Gastrointestinal disorders and renal failure: exploring the connection

Functional gastrointestinal disorders, mental health, genetic susceptibility, and incident chronic kidney disease

BACKGROUND

Whether functional gastrointestinal disorders (FGIDs) are associated with the long-term risk of chronic kidney disease (CKD) remains unclear. We aimed to investigate the prospective association of FGIDs with CKD and examine whether mental health mediated the association.

METHODS

About 416,258 participants without a prior CKD diagnosis enrolled in the UK Biobank between 2006 and 2010 were included. Participants with FGIDs (including irritable bowel syndrome [IBS], dyspepsia, and other functional intestinal disorders [FIDs; mainly composed of constipation]) were the exposure group, and non-FGID participants were the non-exposure group. The primary outcome was incident CKD, ascertained from hospital admission and death registry records. A Cox proportional hazard regression model was used to investigate the association between FGIDs and CKD, and the mediation analysis was performed to investigate the mediation proportions of mental health.

RESULTS

At baseline, 33,156 (8.0%) participants were diagnosed with FGIDs, including 21,060 (5.1%), 8262 (2.0%), and 6437 (1.6%) cases of IBS, dyspepsia, and other FIDs, respectively. During a mean follow-up period of 12.1 years, 11,001 (2.6%) participants developed CKD. FGIDs were significantly associated with a higher risk of incident CKD compared to the absence of FGIDs (hazard ratio [HR], 1.36; 95% confidence interval [CI], 1.28-1.44). Similar results were observed for IBS (HR, 1.27; 95% CI, 1.17-1.38), dyspepsia (HR, 1.30; 95% CI, 1.17-1.44), and other FIDs (HR, 1.60; 95% CI, 1.43-1.79). Mediation analyses suggested that the mental health score significantly mediated 9.05% of the association of FGIDs with incident CKD and 5.63-13.97% of the associations of FGID subtypes with CKD. Specifically, the positive associations of FGIDs and FGID subtypes with CKD were more pronounced in participants with a high genetic risk of CKD.

CONCLUSION

Participants with FGIDs had a higher risk of incident CKD, which was partly explained by mental health scores and was more pronounced in those with high genetic susceptibility to CKD.

Postoperative Outcomes After Gastrointestinal Surgery in Patients Receiving Chronic Kidney Replacement Therapy: A Population-based Cohort Study

OBJECTIVE

This study evaluated the postoperative mortality and morbidity outcomes following the different subtypes of gastrointestinal (GI) surgery over a 15-year period.

BACKGROUND

Patients receiving chronic kidney replacement therapy (KRT) experience higher rates of general surgery compared with other surgery types. Contemporary data on the types of surgeries and their outcomes are lacking. KRT was defined as patients requiring chronic dialysis (hemodialysis or peritoneal dilaysis) or having a functioning kidney transplant long-term.

METHODS

All incident and prevalent patients aged greater than 18 years identified in the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry as receiving chronic KRT were linked with jurisdictional hospital admission datasets between January 1, 2000 until December 31, 2015. Patients were categorized by their KRT modality [hemodialysis (HD), peritoneal dialysis (PD), home hemodialysis (HHD), and kidney transplant (KT)]. GI surgeries were categorized as upper gastrointestinal (UGI), bowel (small and large bowel), anorectal, hernia surgery, cholecystectomy, and appendicectomy. The primary outcome was the rates of the different surgeries, estimated using Poisson models. Secondary outcomes were risks of 30-day/in-hospital postoperative mortality risk and nonfatal outcomes and were estimated using logistic regression. Independent predictors of 30-day mortality were examined using comorbidity-adjusted Cox models.

RESULTS

Overall, 46,779 patients on chronic KRT were linked to jurisdictional hospital datasets, and 9,116 patients were identified as having undergone 14,540 GI surgeries with a combined follow-up of 76,593 years. Patients on PD had the highest rates of GI surgery (8 per 100 patient years), with hernia surgery being the most frequent. Patients on PD also had the highest risk of 30-day postoperative mortality following the different types of GI surgery, with the risk being more than 2-fold higher after emergency surgery compared with elective procedures. Infective postoperative complications were more common than cardiac complications. This study also observed a U-shaped association between body mass index (BMI) and mortality, with a nadir in the 30 to 35 kg/m 2 group.

CONCLUSIONS

Patients on chronic KRT have high rates of GI surgery and morbidity, particularly in those who receive PD, are older, or are either underweight or moderately obese.

Gastric Acid Suppression Therapy and Its Association with Peritoneal Dialysis-Associated Peritonitis in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS)

Key Points

In a large multinational cohort of PD patients, any GAS use was not associated with an increased risk of all-organism peritonitis. For peritonitis, risks were particularly high among certain classes of organisms particularly for Gram-negative, enteric, and streptococcal peritonitis episodes. The association with enteric peritonitis appeared to be stronger among H2RA users.

Background

Peritonitis is a major peritoneal dialysis–related complication. We determined whether gastric acid suppression (GAS) (proton pump inhibitor [PPI] or histamine-2 receptor antagonists [H2RAs]) use was associated with all-cause and organism-specific peritonitis in peritoneal dialysis patients.

Methods

In the Peritoneal Dialysis Outcomes and Practice Patterns Study (595 facilities, eight countries, years 2014–2022), associations between GAS use and time to first episode of all-cause peritonitis were examined using Cox proportional hazards models. The primary exposure of interest was GAS and secondarily PPI or H2RA use. Secondary outcomes were organism-specific peritonitis, peritonitis cure rates, and death.

Results

Among patients (N =23,797) at study baseline, 6020 (25.3%) used PPIs, and 1382 (5.8%) used H2RAs. Overall risks of GAS use and peritonitis risk (adjusted hazard ratio [AHR]=1.05, 95% confidence interval [CI], 0.98 to 1.13]) and use of PPI (AHR 1.06 [95% CI, 0.99 to 1.14]) or H2RA (AHR 1.02 [95% CI, 0.88 to 1.18]) did not reach statistical significance. In organism-specific analyses, GAS users displayed higher peritonitis risks for Gram-negative (AHR 1.29, 95% CI, 1.05 to 1.57), Gram-positive (AHR 1.15, 95% CI, 1.01 to 1.31), culture-negative (AHR 1.20, 95% CI, 1.01 to 1.42), enteric (AHR 1.23, 95% CI, 1.03 to 1.48), and particularly Streptococcal (AHR 1.47, 95% CI, 1.15 to 1.89) peritonitis episodes. GAS was also associated with higher overall mortality (AHR 1.13 [95% CI, 1.05 to 1.22]).

Conclusion

The association between GAS use and peritonitis risk was weaker (hazard ratio [HR] 1.05 [0.98 to 1.13]) than for streptococcal (HR 1.57 [1.15 to 1.89]) and Gram-negative (HR 1.29 [1.05 to 1.57]) peritonitis. A better understanding of mechanisms surrounding the differential effects of GAS subtype on peritonitis risks is needed. Clinicians should be cautious when prescribing GAS. The impact of GAS deprescribing on peritonitis risk requires further evaluation.

Primary Midgut Volvulus: An Unusual Case of a Young Adult Necessitating Extensive Bowel Resection

Primary small bowel volvulus (SBV), commonly known as midgut volvulus, is an uncommon condition in which the small intestine rotates around its own mesenteric axis. This case report details the diagnostic and management challenges encountered in a rare presentation of primary SBV in a previously healthy 19-year-old male. Our patient presented with acute abdominal pain, vomiting, and signs of shock, prompting urgent medical attention. He was sent for exploratory laparotomy and underwent extensive resection of the gangrenous bowel. Diagnosis involved an abdominal computed tomography scan revealing the characteristic "whirl sign." According to the World Society of Emergency Medicine, surgical intervention should be done to address the SBV through resection of the gangrenous bowel segments. Despite efforts, the patient's prognosis remained guarded, necessitating ongoing supportive measures. This case highlights the complex challenges associated with primary SBV, emphasizing the need for continued research to enhance diagnostic precision and refine management strategies.

Longitudinal association between dietary protein intake and survival in peritoneal dialysis patients

BACKGROUND

Decreased dietary protein intake (DPI) may lead to protein-energy malnutrition and may be associated with increased mortality risk. We hypothesized that longitudinal changes in dietary protein intake have independent associations with survival in peritoneal dialysis (PD) patients.

METHODS

668 stable PD patients were selected in the study from January 2006 to January 2018 and were followed up until December 2019. Their three-day dietary records were collected at the baseline (the sixth month after PD) and thereafter every 3 months for two and a half years. The latent class mixed models (LCMM) were used to identify subgroups of PD patients with similar longitudinal trajectories of DPI. The relation between DPI (baseline and longitudinal data) and survival was examined using Cox model to estimate death hazard ratios. Meanwhile, different formulae were used to assess nitrogen balance.

RESULTS

The results showed that baseline DPI ≤ 0.60g/kg/day was associated with the worst outcome in PD patients. Patients with DPI 0.80-0.99g/kg/day and DPI ≥ 1.0g/kg/day both presented positive nitrogen balance; patients with DPI 0.61-0.79g/kg/day presented obviously negative nitrogen balance. Longitudinal association between time-dependent DPI and survival was found in PD patients. The consistently low DPI' (0.61-0.79g/kg/d) group was correlated with increased death risk as compared with the 'consistently median DPI' group (0.80-0.99g/kg/d, HR = 1.59, p = 0.008), whereas there was no difference in survival between 'consistently median DPI' group and 'high-level DPI' group (≥1.0 g/kg/d, p > 0.05).

CONCLUSION

Our study revealed that DPI ≥ 0.8 g/kg/day was beneficial to the long-term outcome for the PD population.

Incidence, prevalence and characteristics of multimorbidity in different age groups among urban hospitalized patients in China

The aim of the study was to investigate the incidence, prevalence and characteristics of multimorbidity in urban inpatients of different age groups. This study used data from the National Insurance Claim for Epidemiology Research (NICER) to calculate the overall incidence, prevalence, geographic and age distribution patterns, health care burden, and multimorbidity patterns for multimorbidity in 2017. According to our study, the overall prevalence of multimorbidity was 6.68%, and the overall prevalence was 14.87% in 2017. The prevalence of multimorbidity increases with age. The pattern of the geographic distribution of multimorbidity shows that the prevalence of multimorbidity is relatively high in South East China. The average annual health care expenditure of patients with multimorbidity increased with age and rose rapidly, especially among older patients. Patients with cancer and chronic kidney disease have higher treatment costs. Patients with hypertension or ischemic heart disease had a significantly higher relative risk of multimorbidity than other included noncommunicable diseases (NCDs). Hyperlipidemia has generated the highest number of association rules, which may suggest that hyperlipidemia may be both a risk factor for other NCDs and an outcome of them.

Constipation in Patients With Chronic Kidney Disease

Constipation is a frequent symptom in patients with chronic kidney disease (CKD). This review outlines the mechanisms and management of constipation in patients with CKD from a physician's perspective. Common causes of constipation in patients with CKD include concomitant medications, low dietary fiber intake, water-restricted diet, lack of physical activity, altered gut microbiota, and reduced gastrointestinal motility. Constipation has a negative impact on overall health, and, in particular, the presence of constipation has been associated with worsening kidney function and increased risk of developing advanced stages of CKD. Although lifestyle and dietary modifications may not always be practical for patients with CKD, they are recommended because they are beneficial as they lower mortality in patients with CKD. The use of laxatives containing magnesium salts, bulking agents, and osmotic laxatives may have insufficient efficacy and may be associated with adverse effects. In contrast, lactulose and lubiprostone have been shown to exhibit reno-protective effects. Linaclotide and plecanatide have very limited systemic absorption and appear safe in patients with CKD. Tenapanor reduces paracellular intestinal phosphate absorption in addition to blocking sodium uptake by enterocytes, and provides additional benefit in patients patients with CKD who have hyperphosphatemia and constipation. Prucalopride leads to improvements in bowel function and constipation-related symptoms in cases in which response to conventional laxatives are inadequate. However, the dose of prucalopride should be reduced to 1 mg once daily for patients with CKD. In conclusion, there are important advances on the impact and treatment of constipation in patients with CKD.

Effect of external therapies of traditional Chinese medicine on constipation in patients with CRF: A meta-analysis

OBJECTIVE

The purpose of this study was to evaluate the curative effect of external therapies of traditional Chinese medicine on constipation in patients with chronic renal failure and to provide scientific theoretical basis for clinical practice.

METHOD

We searched the English database of PubMed, EMBASE, the Cochrane Library and the Web of Science and Chinese database of CNKI, Wan fang database, VIP Database and China Biomedical Literature Database up to December 2022. Randomized controlled trials (RCTs) involving constipation in patients with CRF that compared external therapies of traditional Chinese medicine and routine treatment to routine treatment were eligible for the analysis. A meta-analysis of the outcome indicators including total efficiency, weekly defecation times, defecation time, defecation difficulty score, patient-assessment of constipation quality of life and adverse events of treatment were performed. The analysis was performed by using Review Manager version 5.3.

RESULT

A total of 23 studies were included, with 1764 patients. Meta-analysis results showed that compared with the control group, the test group could significantly increase weekly defecation times(MD = 0.94, 95%CI(0.70, 1.18), Z = 7.74, P < 0.00001), reduce defecation time(MD = -2.92, 95%CI(-3.69, -2.16), Z = 7.49, P < 0.00001), reduce defecation difficulty score(MD = -1.92, 95%CI(-2.45, -1.39), Z = 7.11, P < 0.00001), improve the quality of life in patients with constipation(MD = -7.57, 95%CI(-10.23, -4.91), Z = 5.58, P < 0.00001) and obtain a higher total effective rate of treatment(OR = 4.53, 95%CI(3.27, 6.29), Z = 9.07, P < 0.00001). In terms of safety, there was no statistical significance in the incidence of adverse events between two groups(OR = 0.35, 95%CI(0.04, 2.95), Z = 0.96, P = 0.34).

CONCLUSION

The combination of external therapies of traditional Chinese medicine and routine treatment could achieve an excellent curative effect, and there was no specific adverse event. However because of the limited level of current evidence, more high-quality trials are needed in the future.5.

Iron absorption and phosphate-lowering effects of ferric citrate hydrate are not influenced by gastric acid secretion inhibitors in patients with chronic kidney disease: a retrospective post hoc analysis

BACKGROUND

Ferric citrate hydrate (FC), an oral iron product is approved as iron preparation for iron deficiency anemia and phosphate binder for chronic kidney disease (CKD). We investigated whether gastric acid secretion inhibitors (GASI) influenced on iron absorption and phosphate-lowering effects of FC.

METHODS

Two phase 3 studies of FC for treatment of hyperphosphatemia in CKD patients (non-dialysis-dependent, 12 weeks, and hemodialysis, 52 weeks), were retrospectively analyzed. Patients were divided into with or without concomitant GASI and levels of iron- and phosphate-related parameters were analyzed.

RESULTS

In non-dialysis study (FC, 60 patients; placebo, 30 patients), 14 FC patients and 14 placebo patients used GASI. No significant differences were found between the FC and placebo groups for adjusted mean differences (95% CI) of changes from baseline to end of treatment (EOT) in serum ferritin [104.84 ng/mL (35.97, 173.71) with GASI vs 145.30 ng/mL (96.34, 194.25) without GASI, P = 0.34], and transferrin saturation (TSAT) [12.56% (- 0.83, 25.95) with GASI vs 18.56% (8.15, 28.98) without GASI, P = 0.49]. In hemodialysis study, 95/180 patients used GASI. Mean changes (SD) from baseline to EOT in serum ferritin were 166.32 ng/mL (153.70) with GASI and 155.16 ng/mL (139.47) without GASI, and for TSAT were 16.60% (19.44) with GASI and 16.02% (18.81) without GASI. In both studies, there were no differences in the changes from baseline to EOT in serum phosphate between with and without GASI cohorts.

CONCLUSION

GASI did not influence on the changes in serum ferritin, TSAT and serum phosphate by FC administration.

Presence of gastrointestinal symptoms in IgA nephropathy: a cross-sectional study

BACKGROUND

Gastrointestinal (GI) symptoms are common in end-stage kidney disease. Mounting evidence indicates that the intestine plays an important role in the pathogenesis of IgA nephropathy (IgAN). However, no studies have addressed the obvious question; do IgAN patients suffer from GI symptoms?

METHODS

Presence of GI symptoms and health-related quality of life were evaluated using the validated Gastrointestinal Symptom Rating Scale (GSRS) and Psychological General Well-Being (PGWB) questionnaires in 104 patients with kidney biopsy-verified IgAN and in 147 healthy controls. A person was regarded to experience 'increased GI symptoms' if the GSRS score exceeded plus 1 standard deviation of the mean of the corresponding score in the healthy controls.

RESULTS

According to the GSRS total score, the IgAN patients had more GI symptoms than the healthy controls (2.0 vs. 1.7, p < 0.001). Female IgAN patients had higher GSRS total score than male patients (2.2 vs. 1.7, p = 0.001). More IgAN patients with preserved kidney function (eGFR > 60ml/min/1.73m²) suffered from increased symptoms of diarrhoea (76 vs. 25%, p = 0.028), constipation (81 vs. 19%, p = 0.046) and reflux (85 vs. 15%, p = 0.004) than did IgAN patients with reduced kidney function (eGFR < 60ml/min/1.73m²).

CONCLUSIONS

IgAN patients and especially female IgAN patients experienced more GI symptoms than healthy controls. More prevalent GI symptoms were already observed before kidney function was clearly reduced. Systematic enquiry of GI symptoms might increase the standard of care among IgAN patients. Moreover, GI symptoms may provide clues for future studies that examine the pathophysiology of IgAN.

Microbiota and glomerulonephritis: An immunological point of view

Glomerular injury is the major cause of chronic kidney diseases (CKD) worldwide and is characterized by proteinuria. Glomerulonephritis (GN) has a wide spectrum of etiologies, the intensity of glomerular damage, histopathology, and clinical outcomes that can be associated with the landscape of the nephritogenic immune response. Beyond impaired immune responses and genetic factors, recent evidence indicates that microbiota can be contributed to the pathogenesis of GN and patients' outcomes by impacting many aspects of the innate and adaptive immune systems. It is still unknown whether dysbiosis induces GN or it is a secondary effect of the disease. Several factors such as drugs and nutritional problems can lead to dysbiosis in GN patients. It has been postulated that gut dysbiosis activates immune responses, promotes a state of systemic inflammation, and produces uremic toxins contributing to kidney tissue inflammation, apoptosis, and subsequent proteinuric nephropathy. In this review, the impact of gastrointestinal tract (GI) microbiota on the pathogenesis of the primary GN will be highlighted. The application of therapeutic interventions based on the manipulation of gut microbiota with special diets and probiotic supplementation can be effective in GN.

Trefoil factor 3: New highlights in chronic kidney disease research

Trefoil factor 3 (TFF3, also known as intestinal trefoil factor) is a small-molecule peptide containing a typical trefoil structure. TFF3 has several biological effects, such as wound healing, immune regulation, neuroprotection, and cell migration and proliferation promotion. Although TFF3 binding sites were identified in rat kidneys more than a decade ago, the specific effects of this small-molecule peptide on kidneys remain unclear. Until recently, much of the research on TFF3 in the kidney field has focused exclusively on its role as a biomarker. Notably, a large prospective randomized study of patients with 29 common clinical diseases revealed that chronic kidney disease (CKD) was associated with the highest serum TFF3 levels, which were 3-fold higher than in acute gastroenteritis, which had the second-highest levels. Examination of each stage of CKD revealed that urine and serum TFF3 levels significantly increased with the progression of CKD. These results suggest that the role of TFF3 in CKD needs further research. The present review summarizes the renal physiological expression, biological functions, and downstream signaling of TFF3, as well as the upstream events that lead to high expression of TFF3 in CKD.

Rethinking Chronic Kidney Disease in the Aging Population

The process of aging population will inevitably increase age-related comorbidities including chronic kidney disease (CKD). In light of this demographic transition, the lack of an age-adjusted CKD classification may enormously increase the number of new diagnoses of CKD in old subjects with an indolent decline in kidney function. Overdiagnosis of CKD will inevitably lead to important clinical consequences and pronounced negative effects on the health-related quality of life of these patients. Based on these data, an appropriate workup for the diagnosis of CKD is critical in reducing the burden of CKD worldwide. Optimal management of CKD should be based on prevention and reduction of risk factors associated with kidney injury. Once the diagnosis of CKD has been made, an appropriate staging of kidney disease and timely prescriptions of promising nephroprotective drugs (e.g., RAAS, SGLT-2 inhibitors, finerenone) appear crucial to slow down the progression toward end-stage kidney disease (ESKD). The management of elderly, comorbid and frail patients also opens new questions on the appropriate renal replacement therapy for this subset of the population. The non-dialytic management of CKD in old subjects with short life expectancy features as a valid option in patient-centered care programs. Considering the multiple implications of CKD for global public health, this review examines the prevalence, diagnosis and principles of treatment of kidney disease in the aging population.

Range and consistency of gastrointestinal outcomes reported in peritoneal dialysis trials: A systematic review

BACKGROUND

Gastrointestinal (GI) health is considered vital to the success of peritoneal dialysis (PD) and is critically important to patients, caregivers and clinicians. However, the multiplicity of GI outcome measures in trials undermines the ability to evaluate the frequency, impact and treatment of GI symptoms in patients receiving PD. Therefore, this study aimed to assess the range and consistency of GI outcomes reported in contemporary PD trials.

STUDY DESIGN

Systematic review.

SETTING AND POPULATION

Individuals with kidney failure requiring PD.

SELECTION CRITERIA

All randomised controlled trials involving patients on PD, identified from the PUBMED, EMBASE and COCHRANE Central Registry of controlled Trials (CENTRAL) database, from January 2010 to July 2022.

INTERVENTIONS

Any PD-related intervention.

OUTCOMES

The frequency and characteristics of GI outcome measures were analysed and classified.

RESULTS

Of the 324 eligible PD trials, GI outcomes were only reported in 61 (19%) trials, mostly as patient-reported outcomes (45 trials; 74%). The most frequently reported outcomes were nausea in 27 (43%), diarrhoea in 26 (43%), vomiting in 22 (36%), constipation in 21 (34%) and abdominal pain in 19 (31%) of trials. PD peritonitis was the primary non-GI outcome reported in 24 (40%) trials, followed by death in 13 (21%) trials) and exit-site infection in 9 (15%) trials). Across all trials, 172 GI outcome measures were extracted and grouped into 29 different outcomes. Nausea and diarrhoea contributed to 16% and 15% of GI outcomes, respectively, while vomiting, constipation and abdominal pain contributed to 13%, 12% and 12%, respectively. Most (90%) GI outcomes were patient-reported adverse effects with no defined metrics. Faecal microbiome was reported as the primary study outcome in 3 (100%) trials using the subjective global assessment score, GI symptom rating scale and faecal microbiological and biochemical analysis. Two trials reported nausea as a primary study outcome using symptom assessment score (SAS) and kidney disease quality of life-short-form-36. One trial each reported anorexia and abdominal pain as the primary study outcome using SAS. Bowel habits, constipation and stool type were also reported as the primary study outcome in one trial each using the Bristol stool form scale. GI bleeding was reported as the secondary outcome in three (37%) out of eight trials reporting it.

LIMITATIONS

Restricted sampling frame to focus on contemporary trials.

CONCLUSIONS

Despite the clinical importance of GI outcomes among patients on PD, they are reported in only 19% of PD trials, using inconsistent metrics, often as patient-reported adverse events. Efforts to standardise GI outcome reporting are critical to optimising comparability, reliability and value of trial evidence to improve outcomes for patients receiving PD.

Comparison of Gastrointestinal Symptoms between Patients Undergoing Hemodialysis and Healthy Population

Background: Patients with end-stage renal disease (ESRD) complain of many gastrointestinal (GI) problems. The goal of the current study was to compare the prevalence of GI disorders in a relatively large group of patients with ESRD with healthy participants. Methods: In a matched case-control study, 597 patients undergoing hemodialysis and 740 healthy participants were investigated. All subjects were asked to complete Rome III questionnaire, including five modules to evaluate GI disorders. The Hospital Anxiety and Depression questionnaire, as well as the 12-general health questionnaire for psychological disorders assessment, were used. Results: Our results showed that in patients undergoing hemodialysis, the prevalence of irritable bowel syndrome (IBS) (OR=1.75), gastroesophageal reflux disease (GERD) (OR=1.55), and dyspepsia (OR=3.39) was significantly higher than in healthy control participants, while no significant difference was found in terms of constipation (OR=0.88). The association remained significant for dyspepsia and IBS even after controlling for psychological disorders as important potential confounding variables. On the other hand, adjustment for psychological disorders led to an insignificant association between hemodialysis and GERD. Surprisingly a significant relationship was observed between constipation and hemodialysis after adjustment for mentioned psychological factors. Conclusion: Our results showed that there was a significant relationship between hemodialysis and some GI complaints such as IBS, dyspepsia, GERD, and bloating. Psychological disorders only influence GERD prevalence in patients undergoing hemodialysis.

Delayed gastric emptying in nondiabetic patients with end-stage kidney disease

Objective

This study aimed to assess the gastric emptying capacity in nondiabetic patients with end-stage kidney disease (ESKD) by ultrasound.

Methods

Consecutive hemodialysis patients with ESKD (n = 37) and healthy controls (n = 37) were enrolled. All ESKD patients underwent ultrasound examinations on the day of hemodialysis (dialysis day) and the day after hemodialysis (nondialysis day). Standard ultrasound examinations were performed after overnight fasting, immediately after a light meal, and at 6 h after a meal. The antral cross-sectional area and gastric emptying according to the Perlas grading system were evaluated.

Results

Compared with the controls, patients with ESKD, on both dialysis and non-dialysis days, had significantly larger antral areas when examined in the supine position (p = 0.002 and p = 0.003, respectively), but not in the right lateral decubitus position (p = 0.452 and p = 0.512, respectively). In the supine position, the antral area of ESKD patients before dialysis (8 a.m. on the dialysis day) was larger than that at the same time on the nondialysis day (p = 0.028). The controls had a Perlas grade of either 0 or 1 at 6 h after a meal, whereas five patients (13.5%) and 11 patients (29.7%) in the ESKD group had Perlas grade 2 on the dialysis and non-dialysis days, respectively. Among patients with or without delayed gastric emptying, no differences were detected in the dialysis duration or levels of biochemical markers, except blood urea nitrogen (p = 0.038) and serum creatinine (p = 0.003).

Conclusion

Nondiabetic patients with ESKD had significantly delayed gastric emptying. Hemodialysis might improve gastric emptying and reduce gastric emptying delay.

[Recent topics on interorgan communication networks and gut microbiota]

The living body is composed of diverse organ systems, each of which has its own characteristic control mechanisms and complex in vivo responses. Between the brain and organs such as the heart, kidney, liver, pancreas, gastrointestinal tract, and even muscles, there is a sophisticated and complex regulatory system. Coordinated interactions through communication between organs are essential for maintaining health. In this review, we introduce four research trends in inter-organ networks, with a focus on the digestive system: 1) Inter-organ networks on metabolic systems, 2) Inter-organ networks originating from the gastrointestinal tract, 3) Intestinal bacteria, that is one of the biggest topics in recent years, 4) Research results on the involvement of gut microbiota in the inter-organ network between the kidney and the gastrointestinal tract. An integrated understanding and investigation of the regulatory mechanisms of inter-organ communication networks are expected to extend healthy life span and improve quality of life.

Feeling gutted in chronic kidney disease (CKD): Gastrointestinal disorders and therapies to improve gastrointestinal health in individuals CKD, including those undergoing dialysis

Chronic kidney disease (CKD) affects 9.1% of the population worldwide. CKD may lead to structural and functional gastrointestinal alterations, including impairment in the intestinal barrier, digestion and absorption of nutrients, motility, and changes to the gut microbiome. These changes can lead to increased gastrointestinal symptoms in people with CKD, even in early grades of kidney dysfunction. Gastrointestinal symptoms have been associated with lower quality of life and reduced nutritional status. Therefore, there has been considerable interest in improving gastrointestinal health in this clinical population. Gastrointestinal health can be influenced by lifestyle and medications, particularly in advanced grades of kidney dysfunction. Therapies focused on gastrointestinal health have been studied, including the use of probiotics, prebiotics, and synbiotics, yielding limited and conflicting results. This review summarizes the alterations in the gastrointestinal tract structure and function and provides an overview of potential nutritional interventions that kidney disease professionals can provide to improve gastrointestinal health in individuals with CKD.

Association between renal function and co-infection with Clonorchis sinensis and Helicobacter pylori: a cross-sectional study

Background

Studies have shown that liver fluke infections may be associated with kidney injury and that Helicobacter pylori (Hp) may be involved in the pathogenesis of kidney diseases. However, no studies have reported the relationship between co-infection with Clonorchis sinensis (Cs) and Hp and renal function. The aim of this study was to examine the relationship between co-infection with Cs and Hp and estimated glomerular filtration rate (eGFR) in a general population, and gender-related differences were also investigated.

Methods

In the cross-sectional study, 4122 subjects from the Health Examination Center of Guangdong Provincial Hospital of Integrated Traditional Chinese and Western Medicine from January 2017 to December 2018 were enrolled. All participants underwent stool examination for the diagnosis of Cs infection and ¹³C-urea breath test (UBT) for the diagnosis of Hp infection. Participants were categorized into four groups: (1) co-infection with Cs and Hp group comprising 207 cases (Hp(+) + Cs(+) group), (2) Cs infection group comprising 1392 cases (Hp(−) + Cs(+)group), (3) Hp infection group comprising 275 cases (Hp(+) + Cs(−) group), and (4) non-infection group comprising 2248 cases (Hp(−) + Cs(−) group). Multiple linear regression analysis was performed to evaluate the relationship between co-infection with Cs and Hp and eGFR.

Results

Hp infection without Cs infection was present in 6.67% (275/4122) of subjects, while Cs infection without Hp infection was present in 33.77% (1392/4122) of subjects. Co-infection with Hp and Cs were present in 5.02% (207/4122) of subjects. Median age of the participants was 43 years (IQR 35–51). Most of the participants were male (2955/4122, 71.69%). Median eGFR was 96.61 ml/min/1.73 m² (IQR 85.05–106.24). Co-infection with Cs and Hp was negatively associated with eGFR after full adjusting (β = − 1.89, 95% CI: − 3.33 to − 0.45, p = 0.01). The relationship remained significant in females (β = − 9.37, 95% CI: − 11.60 to − 7.1, p < 0.001), but not in males.

Conclusion

Our findings suggest that co-infection with Cs and Hp may be associated with reduced renal function in females, but not in males.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05616-0.

Phytobezoar-induced small bowel obstruction in an elderly patient undergoing dialysis: a case report

A phytobezoar is defined as an accumulation of poorly digested fruit and vegetable fibers in the gastrointestinal tract. Phytobezoar-induced small bowel obstruction is an uncommon entity and is usually removed surgically. We herein describe an elderly man undergoing dialysis who developed a phytobezoar because of excessive consumption of high-fiber fruits and inappropriate chewing. His potential predisposing factors were dialysis-related lifestyle changes, reduced activity levels, fluid restriction, and gastrointestinal motility dysfunction; however, he had no history of gastric surgery. The patient’s clinical history and characteristic imaging features aided in the diagnosis. He underwent medical treatment, and his recovery was uneventful. This case highlights the importance of an awareness of phytobezoar-induced small bowel obstruction in patients at increased risk of developing bezoars and demonstrates that this condition can occur in the absence of previous gastric surgery. We believe that elderly patients undergoing dialysis are at increased risk of developing bezoars. Excessive consumption of a strictly fibrous diet and insufficient chewing exacerbate the risk. A detailed dietary history and imaging features can aid in early diagnosis, leading to appropriate medical or surgical care. Surgical treatment is not inevitable in all cases. Individualized dietary suggestions in these patients are important for effective preventive control.

Laxative use in patients with advanced chronic kidney disease transitioning to dialysis

BACKGROUND

Constipation is highly prevalent in patients with chronic kidney disease (CKD), particularly among those with end-stage renal disease (ESRD), partly due to their dietary restrictions, comorbidities and medications. Laxatives are typically used for constipation management; however, little is known about laxative use and its associated factors in patients with advanced CKD transitioning to ESRD.

METHODS

In a retrospective cohort of 102 477 US veterans transitioning to dialysis between October 2007 and March 2015, we examined the proportion of patients who filled a prescription for any type of laxative within each 6-month period over 36 months pre- and post-transition to ESRD. Factors associated with laxative use during the last 1-year pre-ESRD period were identified by multivariable logistic regression.

RESULTS

The proportion of patients prescribed laxatives increased as patients progressed to ESRD, peaking at 37.1% in the 6 months immediately following ESRD transition, then remaining fairly stable throughout the post-ESRD transition period. Among laxative users, stool softeners were the most commonly prescribed (∼30%), followed by hyperosmotics (∼20%), stimulants (∼10%), bulk formers (∼3%), chloride channel activator (<1%) and several combinations of these. The use of anticoagulants, oral iron supplements, non-opioid analgesics, antihistamines and opioid analgesics were among the factors independently associated with pre-ESRD laxative use.

CONCLUSION

The use of laxatives increased considerably as patients neared transition to ESRD, likely mirroring the increasing burden of drug-induced constipation during the ESRD transition period. Findings may provide novel insight into better management strategies to alleviate constipation symptoms and reduce medication requirements in patients with advanced CKD.

Laxative Use and Change in Estimated Glomerular Filtration Rate in Patients With Advanced Chronic Kidney Disease

OBJECTIVES

Constipation is highly prevalent in advanced chronic kidney disease (CKD), due in part to dietary (e.g., fiber) restrictions, and is often managed by laxatives; however, the effect of laxative use on kidney function in advanced CKD remains unclear. We aimed to examine the association of laxative use with longitudinal change in estimated glomerular filtration rate (eGFR) in patients with advanced CKD.

DESIGN AND METHODS

In a retrospective cohort of 43,622 US veterans transitioning to end-stage renal disease (ESRD) from 2007 to 2015, we estimated changes in eGFR (slope) by linear mixed-effects models using ≥2 available outpatient eGFR measurements during the 2-year period before transition to ESRD. The association of laxative use with change in eGFR was examined by testing the interaction of time-varying laxative use with time for eGFR slope in the mixed-effects models with adjustment for fixed and time-varying confounders.

RESULTS

Laxatives were prescribed in 49.8% of patients during the last 2-year pre-ESRD period. In the crude model, time-varying laxative use was modestly associated with more progressive eGFR decline compared with non-use of laxatives (median [interquartile interval] -7.1 [-11.9, -4.3] vs. -6.8 [-11.6, -4.0] mL/min/1.73 m²/year, P < .001). After multivariable adjustment, a faster eGFR decline associated with laxative use (vs. non-use of laxatives) remained statistically significant, although the between-group difference in eGFR slope was minimal (median [interquartile interval] -8.8 [-12.9, -5.9] vs. -8.6 [-12.6, -5.6] mL/min/1.73 m²/year, P < .001). The significant association was no longer evident across different types of laxatives (i.e., stool softeners, stimulants, or hyperosmotics).

CONCLUSIONS

There was a clinically negligible association of laxative use with change in eGFR during the last 2-year pre-ESRD period, suggesting the renal safety profile of laxatives in advanced CKD patients.

Influence of bowel habits on gut-derived toxins in peritoneal dialysis patients

BACKGROUND

Gut-derived uremic toxins have been associated with adverse outcomes in chronic kidney disease (CKD). Alterations in bowel habits, including constipation, seem to play an additional role in uremic toxicity. The aim of this study is to investigate the association of bowel habits with gut-derived uremic toxins and intestinal permeability in patients on automated peritoneal dialysis (APD).

METHODS

This cross-sectional study enrolled 58 APD patients (age 52.5 ± 15.1 years; dialysis vintage 14.1 (6.0-36.5) months). Constipation was defined according to the Rome IV criteria. Bowel habits were assessed by the Bristol Stool Scale (BSS < 3 characterized by hard consistency of stools and/or low frequency of evacuation, a surrogate of slow intestinal transit time, and BSS ≥ 3, defining regular bowel habit). The total and free serum concentration of p-cresyl sulfate (PCS), indoxyl sulfate (IS) and indole-3-acetic acid (IAA) were dosed by high-performance liquid chromatography. Lipopolysaccharide (LPS) and zonulin were assessed by ELISA and D(-)-lactate by colorimetric method. Dietary intake was assessed by the 3-day food records.

RESULTS

No differences were observed in clinical, demographic, and dietary characteristics between constipated (n = 30) and non-constipated (n = 28) groups. A trend for higher total PCS (p = 0.07) and free PCS (p = 0.06) was found in constipated patients. Patients with BSS < 3 (n = 11) exhibited significantly higher levels of total and free PCS (p < 0.01) and total IAA (p = 0.04). Conversely, No difference was found in IS levels. Except for a lower serum level of D(-)-lactate in patients with BSS < 3 (p = 0.01), zonulin and LPS levels were not different.

CONCLUSIONS

Disturbed bowel habits, mainly characterized by slow transit time, may play a role in the accumulation of uremic toxins, particularly PCS, in patients on automatized peritoneal dialysis.

Prevalence, short term outcome and factors associated with survival in patients suffering from upper gastrointestinal bleeding in a resource limited-setting, the case of Mulago hospital in Kampala, Uganda

BACKGROUND

Upper gastrointestinal bleeding (UGIB) is a common cause of admission and death in the gastroenterology service. The prevalence, risk factors and the case fatality rate of UGIB may differ by settings.

OBJECTIVES

Our objective was to determine the prevalence of symptoms and the case fatality rate of UGIB among patients at the gastroenterology service of Mulago Hospital in Kampala, Uganda and to describe the clinical and laboratory risk factors associated with the survival of these patients.

METHODS

In a cross-sectional study performed between September 2013 and April 2014, patients were screened for UGIB symptoms. Data was collected on socio-demographic characteristics, clinical presentation and patient's outcome within one week of admission. Bivariate, multivariate, and survival analysis were performed to identify variables that were significantly associated with mortality.

RESULTS

Out of 1085 patients screened, we identified the prevalence of UGIB symptoms in 220 patients (20.3%). Among these, 150 met the inclusion criteria for our study. The majority were males (70.7%) and 40 years of age or less (60%). The most prevalent clinical diagnosis were gastritis (39.3%), esophageal varices (17.3%) and peptic ulcer disease (PUD) (16%). Among patients who underwent endoscopy, esophageal varices (42.2%), PUD (26.3%) and gastritis (15.8%) were the leading causes of bleeding. The overall case fatality rate was 16.7% (25/150). Uremia remained associated with mortality after controlling for confounders.Survival was significantly reduced for males as well as for patients with uremia and malignancy.

CONCLUSION

the prevalence of symptoms and the case fatality rate of UGIB among patients admitted to the gastroenterology ward in Mulago hospital were higher than in developed countries and similar to other resource-limited setting. The majority of patients were young men and presented with both hematemesis and melena. The most common causes of UGIB were esophageal varices, gastritis and PUD. Survival analysis indicate that male gender, uremia, and malignancy are associated with reduced survival.

Particular aspects of gastroenterological disorders in chronic kidney disease and end-stage renal disease patients: a clinically focused review

Besides renal disease, gastrointestinal (GI) disorders are frequently reported in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Related gastrointestinal symptoms tend to increase as the renal disease progresses. Also, in patients with ESRD, the modality of dialysis is related to particular forms of GI disorders.The kidney can interact with the digestive organs through functional endogenous systems such as the 'kidney-colon axis' and the 'kidney-liver axis'. Digestive diseases are one of the visible manifestations of the disturbance between hemostatic, hemodynamic and immunological balance in such patients.No clear management guidelines currently exist for many of the gastrointestinal problems that accompany renal failure. This review aims to describe the particular aspects of GI diseases present in CKD/ESRD. We focus our discussion in the specificities of epidemiology, diagnosis, and prognosis of such disorders between the different segments of the digestive system.

Constipation in CKD

Constipation is one of the most common gastrointestinal disorders among patients with chronic kidney disease (CKD) partly because of their sedentary lifestyle, low fiber and fluid intake, concomitant medications (e.g., phosphate binders), and multiple comorbidities (e.g., diabetes). Although constipation is usually perceived as a benign, often self-limited condition, recent evidence has challenged this most common perception of constipation. The chronic symptoms of constipation negatively affect patients' quality of life and impose a considerable social and economic burden. Furthermore, recent epidemiological studies have revealed that constipation is independently associated with adverse clinical outcomes, such as end-stage renal disease (ESRD), cardiovascular (CV) disease, and mortality, potentially mediated by the alteration of gut microbiota and the increased production of fecal metabolites. Given the importance of the gut in the disposal of uremic toxins and in acid-base and mineral homeostasis with declining kidney function, the presence of constipation in CKD may limit or even preclude these ancillary gastrointestinal roles, potentially contributing to excess morbidity and mortality. With the advent of new drug classes for constipation, some of which showing unique renoprotective properties, the adequate management of constipation in CKD may provide additional therapeutic benefits beyond its conventional defecation control. Nevertheless, the problem of constipation in CKD has long been underrecognized and its management strategies have scarcely been documented. This review outlines the current understanding of the diagnosis, prevalence, etiology, outcome, and treatment of constipation in CKD, and aims to discuss its novel clinical and therapeutic implications.

Phosphate Binders and Nonphosphate Effects in the Gastrointestinal Tract

Phosphate binders are commonly prescribed in patients with end-stage kidney disease to prevent and treat hyperphosphatemia. These binders are usually associated with gastrointestinal distress, may bind molecules other than phosphate, and may alter the gut microbiota, altogether having systemic effects unrelated to phosphate control. Sevelamer is the most studied of the available binders for nonphosphate-related effects including binding to bile acids, endotoxins, gut microbiota-derived metabolites, and advanced glycation end products. Other binders (calcium- and noncalcium-based binders) may bind vitamins, such as vitamin K and folic acid. Moreover, the relatively new iron-based phosphate binders may alter the gut microbiota, as some of the iron or organic ligands may be used by the gastrointestinal bacteria. The objective of this narrative review is to provide the current evidence for the nonphosphate effects of phosphate binders on gastrointestinal function, nutrient and molecule binding, and the gut microbiome.

Upper Gastrointestinal Manifestation of Bezoars and the Etiological Factors: A Literature Review

A gastric bezoar is a compact mass of indigestible foreign materials that accumulate and consolidate in the stomach; however, it can be found in other sites of the gastrointestinal tract. The causative manner of this condition is complex and multifactorial. The main purpose of the review was to raise awareness among clinicians, particularly gastroenterologists, that patients with certain risk factors or comorbid conditions are predisposed to gastric bezoar formation. Early diagnosis and prompt intervention are crucial to avoid bezoar-induced complications. Upper gastrointestinal endoscopy is the standard diagnostic and therapeutic method for gastric bezoars. However, for large size bezoars, surgical intervention is needed.

Association between duration of dialysis and Helicobacter pylori infection in dialysis patients: a meta-analysis

PURPOSE

The association between Helicobacter pylori (HP) infection and duration of dialysis in dialysis patients is conflicting, this meta-analysis was conducted to elucidate the association between duration of dialysis and HP infection status in dialysis patients, and subgroup study was conducted to explore its influencing factors. Furthermore, our study aims to provide advice on the treatment of dialysis patients.

METHODS

Articles published up to 30 September 2018 were searched from PubMed, Embase, Sinomed, Medline, China Knowledge Resource Integrated Database (CNKI) and Wang fang database. Two researchers independently identified whether studies met the eligibility criteria. The adjusted relative risk (RR) or the weighted mean difference (WMD) and their 95% CI were estimated. I² was performed to evaluate the statistical heterogeneity. Publication bias was evaluated using Egger's test and a funnel plot.

RESULTS

Fourteen studies were included involving 2087 dialysis patients, 815 of them were HP positive, 1272 of them were HP negative. Quantitative data and qualitative data were analyzed, respectively. For quantitative data, statistical differences were observed in the association between HP infection and duration of dialysis (P = 0.008), also in the hemodialysis subgroup (P = 0.006). After stratifying by detection methods, differences still existed in groups with different detection methods (P = 0.001, P = 0.033). For qualitative data, there was no statistical difference in the association between HP infection rate and duration of dialysis (P = 0.295). Furthermore, we found that the age was higher in HP positive patients than in HP negative patients (P < 0.001).

CONCLUSION

Our meta-analysis found that HP infection rate was negatively correlated with accumulative dialysis time, and methods of HP detection did not influence the association between HP infection and accumulative dialysis time. We also found that age was the risk factor of HP infection in dialysis patients. Further studies need to be performed to elucidate the mechanism of the correlation between HP infection and duration of dialysis, to explore which timing period of dialysis is most susceptible to HP infection, then, improve the prognosis of patients with renal diseases.

Use of gastric-acid suppressants may be a risk factor for enteric peritonitis in patients undergoing peritoneal dialysis: A meta-analysis

WHAT IS KNOWN AND OBJECTIVE

Mounting evidence suggests that long-term use of gastric-acid suppressants (GASs) may be associated with adverse effects. Whether GAS use increases the risk of enteric peritonitis in patients undergoing peritoneal dialysis (PD) is not known. The aim of this meta-analysis was to evaluate the association between GAS use and enteric peritonitis in PD patients.

METHODS

We searched PubMed, Embase and Cochrane Library databases from inception to 23 January 2018 to identify eligible studies. The primary outcome was an association between GAS use and enteric peritonitis in PD patients.

RESULTS AND DISCUSSION

Six studies involving 829 people were included in this meta-analysis. Pooled data showed that GAS use in PD patients was associated with an increased risk of enteric peritonitis (odds ratio [OR] = 1.27; 95% confidence interval [CI]: 1.02-1.57, I²  = 48%). Subgroup analyses based on GAS type revealed that histamine-2 receptor antagonists (H₂ RAs) might increase the risk of enteric peritonitis in PD patients (OR = 1.40; 95% CI: 1.01-1.93; I²  = 8%), but proton pump inhibitors (PPIs) might not (1.13; 0.72-1.77; 6; 34%).

WHAT IS NEW AND CONCLUSION

Gastric-acid suppressants use might be a risk factor for enteric peritonitis in PD patients. In particular, H₂ RAs increased the risk of enteric peritonitis, but PPIs did not. Therefore, to prevent enteric peritonitis, H₂ RAs should probably be prescribed with caution for PD patients.

Psychosocial consequences of gastrointestinal symptoms and dietary changes in people receiving automated peritoneal dialysis

BACKGROUND

Gastrointestinal (GI) symptoms are associated with poor psychosocial wellbeing among people receiving peritoneal dialysis (PD). The mind-gut axis represents one possible explanatory mechanism for this relationship. Despite existing evidence, the individual's experience of GI symptoms and their potential psychosocial consequences have not been explored.

OBJECTIVE

To understand the experiences of people receiving peritoneal dialysis regarding their gastrointestinal health and psychosocial wellbeing.

METHOD

Ten people undergoing automated PD (five females, five males) aged 31-77 years (Mean = 59.3, SD = 15.67) participated in a single one-on-one qualitative interview. Interviews ceased at thematic saturation. Transcripts were analysed using the framework approach.

RESULTS

A central theme of Autonomy emerged from the data representing participants' experiences of the psychosocial consequences of dialysis, GI symptoms, and dietary changes. This overarched two main themes: 1) Loss of Autonomy [Sub-themes: Interference to Daily Life (Dialysis process and sleep, Impacts on relationships), Powerlessness, Frustration, Food Aversion, and Restriction (Friendships and social life, Impacts on partner)] and 2) Attempts to Gain Autonomy (Sub-themes: Coping Well, Pragmatism, and Maintaining Normality). A related sub-theme of Partner as a Carer emerged as part of Loss of Autonomy.

CONCLUSION

GI symptoms and diet and fluid restrictions have psychosocial consequences resulting in multiple losses of autonomy for people receiving PD, who employ strategies to attempt to regain autonomy in the face of these issues. Dietary and GI symptom management advice should aim to enhance patient autonomy within the confines of PD therapy and thus reduce its psychosocial impacts.

Chronic kidney disease after 5/6 nephrectomy disturbs the intestinal microbiota and alters intestinal motility

Organ-organ crosstalk is involved in homeostasis. Gastrointestinal symptoms are common in patients with renal failure. The aim of this study was to elucidate the relationship between gastrointestinal motility and gastrointestinal symptoms in chronic kidney disease. We performed studies in C57BL/6 mice with chronic kidney disease after 5/6 nephrectomy. Gastrointestinal motility was evaluated by assessing the ex vivo responses of ileum and distal colon strips to electrical field stimulation. Feces were collected from mice, and the composition of the gut microbiota was analyzed using 16S ribosomal RNA sequencing. Mice with chronic kidney disease after 5/6 nephrectomy showed a decreased amount of stool, and this constipation was correlated with a suppressed contraction response in ileum motility and decreased relaxation response in distal colon motility. Spermine, one of the uremic toxins, inhibited the contraction response in ileum motility, but four types of uremic toxins showed no effect on the relaxation response in distal colon motility. The 5/6 nephrectomy procedure disturbed the balance of the gut microbiota in the mice. The motility dysregulation and constipation were resolved by antibiotic treatments. The expression levels of interleukin 6, tumor necrosis factor-α, and iNOS in 5/6 nephrectomy mice were increased in the distal colon but not in the ileum. In addition, macrophage infiltration in 5/6 nephrectomy mice was increased in the distal colon but not in the ileum. We found that 5/6 nephrectomy altered gastrointestinal motility and caused constipation by changing the gut microbiota and causing colonic inflammation. These findings indicate that renal failure was remarkably associated with gastrointestinal dysregulation.

Dyspepsia Amongst End Stage Renal Disease Undergoing Hemodialysis: Views from a Large Tertiary Care Center

Background and Objectives

Gastrointestinal symptoms are common in patients with end stage renal disease (ESRD) among which dyspepsia is frequently observed. The aim of the study was to determine the frequency and associations of dyspepsia in ESRD patients using the Leeds questionnaire.

Methods

All ESRD patients on maintenance hemodialysis were consecutively enrolled in the study. Leeds questionnaire was used to interrogate the patients for the assessment of dyspepsia. Mean and standard deviation were calculated for age, body mass index (BMI), disease duration and number of hemodialysis sessions. Independent t-test and Chi square tests were used for statistical analysis.

Results

Total number of patients was 200, out which 118 (59.3%) were male. The mean age was of 41.4 years. According to the Leeds questionnaire, dyspepsia was present in 62 (63.9%) patients. Younger patients (age 20–40 years) more frequently had dyspeptic symptoms (61.5% patients), retrosternal pain (156 patients, 78.0%), regurgitation (127 patients, 63.5%), dysphagia (67 patients, 33.5%), and nausea (142 patients, 71.0%). Patients presented with intermittent pattern of symptoms in 179 (89.5%) cases, while continuous symptoms in 6 (3.0%). Dyspepsia was associated with aspartate aminotransferase (AST) levels > 25 U/L (P = 0.001), alanine aminotransferase (ALT) levels > 28U/L (P = 0.000) and gamma glutamyl transferase (GGT) levels > 34 U/L (P = 0.002). On multivariate analysis, urea, creatinine, and presenting symptoms of dysphagia and belching showed significant statistical association with dyspepsia.

Conclusion

Dyspepsia is a common problem affecting patients with end stage renal disease and is associated with raised serum AST, ALT and GGT in such patients.

Relationship between Nutritional Status and Gastrointestinal Symptoms in Geriatric Patients with End-Stage Renal Disease on Dialysis

Gastrointestinal symptoms (GIS) are common in patients with end-stage renal disease (ESRD) and are associated with nutritional risks resulting from low food intake. Little is known about the relationship between GIS and malnutrition in geriatric patients with ESRD. The main objective of this study was to determine the relationship between nutritional status and severity of GIS in geriatric patients on dialysis therapy. Clinically-stable geriatric patients (older than 60 years old) who were dialysis outpatients were included in this cross-sectional study. The severity of GIS was assessed using the Gastrointestinal Symptoms Questionnaire (GSQ, short version), with patients classified into three groups: mild, moderate, and severe. Nutritional status was evaluated with the Malnutrition Inflammation Score (MIS), anthropometric assessment, biochemical parameters, and bioelectrical impedance. Descriptive statistics were used and differences between groups were analyzed with ANOVA and Kruskal Wallis, with a p < 0.05 considered to indicate significance. Fifty patients completed the study; the median age was 67 years old. Twenty-three patients were on hemodialysis (HD) and 27 were on peritoneal dialysis (PD). No significant differences were found according to dialysis modality, presence of diabetes, or gender. Ninety percent of patients had at least one GIS. Poorer nutritional status (evaluated by MIS) was related to a higher severity of GIS. There were no significant differences with other nutritional parameters. Our study showed a high prevalence of GIS in geriatric patients. There were no differences in observed GIS values that were attributed to dialysis modality, gender, or presence of type 2 diabetes mellitus (DM2). Severe GIS values were associated with poorer nutritional status determined by MIS, however, there was no association with anthropometry, biochemical values, or bioimpedance vector analysis.

Personalizing protein nourishment

Proteins are not equally digestible-their proteolytic susceptibility varies by their source and processing method. Incomplete digestion increases colonic microbial protein fermentation (putrefaction), which produces toxic metabolites that can induce inflammation in vitro and have been associated with inflammation in vivo. Individual humans differ in protein digestive capacity based on phenotypes, particularly disease states. To avoid putrefaction-induced intestinal inflammation, protein sources, and processing methods must be tailored to the consumer's digestive capacity. This review explores how food processing techniques alter protein digestibility and examines how physiological conditions alter digestive capacity. Possible solutions to improving digestive function or matching low digestive capacity with more digestible protein sources are explored. Beyond the ileal digestibility measurements of protein digestibility, less invasive, quicker and cheaper techniques for monitoring the extent of protein digestion and fermentation are needed to personalize protein nourishment. Biomarkers of protein digestive capacity and efficiency can be identified with the toolsets of peptidomics, metabolomics, microbial sequencing and multiplexed protein analysis of fecal and urine samples. By monitoring individual protein digestive function, the protein component of diets can be tailored via protein source and processing selection to match individual needs to minimize colonic putrefaction and, thus, optimize gut health.

Constipation and Incident CKD

Constipation is one of the most prevalent conditions in primary care settings and increases the risk of cardiovascular disease, potentially through processes mediated by altered gut microbiota. However, little is known about the association of constipation with CKD. In a nationwide cohort of 3,504,732 United States veterans with an eGFR ≥60 ml/min per 1.73 m², we examined the association of constipation status and severity (absent, mild, or moderate/severe), defined using diagnostic codes and laxative use, with incident CKD, incident ESRD, and change in eGFR in Cox models (for time-to-event analyses) and multinomial logistic regression models (for change in eGFR). Among patients, the mean (SD) age was 60.0 (14.1) years old; 93.2% of patients were men, and 24.7% were diabetic. After multivariable adjustments, compared with patients without constipation, patients with constipation had higher incidence rates of CKD (hazard ratio, 1.13; 95% confidence interval [95% CI], 1.11 to 1.14) and ESRD (hazard ratio, 1.09; 95% CI, 1.01 to 1.18) and faster eGFR decline (multinomial odds ratios for eGFR slope <-10, -10 to <-5, and -5 to <-1 versus -1 to <0 ml/min per 1.73 m² per year, 1.17; 95% CI, 1.14 to 1.20; 1.07; 95% CI, 1.04 to 1.09; and 1.01; 95% CI, 1.00 to 1.03, respectively). More severe constipation associated with an incrementally higher risk for each renal outcome. In conclusion, constipation status and severity associate with higher risk of incident CKD and ESRD and with progressive eGFR decline, independent of known risk factors. Further studies should elucidate the underlying mechanisms.

Evaluation of scoring models for identifying the need for therapeutic intervention of upper gastrointestinal bleeding: A new prediction score model for Japanese patients

BACKGROUND AND AIM

Multiple scoring systems have been developed to predict outcomes in patients with upper gastrointestinal bleeding. We determined how well these and a newly established scoring model predict the need for therapeutic intervention, excluding transfusion, in Japanese patients with upper gastrointestinal bleeding.

METHODS

We reviewed data from 212 consecutive patients with upper gastrointestinal bleeding. Patients requiring endoscopic intervention, operation, or interventional radiology were allocated to the therapeutic intervention group. Firstly, we compared areas under the curve for the Glasgow-Blatchford, Clinical Rockall, and AIMS65 scores. Secondly, the scores and factors likely associated with upper gastrointestinal bleeding were analyzed with a logistic regression analysis to form a new scoring model. Thirdly, the new model and the existing model were investigated to evaluate their usefulness.

RESULTS

Therapeutic intervention was required in 109 patients (51.4%). The Glasgow-Blatchford score was superior to both the Clinical Rockall and AIMS65 scores for predicting therapeutic intervention need (area under the curve, 0.75 [95% confidence interval, 0.69-0.81] vs 0.53 [0.46-0.61] and 0.52 [0.44-0.60], respectively). Multivariate logistic regression analysis retained seven significant predictors in the model: systolic blood pressure <100 mmHg, syncope, hematemesis, hemoglobin <10 g/dL, blood urea nitrogen ≥22.4 mg/dL, estimated glomerular filtration rate ≤ 60 mL/min per 1.73 m² , and antiplatelet medication. Based on these variables, we established a new scoring model with superior discrimination to those of existing scoring systems (area under the curve, 0.85 [0.80-0.90]).

CONCLUSION

We developed a superior scoring model for identifying therapeutic intervention need in Japanese patients with upper gastrointestinal bleeding.

Inhibition of Gastric Acid Secretion by H2 Receptor Antagonists Associates a Definite Risk of Enteric Peritonitis and Infectious Mortality in Patients Treated with Peritoneal Dialysis

BACKGROUND

Evidences linking treatment with inhibitors of gastric acid secretion (IGAS) and an increased risk of serious infections are inconclusive, both in the population at large and in the particular case of patients with chronic kidney disease. We have undertaken an investigation to disclose associations between treatment with IGAS and infectious outcomes, in patients undergoing chronic Peritoneal Dialysis (PD).

METHOD

Observational, historic cohort, single center design. Six hundred and ninety-one patients incident on PD were scrutinized for an association among treatment with IGAS (H2 antagonists H2A or proton pump inhibitors PPI) (main study variable), on one side, and the risks of enteric peritoneal infection (main outcome), overall peritoneal infection, and general and infectious mortality (secondary outcomes). We applied a three-step multivariate approach, based on classic Cox models (baseline variables), time-dependent analyses and, when appropriate, competing risk analyses.

MAIN RESULTS

The clinical characteristics of patients treated with H2A, PPI or none of these were significantly different. Multivariate analyses disclosed a consistently increased risk of enteric peritonitis in patients treated with IGAS (RR 1.65, 95% CI 1.08-2.55, p = 0.018, Cox). Stratified analysis indicated that patients treated with H2A, rather than those on PPI, supported the burden of this risk. Similar findings applied for the risk of infectious mortality. On the contrary, we were not able to detect any association among the study variables, on one side, and the general risks of peritonitis or mortality, on the other.

CONCLUSIONS

Treatment with IGAS associates increased incidences of enteric peritonitis and infectious mortality, among patients on chronic PD. The association is clear in the case of H2A but less consistent in the case of PPI. Our results support the convenience of preferring PPI to H2A, for gastric acid inhibition in PD patients.

Diagnostic utility of immunochemical fecal occult blood tests to detect lower gastrointestinal lesions in patients with chronic kidney disease

PURPOSE

The immunochemical fecal occult blood test (iFOBT) is a useful method to screen for lower gastrointestinal (GI) bleeding-related lesions. However, few studies have investigated the diagnostic utility of iFOBT in chronic kidney disease (CKD).

METHODS

We included 691 patients with nondialysis-dependent CKD stages 2-5 or those receiving dialysis. Bleeding-related lower GI lesions were identified by colonoscopy, and the diagnostic utility of iFOBT was evaluated.

RESULTS

Bleeding-related lower GI lesions were found in 9.2% of 491 patients with CKD stage 2, 17.8% of 107 patients with CKD stage 3/4, and 25.8% of 93 patients with CKD stage 5/dialysis (p < 0.001). Compared with CKD stage 2, CKD stage 5/dialysis was independently associated with a 2.80-fold risk for bleeding-related lesions (p = 0.019). The iFOBT was positive in 92 (13.3%) patients and the area under the receiver operating curve (AUC) for a bleeding-related lesion was 0.64 (p < 0.001). The sensitivity of iFOBT increased as the CKD stage worsened (20.0 vs 52.6 vs 58.3%; p = 0.002). However, the specificity to detect bleeding-related lesions decreased with the severity of CKD stage (94.6 vs. 78.4 vs. 76.8%; p < 0.001). The AUC of iFOBT to detect adenoma or carcinoma was 0.54 (p = 0.046), and a similar pattern of sensitivity and specificity was observed between different CKD stages.

CONCLUSIONS

The prevalence of bleeding-related lower GI lesions and the sensitivity of iFOBT to detect these GI lesions increased in advanced CKD. However, iFOBT should be used cautiously in these patients because its specificity decreased.

The short-term effects of olive oil and flaxseed oil for the treatment of constipation in hemodialysis patients

OBJECTIVES

To evaluate the effects of olive oil and flaxseed oil compared with mineral oil for the treatment of constipation in patients undergoing hemodialysis.

METHODS

A 4-week, double-blind, randomized, and controlled trial was conducted. Fifty constipated patients (29% male, 51 ± 12 years) diagnosed by the Rome III criteria were randomly assigned to receive mineral oil (control group; n = 17), olive oil (n = 16), or flaxseed oil (n = 17). The initial oil dose was 4 mL/day, and adjustments during the follow-up could be made as needed. The impact of the intervention was assessed by the Rome III criteria scores.

RESULTS

The most frequent symptoms of constipation evaluated by the Roma III criteria at baseline were comparable among the groups and included "incomplete evacuation" (92%), "lumpy or hard stools," (72%) and "anorectal obstruction" (70%). The Rome III score improved significantly in patients receiving mineral oil (10.5 ± 5.0 to 4.1 ± 4.0; P < .01), olive oil (10.3 ± 4.2 to 3.2 ± 3.8; P = .01), and flaxseed oil (9.6 ± 4.2 to 6.0 ± 5.1; P < .01), with no significant group-by-time interaction (P = .15). The scores of 5 from 6 constipation symptoms reduced similarly in the mineral oil and olive oil groups, whereas only the frequency of evacuation and the consistency of stools improved in the flaxseed oil group.

CONCLUSIONS

We demonstrated that the daily use of olive oil or flaxseed oil was as effective as mineral oil in the treatment of constipation in patients undergoing hemodialysis.

Dyspepsia and gastric emptying in end-stage renal disease patients on hemodialysis

Background

Dyspepsia is common among end-stage renal disease (ESRD) patients and its association with delayed gastric emptying is not well established. We assessed the association of dyspepsia with gastric emptying time in ESRD patients undergoing hemodialysis (HD).

Methods

Dyspepsia was assessed through the Porto Alegre Dyspeptic Symptoms Questionnaire (PADYQ). PADYQ’s scores ≥ 6 classified participants as dyspeptic. The octanoic acid breath test using ¹³carbon was employed to assess the gastric emptying time. Based on the test, time in minutes to metabolize the first half of the ¹³carbon in the test meal (t1/2) was calculated. Association of dyspepsia with gastric emptying time was tested by the correlation between PADYQ scores and t1/2, and also by comparing t1/2 between dyspeptics and non-dyspeptics.

Results

There were 34 (68.0%) dyspeptic patients. Dyspepsia score was positively correlated with t1/2 (r = 0.366; p = 0.009). Dyspeptics had longer t1/2 compared to non-dyspeptics, respectively, 238.0 ± 92.9 versus 185.5 ± 45.5 minutes (p = 0.042).

Conclusions

Delayed gastric emptying was associated with dyspepsia. Prokinetic medications could have a role in preventing or relieving dyspeptic symptoms among HD patients. Future research in larger samples is necessary to confirm this association.

Persistent gastric colonization with Burkholderia pseudomallei and dissemination from the gastrointestinal tract following mucosal inoculation of mice

Melioidosis is a disease of humans caused by opportunistic infection with the soil and water bacterium Burkholderia pseudomallei. Melioidosis can manifest as an acute, overwhelming infection or as a chronic, recurrent infection. At present, it is not clear where B. pseudomallei resides in the mammalian host during the chronic, recurrent phase of infection. To address this question, we developed a mouse low-dose mucosal challenge model of chronic B. pseudomallei infection and investigated sites of bacterial persistence over 60 days. Sensitive culture techniques and selective media were used to quantitate bacterial burden in major organs, including the gastrointestinal (GI) tract. We found that the GI tract was the primary site of bacterial persistence during the chronic infection phase, and was the only site from which the organism could be consistently cultured during a 60-day infection period. The organism could be repeatedly recovered from all levels of the GI tract, and chronic infection was accompanied by sustained low-level fecal shedding. The stomach was identified as the primary site of GI colonization as determined by fluorescent in situ hybridization. Organisms in the stomach were associated with the gastric mucosal surface, and the propensity to colonize the gastric mucosa was observed with 4 different B. pseudomallei isolates. In contrast, B. pseudomallei organisms were present at low numbers within luminal contents in the small and large intestine and cecum relative to the stomach. Notably, inflammatory lesions were not detected in any GI tissue examined in chronically-infected mice. Only low-dose oral or intranasal inoculation led to GI colonization and development of chronic infection of the spleen and liver. Thus, we concluded that in a mouse model of melioidosis B. pseudomallei preferentially colonizes the stomach following oral inoculation, and that the chronically colonized GI tract likely serves as a reservoir for dissemination of infection to extra-intestinal sites.

Decisive indicator for gastrointestinal workup in anemic patients with nondialysis chronic kidney disease

BACKGROUND

Anemia and iron deficiency are universal problems in patients with chronic kidney disease (CKD). However, decisive indicator to guide the further gastrointestinal (GI) workup has not been determined.

METHODS

We included 104 anemic patients with nondialysis-dependent CKD stages 3-5 (38 patients at stage 3, 26 patients at stage 4, and 40 patients at stage 5). Hemoglobin, serum ferritin, transferrin saturation (TSAT), mean corpuscular volume (MCV), and corrected reticulocyte count data were assessed to evaluate diagnostic utility for bleeding-related GI lesions, which were identified by esophagogastroduodenoscopy and colonoscopy.

RESULTS

Bleeding-related GI lesions were found in 55 (52.9%) patients, and patients with stage 5 CKD had a higher prevalence of gastric lesions than patients with CKD stage 3 or 4 (all p < 0.05). The areas under the receiver operating characteristic curves used to predict bleeding-related lesions were 0.69 for TSAT (p = 0.002) and 0.61 for serum ferritin (p = 0.085). The sensitivity and specificity of a cutoff value for TSAT < 20% were 0.59 and 0.74, respectively. Hemoglobin, MCV, and corrected reticulocyte levels had no significant diagnostic utility. On multivariable logistic regression, the chance of GI lesions increased by 6% for each 1% reduction in TSAT and increased 4.1-fold for patients with CKD stage 5 (all p < 0.05).

CONCLUSIONS

TSAT is a useful indicator for determining the GI workup in anemic patients with nondialysis-dependent CKD stages 3-5. Stage 5 CKD is independently associated with bleeding-related lesions and TSAT should be used cautiously in these patients.

Anemia of renal disease: what it is, what to do and what's new

PATIENT GROUP

It is estimated that 15-30% of geriatric cats will develop chronic kidney disease (CKD), and that 30-65% of these cats will develop anemia as their renal disease worsens. Anemia of renal disease is multifactorial in its pathogenesis, but the main cause is reduced production of erythropoietin, a renal hormone that controls the bone marrow's production of red blood cells, as kidney disease progresses.

PRACTICAL RELEVANCE

It is important to recognize the presence of anemia of renal disease so that adequate treatment may be instituted to improve quality of life and metabolic function. Erythrocyte-stimulating agents (ESAs), such as epoetin alfa, epoetin beta and darbepoetin alfa, have been developed to counteract the effects of decreased erythropoietin production by the kidneys. These treatments, which are the focus of this review, have 83% similarity in amino acid sequence to the feline hormone. On average, the target packed cell volume (>25%) is reached within 3-4 weeks of ESA therapy.

CLINICAL CHALLENGES

The use of ESAs has been associated with a number of complications, such as iron deficiency, hypertension, arthralgia, fever, seizures, polycythemia and pure red cell aplasia (PRCA). Darbepoetin has a prolonged half-life compared with epoetin and thus can be given only once a week, instead of three times a week. The incidence of PRCA appears to be decreased with darbepoetin use when compared with epoetin use in cats.

EVIDENCE BASE

There is limited published evidence to date to underpin the use of ESAs in cats. This review draws on the relevant publications that currently exist, and the authors' personal experience of using these therapies for over 5 years.

Daily protein intake and survival in patients on peritoneal dialysis

BACKGROUND

The decreased protein intake may lead to protein-energy wasting and poor survival. It is unknown what the appropriate protein intake in patients on peritoneal dialysis (PD) is. We aimed to explore the appropriate levels of daily protein intake (DPI) in favor of outcome in a large PD cohort.

METHODS

Our study enrolled 305 incident patients, who could be followed regularly. Demographic data were collected at baseline. Biochemical, dietary and nutritional data and dialysis adequacy were measured at the baseline and thereafter at regular intervals. Outcome events included all-cause death, cardiovascular disease (CVD) death and first-episode peritonitis.

RESULTS

A total of 127 patients died during the 44.5-month follow-up, 41.7% of whom died from CVD. A total of 129 cases first-episode peritonitis were observed. Patients with a high tertile of baseline DPI (≥ 0.94 g/kg/day) had significantly higher serum albumin, prealbumin, hemoglobin, lean body mass and handgrip strength compared to the low tertile group (≤ 0.73 g/kg/day) (P < 0.05-0.001). They also had significantly lower risk for all-cause, CVD death and first-episode peritonitis than the low tertile group adjusted for commonly recognized confounders. Although patients in the middle tertile of DPI (0.74-0.93 g/kg/day) did not show significant differences in the majority of nutritional markers, all-cause and CVD mortality compared to high tertile group, they had a trend to a negative nitrogen balance and similar risk for first-episode peritonitis to the low tertile group. The DPI included as a time-dependent variable could not predict any outcome events in multivariate Cox models.

CONCLUSIONS

Our study revealed that DPI <0.73 g/kg/day was associated with protein-energy wasting and worst outcome for PD patients. The DPI >0.94 g/kg/day was in favor of nutrition status and long-term outcome in this population.