Prevalence of Taste Changes and Association with Other Nutrition-Related Symptoms in End-Stage Kidney Disease Patients

Dysgeusia and Chronic Kidney Disease: A Scoping Review

Dysgeusia is a common altered taste perception in chronic kidney disease patients. The study aims to identify available treatments for educating, screening, and clinically managing dysgeusia in this population. A scoping review was conducted following the protocol of Arksey and O'Malley, incorporating the Joanna Briggs Institute methodology, and adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. Among the 424 identified records, 13 studies were included. Screening methodologies, educational strategies, particularly a hospital-based program focusing on salt reduction, showed a significant improvement in dysgeusia (P < .001). The identified clinical treatments exclusively included oral zinc supplementation, with dosages ranging from 50 to 220 mg, reporting heterogeneous results not consistent across different studies. The personalized management of dysgeusia associated with chronic kidney disease is crucial, requiring targeted education and treatment protocols to prevent and address nutritional complications such as malnutrition.

Relationship between altered taste and smell with malnutrition among hemodialysis patients

INTRODUCTION

Alterations in taste and smell are among the most distressing symptoms experienced by haemodialysis patients. There is limited research on the relationship between these two symptoms and malnutrition in haemodialysis patients. This study aimed to investigate alterations in taste and smell in hemodialysis patients and their relationship with malnutrition.

METHODS

This cross-sectional study was carried out with 149 hemodialysis patients at the dialysis centers of three state hospitals. The Taste and Smell Dysfunction Questionnaire was used to assess the changes in patients' taste and smell, and the Prognostic Nutritional Index (PNI), as well as the Controlling Nutritional Status (CONUT) tool, were utilized to evaluate their nutritional status.

FINDINGS

A substantial percentage (45.6%) of patients reported an altered sense of smell, and 40.2% reported an altered sense of taste. The aspect of taste that was most abnormal was bitterness (46.7%); 53.0% of the patients were at moderate risk of malnutrition by PNI score, and 14.8% were categorized as malnourished by CONUT score. Malnutrition was related to dialysis vintage: a 1-year increase in vintage was associated with an increased risk of malnutrition (OR: 1.17, 95% CI 1.02-1.32, p < 0.001). Altered taste was associated with malnutrition: one-unit increase in the standard deviation of the taste subdimension score was associated with a relative risk of malnutrition (OR: 6.89, 95% CI 1.67-28.39, p < 0.001). A one-unit increase in the standard deviation of the smell subdimension was associated with relative risk of malnutrition (OR: 1.35, 95% CI 1.10-1.64, p < 0.001).

DISCUSSION

Malnutrition was found in a significantpercentage of hemodialysis patients. Altered taste and smell and the durationof dialysis treatment were significantly associated with malnutrition scores It isrecommended that healthcare professionals regularly assess alterations in tasteand smell in hemodialysis patients, as these alterations may be associated withmalnutrition, and manage these alterations accordingly.

The Association of Frailty and Malnutrition With Dietary Intake and Gastrointestinal Symptoms in People With Kidney Failure: 2-Year Prospective Study

BACKGROUND

Frailty and malnutrition are both associated with worsening morbidity and mortality and become more prevalent in the elderly and as kidney function declines. Anorexia and reduced oral intake are common features of both frailty and malnutrition. However, there are sparse data evaluating the impact of other gastrointestinal (GI) symptoms, such as taste changes, on rates of frailty and malnutrition in people with kidney failure. The aim of this study is to describe the prevalence of frailty and malnutrition and their association with dietary intake and nutrition-related symptoms in people with kidney failure.

METHODS

This observational study recruited people with kidney failure who were commencing Conservative Kidney Management or elderly people (aged > 75 years) newly commenced on dialysis from 3 renal units. Participants underwent assessments of frailty, nutritional status, dietary intake, and GI symptom burden when they attended clinic appointments, approximately every 6 months.

RESULTS

Of the 85 participants, 57% were assessed as being frail and 33% were assessed as being malnourished. Participants assessed as frail reported more GI symptoms (3 vs. 2, P < .001) that were more severe (1.75 vs. 1.0, P < .001) compared to nonfrail participants. Being malnourished was associated with a 5 times higher chance of being frail (odds ratio 5.8; 95% confidence interval 1.5, 21.8; P = .015) and having more severe symptoms was associated with a 2 times higher chance (odds ratio 2.8; 95% CI 1.1, 7.0; P = .026) of being frail. In addition to experiencing more GI symptoms, that were more severe, participants who were malnourished consumed significantly less energy (1234 kcal vs. 1400 kcal, P = .01) and protein (51 g vs. 74 g, P < .001).

CONCLUSIONS

Frailty and malnutrition are common and are associated with a higher GI symptom burden and poorer dietary intake. Future research is needed to determine effective interventions targeting frailty and malnutrition, including nutrition-related symptoms and optimal protein intake.

Nutrition in Conservative Kidney Management: From Evidence to Practice

Conservative kidney management (CKM) is a treatment option for kidney failure, particularly for the elderly and those with co-morbidities. Dietitians can play an important role in the provision of CKM by enhancing patients' quality of life through the management of nutrition impact symptoms (symptoms that result in decreased eating, including anorexia, nausea, dry mouth, and taste changes), as well as symptoms that result from malnutrition, including fatigue, weakness, activity intolerance, slow wound healing, and low mood. There are many gaps in the literature regarding optimal nutritional recommendations for patients on CKM. More research is needed on symptom management and interventions to delay or slow the progression of malnutrition and frailty. This article provides an overview of important nutritional considerations, a synthesis of the current literature, and recommendations for application of evidence into the practice of CKM.

Prevalence and Severity of Lower Gastrointestinal Symptoms amongst Non-Dialysis Chronic Kidney Disease Patients: A Systematic Review and Meta-Analysis

Chronic kidney disease (CKD) patients experience a wide range of symptoms that deteriorate their health-related quality of life (HRQoL). We aimed to estimate the prevalence and severity of lower gastrointestinal (GI) symptoms in non-dialysis CKD adult outpatients, and to summarize the relationships between these symptoms and HRQoL, laboratory test results, and clinical data. The protocol of the study was preregistered (PROSPERO CRD42021255122). We searched MEDLINE, Scopus, Web of Science, and grey literature sources from the databases' inception up until 27 November 2021. Wide citation chasing was conducted. Single proportions (prevalence of functional constipation, self-reported constipation, diarrhea, abdominal bloating, fecal incontinence, and abdominal/rectal pain) were pooled using generalized linear mixed models. A total of 37 studies with 12,074 patients were included. We found that lower GI symptoms, especially self-reported abdominal bloating [CKD G1-2: 48.45% (95% CI: 43.5-53.4%; 2 studies); G3: 46.95% (95% CI: 45.0-48.9%; 2 studies), G4-5: 36.1% (95% CI: 25.4-48.5%; 8 studies)] and constipation [CKD G1-2: 31.8% (95% CI: 13.9-54.9%); G3: 29.8% (95% CI: 21.2-40.1%; 4 studies); G4-5: 38.8% (95% CI: 30.9-47.4%); 22 studies)], were common in non-dialysis CKD patients. The severity of the symptoms was limited. Self-reported constipation was most consistently associated with worse HRQoL, whereas hard stool consistency was associated with higher uremic toxins levels. To conclude, since lower GI symptoms are common in CKD, using symptom questionnaires that do not take them into account cannot provide full insight into the patient's experience. Further studies are needed to cover identified knowledge gaps, including the exploration of the pathophysiology of GI symptoms in CKD with multi-omics data.

Validity and Reliability Study of the Turkish Adaptation of Taste and Smell Dysfunction Questionnaire in Hemodialysis Patients

AIM

This study was conducted to assess the validity and reliability of the Turkish adaptation of the Taste and Smell Dysfunction Questionnaire (TSDQ) in hemodialysis patients.

MATERIALS AND METHODS

This study involves 125 hemodialysis patients. Research data were collected using the Descriptive Characteristics Form for Hemodialysis Patients, the TSDQ, and the Questionnaire for the Assessment of Self-Reported Olfactory Functioning and Olfaction-Related Quality of Life. In addition, the questionnaire's language and content validity, construct validity, and reliability were evaluated.

RESULTS

With regard to content validity, a high degree of agreement was determined between expert opinions on the questionnaire items (CGI = 0.96). Exploratory factor analysis revealed that the questionnaire has a two-factor structure explaining 79.33% of the total variance. The confirmatory factor analysis demonstrated that the model is within acceptable fit index limits with factor loads between 0.692 and 0.964. The Cronbach's alpha reliability coefficients of the scale and its two sub-dimensions are 0.928, 0.968, and 0.782, respectively.

CONCLUSION

The TSDQ is a valid and reliable tool for evaluating taste and smell changes in hemodialysis patients.

A Novel Approach for Managing Protein-Energy Wasting in People With Kidney Failure Undergoing Maintenance Hemodialysis: Rationale and Call for Trials

Protein-energy wasting (PEW) is a unique presentation of protein-energy malnutrition in people with kidney disease that is characterized by body protein catabolism exceeding anabolism. PEW is especially common in patients undergoing maintenance hemodialysis (HD) treatment. Dietary guidelines for managing PEW in HD patients primarily focus on protein adequacy and typically promote the intake of animal-based protein foods. Although intake of protein and essential amino acids is important for protein synthesis, the emphasis on protein adequacy largely fails to address-and may actually exacerbate-many of the root causes of PEW. This perspective examines the dietary determinants of PEW in people undergoing HD treatment, with an emphasis on upstream disease-related factors that reduce dietary protein utilization and impair dietary intakes. From this, we present a theoretical diet model for managing PEW that includes etiology-based dietary strategies to address barriers to intake and treat disease-related factors, as well as supportive dietary strategies to promote adequate energy and protein intakes. Given the complexity of diet-disease interactions in the pathogenesis of PEW, and its ongoing burden in HD patients, interventional trials are urgently needed to evaluate alternative diet therapy approaches for PEW in this population.

Disease-related malnutrition in chronic kidney disease

PURPOSE OF REVIEW

Disease-related malnutrition has complex and multifactorial pathophysiology. It is common in patients with chronic kidney disease (CKD) and has a devastating impact on morbidity and mortality. Given the rising numbers of patients diagnosed with CKD, disease-related malnutrition is an escalating clinical challenge. This review summarises current knowledge in relation to the development, screening and treatments for disease-related malnutrition in CKD.

RECENT FINDINGS

New research has identified other potential causes for the development of malnutrition in CKD, including changes in taste and smell, and effects of polypharmacy. Screening and assessment studies have investigated different tools in relation to the new Global Leadership Initiative on Malnutrition (GLIM) criteria. Different modalities of low protein diets and the potential use of pre and probiotics are being explored. Furthermore, the importance of nutritional support, and possibly exercise during dialysis is being examined in terms of reducing anabolic resistance and catabolism.

SUMMARY

Further research is required to better understand the nuances of the pathophysiology of disease-related malnutrition in CKD. This work should inform not only consistent terminology and the application of assessment tools specific to disease-related malnutrition in CKD but also the development of novel interventions that reflect its multifaceted pathophysiology and impact.

Medication Prescription, Common Side-effects, and Nutritional Status are Associated in Patients With Chronic Kidney Disease

OBJECTIVE

Chronic kidney disease (CKD) is associated with metabolic, nutritional, and extra-renal changes, as well as a high rate of comorbidities, which necessitates the prescription of numerous medications. Patients with CKD often experience poor nutritional status related to disease severity and prescribed medication; however, this association has not been investigated in depth. Therefore, this study aimed at investigating the association between prescribed medication and nutritional status in patients with CKD.

METHODS

Assessment of nutritional status was performed using anthropometric and functional measurements and by biochemical measures. Patient history and the number and type of currently prescribed medications were collected from patients' records. We evaluated the total number and the number of specific medicines with common or very common side-effects of nausea or xerostomia.

RESULTS

Two hundred seventeen patients with CKD were included in this cross-sectional study (n = 112 with pre-dialysis CKD stages 3-5, n = 33 with hemodialysis, and n = 72 with kidney transplant). On average, patients were prescribed nine medications concurrently. The number of prescribed medications was inversely associated with mid-upper arm circumference, skinfold thickness triceps, handgrip strength, serum albumin, and hemoglobin after adjustment for age, sex, and kidney function. Prescription of medications with nausea as a side-effect showed similar associations, whereas prescription of medications with xerostomia as a side-effect was associated with lower handgrip strength.

CONCLUSION

Medication prescription was associated with poor nutritional status in patients with CKD, and monitoring of nutritional status in patients with CKD with long medication lists is warranted to identify and treat patients with poor nutritional status.

A Novel Clinical Tool for the Management of Taste Changes in Patients With Chronic Kidney Disease: The Chronic Kidney Disease Taste Plate

Taste alteration is a common, but poorly understood, symptom in end-stage kidney disease. The pathophysiology of taste alteration is complex; to date, management has been largely empirical. As our understanding of pathophysiology grows so does the evidence base for its management. This article introduces a clinical tool-the CKD Taste Plate-to assist clinicians in directing management to the underlying pathophysiology of taste alterations in chronic kidney disease.

Association between Reduced Serum Zinc and Diastolic Dysfunction in Maintenance Hemodialysis Patients

Diastolic dysfunction is an emerging challenge among hemodialysis (HD) patients, and the associations between serum zinc with echocardiographic parameters and diastolic function remain uncertain. A total of 185 maintenance HD patients were stratified by the tertiles of serum zinc level to compare their clinical characteristics and echocardiography. Correlations of serum zinc levels with echocardiographic parameters were examined using Pearson’s analysis. Univariate and multivariate logistic regression analyses were performed to investigate the determinants of E/e’ ratio >15 and left atrial volume index (LAVI) > 34 mL/m², both indicators of diastolic dysfunction. Patients belonging to the first tertile of serum zinc level had a significantly higher E/e’ ratio and LAVI. Serum zinc levels were negatively correlated with E (r = −0.204, p = 0.005), E/e’ ratio (r = −0.217, p = 0.003), and LAVI (r = −0.197, p = 0.007). In a multivariate analysis, older age, diabetes, coronary artery disease, and lower serum zinc levels (OR = 0.974, 95% CI = 0.950–0.999, p = 0.039) were significantly associated with E/e’ ratio >15. Furthermore, diabetes and lower serum zinc levels (OR = 0.978, 95% CI = 0.958–0.999, p = 0.041) were significantly associated with LAVI >34 mL/m². Reduced serum zinc level was significantly associated with diastolic dysfunction among HD patients. Further prospective studies are warranted to investigate whether zinc supplementation can attenuate cardiac dysfunction in maintenance HD patients.

Association of Zinc Deficiency with Development of CVD Events in Patients with CKD

Deficiency of the micronutrient zinc is common in patients with chronic kidney disease (CKD). The aim of this review is to summarize evidence presented in literature for consolidation of current knowledge regarding zinc status in CKD patients, including those undergoing hemodialysis. Zinc deficiency is known to be associated with various risk factors for cardiovascular disease (CVD), such as increased blood pressure, dyslipidemia, type 2 diabetes mellitus, inflammation, and oxidative stress. Zinc may protect against phosphate-induced arterial calcification by suppressing activation of nuclear factor kappa light chain enhancer of activated B. Serum zinc levels have been shown to be positively correlated with T₅₀ (shorter T₅₀ indicates higher calcification propensity) in patients with type 2 diabetes mellitus as well as those with CKD. Additionally, higher intake of dietary zinc was associated with a lower risk of severe abdominal aortic calcification. In hemodialysis patients, the beneficial effects of zinc supplementation in relation to serum zinc and oxidative stress levels was demonstrated in a meta-analysis of 15 randomized controlled trials. Thus, evidence presented supports important roles of zinc regarding antioxidative stress and suppression of calcification and indicates that zinc intake/supplementation may help to ameliorate CVD risk factors in CKD patients.