludes that these compounds of C. sinensis peel extract compounds are responsible as novel inhibitors against human CTP and extend their use in the pharmaceutical drug development process.

Exploring the characteristics of gut microbiome in patients of Southern Fujian with hypocitraturia urolithiasis and constructing clinical diagnostic models

PURPOSE

Hypocitraturia is an important cause of urolithiasis. Exploring the characteristics of the gut microbiome (GMB) of hypocitriuria urolithiasis (HCU) patients can provide new ideas for the treatment and prevention of urolithiasis.

METHODS

The 24 h urinary citric acid excretion of 19 urolithiasis patients was measured, and patients were divided into the HCU group and the normal citrate urolithiasis (NCU) group. The 16 s ribosomal RNA (rRNA) was used to detect GMB composition differences and construct operational taxonomic units (OTUs) coexistence networks. The key bacterial community was determined by Lefse analysis, Metastats analysis and RandomForest analysis. Redundancy analysis (RDA) and Pearson correlation analysis visualized the correlation between key OTUs and clinical features and then established the disease diagnosis model of microbial-clinical indicators. Finally, PICRUSt2 was used to explore the metabolic pathway of related GMB in HCU patients.

RESULTS

The alpha diversity of GMB in HCU group was increased and Beta diversity analysis suggested significant differences between HCU and NCU groups, which was related to renal function damage and urinary tract infection. Ruminococcaceae_ge and Turicibacter are the characteristic bacterial groups of HCU. Correlation analysis showed that the characteristic bacterial groups were significantly associated with various clinical features. Based on this, the diagnostic models of microbiome-clinical indicators in HCU patients were constructed with the areas under the curve (AUC) of 0.923 and 0.897, respectively. Genetic and metabolic processes of HCU are affected by changes in GMB abundance.

CONCLUSION

GMB disorder may be involved in the occurrence and clinical characteristics of HCU by influencing genetic and metabolic pathways. The new microbiome-clinical indicator diagnostic model is effective.

The management of recurrent urinary tract infections within a nurse-led urology team

The aim of this article is to share experience and learning of managing recurrent urinary tract infections (UTIs) within a specialist urology nurse-led team based at a district general hospital. It looks at current practice and supporting evidence for how to manage and treat recurrent UTIs in both male and female patients. Two case studies are presented to illustrate the management strategies and outcomes, demonstrating a planned approach that informs the design of a local management guideline to organise patients' care.

Incidence of Kidney Stones After Metabolic and Bariatric Surgery-Data from the Scandinavian Obesity Surgery Registry

PURPOSE

Obesity is associated with increased incidence of kidney stones, a risk further increased by metabolic and bariatric surgery, particularly after procedures with a malabsorptive component. However, there is a paucity in reports on baseline risk factor and on larger population-based cohorts. The objective was to evaluate incidence and risk factors for kidney stones after bariatric surgery by comparing them to an age-, sex-, and geographically matched cohort from the normal population.

MATERIAL AND METHODS

Patients operated with primary Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), or biliopancreatic diversion with duodenal switch (BPD-DS) from 2007 until 2017 within the Scandinavian Obesity Surgery registry were matched 1:10 to controls from the normal population. Hospital admission or outpatient visits due to kidney stones registered in the National Patient Registry were considered as endpoint.

RESULTS

The study included 58,366 surgical patients (mean age 41.0±11.1, BMI 42.0±5.68, 76% women) with median follow-up time 5.0 [IQR 2.9-7.0] years and 583,660 controls. All surgical procedures were associated with a significantly increased risk for kidney stones (RYGB, HR 6.16, [95% CI 5.37-7.06]; SG, HR 6.33, [95% CI 3.57-11.25]; BPD/DS, HR 10.16, [95% CI 2.94-35.09]). Higher age, type 2 diabetes hypertension at baseline, and a preoperative history of kidney stones were risk factors for having a postoperative diagnosis of kidney stones.

CONCLUSION

Primary RYGB, SG, and BPD/DS were all associated with a more than sixfold increased risk for postoperative kidney stones. The risk increased with advancing age, two common obesity-related conditions, and among patients with preoperative history of kidney stones.

Dietary advice for patients with bowel-related conditions and malabsorption

PURPOSE

To explain the pathophysiology of kidney stone formation and appropriate dietary recommendations in inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD) and after bariatric surgery, focusing on the current literature.

METHODS

A narrative review methodology was performed. A literature search was conducted using PubMed, MEDLINE, and Google Scholar. Studies on the relationship between IBD or bariatric surgery and the risk of kidney stone formation were included.

RESULTS

Dietary composition has a critical role in urinary stone formation. Nutritional factors such as fluid intake, dietary protein, carbohydrates, oxalate, and calcium contribute to the risk of stone formation. Bowel-related malabsorptive conditions (IBD, after bariatric surgery, etc.) are associated with an increased risk of kidney stone formation due to metabolic and physiological changes such as hyperoxaluria, hypocitraturia, and decreased fluid intake or absorption. While the risk is lower in restrictive bariatric surgeries, the risk of kidney stone formation increases, especially after malabsorptive procedures. Dietary recommendations for these patients could profit alleviate urinary changes and reduce the risk of kidney stones.

CONCLUSION

Bowel-related malabsorptive conditions such as IBD and bariatric surgery are associated with an increased risk of kidney stones. Appropriate dietary recommendations can improve urinary metabolic changes and reduce kidney stone formation and the possibility of stone-related surgery.

Dietary advices for patients with metabolic syndrome and obesity

Obesity and metabolic syndrome are two important health problems that have increased in incidence in recent years in all around world. Stone occurrence and recurrence risks are increased in these diseases. Apart from general dietary recommendations for stone patients, metabolic evaluation and personalized dietary recommendations are important in these patients. Achieving a normal BMI also reduces the risks of stone occurrence and recurrence. In these patients, the Mediterranean diet and DASH diet, in which the lower animal protein intake and the higher consumption of vegetables and fruits, can be considered as suitable options in the diets to be applied to lose weight.

Dietary Management of Chronic Kidney Disease and Secondary Hyperoxaluria in Patients with Short Bowel Syndrome and Type 3 Intestinal Failure

Short gut syndrome can lead to type 3 intestinal failure, and nutrition and hydration can only be achieved with parenteral nutrition (PN). While this is a lifesaving intervention, it carries short- and long-term complications leading to complex comorbidities, including chronic kidney disease. Through a patient with devastating inflammatory bowel disease’s journey, this review article illustrates the effect of short gut and PN on kidney function, focusing on secondary hyperoxaluria and acute precipitants of glomerular filtration. In extensive small bowel resections colon in continuity promotes fluid reabsorption and hydration but predisposes to hyperoxaluria and stone disease through the impaired gut permeability and fat absorption. It is fundamental, therefore, for dietary intervention to maintain nutrition and prevent clinical deterioration (i.e., sarcopenia) but also to limit the progression of renal stone disease. Adaptation of both enteral and parenteral nutrition needs to be individualised, keeping in consideration not only patient comorbidities (short gut and jejunostomy, cirrhosis secondary to PN) but also patients’ wishes and lifestyle. A balanced multidisciplinary team (renal physician, gastroenterologist, dietician, clinical biochemist, pharmacist, etc.) plays a core role in managing complex patients, such as the one described in this review, to improve care and overall outcomes.

Long-term complications after gastric bypass and sleeve gastrectomy: What information to give to patients and practitioners, and why?

Bariatric surgery is now recognized as the most effective treatment of morbid obesity, leading to durable weight loss and resolution of associated co-morbidities. Roux-en-Y gastric bypass and sleeve gastrectomy are the two most widely used operations today. However, potentially serious medical, surgical, and/or psychiatric complications can occur that raise questions regarding the benefits of this type of surgery. These complications can lead to surgical re-operations, iterative hospitalizations, severe nutritional deficiencies and psychological disorders. Indeed, death from suicide is said to be three times higher than in non-operated obese patients. These results are of concern, all the more because of the high prevalence of patients lost to follow-up (for various and multifactorial reasons) after bariatric surgery. However, better knowledge of post-surgical sequelae could improve the information provided to patients, the preoperative evaluation of the benefit/risk ratio, and, for patients undergoing surgery, the completeness and quality of follow-up as well as the detection and management of complications. The development of new strategies for postoperative follow-up such as telemedicine but also the mobilization of all the actors along the healthcare pathway can make inroads and warrant further study.

Renal Function Following Bariatric Surgery: a Literature Review of Potential Mechanisms

Obesity is a major and independent risk factor for onset and progression of many renal diseases. Bariatric surgery (BS) improves renal function by improving obesity-related metabolic disorders. However, the procedure is also accompanied by renal risks, including acute kidney injury (AKI) and oxalate nephropathy. Here, we briefly review the history and principle of frequently applied technique for BS and summarize the comprehensive BS effect on kidney function. Importantly, we highlight the possible molecular mechanisms associated with the recovery of renal function to provide novel ideas for future studies and clinical applications.

Primary hyperoxaluria diagnosed after kidney transplantation: a case report and literature review

Background

Primary hyperoxaluria (PH) is a rare inherited autosomal recessive disease caused by disturbed glyoxylate metabolism. The disease is characterized by calcium oxalate crystal deposition in various organs, especially in the kidney. Due to the lack of current understanding of PH, nearly all patients are only initially diagnosed with PH when recurrent lithiasis and progressive end-stage renal disease occur. Many cases are not diagnosed in patients until renal allograft insufficiency occurs after renal transplantation. This case report and literature review aim to emphasize the need for careful pre-transplant PH screening of patients with bilateral nephrocalcinosis or nephrolithiasis.

Case presentation

Renal allograft insufficiency was diagnosed as PH after kidney transplantation. Here, we detail the complete clinical course, including computed tomography images of the original kidney and renal graft, histopathological images of a biopsy of the transplanted kidney, the results of laboratory and molecular genetic tests, and the treatment. In addition, we reviewed the literature from 2000 to 2021 and analyzed 19 reported cases of PH diagnosed after kidney transplantation, and provide a summary of the characteristics, complications, treatment, and prognosis of these cases.

Conclusions

By reviewing and analyzing these cases, we concluded that patients with a history of nephrocalcinosis or nephrolithiasis in both kidneys need preoperative screening for PH and appropriate treatment before kidney transplantation. Delayed graft function caused by PH is easily misdiagnosed as acute rejection, and needle biopsy should be performed at an early stage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02546-0.

Micronutrients deficiences in patients after bariatric surgery

Bariatric surgery is an effective option for managing obesity and has gained general acceptance among patients in recent years. Generally, despite the high caloric intake, a bad nutritional habit of obese people results in the deficiency of several vitamins, minerals, and trace elements essential for body metabolism and normal physiological processes. Additionally, the current bariatric surgical approaches such as sleeve gastrectomy (SG), Roux-en-Y-gastric bypass (RYGB), laparoscopic adjustable gastric banding (LAGB), and jejunoileal bypass (JIB) can cause or exacerbate these deficiencies. Based on several reports, it appears that the various bariatric surgical procedures affect nutrient absorption differently. Being purely restrictive, LAGB and SG affect the absorption of iron, selenium, and vitamin B₁₂, while RYGB, JIB, and biliopancreatic diversion have a more profound impact on the absorption of essential vitamins, minerals, and trace elements. Nutritional deficiencies in vitamins, minerals, and trace elements may follow bariatric surgery and are associated with clinical manifestations and diseases, including anemia, ataxia, hair loss, and Wernicke encephalopathy. The present review summarizes some of the major vitamin and micronutrient deficiencies associated with bariatric surgery, particularly those presented post-surgically. To avoid any adverse consequences of vitamin and trace element deficiency, proper monitoring and tests are recommended at any stage, from pre- to post-surgery (periodical check-up), followed by specific and individual nutritional supplementation treatments and a proper healthy diet.

Polycyclic Aromatic Hydrocarbons and the Risk of Kidney Stones in US Adults: An Exposure-Response Analysis of NHANES 2007-2012

Background

Polycyclic aromatic hydrocarbons (PAHs) exposure may cause various diseases. However, the association between PAHs exposure and kidney stones remains unclear. The purpose of this study was to examine the relationship between PAHs and the risk of kidney stones in the US population.

Methods

The study included a total of 30,442 individuals (≥20 years) from the 2007–2012 National Health and Nutrition Examination Survey (NHANES). Nine urinary PAHs were included in this study. Logistic regression and dose–response curves were used to evaluate the association between PAHs and the risk of kidney stones.

Results

We selected 4385 participants. The dose–response curves showed a significant positive association between total PAHs, 2-hydroxynaphthalene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 9-hydroxyfluorene and the risk of kidney stones after adjusting for confounding factors. Compared with the low group, an increased risk of kidney stones was observed in the high group of total PAHs [OR (95% CI), 1.32 (1.06–1.64), P=0.013], 2-hydroxynaphthalene [OR (95% CI), 1.37 (1.10–1.71), P=0.005], 1-hydroxyphenanthrene [OR (95% CI), 1.24 (1.00–1.54), P=0.046] and 9-hydroxyfluorene [OR (95% CI), 1.36 (1.09–1.70), P=0.007].

Conclusion

High levels of PAHs were positively associated with the risk of kidney stones in the US population.

Association between Daily Urinary Sodium Excretion, Ratio of Extracellular Water-to-Total Body Water Ratio, and Kidney Outcome in Patients with Chronic Kidney Disease

Whether dietary salt intake affects chronic kidney disease (CKD) progression remains unclear. We conducted a retrospective cohort study to analyze the effects of both daily salt intake (DSI) and volume status on renal outcomes in 197 CKD patients. DSI was estimated by 24-h urinary sodium excretion and volume status was assessed by the ratio of extracellular water (ECW) to total body water (TBW) measured by bioelectrical impedance analysis (BIA). We divided patients into two groups according to DSI (6 g/day) or median ECW/TBW (0.475) and compared renal outcomes of each group. Furthermore, we classified and analyzed four groups according to both DSI and ECW/TBW. The higher DSI group showed a 1.69-fold (95% confidence interval (CI) 1.12–2.57, p = 0.01) excess risk of outcome occurrence compared to the lower group. Among the four groups, compared with Group 1 (low DSI and low ECW/TBW), Group 3 (high DSI and low ECW/TBW) showed a 1.84-fold (95% CI 1.03–3.30, p = 0.04) excess risk of outcome occurrence; however, Group 2 (low DSI and high ECW/TBW) showed no significant difference. High salt intake appears to be associated with poor renal outcome independent of blood pressure (BP), proteinuria, and volume status.