Effects of dietary interventions on incidence and progression of CKD

Sodium and water dynamics in the progression of chronic kidney disease: mechanisms and clinical significance

AIM

Lifestyle modifications can postpone the progression of chronic kidney disease toward its terminal stage. This mini-review aims to explore the impact of salt and water intake on the progression of chronic kidney disease (CKD) and provide insights into the optimal consumption levels to preserve the glomerular filtration rate.

METHODS

We reviewed relevant literature to examine the association between salt and water consumption and CKD progression. Our analysis includes discussions on the pathophysiology, findings from clinical trials, and recommended intake guidelines.

RESULTS

Sodium intake, often linked to cardiovascular risk and CKD progression, has shown a complex J-shaped association in some studies, leading to uncertainty about the ideal salt intake level. Sodium and fluid retention are key factors contributing to hypertension, a well-established risk factor for CKD progression. Low-sodium diets have demonstrated promise in reducing blood pressure and enhancing the effects of renin-angiotensin-aldosterone system inhibitors in non-dialysis CKD patients. However, a debate persists regarding the independent effect of salt restriction on CKD progression. Despite medical recommendations, salt consumption remains high among CKD patients. Additionally, the role of water consumption in CKD remains controversial despite its established benefits for CKD prevention in the general population.

CONCLUSION

Lifestyle modifications involving salt and water intake can influence the progression of CKD. While low-sodium diets have shown potential for mitigating hypertension and proteinuria in non-dialysis CKD patients, their independent impact on CKD progression warrants further investigation. The role of water consumption in CKD remains uncertain, and there is a need for additional research in this area. Clinicians should consider individualized dietary recommendations for CKD patients to help preserve the glomerular filtration rate and improve overall outcomes.

Urinary Na/K ratio is a predictor of developing chronic kidney disease in the general population

Chronic kidney disease (CKD) is a major risk factor for cardiovascular diseases as well as end-stage kidney disease. Increased dietary sodium (Na) or decreased dietary potassium (K) deteriorates kidney function; however, findings regarding the association of dietary Na/K ratio with kidney function are limited and conflicting. Therefore, the present study investigated the impact of urinary Na/K ratio on the development of CKD, defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2, in the Japanese general population. In total, 14,549 subjects without CKD who participated in our medical checkup were enrolled. The urinary Na/K ratio was measured using a sample of overnight urine. The subjects were followed up until the endpoint (onset of CKD). During the median follow-up period of 61.4 months, CKD developed in 2096 participants (25.9 per 1000 person-years). The risk of developing CKD increased across the quartiles of baseline urinary Na/K ratio in the Kaplan-Meier analysis (log-rank, P < 0.001). In multivariate Cox proportional hazard regression analysis, urinary Na/K ratio was a significant predictor of new-onset CKD after adjustment for important factors including eGFR at baseline (hazard ratio, 2.013; 95% confidence interval, 1.658-2.445; p < 0.001). Moreover, baseline urinary Na/K ratio was found to be independently correlated with yearly decline in eGFR. Similar results were obtained in subgroups of participants with and without hypertension. Thus, urinary Na/K ratio is significantly associated with the development of CKD in the general population.

The association of dietary patterns with incident chronic kidney disease and kidney function decline among middle-aged Korean adults: a cohort study

OBJECTIVES

This study assessed the association of dietary patterns with the incidence of chronic kidney disease (CKD) and kidney function decline among Korean adults.

METHODS

Data were collected from the records of 20,147 men and 39,857 women who participated in the Health Examinees study. Principal component analysis was used to identify 3 dietary patterns (prudent, flour-based food and meat, and white rice-based), and CKD risk was defined using the Epidemiology Collaboration equation for estimated glomerular filtration rate: (eGFR) <60 mL/min/1.73 m2. A kidney function decline was defined as a >25% decrease in eGFR from baseline.

RESULTS

During the 4.2-year follow-up, 978 participants developed CKD and 971 had a 25% decline in kidney function. After adjusting for potential impact variables, compared with the lowest quartile of the prudent dietary pattern, participants in the highest quartile had a 37% lower risk of kidney function decline among men (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.47 to 0.85); while higher adherence to the flour-based food and meat dietary pattern was associated with an increased risk of CKD in both men (HR, 1.63; 95% CI, 1.22 to 2.19) and women (HR, 1.47; 95% CI, 1.05 to 2.05) as well as a decline in kidney function in both men (HR, 1.49; 95% CI, 1.07 to 2.07) and women (HR, 1.77; 95% CI, 1.33 to 2.35).

CONCLUSIONS

Although a higher adherence to the prudent dietary pattern was inversely associated with the risk of kidney function decline in men, there was no association with CKD risk. In addition, a higher adherence to the flour-based food and meat dietary pattern increased the risk of CKD and kidney function decline. Further clinical trials are needed to confirm these associations.

Nutrition and quality of life in chronic kidney disease patients: a practical approach for salt restriction

The clinical practice guidelines (CPGs) for nutrition in chronic kidney disease (CKD) were updated after 20 years from the previous guidelines by the Kidney Disease Outcomes Quality Initiative (KDOQI). During this period, the severity of CKD was defined by eGFR and albuminuria by the organization Kidney Disease: Improving Global Outcomes (KDIGO). Main risk factors for CKD such as hypertension, hyperlipidemia, obesity, metabolic syndrome, and diabetes mellitus are closely related to lifestyle. Nutritional management is important to prevent and retard the progression of CKD. Members of the International Society of Renal Nutrition and Metabolism (ISRNM) reviewed the KDOQI CPG draft. ISRNM is an international scientific society comprising members of multiple subspecialties. ISRNM proposed the medical term protein-energy wasting (PEW), which is a keyword in renal nutrition. The prevalence of PEW among dialysis patients is high. The success of dietary therapy depends on adherence to the diet. It has to be palatable, otherwise eating habits will not change. To prevent the development and progression of CKD and PEW, regular consultation with an expert dietitian is required, especially regarding salt and protein restriction. Our cluster-randomized trial showed that intervention by a dietician was effective at retarding the progression of stage 3 CKD. In this review, I focus on salt (sodium) restriction and introduce tips for salt restriction and Japanese kidney-friendly recipes. Due to the lack of randomized controlled trials, nutritional management of CKD inevitably relies on expert opinion. In this regard, well-designed observational studies are needed. Too strict salt restriction may decrease quality of life and result in PEW.

Awareness of Chronic Kidney Disease, Medication, and Laboratory Investigation among Nephrology and Urology Patients of Quetta, Pakistan

Patients’ awareness is critical in medical care, as it can serve as an input into the adjustment of interventions. The aim of study was to explore the level of awareness regarding chronic kidney disease (CKD), its medications, and laboratory investigations among nephrology and urology patients of Quetta. The cross-sectional study was used by adopting and culturally modifying a questionnaire. By convenient sampling technique, a total of 500 questionnaires were self-administered to inpatients, outpatients, and dialysis patients, and 468 responses (response rate 93.6%) were analyzed. Descriptive statistics, inferential statistics, and reliability analysis were performed on SPSS v25. A majority, 50.3% (n = 235), was unaware of symptoms that will develop due to worsening of disease, while 56.2% (n = 263) were unaware of what aggravates their kidney function. Almost half of the affected individuals, 47.4% (n = 222), have no understanding about the long-term prognosis of the disease. The majority of the respondents, 51.5% (n = 248), do not know about the names and usage of medications, and 62.4% (n = 292) were unaware of the medicines that may impair kidney function; more than half, 66.7% (n = 312), were unaware about the necessary laboratory investigations. A strong association between awareness and patient education level was found (p < 0.001). Awareness regarding disease condition, medications, and laboratory investigations of CKD among nephrology and urology patients of Quetta was found out to be low, which needs immediate educational intervention.

Update on Existing Care Models for Chronic Kidney Disease in Low- and Middle-Income Countries: A Systematic Review

Background:

Approximately 78% of chronic kidney disease (CKD) cases reside in low- and middle-income countries (LMICs). However, little is known about the care models for CKD in LMICs.

Objective:

Our objective was to update a prior systematic review on CKD care models in LMICs and summarize information on multidisciplinary care and management of CKD complications.

Design:

We searched MEDLINE, EMBASE, and Global Health databases in September 2020, for papers published between January 1, 2017, and September 14, 2020. We used a combination of search terms, which were different iterations of CKD, care models, and LMICs. The World Bank definition (2019) was used to identify LMICs.

Setting:

Our review included studies published in LMICs across 4 continents: Africa, Asia, North America (Mexico), and Europe (Ukraine). The study settings included tertiary hospitals (n = 6), multidisciplinary clinics (n = 1), primary health centers (n = 2), referral centers (n = 2), district hospitals (n = 1), teaching hospitals (n = 1), regional hospital (n = 1), and an urban medical center (n = 1).

Patients:

Eighteen studies met inclusion criteria, and encompassed 4679 patients, of which 4665 were adults. Only 9 studies reported mean eGFR which ranged from 7 to 45.90 ml/min/1.73 m².

Measurements:

We retrieved the following details about CKD care: funding, urban or rural location, types of health care staff, and type of care provided, as defined by Kidney Disease Improving Global Outcomes (KDIGO) guidelines for CKD care.

Methods:

We included studies which met the following criteria: (1) population was largely adults, defined as age 18 years and older; (2) most of the study population had CKD, and not end-stage kidney disease (ESKD); (3) population resided in an LMIC as defined by the World Bank; (4) manuscript described in some detail a clinical care model for CKD; (5) manuscript was in either English or French. Animal studies, case reports, comments, and editorials were excluded.

Results:

Eighteen studies (24 care models with 4665 patients) met inclusion criteria. Out of 24 care models, 20 involved interdisciplinary health care teams. Twenty models incorporated international guidelines for CKD management. However, conservative kidney management (management of kidney failure without dialysis or renal transplant) was in a minority of models (11 of 24). Although there were similarities between all the clinical care models, there was variation in services provided and in funding arrangement; the latter ranged from comprehensive government funding (eg, Sri Lanka, Thailand), to out-of-pocket payments (eg, Benin, Togo).

Limitations:

These include (1) lack of detail on CKD care in many of the studies, (2) small number of included studies, (3) using a different definition of care model from the original Stanifer et al paper, and (4) using the KDIGO Guidelines as the standard for defining a CKD care model.

Conclusions:

Most of the CKD models of care include the key elements of CKD care. However, access to such care depends on the funding mechanism available. In addition, few models included conservative kidney management, which should be a priority for future investment.

Trial registration:

Not applicable.

Management of type 2 diabetes in chronic kidney disease

The management of patients with type 2 diabetes and chronic kidney disease (CKD) encompasses lifestyle modifications, glycemic control with individualized HbA1c targets, and cardiovascular disease risk reduction. Metformin and sodium-glucose cotransporter-2 inhibitors are first-line agents. Glucagon-like peptide-1 receptor agonists are second-line agents. The use of other antidiabetic agents should consider patient preferences, comorbidities, drug costs, and the risk of hypoglycemia. Renin-angiotensin-aldosterone system inhibitors are strongly recommended for patients with diabetes, hypertension, and albuminuria. Non-steroidal mineralocorticoid receptor antagonists, which pose less risk of hyperkalemia than steroidal agents, are undergoing further evaluation among patients with diabetic kidney disease. Here, we discuss important advancements in the management of patients with type 2 diabetes and CKD.

Plasma Metabolomic Signatures of Healthy Dietary Patterns in the Chronic Renal Insufficiency Cohort (CRIC) Study

BACKGROUND

In individuals with chronic kidney disease (CKD), healthy dietary patterns are inversely associated with CKD progression. Metabolomics, an approach that measures many small molecules in biofluids, can identify biomarkers of healthy dietary patterns.

OBJECTIVES

We aimed to identify known metabolites associated with greater adherence to 4 healthy dietary patterns in CKD patients.

METHODS

We examined associations between 486 known plasma metabolites and Healthy Eating Index (HEI)-2015, Alternative Healthy Eating Index (AHEI)-2010, the Dietary Approaches to Stop Hypertension (DASH) diet, and alternate Mediterranean diet (aMED) in 1056 participants (aged 21-74 y at baseline) in the Chronic Renal Insufficiency Cohort (CRIC) Study. Usual dietary intake was assessed using a semiquantitative FFQ. We conducted multivariable linear regression models to study associations between healthy dietary patterns and individual plasma metabolites, adjusting for sociodemographic characteristics, health behaviors, and clinical factors. We used principal component analysis to identify groups of metabolites associated with individual food components within healthy dietary patterns.

RESULTS

After Bonferroni correction, we identified 266 statistically significant diet-metabolite associations (HEI: n = 60; AHEI: n = 78; DASH: n = 77; aMED: n = 51); 78 metabolites were associated with >1 dietary pattern. Lipids with a longer acyl chain length and double bonds (unsaturated) were positively associated with all 4 dietary patterns. A metabolite pattern low in saturated diacylglycerols and triacylglycerols, and a pattern high in unsaturated triacylglycerols was positively associated with intake of healthy food components. Plasmalogens were negatively associated with the consumption of nuts and legumes and healthy fat, and positively associated with the intake of red and processed meat.

CONCLUSIONS

We identified many metabolites associated with healthy dietary patterns, indicative of food consumption. If replicated, these metabolites may be considered biomarkers of healthy dietary patterns in patients with CKD.

Awareness, knowledge, and perception of chronic kidney disease patients at renal medicine outpatients' clinic

Chronic kidney disease (CKD) is a major cause of morbidity and mortality. Awareness and education of CKD patients positively influence its medical management and significantly diminish the economic burden on public health. We conducted a pretested, structured, questionnaire-based survey to assess the awareness, knowledge, and perception of CKD patients at Renal Medicine Outpatients' Clinic. The questionnaire was distributed to all CKD patients of at least one-year duration after their diagnosis. A total of 200 patients completed this study, mainly from the capital region. The mean age was 50 (17.1) years for males and 42.3 (16) years for females. The majority (74%) knew the reason for their referral to a nephrologist. Nearly 38% of the patients with CKD reported their shock and anger when informed about their kidney status by the nephrologist at the first encounter. Almost 64% of the patients reported having no knowledge of their CKD status and only 18% of the participants were aware that they were in CKD Stage 5, but according to the medical health computerized system, 44% were in CKD Stage 5. In addition, only 50% of them were aware of renal replacement therapy options. Patients and their family should receive enough information and education regarding the nature of kidney disease and the treatment options to allow them to make an informed decision about the management of their CKD. A well-informed decision-making in the treatment of CKD can provide health professionals with evidence on how to best deliver education programs for patients and their families. It may also enhance communication and improve the capacity of patient and family involvement in shared decision-making.

Association between dietary patterns and renal function in a cross-sectional study using baseline data from the ELSA-Brasil cohort

Previous analyses of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) identified four main dietary patterns (DP). The aim of this study was to explore the association between the previously defined DP and renal function (RF). A cross-sectional study using the ELSA-Brasil baseline data was carried out. DP (“traditional”, “fruits and vegetables”, “bakery”, and “low sugar/low fat), metabolic syndrome (MS) using the Joint Interim Statement criteria, microalbuminuria (MA), and glomerular filtration rate (eGFR) through the CKD-EPI equation were evaluated. Abnormal RF was defined as eGFR<60 mL·min^-1·(1.73 m²)^-1 and MA≥3.0 mg/dL. Factors associated with RF were determined and mediation analysis was performed to investigate the association between DP, MS, and RF. A total of 15,105 participants were recruited, with a mean age of 52±9 years; 8,134 participants (54%) were females. The mediation analysis identified indirect associations between “bakery” and “fruits and vegetables”, and both were associated with decreased eGFR and albuminuria in both genders, compared with “traditional” and “low sugar/low fat” patterns in the general population. There was a direct association of the “bakery” pattern with MA in men (OR: 1.17, 95%CI: 1.92-1.48). The “fruits and vegetables” pattern also showed a direct association with reduced eGFR in women (OR: 1.65, 95%CI: 1.28-2.12), although there was no significance after adjustment. The “fruits and vegetables” and “bakery” DPs were associated with renal dysfunction. The only independent, direct association was between “bakery” DP and MA in men, raising concerns about DP and renal damage in men.

Reduced risk for chronic kidney disease after recovery from metabolic syndrome: A nationwide population-based study

Background

Metabolic syndrome (MetS) is linked to various chronic comorbidities, including chronic kidney disease (CKD). However, few large studies have addressed whether recovery from MetS is associated with reduction in the risks of such comorbidities.

Methods

This nationwide population-based study in Korea screened 10,664,268 people who received national health screening ≥ 3 times between 2012 and 2016. Those with a history of major cardiovascular events or preexisting CKD were excluded. We classified study groups into four, according to the course of MetS state, as defined by the harmonizing criteria. The main study outcome was incidental CKD (estimated glomerular filtration rate < 60 mL/min/1.73 m² which was persistent until the last health exams). The study outcomes were investigated using multivariable logistic regression analysis, which was adjusted for clinical variables and the previous severity of MetS.

Results

Four study groups included 6,315,301 subjects: 4,537,869 people without MetS, 1,034,605 with chronic MetS, 438,287 who developed MetS, and 304,540 who recovered from preexisting MetS. Those who developed MetS demonstrated higher risk of CKD (adjusted odds ratio [OR], 1.26 [1.23-1.29]) than did those who did not develop MetS. In contrast, MetS-recovery was associated with decreased risk of CKD (adjusted OR, 0.84 [0.82-0.86]) than that in people with chronic MetS. Among the MetS components, change in hypertension was associated with the largest difference in CKD risk.

Conclusion

Reducing or preventing MetS may reduce the burden of CKD on a population-scale. Clinicians should consider the clinical importance of altering MetS status for risk of CKD.

Sodium Intake and Target Organ Damage in Hypertension-An Update about the Role of a Real Villain

Salt intake is too high for safety nowadays. The main active ion in salt is sodium. The vast majority of scientific evidence points out the importance of sodium restriction for decreasing cardiovascular risk. International Guidelines recommend a large reduction in sodium consumption to help reduce blood pressure, organ damage, and cardiovascular risk. Regulatory authorities across the globe suggest a general restriction of sodium intake to prevent cardiovascular diseases. In spite of this seemingly unanimous consensus, some researchers claim to have evidence of the unhealthy effects of a reduction of sodium intake, and have data to support their claims. Evidence is against dissenting scientists, because prospective, observational, and basic research studies indicate that sodium is the real villain: actual sodium consumption around the globe is far higher than the safe range. Sodium intake is directly related to increased blood pressure, and independently to the enlargement of cardiac mass, with a possible independent role in inducing left ventricular hypertrophy. This may represent the basis of myocardial ischemia, congestive heart failure, and cardiac mortality. Although debated, a high sodium intake may induce initial renal damage and progression in both hypertensive and normotensive subjects. Conversely, there is general agreement about the adverse role of sodium in cerebrovascular disease. These factors point to the possible main role of sodium intake in target organ damage and cardiovascular events including mortality. This review will endeavor to outline the existing evidence.

Intakes of long-chain omega-3 polyunsaturated fatty acids and non-fried fish in relation to incidence of chronic kidney disease in young adults: a 25-year follow-up

PURPOSE

The prevalence of chronic kidney disease (CKD) is increasing rapidly in many countries and has become a major public health concern. Although intakes of long-chain omega-3 polyunsaturated fatty acids (LCω3PUFA) and its food source-fish-may have renal protective effects, little is known about the longitudinal association between these dietary factors and CKD incidence.

METHODS

A total of 4133 healthy individuals of black and white race aged 18-30 at baseline (1985-1986) from the Coronary Artery Risk Development in Young Adults study were enrolled and followed up over 25 years. LCω3PUFA and fish intake were assessed by an interview-based dietary history questionnaire at baseline, year 7 (1992-1993) and 20 (2005-2006).

RESULTS

Four hundred and eighty-nine incident cases of CKD were identified. After adjustment for potential confounders, LCω3PUFA intake was inversely associated with CKD incidence [HR = 0.73 (95% CI 0.60-0.89), P = 0.002, with one standard division (0.19 g/day) increment in LCω3PUFA]. This inverse association was persisted among females [0.64 (95% CI 0.48, 0.84; P = 0.002], but not males (Pinteraction = 0.070). A marginal significant inverse association was also found between non-fried fish consumption and CKD incidence (HR = 0.86, 95% CI 0.73, 1.01; P = 0.073).

CONCLUSIONS

Dietary LCω3PUFA intake was inversely associated with incidence of CKD among American young adults over 25 years of follow-up. The suggestive evidence of the inverse association between non-fried fish consumption with CKD incidence needs further confirmation.

Potassium Homeostasis, Chronic Kidney Disease, and the Plant-Enriched Diets

There are data demonstrating that ingestion of potassium-rich foods reduces the incidence of stroke, hypertension, nephrolithiasis, and osteoporosis. Dietary-consumption data indicate Westernized diets are high in processed foods, high in sodium content, and low in potassium. In fact, there are data suggesting individuals are not consuming enough potassium in their diet. Although consumption of diets high in plant proteins, fruits, and vegetables—which are excellent sources of potassium—is recognized as healthy and beneficial, individuals with decrements in their kidney function have been advised to avoid these foods. In reviewing the literature that provides the rationale for potassium restriction in patients with reductions in kidney function, it appears there is little direct evidence to support the levels of restriction which are now prescribed. Additionally, there are two new potassium-binding agents which are well tolerated and have been documented to be effective in controlling serum potassium. Therefore, with the new binding agents and the lack of empirical evidence supporting the stringent dietary potassium restrictions, the authors conclude by indicating the pressing need for further research focusing on dietary liberalization of potassium in patients with reductions in kidney function to enhance overall health and well being, to provide them cardiovascular benefits, and to reduce overall risk of mortality through the incorporation of potassium-enriched foods.

Associations of Waist Circumference, Socioeconomic, Environmental, and Behavioral Factors with Chronic Kidney Disease in Normal Weight, Overweight, and Obese People

Background: Chronic kidney disease (CKD) places a heavy burden on the healthcare system worldwide. The risk factors may vary by body adiposity. We aimed to investigate the associations of socioeconomic, environmental, and behavioral factors with CKD in different groups of body mass indexes (BMI). Methods: A case-control study was conducted in 3280 participants (1048 CKD and 2232 non-CKD) from seven hospitals and nearby communities from May 2012 to August 2015. Personal characteristics, anthropometrics, environmental exposures, and health-related behaviors were assessed using a structured questionnaire. The logistic regression models were utilized for analysis. Results: Older age (odd ratio, OR = 2.85; p < 0.001), being men (OR = 4.23; p < 0.001), smoking (OR = 3.36; p < 0.001), stable income (OR = 0.33; p < 0.001), higher education (OR = 0.37~0.38; p < 0.001), and daily adequate water intake (OR = 0.64; p = 0.010) were associated with CKD in normal weight people. Older age (OR = 2.49; p < 0.001), being men (OR = 3.36; p < 0.001), education (OR = 0.44, p = 0.004), hypertension (OR = 2.93; p<0.001), diabetes (OR = 1.83; p = 0.004), and using traditional Chinese medicine (OR = 2.03, p = 0.014) were associated with CKD in overweight people. Older age (OR = 2.71; p < 0.001), being men (OR = 2.69; p < 0.001), hypertension (OR = 2.93; p < 0.001), diabetes (OR = 1.94; p = 0.001) were associated with CKD in obese people. Conclusions: The associated factors of CKD varied by different groups of BMI. These findings may help to develop potential interventions to manage CKD.

Influence of Dietary Ingredients on Lean Body Percent, Uremic Toxin Concentrations, and Kidney Function in Senior-Adult Cats

The goal of this study was to determine if modification of currently available maintenance foods with alternative ingredients, botanicals (fruit and vegetables), and increased amounts of functional lipids (fish oil) would delay the age-associated decline in glomerular filtration rate (GFR) and lean body mass (LBM) in senior-adult cats. Forty-four healthy cats (mean age, 12.2 years; range 10.7 to 14.0 years) were fed one of three foods (n = 14 or 15 per group) for six months: control food with 32.6% protein (as fed), or control food supplemented with increasing amounts of functional food bioactives: fish oil, fruit and vegetables, different protein sources, and <32.0% protein [functional foods one (FF1) and two (FF2)]. Senior-adult cats were compared before and after the feeding trial with 20 young-adult cats (mean age, 3.5 years; range 2.1 to 4.9 years). Compared with younger cats, older cats had decreased lean-body percent and serum albumin concentrations. Feeding FF1 and FF2 for six months increased lean-body percent, maintained serum albumin concentrations, increased GFR, decreased serum symmetric dimethylarginine (SDMA) concentrations, and decreased concentrations of the uremic toxin 3-indoxyl sulfate. These dietary changes may assist in offsetting sarcopenia and the chronic inflammation associated with aging in senior-adult cats.

The pathobiology of polycystic kidney disease from a metabolic viewpoint

Autosomal dominant polycystic kidney disease (ADPKD) affects an estimated 1 in 1,000 people and slowly progresses to end-stage renal disease (ESRD) in about half of these individuals. Tolvaptan, a vasopressin 2 receptor blocker, has been approved by regulatory authorities in many countries as a therapy to slow cyst growth, but additional treatments that target dysregulated signalling pathways in cystic kidney and liver are needed. Metabolic reprogramming is a prominent feature of cystic cells and a potentially important contributor to the pathophysiology of ADPKD. A number of pathways previously implicated in the pathogenesis of the disease, such as dysregulated mTOR and primary ciliary signalling, have roles in metabolic regulation and may exert their effects through this mechanism. Some of these pathways are amenable to manipulation through dietary modifications or drug therapies. Studies suggest that polycystin-1 and polycystin-2, which are encoded by PKD1 and PKD2, respectively (the genes that are mutated in >99% of patients with ADPKD), may in part affect cellular metabolism through direct effects on mitochondrial function. Mitochondrial dysfunction could alter the redox state and cellular levels of acetyl-CoA, resulting in altered histone acetylation, gene expression, cytoskeletal architecture and response to cellular stress, and in an immunological response that further promotes cyst growth and fibrosis.

Associations between psychological distress and health-related behaviors among adults with chronic kidney disease

Chronic kidney disease (CKD) affects 15% of the US general population, and this rate is projected to increase. A healthy lifestyle is important for individuals with CKD to reduce risk for CKD progression and adverse heath events. Adults with CKD also have high rates of psychological distress, which may be associated with unhealthy behaviors. Using the 2013-2017 public use data files of the US National Health Interview Survey, we compared health behaviors (smoking, alcohol use, and physical activity [PA]) and psychological distress (assessed with the Kessler-6 scale) between adults with a CKD diagnosis in the preceding year and a matched sample of adults without a CKD diagnosis. We then examined the association between psychological distress and health behaviors among adults with CKD (n = 3923) using multinomial logistic regression models. Compared to those without CKD, those with CKD had lower rates of smoking, heavy alcohol use, and engagement in any type of PA 3+ times a week and higher rates of psychological distress. In addition to the health concerns posed by the high smoking rate (17%) and low physical activity rate (34%) among those with CKD, smoking and lack of PA were associated with greater risk of mild-moderate and/or serious psychological distress. Compared to no unhealthy behaviors, 2-3 unhealthy behaviors were associated with 4.72 (95% CI = 2.97-7.48) times greater risk of serious psychological distress. Adults with CKD and unhealthy behaviors need help with lifestyle modifications and assessment and treatment of psychological distress to reduce CKD progression and prevent other health complications.

A chronic kidney disease patient awareness questionnaire: Development and validation

Background

With the advance of medical care, chronic non-communicable diseases, like chronic kidney disease (CKD), have become the predominant diseases around the world. With heavy society and economy burden, we shall make full use of chronic disease management, including precision therapies. And the prerequisite for implementing precision medicine is to fully understand the characteristics of patients. Being the basis of the Knowledge-Attitude-Practice Model, patient’s awareness is essential to conduct individualized treatments. However, there have been no validated questionnaires specific to the awareness of patients with CKD. Therefore, this study aims to develop and validate an awareness questionnaire for patients with CKD.

Methods

From March 2013 to September 2014, a cross-sectional study was conducted at Guangdong Provincial Hospital of Chinese Medicine. Age 18 or above were enrolled in the study. After signing the informed consent, they received a self-developed questionnaire to evaluate their CKD-related awareness. Then we collected their demographic data for further analyses. We also conducted item analyses/ validity and reliability analysis to filter out improper items and to retain the eligible ones.

Results

We totally distributed 110 copies of the questionnaires and 100 of them were returned. After item analyses, 2 items were excluded because of Cronbach’s Alpha analysis. In total, 18 items were retained, comprising the final set of the questionnaire. For validity analysis, 4 components could explain the cumulative 73.966% extraction sums of the squared loadings; for reliability analysis, the Guttman Split-Half coefficient was 0.918.

Conclusions

This awareness questionnaire has favorable validity and reliability. It is a sound method for evaluating and measuring levels of disease-related awareness in CKD patients.

A Diet Rich in Vegetables and Fruit and Incident CKD: A Community-Based Prospective Cohort Study

RATIONALE & OBJECTIVE

A diet rich in vegetables and fruit can lower blood pressure and may reduce cardiovascular risk. However, the association between this dietary pattern and incident chronic kidney disease in the general population is unknown.

STUDY DESIGN

A community-based prospective cohort study.

SETTING & PARTICIPANTS

9,229 study participants with normal kidney function from the Korean Genome and Epidemiology Study database.

PREDICTORS

Daily consumption of nonfermented and fermented vegetables and fruit classified into tertiles based on a validated semiquantitative food-frequency questionnaire.

OUTCOMES

Incident occurrence of estimated glomerular filtration rate (eGFR) < 60mL/min/1.73m², incident proteinuria (≥1+ by dipstick test), and repeated measures of estimated net endogenous acid production.

ANALYTICAL APPROACH

Multivariable cause-specific hazards model to assess the association of vegetable and fruit intake with incident chronic kidney disease.

RESULTS

During a mean follow-up of 8.2 years, 1,741 (21.9/1,000 person-years [PY]) participants developed eGFRs < 60mL/min/1.73m². Incident eGFR < 60mL/min/1.73m² occurred less frequently with higher intake of nonfermented vegetables, occurring at rates of 22.8/1,000 PY, 22.7/1,000 PY, and 20.1/1,000 PY for the lowest, middle, and highest tertiles, respectively; P for trend < 0.001. The incidence of proteinuria was also lower in the middle and highest tertiles. In a multivariable cause-specific hazards model, the highest tertile of nonfermented vegetable intake was associated with 14% lower risk for incident eGFR < 60mL/min/1.73m² than the lowest tertile. The highest tertile was also associated with 32% lower risk for proteinuria than the lowest tertile. There were no associations of fermented vegetable and fruit intake with incidence of eGFR < 60mL/min/1.73m². However, the highest tertiles of both fermented vegetable and fruit intake were associated with 14% and 45% lower risks for incident proteinuria compared with the lowest tertiles (both P < 0.001). During follow-up, estimated net endogenous acid production increased in the lowest tertile of intake of nonfermented or fermented vegetables and fruit, whereas it decreased in the highest tertile.

LIMITATIONS

Self-reported dietary intake, single ethnicity population.

CONCLUSIONS

A diet rich in vegetables and fruit may reduce the risk for kidney disease.

Serum metabolites associated with dietary protein intake: results from the Modification of Diet in Renal Disease (MDRD) randomized clinical trial

BACKGROUND

Accurate assessment of dietary intake is essential, but self-report of dietary intake is prone to measurement error and bias. Discovering metabolic consequences of diets with lower compared with higher protein intake could elucidate new, objective biomarkers of protein intake.

OBJECTIVES

The goal of this study was to identify serum metabolites associated with dietary protein intake.

METHODS

Metabolites were measured with the use of untargeted, reverse-phase ultra-performance liquid chromatography-tandem mass spectrometry quantification in serum specimens collected at the 12-mo follow-up visit in the Modification of Diet in Renal Disease (MDRD) Study from 482 participants in study A (glomerular filtration rate: 25-55 mL · min-1 · 1.73 m-2) and 192 participants in study B (glomerular filtration rate: 13-24 mL · min-1 · 1.73 m-2). We used multivariable linear regression to test for differences in log-transformed metabolites (outcome) according to randomly assigned dietary protein intervention groups (exposure). Statistical significance was assessed at the Bonferroni-corrected threshold: 0.05/1193 = 4.2 × 10-5.

RESULTS

In study A, 130 metabolites (83 known from 28 distinct pathways, including 7 amino acid pathways; 47 unknown) were significantly different between participants randomly assigned to the low-protein diet compared with the moderate-protein diet. In study B, 32 metabolites (22 known from 8 distinct pathways, including 4 amino acid pathways; 10 unknown) were significantly different between participants randomly assigned to the very-low-protein diet compared with the low-protein diet. A total of 11 known metabolites were significantly associated with protein intake in the same direction in both studies A and B: 3-methylhistidine, N-acetyl-3-methylhistidine, xanthurenate, isovalerylcarnitine, creatine, kynurenate, 1-(1-enyl-palmitoyl)-2-arachidonoyl-GPE (P-16:0/20:4), 1-(1-enyl-stearoyl)-2-arachidonoyl-GPE (P-18:0/20:4), 1-(1-enyl-palmitoyl)-2-arachidonoyl-GPC (P-16:0/20:4), sulfate, and γ-glutamylalanine.

CONCLUSIONS

Among patients with chronic kidney disease, an untargeted serum metabolomics platform identified multiple pathways and metabolites associated with dietary protein intake. Further research is necessary to characterize unknown compounds and to examine these metabolites in association with dietary protein intake among individuals without kidney disease.This trial was registered at clinicaltrials.gov as NCT03202914.

Health Behaviors in Younger and Older Adults With CKD: Results From the CRIC Study

INTRODUCTION

A cornerstone of kidney disease management is participation in guideline-recommended health behaviors. However, the relationship of these health behaviors with outcomes, and the identification of barriers to health behavior engagement, have not been described among younger and older adults with chronic kidney disease.

METHODS

Data from a cohort study of 5499 individuals with chronic kidney disease was used to identify health behavior patterns with latent class analysis stratified by age <65 and ≥65 years. Cox models, stratified by diabetes, assessed the association of health behavior patterns with chronic kidney disease (CKD) progression, atherosclerotic events, and death. Logistic regression was used to assess for barriers to health behavior engagement.

RESULTS

Three health behavior patterns were identified: 1 "healthy" pattern, and 2 "less healthy" patterns comprising 1 pattern with more obesity and sedentary activity and 1 with more smoking and less obesity. Less healthy patterns were associated with an increased hazard of poor outcomes. Among participants <65 years of age, the less healthy patterns (vs. healthy pattern) was associated with an increased hazard of death in diabetic individuals (hazard ratio [HR] = 2.17, 95% confidence interval [CI] = 1.09-4.29; and HR = 2.50, 95% CI = 1.39-4.50) and cardiovascular events among nondiabetic individuals (HR = 1.49, 95% CI = 1.04-2.43; and HR = 2.97, 95% CI = 1.49-5.90). Individuals with the more obese/sedentary pattern had an increased risk of CKD progression in those who were diabetic (HR = 1.34, 95% CI = 1.13-1.59). Among older adults, the less healthy patterns were associated with increased risk of death (HR = 2.97, 95% CI = 1.43-6.19; and HR = 3.47, 95% CI = 1.48-8.11) in those who were nondiabetic. Potential barriers to recommended health behaviors include lower health literacy and self-efficacy.

CONCLUSION

Identifying health behavior patterns and barriers may help target high-risk groups for strategies to increase participation in health behaviors.

Cardiovascular risk in chronic kidney disease: what is new in the pathogenesis and treatment?

The prevalence of chronic kidney disease (CKD) has increased markedly over past decades due to the aging of the worldwide population. Despite the progress in the prevention and treatment, the cardiovascular (CV) morbidity and mortality remain high among patients with CKD. Although CKD is a progressive and irreversible condition, it is possible to slow decreasing kidney function, as well as the development and progression of associated with kidney disease comorbidities. Diabetes mellitus has become major cause of CKD worldwide. It is estimated that the prevalence of diabetes will increase from 425 million worldwide in 2017 to 629 million by 2045, substantially the percentage of diabetic nephropathy among CKD patients is set to rise markedly. The results of multicenter trials concerning novel antidiabetic drugs suggest that efficacy in reducing CV risk is independent of the improvement in glycemic control. This review discusses underlying causes of high CV risk and strategies reducing individual burden among CKD patients.

Weight loss has an additive effect on the proteinuria reduction of angiotensin II receptor blockers in hypertensive patients with chronic kidney disease

Background

Weight reduction is a lifestyle intervention that has been introduced for prevention and management of chronic kidney disease (CKD). We investigate the additive anti-proteinuric effect of weight reduction on the usage of angiotensin II receptor blockers (ARBs) and its potential mechanisms in hypertensive CKD patients.

Methods

This study is a subanalysis of data from an open-label, randomized, controlled clinical trial. Among the 235 participants, 227 were assigned to subgroups according to changes in body weight.

Results

Fifty-eight participants (25.6%) were assigned to group 1 (≥1.5% decrease in body weight after 16 weeks), 32 participants (14.1%) were assigned to group 2 (1.5–0.1% decrease in body weight), and 136 participants (59.9%) were assigned to group 3 (≥ 0.0% increase in body weight). Characteristics at enrollment were not different among the three groups, but mean differences in weight and percent changes in urinary sodium excretion over the period were statistically different (P < 0.001 and P = 0.017). Over the study period, unintentional weight loss independently increased the probability of reduced albuminuria (group 1, relative risk 6.234, 95% confidence interval 1.913–20.315, P = 0.002). Among urinary cytokines, only podocalyxin level decreased significantly in participants who lost weight (P = 0.013).

Conclusion

We observed that weight loss had an additive effect on the anti-proteinuric effects of ARBs in nondiabetic hypertensive CKD patients, although it was minimal. An additive effect was shown in both obese and non-obese participants, and its possible mechanism is related to reduction of podocyte damage.

Self-management of dietary intake using mindful eating to improve dietary intake for individuals with early stage chronic kidney disease

Using mindful eating to improve specific dietary recommendations has not been adequately studied. This feasibility study examined an intervention, self-management of dietary intake using mindful eating, with 19 participants that had mild to moderate chronic kidney disease, using a prospective, single group, pretest-posttest design. The intervention had six weekly classes focused on self-management using mindful eating, goal-setting, problem-solving, and food label reading. Weight, body mass index (BMI), 3-day 24-h dietary recalls and fasting blood samples were measured. Participants improved significantly in mean weight (203.21 ± 42.98 vs 199.91 ± 40.36 lbs; P = 0.03) and BMI (32.02 ± 5.22 vs 31.57 ± 5.27 kg/m2; P = 0.04), but not in dietary intake nor blood measures with the exception of cis-beta-carotene levels (0.020 + 0.012 vs 0.026 + 0.012 mcg/mL; P = 0.008), which correlates to fruit and vegetable servings. These promising results warrant further testing of the intervention in randomized control trials.

Food Insecurity, CKD, and Subsequent ESRD in US Adults

BACKGROUND

Poor access to food among low-income adults has been recognized as a risk factor for chronic kidney disease (CKD), but there are no data for the impact of food insecurity on progression to end-stage renal disease (ESRD). We hypothesized that food insecurity would be independently associated with risk for ESRD among persons with and without earlier stages of CKD.

STUDY DESIGN

Longitudinal cohort study.

SETTING & PARTICIPANTS

2,320 adults (aged ≥ 20 years) with CKD and 10,448 adults with no CKD enrolled in NHANES III (1988-1994) with household income ≤ 400% of the federal poverty level linked to the Medicare ESRD Registry for a median follow-up of 12 years.

PREDICTOR

Food insecurity, defined as an affirmative response to the food-insecurity screening question.

OUTCOME

Development of ESRD.

MEASUREMENTS

Demographics, income, diabetes, hypertension, estimated glomerular filtration rate, and albuminuria. Dietary acid load was estimated from 24-hour dietary recall. We used a Fine-Gray competing-risk model to estimate the relative hazard (RH) for ESRD associated with food insecurity after adjusting for covariates.

RESULTS

4.5% of adults with CKD were food insecure. Food-insecure individuals were more likely to be younger and have diabetes (29.9%), hypertension (73.9%), or albuminuria (90.4%) as compared with their counterparts (P<0.05). Median dietary acid load in the food-secure versus food-insecure group was 51.2 mEq/d versus 55.6 mEq/d, respectively (P=0.05). Food-insecure adults were more likely to develop ESRD (RH, 1.38; 95% CI, 1.08-3.10) compared with food-secure adults after adjustment for demographics, income, diabetes, hypertension, estimated glomerular filtration rate, and albuminuria. In the non-CKD group, 5.7% were food insecure. We did not find a significant association between food insecurity and ESRD (RH, 0.77; 95% CI, 0.40-1.49).

LIMITATIONS

Use of single 24-hour diet recall; lack of laboratory follow-up data and measure of changes in food insecurity over time; follow-up of cohort ended 10 years ago.

CONCLUSIONS

Among adults with CKD, food insecurity was independently associated with a higher likelihood of developing ESRD. Innovative approaches to address food insecurity should be tested for their impact on CKD outcomes.

A systematic review to determine the most effective interventions to increase water intake

BACKGROUND

Maintaining adequate fluid intake has been hypothesized to be beneficial for the progression of chronic kidney disease (CKD). The aim of this study was to undertake a systematic review to determine the most effective interventions to increase water intake.

METHODS

Six electronic databases were searched from 1910 until March 2015 in the English language. Additional sources through hand-searches, expert recommendations and reviews were checked. Intervention studies increasing water intake in adults through non-pharmacological methods were eligible for inclusion. The quality of included studies was assessed.

RESULTS

A total of 950 studies were found of which 16 met the inclusion criteria. Eight studies were randomized controlled trials, and seven studies spanned 6 months or longer. The study populations varied and included patients with recurrent nephrolithiasis (n = 6), autosomal dominant polycystic kidney disease (n = 3), CKD (n = 1), urinary tract infection (n = 1) and other miscellaneous conditions (n = 5). The quality of the studies was mostly neutral (63%) with no studies of high quality. Interventions ranged from instruction alone to self-monitoring tools, providing water bottles and counselling and education. Most interventions successfully increased water intake with 13 studies reporting an increase of at least 500 mL. The most effective strategies were instruction and self-monitoring using urine dipstick or 24 h urine volume.

CONCLUSION

All interventions carried out in the studies succeeded in increasing water intake, with none leading to decreases in intake, and these could be implemented in potential clinical trials in CKD. However, more high quality long-term intervention studies are required to further validate findings.

Glomerular Hyperfiltration in Diabetes: Mechanisms, Clinical Significance, and Treatment

An absolute, supraphysiologic elevation in GFR is observed early in the natural history in 10%-67% and 6%-73% of patients with type 1 and type 2 diabetes, respectively. Moreover, at the single-nephron level, diabetes-related renal hemodynamic alterations-as an adaptation to reduction in functional nephron mass and/or in response to prevailing metabolic and (neuro)hormonal stimuli-increase glomerular hydraulic pressure and transcapillary convective flux of ultrafiltrate and macromolecules. This phenomenon, known as glomerular hyperfiltration, classically has been hypothesized to predispose to irreversible nephron damage, thereby contributing to initiation and progression of kidney disease in diabetes. However, dedicated studies with appropriate diagnostic measures and clinically relevant end points are warranted to confirm this assumption. In this review, we summarize the hitherto proposed mechanisms involved in diabetic hyperfiltration, focusing on ultrastructural, vascular, and tubular factors. Furthermore, we review available evidence on the clinical significance of hyperfiltration in diabetes and discuss currently available and emerging interventions that may attenuate this renal hemodynamic abnormality. The revived interest in glomerular hyperfiltration as a prognostic and pathophysiologic factor in diabetes may lead to improved and timely detection of (progressive) kidney disease, and could provide new therapeutic opportunities in alleviating the renal burden in this population.

[Chronic kidney disease : What is currently available for treatment?]

Chronic kidney disease is common in the general population with an estimated prevalence of roughly 2 million in Germany. Typically, chronic kidney disease is progressive and in the terminal stage the patients require dialysis or kidney transplantation. In many cases the disease remains silent for a long time but early stages are already associated with increasing morbidity and mortality. Therefore early detection is very important. In recent years several new concepts have been introduced that might help to slow the progression of chronic kidney disease or improve the accompanying risks. Here, we want to provide a nephrologist's perspective on the current guidelines for the treatment and prevention of chronic kidney disease. We summarize which diagnostic approaches are useful for general practitioners and we take a pragmatic look at the existing opportunities for combating renal functional decline. We also shed light on established measures to minimize the risk of comorbidities.

Positive Impact of Nutritional Interventions on Serum Symmetric Dimethylarginine and Creatinine Concentrations in Client-Owned Geriatric Dogs

A prospective study was conducted in client-owned geriatric dogs to evaluate the short-term effects of a test food on serum symmetric dimethylarginine (SDMA) and creatinine (Cr) concentrations. Test food contained functional lipids (fish oil), antioxidants (lipoic acid, vitamins C and E), L-carnitine, botanicals (fruits and vegetables), controlled sodium concentration, and high quality protein sources (high bioavailability and an ideal amino acid composition). Dogs (n = 210) were fed either test food or owner's-choice foods (non-nutritionally controlled cohort). Dogs were included based on age and body weight: small (6.8 to 11.4 kg) and medium dogs (11.5 to 22.7 kg) were ≥ 9 years, whereas dogs >22.7 kg were ≥ 7 years at baseline. At baseline, all dogs had to have serum Cr concentrations within the reference interval and be free of chronic disease. Renal function biomarkers and urinalysis results at baseline, and after consuming test food or owner's-choice foods for 3 and 6 months, were evaluated. Only dogs consuming test food showed significant decreases in serum SDMA and Cr concentrations (both P ≤ 0.05) across time. At baseline or during the 6-month feeding trial, 18 dogs (8.6%) had increased serum SDMA, but normal serum Cr, consistent with IRIS Stage 1 chronic kidney disease. This included 9 dogs fed test food and 9 dogs fed owner's-choice foods. Compared with baseline, after feeding 9 dogs test food for 6 months, serum SDMA decreased in 8 dogs and increased in 1 dog. After feeding 9 dogs owner's-choice foods for 6 months, serum SDMA decreased in 4 dogs and increased in 4 dogs (remained stable in 1 dog). The decreases in serum SDMA and Cr concentrations were significant (both P = 0.03) only for dogs fed test food. These results suggest that nonazotemic dogs with elevated serum SDMA (early renal insufficiency) when fed a test food designed to promote healthy aging are more likely to demonstrate improved renal function compared with dogs fed owner's-choice foods.

Nutritional Interventions that Slow the Age-Associated Decline in Renal Function in a Canine Geriatric Model for Elderly Humans

OBJECTIVE

To determine the effects of feeding traditional and renal protective foods (RPF) supplemented with functional food bioactives on glomerular filtration rate (GFR), lean body percent (LB%), and selected circulating biomarker and metabolite concentrations in a geriatric dog model.

DESIGN

Randomized block design and cross-sectional study.

SETTING

Hill's Pet Nutrition, Inc. dog colony.

PARTICIPANTS

Eighty-one geriatric dogs (mean age, 10.4; range, 7.9-14.2 years) and 30 mature-adult dogs (mean age, 5.0; range, 3.3-6.9 years).

INTERVENTION

Geriatric dogs were fed one of three foods (n = 27 per group) for 6 months: a traditional RPF (control) that was energy dense and mildly protein-restricted, or control food supplemented with increasing amounts of functional food bioactives: fish oil, lipoic acid, fruits and vegetables, and higher quality protein sources [functional foods one (FF1) and two (FF2)]. Geriatric dogs were compared before and after the feeding trial with mature adult dogs.

MEASUREMENTS

Renal function was assessed by GFR, LB% was determined by dual energy x-ray absorptiometry, and circulating biomarkers and metabolites were measured in blood.

RESULTS

Before the feeding trial, GFR (+28.2%), LB% (+18.6%), and serum total protein (+10.0%) were higher in mature versus healthy geriatric dogs (all P<0.001). Geriatric dogs consuming all three foods increased (P<0.001) GFR over time; group averages ranged from 13.0-16.9%. Dogs fed the highest supplemented level of bioactives (FF2) had lower (P<0.001) symmetric dimethylarginine (SDMA) concentrations (-14.3%). Feeding functional foods did not alter body weight, but increased (P<0.001) serum protein concentration (+6.7%).

CONCLUSION

Supplementation with functional food bioactives can temporarily reverse the age-associated decline in renal function and serum total protein.

Recent developments in epigenetics of acute and chronic kidney diseases

The growing epidemic of obesity and diabetes, the aging population as well as prevalence of drug abuse has led to significant increases in the rates of the closely associated acute and chronic kidney diseases, including diabetic nephropathy. Furthermore, evidence shows that parental behavior and diet can affect the phenotype of subsequent generations via epigenetic transmission mechanisms. These data suggest a strong influence of the environment on disease susceptibility and that, apart from genetic susceptibility, epigenetic mechanisms need to be evaluated to gain critical new information about kidney diseases. Epigenetics is the study of processes that control gene expression and phenotype without alterations in the underlying DNA sequence. Epigenetic modifications, including cytosine DNA methylation and covalent post translational modifications of histones in chromatin are part of the epigenome, the interface between the stable genome and the variable environment. This dynamic epigenetic layer responds to external environmental cues to influence the expression of genes associated with disease states. The field of epigenetics has seen remarkable growth in the past few years with significant advances in basic biology, contributions to human disease, as well as epigenomics technologies. Further understanding of how the renal cell epigenome is altered by metabolic and other stimuli can yield novel new insights into the pathogenesis of kidney diseases. In this review, we have discussed the current knowledge on the role of epigenetic mechanisms (primarily DNA me and histone modifications) in acute and chronic kidney diseases, and their translational potential to identify much needed new therapies.

Chronic kidney disease influences multiple systems: describing the relationship between oxidative stress, inflammation, kidney damage, and concomitant disease

Chronic kidney disease (CKD) is characterized by increased levels of oxidative stress and inflammation. Oxidative stress and inflammation promote renal injury via damage to molecular components of the kidney. Unfortunately, relationships between inflammation and oxidative stress are cyclical in that the inflammatory processes that exist to repair radical-mediated damage may be a source of additional free radicals, resulting in further damage to renal tissue. Oxidative stress and inflammation also have the ability to become systemic, serving to injure tissues distal to the site of original insult. This review describes select mediators in the exacerbatory relationship between oxidative stress, inflammation, and CKD. This review also discusses oxidative stress, inflammation, and CKD as they pertain to the development and progression of common CKD-associated comorbidities. Lastly, the utility of several widely accessible and cost-effective lifestyle interventions and their ability to reduce oxidative stress and inflammation are discussed and recommendations for future research are provided.

A Cross-Sectional Comparison of Health Literacy Deficits Among Patients With Chronic Kidney Disease

Inadequate health literacy in people with chronic kidney disease (CKD) is associated with poorer disease management and greater complications. There are limited data on the health literacy deficits of people with CKD. The aim of this study was to investigate the types and extent of health literacy deficits in patients with CKD using the multidimensional Health Literacy Management Scale (HeLMS) and to identify associations between patient characteristics and the domains of health literacy measured by the HeLMS. Invitations to participate were sent to patients with CKD attending the renal unit of a regional Australian hospital. These patients included predialysis, dialysis (peritoneal and hemodialysis), and kidney transplant patients. This study identified that inadequate health literacy--especially in the domains relating to attending to one's health needs, understanding health information, social support, and socioeconomic factors--was common. Male gender and education level were significantly associated with inadequate health literacy. The type and extent of health literacy deficits varied among CKD groups, and transplant patients had more deficits than other CKD patient groups. This study provides useful information for health professionals treating patients with CKD, especially with regard to the design of self-management interventions and health information.