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Introduction: Nutrition and physical activity are two major issues in the management of CKD patients who are often older, have comorbidities and are prone to malnutrition and physical inactivity, conditions that cause loss of quality of life and increase the risk of death. We performed a multidimensional assessment of nutritional status and of physical performance and activity in CKD patients on conservative therapy in order to assess the prevalence of sedentary behaviour and its relationship with body composition., Methods: 115 consecutive stable CKD patients aged 45-80 years were included in the study. They had no major skeletal, muscular or neurological disabilities. All patients underwent a multidimensional assessment of body composition, physical activity and exercise capacity., Results: Sedentary patients, as defined by mean daily METs < 1.5 were older and differed from non-sedentary patients in terms of body composition, exercise capacity and nutrient intake, even after adjusting for age. Average daily METs were positively associated with lean body mass, muscle strength, 6-MWT performance, but negatively associated with fat body mass, body mass index and waist circumference. In addition, a sedentary lifestyle may have negative effects on free fat mass, muscle strength and exercise capacity, and may increase fat body mass. Conversely, s decrease in muscle mass and/or an increase in fat mass may lead to a decrease in physical activity and exercise capacity., Conclusion: There is a clear association and potential interrelationship between nutritional aspects and exercise capacity in older adults with CKD: they are really the two sides of the same coin., (The Author(s). Published by S. Karger AG, Basel.)

The Italian Society of Nephrology has tasked its Working Group on Physical Exercise with developing a consensus statement document on physical activity and exercise in patients with chronic kidney disease (CKD). This paper consists of 16 points that were discussed, and approved using the mini-Delphi method by 15 members of the working group. Each statement is based on a comprehensive review of the literature, clinical experience, and expert opinions. Overall, the statements affirm that regular physical activity and exercise training offer numerous benefits to CKD patients, including improved physical function, enhanced cardiometabolic and neuromuscular function, cognitive benefits, and an overall improvement in quality of life. Furthermore, exercise may provide nephroprotection and reduce mortality. These advantages are observed across all CKD stages, whether on conservative therapy or kidney replacement therapy (hemodialysis or peritoneal dialysis), and in kidney transplant recipients. Moreover, when physical activity and exercise training are implemented with appropriate precautions, they are safe in CKD patients. Gradual physical activity and customized exercise programs should be tailored to the patient's exercise tolerance, potentially enhancing compliance. Clinicians are encouraged to use a series of questionnaires and tests to assess the patient's level of physical activity and performance. However, exercise and physical activity are poorly implemented in clinical practice due to many barriers related to patients and healthcare staff. Overcoming these barriers requires the proactive role of the nephrologists, who should actively incorporate exercise training and promote physical activity within routine care plans. Adopting a multidisciplinary team approach, which includes nephrologists, nurses, exercise professionals, and dietitians, is crucial for providing comprehensive rehabilitation for CKD patients. Integrating new technologies and remote check ups could further enhance the effectiveness of these interventions., (© 2024. The Author(s).)

The presence of sarcopenia has been associated with the worst outcome of Crohn's disease (CD). At present, no studies have evaluated the impact of ustekinumab (UST) in terms of its effects on body composition. The aim of this prospective study was to evaluate whether UST treatment could modify the parameters of body composition as assessed by bioelectrical impedance assay (BIA) in patients with CD. We prospectively enrolled consecutive patients with CD treated with UST, evaluating the therapeutic outcome at week 48 in terms of clinical remission and mucosal healing. BIA was performed at baseline and at week 48, assessing body cellular mass, total body water, phase angle, and body mass index. Out of 44 patients enrolled, 26 (59%) were in clinical remission and 22 (50%) achieved mucosal healing at the end of follow up. No significant differences were observed at baseline in all the BIA parameters between responders and non-responders. Phase angle increased over time in responders, while this was not observed in non-responders (test for the interaction between time and outcome, p -value = 0.009 and 0.007 for clinical remission and mucosal healing, respectively). The same differential increase was observed for body cellular mass (test for the interaction between time and outcome, p -value = 0.03 and 0.05 for clinical remission and mucosal healing, respectively). Total body water and BMI increased homogenously over time regardless of the outcomes (tests for the association with time, p -values of 0.01). To conclude, responsiveness to UST therapy seems to be associated with body composition modifications in patients with CD. In particular, the increase in phase angle in responders suggests that a significant improvement of nutritional status occurred in these patients.

Nutritional and pharmacological therapies represent the basis for non-dialysis management of CKD patients. Both kinds of treatments have specific and unchangeable features and, in certain cases, they also have a synergic action. For instance, dietary sodium restriction enhances the anti-proteinuric and anti-hypertensive effects of RAAS inhibitors, low protein intake reduces insulin resistance and enhances responsiveness to epoetin therapy, and phosphate restriction cooperates with phosphate binders to reduce the net phosphate intake and its consequences on mineral metabolism. It can also be speculated that a reduction in either protein or salt intake can potentially amplify the anti-proteinuric and reno-protective effects of SGLT2 inhibitors. Therefore, the synergic use of nutritional therapy and medications optimizes CKD treatment. Quality of care management is improved and becomes more effective when compared to either treatment alone, with lower costs and fewer risks of unwanted side effects. This narrative review summarizes the established evidence of the synergistic action carried out by the combination of nutritional and pharmacological treatments, underlying how they are not alternative but complementary in CKD patient care.

The aim of this study was to evaluate urinary potassium (K) excretion as a reliable marker of dietary K intake, in a cohort of CKD patients with or without Renin-Angiotensin-Aldosterone System (RAAS) inhibitor therapy. One hundred and thirty-eight consecutive out-patients (51 f and 87 m) aged 60 ± 13 years and affected by CKD stage 3-4, who were metabolically and nutritionally stable, entered the study between November 2021 and October 2022. No difference was observed between patients with ( n = 85) or without ( n = 53) RAAS inhibitor therapy, regarding dietary intakes, blood biochemistry, and 24-h urine excretion parameters. Considering all patients, urinary K showed a weak relationship with eGFR (r = 0.243, p < 0.01), and with dietary K intake (r = 0.184, p < 0.05). Serum K was not associated with dietary K intake, but an inverse relationship was observed with eGFR (r = -0.269, p < 0.01). When patients were examined depending on whether they were receiving RAAS inhibitor therapy, the weak inverse relationship between serum K and eGFR was maintained in both groups. Conversely, urinary K excretion remained positively associated with dietary K intake only in the no RAAS inhibitor group. In conclusion, 24-h urine K excretion may be used as a surrogate of K intake, but RAAS inhibitor therapy reduces the association between 24-h urine K excretion and dietary K intake in CKD patients., Competing Interests: The authors declare no conflict of interest.

A number of studies in the general population showed that healthy dietary patterns, such as the Mediterranean Diet, can improve or prevent the development of several chronic diseases and are associated with a significant reduction in all-cause and cardiovascular mortality. The Mediterranean diet may also have favorable effects for the prevention of chronic kidney disease (CKD), but no evidence of renoprotection exists in CKD patients. The Mediterranean Renal (MedRen) diet is an adaptation of the Mediterranean diet recommendations comprising a quantitative reduction in the RDA values of protein, salt and phosphate intake for the general population. Hence, MedRen supplies 0.8 g/Kg of protein, 6 g of salt and less than 800 mg of phosphate daily. Obviously, there is a preference for products of plant origin, which contain more alkali, fibers, unsaturated fatty acids than animal-based food. The MedRen diet can be implemented easily in mild-to-moderate stages of CKD with good results, both in terms of adherence to prescriptions and metabolic compensation. In our opinion, it should be the first step of CKD stage 3 nutritional management. This paper describes the features and reports our experience in the implementation of the MedRen diet as an early nutritional approach to CKD.

Complementary and alternative medicine (CAM) is often implemented in kidney stone patients. It consists of preparations including different ingredients, such as herbs, probiotics, and vitamins, often together with alkali, that are classified within the dietary supplementation category. The majority of dietary supplements claiming to treat or prevent kidney stones contain ingredients with conflicting or no scientific evidence to support their claims. Clinicians should advise stone formers that the effects of most supplements are unknown or unstudied in humans and that the absence of evidence does not imply absence of potential harm. Unfortunately, the CAM preparation consists of a mix of different molecules, often including alkali, with different potential mechanisms of action and, even when favorable results are reported, the role of the single molecules cannot be assessed. Despite all these concerns, CAM products remain quite popular among kidney stone patients. The scarce knowledge in this field prevents one from recommending CAM products in daily clinical practice; only a weak suggestion for their use in kidney stone patients may be reasonable.

Background: data regarding the association between obesity and morbidity/mortality in patients with chronic kidney disease (CKD) are uncertain and sometimes contradictory. The aims of our study were to determine the associations among different measures of obesity and adiposity, and the risk of all-cause mortality or dialysis entry in stage 3-5 CKD patients., Materials: this observational cohort study included 178 CKD patients followed for a median of 71 months. Biochemistry, anthropometric measures such as body mass index (BMI), waist-to-hip ratio, mid-arm muscle circumference (MAMC) and body composition by bioimpedance analysis were evaluated., Results: we found a weak agreement between BMI and other measures of adiposity. In multivariable regression analysis, all measures of obesity such as BMI, waist circumference and waist-to-height ratio were not associated with dialysis entry and/or mortality. Instead, MAMC was associated with dialysis entry HR 0.82 [95% CI: 0.75-0.89] and high FM% with mortality HR 2.08 [95% CI: 1.04-4.18]., Conclusions: in our CKD population, lower MAMC was predictive of dialysis commencing, while a higher percentage of fatty mass was a predictor of mortality. Instead, obesity, as defined by BMI, is not associated with dialysis commencing or all-cause mortality.

Previous literature studies explored the association between brain neurometabolic changes detected by MR spectroscopy and symptoms in patients with tremor, as well as the outcome after deep brain stimulation (DBS) treatment. The purpose of our study was to evaluate the possible changes in cerebello-thalamo-cortical neurometabolic findings using MR spectroscopy in patients submitted to MRgFUS thalamotomy. For this pilot study, we enrolled 10 ET patients eligible for MRgFUS thalamotomy. All patients were preoperatively submitted to 3T MR spectroscopy. Single-voxel MRS measurements were performed at the level of the thalamus contralateral to the treated side and the ipsilateral cerebellar dentate nucleus. Multivoxel acquisition was used for MRS at the level of the contralateral motor cortex. At the 6-month follow-up after treatment, we found a statistically significant increase in the Cho/Cr ratio at the level of the thalamus, a significant increase of the NAA/Cr ratio at the level of the dentate nucleus and a significant decrease of the NAA/Cho ratio at the level of the motor cortex. We found a significant positive correlation between cortical NAA/Cr and clinical improvement (i.e., tremor reduction) after treatment. A significant negative correlation was found between clinical improvement and thalamic and cerebellar NAA/Cr. Confirming some previous literature observations, our preliminary results revealed neurometabolic changes and suggest a possible prognostic role of the MRS assessment in patients with ET treated by MRgFUS.

Hyperkalemia is a major concern in chronic kidney disease and in end-stage renal disease, representing a predictor of hospitalization and mortality. To prevent and treat hyperkalemia, dietary management is of great clinical interest. Currently, the growing use of plant-based diets causes an increasing concern about potassium load in renal patients. The aim of this study was to assess the bioaccessibility of potassium in vegetables, concerning all aspects of the plants (fruit, flower, root, tuber, leaf and seed) and to what extent different boiling techniques affect potassium content and bioaccessibility of plant-based foods. Bioaccessibility was evaluated by an in vitro digestion methodology, resembling human gastro-intestinal tract. Potassium content was higher in seeds and leaves, despite it not being possible to define a common "rule" according to the type of organ, namely seed, leaf or fruit. Boiling reduced potassium content in all vegetables excluding carrot, zucchini, and cauliflower; boiling starting from cold water contributed to a greater reduction of the potassium content in potato, peas, and beans. Bioaccessibility after in vitro digestion ranged from 12 (peas) to 93% (tomato) regardless of species and organs. Higher bioaccessibility was found in spinach, chicory, zucchini, tomato, kiwi, and cauliflower, and lower bioaccessibility in peas. Potassium from leaf resulted in the highest bioaccessibility after digestion; as a whole potassium bioaccessibility in the fruits and vegetables studied was 67% on average, with differences in relation to the different organs and species. Further, considering the method of boiling to reduce potassium content, these data indicate that the effective potassium load from plant-based foods may be lower than originally expected. This supports the clinical advices to maintain a wide use of plant-based food in the management of renal patients.

The beneficial effects of vegetarian diets are known in the general population and in patients with chronic kidney disease (CKD). In recent years, the market has developed a number of processed plant-based products because of several factors (lifestyle changes, ethical concerns, and sustainability). The composition in terms of nutrients, ingredients, and additives of 560 products available on the market and on online shopping sites was analyzed to understand the characteristics of these products. Processed plant-based meat substitutes have a higher content of salt (+467%), lipids (+26%), mostly unsaturated, and fiber with respect to regular animal-based ones. Protein content is lower (-40%) in plant-based products with respect to corresponding animal ones. Of the 49 additives on the label (on average 2 per product), 20 contain phosphorus, sodium, potassium, or nitrogen. Several plant-based processed products may contain elevated amounts of salt and additives, which make them not optimal for CKD patients. Although a plant-based diet remains a very important tool for CKD nutritional management, patients should be aware regarding the extra content of sodium and additives in processed plant-based products compared to animal-based processed food.

Drugs and food interact mutually: drugs may affect the nutritional status of the body, acting on senses, appetite, resting energy expenditure, and food intake; conversely, food or one of its components may affect bioavailability and half-life, circulating plasma concentrations of drugs resulting in an increased risk of toxicity and its adverse effects, or therapeutic failure. Therefore, the knowledge of these possible interactions is fundamental for the implementation of a nutritional treatment in the presence of a pharmacological therapy. This is the case of chronic kidney disease (CKD), for which the medication burden could be a problem, and nutritional therapy plays an important role in the patient's treatment. The aim of this paper was to review the interactions that take place between drugs and foods that can potentially be used in renal patients, and the changes in nutritional status induced by drugs. A proper definition of the amount of food/nutrient intake, an adequate definition of the timing of meal consumption, and a proper adjustment of the drug dosing schedule may avoid these interactions, safeguarding the quality of life of the patients and guaranteeing the effectiveness of drug therapy. Hence, a close collaboration between the nephrologist, the renal dietitian, and the patient is crucial. Dietitians should consider that food may interact with drugs and that drugs may affect nutritional status, in order to provide the patient with proper dietary suggestions, and to allow the maximum effectiveness and safety of drug therapy, while preserving/correcting the nutritional status.

The correct management of energy intake is crucial in CKD (chronic kidney disease) patients to limit the risk of protein energy wasting especially during low-protein regimes, but also to prevent overweight/obesity. The aim of this study was to assess the energy requirement of older CKD patients using objective measurements. This cross-sectional study enrolled 67 patients (aged 60-86 years) with CKD stages 3-5 not on dialysis, all of whom were metabolically and nutritionally stable. All patients underwent indirect calorimetry and measurement of daily physical activity level expressed by the average daily Metabolic Equivalent Task, using an accelerometer, in order to measure total energy expenditure (mTEE). Estimated TEE (eTEE) was derived from predictive equations for resting energy expenditure and physical activity levels coefficients. The mTEE were lower than eTEE-based on Harris-Benedict or Schofield or Mifflin equations (1689 ± 523 vs. 2320 ± 434 or 2357 ± 410 or 2237 ± 375 Kcal, p < 0.001, respectively). On average mTEE was 36.5% lower than eTEE. When eTEE was recalculated using ideal body weight the gap between mTEE and eTEE was reduced to 26.3%. A high prevalence of a sedentary lifestyle and reduced physical capabilities were also detected. In conclusion, our data support the energy intake of 25-35 Kcal/Kg/d recently proposed by the NKF-KDOQI (National Kidney Foundation-Kidney Disease Improving Quality Initiative) guidelines on nutritional treatment of CKD, which seem to be more adequate and applicable than that of previous guidelines (30-35 Kcal/Kg/d) in elderly stable CKD patients with a sedentary lifestyle. According to our findings we believe that an energy intake even lower than 25 Kcal/Kg/d may be adequate in metabolically stable, elderly CKD patients with a sedentary lifestyle.

The retention of uremic toxins and their pathological effects occurs in the advanced phases of chronic kidney disease (CKD), mainly in stage 5, when the implementation of conventional thrice-weekly hemodialysis is the prevalent and life-saving treatment. However, the start of hemodialysis is associated with both an acceleration of the loss of residual kidney function (RKF) and the shift to an increased intake of proteins, which are precursors of uremic toxins. In this phase, hemodialysis treatment is the only way to remove toxins from the body, but it can be largely inefficient in the case of high molecular weight and/or protein-bound molecules. Instead, even very low levels of RKF are crucial for uremic toxins excretion, which in most cases are protein-derived waste products generated by the intestinal microbiota. Protection of RKF can be obtained even in patients with end-stage kidney disease (ESKD) by a gradual and soft shift to kidney replacement therapy (KRT), for example by combining a once-a-week hemodialysis program with a low or very low-protein diet on the extra-dialysis days. This approach could represent a tailored strategy aimed at limiting the retention of both inorganic and organic toxins. In this paper, we discuss the combination of upstream (i.e., reduced production) and downstream (i.e., increased removal) strategies to reduce the concentration of uremic toxins in patients with ESKD during the transition phase from pure conservative management to full hemodialysis treatment.

Background: Dry weight assessment in hemodialysis (HD) remains a challenge. The aim of the study was to investigate the prevalence of subclinical pulmonary congestion using lung ultrasound (LUS) in maintenance HD patients with no clinical or bioimpedance signs of hyperhydration. The correlation between B-lines Score (BLS) and brain natriuretic peptide (BNP) was also evaluated., Methods: Twenty-four HD patients underwent LUS and BNP dosage at the end of the mid-week HD session, monthly for 6 months . LUS was considered as positive when BLS was >15. Hospitalizations and cardiovascular events were also evaluated in relation to the BLS., Results: LUS+ patients at baseline were 16 (67%), whereas 11 (46%) showed LUS + in at least 50% of the measurements (rLUS+ patients). Only the rLUS+ patients had a higher number of cardiovascular events [p=0.019, OR: 7.4 (CI 95%. 1.32-39.8)] and hospitalizations [p=0.034, OR 5.5 (CI 95% 1.22- 24.89)]. A BNP level of 165 pg/ml was identified as cut-off value for predicting pulmonary congestion, defined by BLS >15., Conclusion: Prevalence of pulmonary congestion as assessed by LUS and persistent or recurrent BLS >15 were quite prevalent findings in euvolemic HD patients. In the patients defined as rLUS+, a higher rate of cardiovascular events and hospital admissions was registered. BNP serum levels > 165 pg/ml resulted predictive of pulmonary congestion at LUS. In the dialysis care, regular LUS examination should be reasonably included among the methods useful to detect subclinical lung congestion and to adjust patients' dry weight.

Dialysis patients show a high rate of reduced functional capacity, morbidity and mortality. Cardiovascular disorders, muscle atrophy and malnutrition play an essential role among the aetiological factors. Sedentary lifestyle characterizes them and contributes to the aggravation of the disorders. On the contrary, exercise training is an important preventive and therapeutic tool both for cardiovascular problems and for the appearance of muscle atrophy in dialysis patients. Regular exercise causes both central (cardiac) and peripheral (muscular) adaptations, improving functional capacity. In particular, circulatory system clinical trials in haemodialysis (HD) patients documented that exercise has favourable effects on heart function, promotes balance on the cardiac autonomic nervous system and contributes to the management of arterial hypertension. In the muscular system, it prevents muscle atrophy or contributes significantly to its treatment. The main preventive mechanisms of the beneficial effect of exercise on the muscles constitute the inhibition of the apoptotic processes and protein degradation. Exercise training in HD patients leads to an increase of muscle fibers, mitochondria and capillaries, and the combination of regular exercise and dietary strategies is even more effective in preventing or treating muscle atrophy. Finally, an improvement in functional capacity and quality of life was found also in peritoneal dialysis patients following exercise training., (© The Author(s) 2021. Published by Oxford University Press on behalf of ERA-EDTA.)

Background: How to manage patients with severe kidney disease in pregnancy is still a matter of discussion, and deciding if and when to start dialysis is based on the specialist's experience and dialysis availability. The effect of toxic substances usually cleared by the kidney may be more severe and readily evident. The review, and related case, underlines the importance of considering the presence of additives in food in delicate conditions, such as CKD pregnancy. The Case: A 39-year-old indigenous woman from a low-resourced area in Mexico was referred to the obstetric nephrology at 25 gestational weeks because of serum creatinine at 3.6 mg/dL, hypertension on low-dose alpha-methyl-dopa, and nephrotic-range proteinuria. Kidney ultrasounds showed small poorly differentiated kidneys; foetal ultrasounds detected a female foetus, normal for gestational age. The patient's baseline protein intake, which was estimated at 1.2-1.3 g/kg/day, was mostly of animal-origin (>70%) poor-quality food ("junk food"). In the proposed diet, protein intake was only slightly reduced (1.0-1.2 g/kg/day), but the source of proteins was changed (only 30% of animal origin) with attention to food quality. A remarkable decrease in BUN was observed, in concomitance with adequate dietary follow-up, with rapid rise of BUN when the patient switched temporarily back to previous habits. A healthy female baby weighing 2,460 g (11th centile for gestational age) was delivered at 37 gestational weeks. Discussion and Literature Review: While data on patients with chronic kidney disease are scant, the long list of contaminants present in food, especially if of low quality, should lead us to reflect on their potential negative effect on kidney function and make us realize that eating healthy, unprocessed "organic" food should be encouraged, in delicate conditions such as pregnancy and breastfeeding and for young children, in particular when kidney function is failing. The case herein described gave us the opportunity to reflect on the importance of diet quality and on the potential risks linked to food additives, many of which, including phosphates and potassium, are not declared on food labels, while others, including dyes, antioxidants, thickeners, emulsifiers, and preservatives, are qualitatively, but not quantitatively, reported., (© 2021 The Author(s). Published by S. Karger AG, Basel.)

Hyperkalemia (HK) is a frequent complication of chronic kidney disease (CKD). Vegetable-based renal diets are considered at risk due to the high potassium (K) content. The aim of this study was to describe the prevalence and correlates of chronic hyperkalemia (HK) in CKD patients on nutritional care, and in particular, the risk of HK in patients on plant-based versus animal-based low-protein diets. We recruited adult patients affected by CKD not on dialysis, afferent to our renal nutrition clinic from November 2014 to May 2019. We evaluated a total of 870 accesses in 219 patients (172 m, 47 f, age 67 ± 13 years). HK was defined as mild when K serum level was 5.1-5.9 mEq/l, moderate when K serum level was 6.0-6.9 mEq/l, and severe HK when K serum level was ≥ 7 mEq/l. Biochemical, anthropometric data and medications were recorded. The prevalence of HK in all the renal nutrition visits was 26.1%; all but six cases were mild HK, whereas no severe HK was observed. The prevalence of HK was associated with decreased eGFR, up to 36.5% for eGFR < 20 ml/min. Medications were similar in hyperkalemic and normokalemic patients, RAASi being present in up to 85% of patients. In a follow-up of 40 ± 14 months, no association was found between HK and mortality, whereas HK, at the start of follow-up, showed a trend to increased ESRD risk. Serum potassium levels and prevalence of HK were not different between patients on animal-based low-protein diet and plant-based low-protein diet. In conclusion, chronic HK is quite prevalent in a renal nutrition clinic, especially when eGFR falls down below 60 ml/min, thereby reaching the highest prevalence in CKD stage 4. Hyperkalemia is mostly mild, being moderate to severe HK quite infrequent. Hyperkalemia was not associated with higher risk of mortality, whereas a trend, although not statistically significant, was observed for lower ESRD-free survival. Plant-based low-protein diet is not associated with significant higher prevalence of HK with respect to animal-based LPD at the same residual kidney function.

Sodium-glucose-transporter 2 inhibitors (SGLT2i) are a new class of anti-diabetic drugs that in large trials such as CREDENCE have shown also a reduction of glomerular hyperfiltration and albuminuria in type 2 diabetic patients. Hence, the interest toward SGLT2i is focused toward this potential nephroprotective effect, in order to reduce the progression to overt nephropathy, and it seems to be confirmed in the most recent DAPA-CKD trial. This is the reason why the indication for SGLT2i treatment has been extended to chronic kidney disease (CKD) patients with eGFR up to 30 ml/min, namely with CKD stage 1-3. In patients with CKD stage 3 to 5, the most recent KDIGO guidelines recommend low-protein diet and plant-based regimens to delay end-stage kidney disease (ESKD) and improve quality of life. Similarly to SGLT2i, low-protein diets exert renal-protective effects by reducing single nephron hyperfiltration and urinary protein excretion. Beyond the glomerular hemodynamic effects, both protein restriction and SGLT2i are able to restore autophagy and, through these mechanisms, they may exert protective effects on diabetic kidney disease. In this perspective, it is likely that diet may modulate the effect of SGLT2i in CKD patients. Unfortunately, no data are available on the outcomes of the association of SGLT2i and low-protein and/or vegan diets. It is therefore reasonable to investigate whether CKD patients receiving SGLT2i may have further advantages in terms of nephroprotection from the implementation of a low-protein and/or plant-based diet or whether this association does not result in an additive effect, especially in vascular nephropathies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Cupisti, Giannese, Moriconi, D'Alessandro, Torreggiani and Piccoli.)

The 2020 Kidney Disease Outcome Quality Initiative (KDOQI) Clinical Practice Guideline for Nutrition in chronic kidney disease (CKD) recommends protein restriction to patients affected by CKD in stages 3 to 5 (not on dialysis), provided that they are metabolically stable, with the goal to delay kidney failure (graded as evidence level 1A) and improve quality of life (graded as evidence level 2C). Despite these strong statements, low protein diets (LPDs) are not prescribed by many nephrologists worldwide. In this review, we challenge the view of protein restriction as an "option" in the management of patients with CKD, and defend it as a core element of care. We argue that LPDs need to be tailored and patient-centered to ensure adherence, efficacy, and safety. Nephrologists, aligned with renal dietitians, may approach the implementation of LPDs similarly to a drug prescription, considering its indications, contra-indications, mechanism of action, dosages, unwanted side effects, and special warnings. Following this framework, we discuss herein the benefits and potential harms of LPDs as a cornerstone in CKD management.

Muscle wasting is a frequent finding in patients with chronic kidney disease (CKD), especially in those with end-stage kidney disease (ESKD) on chronic dialysis. Muscle wasting in CKD is a main feature of malnutrition, and results principally from a vast array of metabolic derangements typical of the syndrome, that converge in determining reduced protein synthesis and accelerated protein catabolism. In this clinical setting, muscle wasting is also frequently associated with disability, frailty, infections, depression, worsened quality of life and increased mortality. On these grounds, the evaluation of nutritional status is crucial for an adequate management of renal patients, and consists of a comprehensive assessment allowing for the identification of malnourished patients and patients at nutritional risk. It is based essentially on the assessment of the extent and trend of body weight loss, as well as of spontaneous dietary intake. Another key component of this evaluation is the determination of body composition, which, depending on the selected method among several ones available, can identify accurately patients with decreased muscle mass. The choice will depend on the availability and ease of application of a specific technique in clinical practice based on local experience, staff resources and good repeatability over time. Surrogate methods, such as anthropometry and bioimpedance analysis (BIA), represent the most readily available techniques. Other methods based on imaging modalities [dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and whole body computed tomography (CT)] are considered to be the "gold standard" reference methods for muscle mass evaluation, but their use is mainly confined to research purposes. New imaging modalities, such as segmental CT scan and muscle ultrasound have been proposed in recent years. Particularly, ultrasound is a promising technique in this field, as it is commonly available for bedside evaluation of renal patients in nephrology wards. However, more data are needed before a routine use of ultrasound for muscle mass evaluation can be recommended in clinical practice., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/qims.2020.03.05). The special issue “Body Composition Imaging” was commissioned by the editorial office without any funding or sponsorship. GG served as the unpaid Guest Editor of the special issue and serves as an unpaid editorial board member of Quantitative Imaging in Medicine and Surgery. AB served as the unpaid Guest Editor of the special issue. The authors have no other conflicts of interest to declare., (2020 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

In the almost 30 years that have passed since the postulation of the "Developmental Origins of Health and Disease" theory, it has been clearly demonstrated that a mother's dietary habits during pregnancy have potential consequences for her offspring that go far beyond in utero development. Protein malnutrition during pregnancy, for instance, can cause severe alterations ranging from intrauterine growth retardation to organ damage and increased susceptibility to hypertension, diabetes mellitus, cardiovascular diseases and chronic kidney disease (CKD) later in life both in experimental animals and humans. Conversely, a balanced mild protein restriction in patients affected by CKD has been shown to mitigate the biochemical derangements associated with kidney disease and even slow its progression. The first reports on the management of pregnant CKD women with a moderately protein-restricted plant-based diet appeared in the literature a few years ago. Today, this approach is still being debated, as is the optimal source of protein during gestation in CKD. The aim of this report is to critically review the available literature on the topic, focusing on the similarities and differences between animal and clinical studies.

Background: Concerns about adherence and quality of life (QoL) limit the diffusion of low-protein diets (LPDs) as a way to slow chronic kidney disease (CKD) progression and postpone dialysis. The aim of this multicentre study is to assess dietary satisfaction in stable CKD patients., Methods: This was a multicentre cross-sectional study with long-term follow-up data. Prevalent patients on LPD for at least 6 months were selected in four Italian centres. QoL was assessed using the World Health Organization Quality of Life questionnaire, and diet satisfaction with the Modification of Diet in Renal Disease satisfaction questionnaire. Comorbidity was assessed by Charlson Comorbidity Index, estimated glomerular filtration rate (eGFR) was calculated by the CKD Epidemiology Collaboration equation and protein intake by Maroni-Mitch formula. Survival was analysed with Kaplan-Meier curves and Cox Proportional Hazard Model., Results: Four hundred and twenty-two CKD Stages 3-5 patients were enrolled. Over 95% were on moderately restricted diets (0.6 g/kg/day). Compliance was good (protein intake: 0.59 g/kg/day at baseline, 0.72 at the end of follow-up). Median dietary satisfaction was 4 on a 1-5 scale. QoL was not affected by the type of diet, but was influenced by age, comorbidity and setting of care. Two years later, at the end of follow-up, 66.6% of the patients were still on a diet; the main causes of discontinuation were dialysis and death. The dropout rate was low (5.5%); in Cox analysis, patient and renal survival were influenced by age and eGFR, but not by QoL, setting of care or type of diet., Conclusions: LPDs are compatible with high dietary satisfaction and minimal dropout, at least in patients who are able to follow such a diet for at least 6 months., (© The Author(s) 2019. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Dialysis and nutrition are two sides of the same coin-dialysis depurates metabolic waste that is typically produced by food intake. Hence, dietetic restrictions are commonly imposed in order to limit potassium and phosphate and avoid fluid overload. Conversely, malnutrition is a major challenge and, albeit to differing degrees, all nutritional markers are associated with survival. Dialysis-related malnutrition has a multifactorial origin related to uremic syndrome and comorbidities but also to dialysis treatment. Both an insufficient dialysis dose and excessive removal are contributing factors. It is thus not surprising that dialysis alone, without proper nutritional management, often fails to be effective in combatting malnutrition. While composite indexes can be used to identify patients with poor prognosis, none is fully satisfactory, and the definitions of malnutrition and protein energy wasting are still controversial. Furthermore, most nutritional markers and interventions were assessed in hemodialysis patients, while hemodiafiltration and peritoneal dialysis have been less extensively studied. The significant loss of albumin in these two dialysis modalities makes it extremely difficult to interpret common markers and scores. Despite these problems, hemodialysis sessions represent a valuable opportunity to monitor nutritional status and prescribe nutritional interventions, and several approaches have been tried. In this concept paper, we review the current evidence on intradialytic nutrition and propose an algorithm for adapting nutritional interventions to individual patients., Competing Interests: None regarding the present concept paper.

Estimating the euvolemia and dry weight of hemodialysis patients still represents a challenge for the nephrologist, since both dehydration and hyperhydration are associated with intradialytic events and cardiovascular complications in the short and long term. Despite the need for a precise and objective definition of the dry weight for the individual patient on dialysis, this is usually determined on a clinical basis. To obtain greater sensitivity the dosage of natriuretic peptides, Bioelectrical Impedance Analysis (BIA) and, more recently, Lung Ultra-Sound (LUS) can all be used. The BIA allows to estimate the subject's body composition and, in particular, the distribution of body fluids. The presence of hyperhydration, as determined through the BIA, is predictive of an increased mortality in numerous observational studies. In recent years, pulmonary ultrasound has taken on an increasingly important role not only within the cardiology and intensive care units, but also in a nephrology setting, especially in dialysis. The purpose of this article is to analyze the advantages and limitations of the methods that can be used to assess the dry weight of patients undergoing hemodialysis treatment., (Copyright by Società Italiana di Nefrologia SIN, Rome, Italy.)

Nutrition is crucial for the management of patients affected by chronic kidney disease (CKD) to slow down disease progression and to correct symptoms. The mainstay of the nutritional approach to renal patients is protein restriction coupled with adequate energy supply to prevent malnutrition. However, other aspects of renal diets, including fiber content, can be beneficial. This paper summarizes the latest literature on the role of different types of dietary fiber in CKD, with special attention to gut microbiota and the potential protective role of renal diets. Fibers have been identified based on aqueous solubility, but other features, such as viscosity, fermentability, and bulking effect in the colon should be considered. A proper amount of fiber should be recommended not only in the general population but also in CKD patients, to achieve an adequate composition and metabolism of gut microbiota and to reduce the risks connected with obesity, diabetes, and dyslipidemia.

Background and objectives : Diabetes is largely prevalent in the chronic kidney disease (CKD) population. Both conditions have metabolic and nutritional abnormalities that affect body composition and the presence of diabetes makes the dietary management of CKD patients more difficult. The aim of this study was to assess peculiar nutritional and functional aspects of diabetic patients in an adult/elderly CKD population, and their predictive significance. Materials and methods : This prospective cohort study included 144 out-patients aged >55 years, affected by stage 3b-4 CKD, on tertiary care clinic; 48 (40 males) were type 2 diabetics and 96 (80 males) were nondiabetics. The two groups have similar age, gender, and residual renal function (30 ± 9 vs. 31 ± 11 mL/min×1.73). All patients underwent a comprehensive nutritional and functional assessment and were followed for 31 ± 14 months. Results : Diabetic CKD patients showed higher waist circumference and fat body mass, lower muscle mass, and lower number of steps per day and average daily METs. Meanwhile, resting energy expenditure (REE), as assessed by indirect calorimetry, and dietary energy intake were similar as well as hand-grip and 6 min walking test. Diabetic patients did not show a greater risk for all-cause mortality and renal death with respect to nondiabetics. Middle arm muscle circumference, phase angle, serum cholesterol, and serum albumin were negatively related to the risk of mortality and renal death after adjustment for eGFR. Conclusions : CKD diabetic patients differed from nondiabetics for a greater fat mass, lower muscle mass, and lower physical activity levels. This occurred at the same REE and dietary energy intake. The outcome of diabetic or nondiabetic CKD patients on tertiary care management was similar in terms of risk for mortality or renal death. Given the same residual renal function, low levels of muscle mass, phase angle, serum albumin, and cholesterol were predictive of poor outcome. Overall, a malnutrition phenotype represents a major predictor of poor outcome in diabetic and nondiabetic CKD patients., Competing Interests: Funding: This research received no external funding

Kidney stone disease should be viewed as a systemic disorder, associated with or predictive of hypertension, insulin resistance, chronic kidney disease and cardiovascular damage. Dietary and lifestyle changes represent an important strategy for the prevention of kidney stone recurrences and cardiovascular damage. A full screening of risk factors for kidney stones and for cardiovascular damage should be recommended in all cases of calcium kidney stone disease, yet it is rarely performed outside of stone specialist clinics. Many patients have a history of kidney stone disease while lacking a satisfactory metabolic profile. Nonetheless, in a real-world clinical practice a rational management of kidney stone patients is still possible. Different scenarios, with different types of dietary approaches based on diagnosis accuracy level can be envisaged. The aim of this review is to give patient-tailored dietary suggestions whatever the level of clinical and biochemistry evaluation. This can help to deliver a useful recommendation, while avoiding excessive dietary restrictions especially when they are not based on a specific diagnosis, and therefore potentially useless or even harmful. We focused our attention on calcium stones and the different scenarios we may find in the daily clinical practice, including the case of patients who reported renal colic episodes and/or passed stones with no information on stone composition, urinary risk factors or metabolic cardiovascular risk factors; or the case of patients with partial and incomplete information; or the case of patients with full information on stone composition, urinary risk factors and metabolic cardiovascular profile.

Background: Sarcopenia is a widespread concern in chronic kidney disease (CKD) as well in elderly patients and is one of the main reasons why low-protein diets for this population are controversial. The aim of this study was to assess the prevalence and correlates of sarcopenia among elderly male patients affected by CKD followed up in an outpatient nephrology clinic, where moderate protein restriction (0.6⁻0.8 g/Kg/day) is routinely recommended to patients in CKD stage 3b-5 not on dialysis., Methods: This observational study included 80 clinically-stable male out-patients aged >60, affected by stage 3b-4 CKD. Forty patients aged ≥75 (older seniors) were compared to the other forty patients aged 60⁻74 (younger seniors). All patients underwent a comprehensive nutritional and functional assessment., Results: Older seniors showed lower serum albumin, hand-grip strength, body mass index (BMI), skeletal muscle mass, and resting energy expenditure. Protein intake was significantly lower in older seniors whereas energy intake was similar. Average daily physical activity was lower in the older seniors than in the younger ones. Sarcopenia was more prevalent in older than in younger seniors. Among older seniors, sarcopenic and non-sarcopenic ones differed in age and performance on the Six-Minute Walk test, whereas the estimated glomerular filtration rate (eGFR), biochemistry, dietary protein, and energy intakes were similar., Conclusions: Older senior CKD male patients have lower muscle mass, muscle strength, and physical capacity and activity levels, with a higher prevalence of sarcopenia than younger patients. This occurs at the same residual renal function and metabolic profile and protein intake. Energy intake was at the target in both subgroups. In this CKD cohort, sarcopenia was associated with age and physical capacity, but not with eGFR or dietary intakes.

CKD-related nutritional therapy (NT) is a crucial cornerstone of CKD patients' treatment, but the role of NT has not been clearly investigated in autosomal dominant polycystic kidney disease (ADPKD). Several clinical studies have focused on new pharmacological approaches to delay cystic disease progression, but there are no data on dietary interventions in ADPKD patients. The aim of this paper is to analyze the evidence from the literature on the impact of five nutritional aspects (water, sodium, phosphorus, protein intake, and net acid load) in CKD-related ADPKD extrapolating-where information is unavailable-from what occurs in CKD non-ADPKD patients Sodium intake restriction could be useful in decreasing the growth rate of cysts. Although further evidence is needed, restriction of phosphorus and protein intake restriction represent cornerstones of the dietary support of renal non-ADPKD patients and common sense can guide their use. It could be also helpful to limit animal protein, increasing fruit and vegetables intake together with a full correction of metabolic acidosis. Finally, fluid intake may be recommended in the early stages of the disease, although it is not to be prescribed in the presence of moderate to severe reduction of renal function.

The Italian nephrology has a long tradition and experience in the field of dietetic-nutritional therapy (DNT), which is an important component in the conservative management of the patient suffering from a chronic kidney disease, which precedes and integrates the pharmacological therapies. The objectives of DNT include the maintenance of an optimal nutritional status, the prevention and / or correction of signs, symptoms and complications of chronic renal failure and, possibly, the delay in starting of dialysis. The DNT includes modulation of protein intake, adequacy of caloric intake, control of sodium and potassium intake, and reduction of phosphorus intake. For all dietary-nutritional therapies, and in particular those aimed at the patient with chronic renal failure, the problem of patient adherence to the dietetic-nutritional scheme is a key element for the success and safety of the DNT and it can be favored by an interdisciplinary and multi-professional approach of information, education, dietary prescription and follow-up. This consensus document, which defines twenty (20) essential points of the nutritional approach to patients with advanced chronic renal failure, has been written, discussed and shared by the Italian nephrologists together with representatives of dietitians (ANDID) and patients (ANED)., (Copyright by Società Italiana di Nefrologia SIN, Rome, Italy.)

The Italian nephrology has a long tradition and experience in the field of dietetic-nutritional therapy (DNT), which is an important component in the conservative management of the patient suffering from a chronic kidney disease, which precedes and integrates the pharmacological therapies. The objectives of DNT include the maintenance of an optimal nutritional status, the prevention and/or correction of signs, symptoms and complications of chronic renal failure and, possibly, the delay in starting of dialysis. The DNT includes modulation of protein intake, adequacy of caloric intake, control of sodium and potassium intake, and reduction of phosphorus intake. For all dietary-nutritional therapies, and in particular those aimed at the patient with chronic renal failure, the problem of patient adherence to the dietetic-nutritional scheme is a key element for the success and safety of the DNT and it can be favored by an interdisciplinary and multi-professional approach of information, education, dietary prescription and follow-up. This consensus document, which defines twenty essential points of the nutritional approach to patients with advanced chronic renal failure, has been written, discussed and shared by the Italian nephrologists together with representatives of dietitians (ANDID) and patients (ANED).

Whereas the adequate intake of potassium is relatively high in healthy adults, i.e., 4.7 g per day, a dietary potassium restriction of usually less than 3 g per day is recommended in the management of patients with reduced kidney function, especially those who tend to develop hyperkalaemia including patients who are treated with angiotensin pathway modulators. Most potassium-rich foods are considered heart-healthy nutrients with high fibre, high anti-oxidant vitamins and high alkali content such as fresh fruits and vegetables; hence, the main challenge of dietary potassium management is to maintain high fibre intake and a low net fixed-acid load, because constipation and metabolic acidosis are per se major risk factors for hyperkalaemia. To achieve a careful reduction of dietary potassium load without a decrease in alkali or fibre intake, we recommend the implementation of certain pragmatic dietary interventions as follows: Improving knowledge and education about the type of foods with excess potassium (per serving or per unit of weight); identifying foods that are needed for healthy nutrition in renal patients; classification of foods based on their potassium content normalized per unit of dietary fibre; education about the use of cooking procedures (such as boiling) in order to achieve effective potassium reduction before eating; and attention to hidden sources of potassium, in particular additives in preserved foods and low-sodium salt substitutes. The present paper aims to review dietary potassium handling and gives information about practical approaches to limit potassium load in chronic kidney disease patients at risk of hyperkalaemia., Competing Interests: A.C. received consulting fees from Vifor Fresenius, Shire, Abbott. C.P.K. received consulting fees from Abbott, Abbvie, Amgen, Bayer, Keryx and Sanofi-aventis and research support from Shire. K.K.-Z. received commercial honoraria and/or support from Abbott, Abbvie, Alexion, Amgen, Astra-Zeneca, Aveo, Chugai, DaVita, Fresenius, Genentech, Haymarket Media, Hospira, Kabi, Keryx, Novartis, Pfizer, Relypsa, Resverlogix, Sandoz, Sanofi, Shire, Vifor, UpToDate and ZS-Pharma. (US government agencies (such as NIH) and non-for profit foundations or societies (such as NKF) are not listed, while K.K.-Z. have also received additional honoraria from such entities).

Background: This study aimed to evaluate the prevalence of sedentarism, and to assess physical capacity and nutritional status in a cohort of older patients on peritoneal dialysis (PD), with respect to age-matched non-dialysis CKD population, using highly accessible, simple methods, namely the Rapid Assessment of Physical activity (RAPA) test and the 30″ Sit-to-stand (STS) test., Methods: This cross-sectional multicenter study included 151 renal patients older than 60 years; 71 pts. (44 m, age 72 ± 7 yrs) were on PD and 80 pts. (63 m, age 74 ± 7 yrs) were affected by 3-4 stage CKD., Results: The prevalence of sedentary/underactive patients was double of that of the active patients as assessed by RAPA test, both in the PD (65.3%) and in the CKD (67.5%) cohort. The 30"STS test showed a reduced physical performance in both groups: 84.5% of PD patients and 87.5% of CKD patients did not reach the expected number of stands by age and gender. A malnutrition-inflammation score (MIS) ≥ 6 occurred in 37 % of PD patients and in 2.5 % of CKD patients. In PD patients, an independent significant association was observed between 30"STS test and MIS (beta -0.510, p = 0.013), as well as between RAPA and MIS (beta -0.544, p = 003) and phase angle (beta -0.506, p = 0.028)., Conclusions: A high prevalence of low- performance capacity and sedentarism has been detected among elderly patients on PD or with CKD stage 3-4. Apart from age, a condition of malnutrition-inflammation was the major determinant of poor physical activity and capacity in PD patients. Better body composition seems to be positively associated with physical activity in PD and with physical capacity in CKD patients. Routine clinical management should include a close evaluation of nutritional status and evaluation of physical activity and capacity which can be easily assessed by RAPA and 30″STS tests.

Renal diets for advanced chronic kidney disease (CKD) are structured to achieve a lower protein, phosphate and sodium intake, while supplying adequate energy. The aim of this nutritional intervention is to prevent or correct signs, symptoms and complications of renal insufficiency, delaying the start of dialysis and preserving nutritional status. This paper focuses on three additional aspects of renal diets that can play an important role in the management of CKD patients: the vitamin K1 and fiber content, and the alkalizing potential. We examined the energy and nutrients composition of four types of renal diets according to their protein content: normal diet (ND, 0.8 g protein/kg body weight (bw)), low protein diet (LPD, 0.6 g protein/kg bw), vegan diet (VD, 0.7 g protein/kg bw), very low protein diet (VLPD, 0.3 g protein/kg bw). Fiber content is much higher in the VD and in the VLPD than in the ND or LPD. Vitamin K1 content seems to follow the same trend, but vitamin K2 content, which could not be investigated, might have a different pattern. The net endogenous acid production (NEAP) value decreases from the ND and LPD to the vegetarian diets, namely VD and VLPD; the same finding occurred for the potential renal acid load (PRAL). In conclusion, renal diets may provide additional benefits, and this is the case of vegetarian diets. Namely, VD and VLPD also provide high amounts of fibers and Vitamin K1, with a very low acid load. These features may have favorable effects on Vitamin K1 status, intestinal microbiota and acid-base balance. Hence, we can speculate as to the potential beneficial effects on vascular calcification and bone disease, on protein metabolism, on colonic environment and circulating levels of microbial-derived uremic toxins. In the case of vegetarian diets, attention must be paid to serum potassium levels.

The history of dialysis and diet can be viewed as a series of battles waged against potential threats to patients' lives. In the early years of dialysis, potassium was identified as "the killer", and the lists patients were given of forbidden foods included most plant-derived nourishment. As soon as dialysis became more efficient and survival increased, hyperphosphatemia, was identified as the enemy, generating an even longer list of banned aliments. Conversely, the "third era" finds us combating protein-energy wasting. This review discusses four questions and four paradoxes, regarding the diet-dialysis dyad: are the "magic numbers" of nutritional requirements (calories: 30-35 kcal/kg; proteins > 1.2 g/kg) still valid? Are the guidelines based on the metabolic needs of patients on "conventional" thrice-weekly bicarbonate dialysis applicable to different dialysis schedules, including daily dialysis or haemodiafiltration? The quantity of phosphate and potassium contained in processed and preserved foods may be significantly different from those in untreated foods: what are we eating? Is malnutrition one condition or a combination of conditions? The paradoxes: obesity is associated with higher survival in dialysis, losing weight is associated with mortality, but high BMI is a contraindication for kidney transplantation; it is difficult to limit phosphate intake when a patient is on a high-protein diet, such as the ones usually prescribed on dialysis; low serum albumin is associated with low dialysis efficiency and reduced survival, but on haemodiafiltration, high efficiency is coupled with albumin losses; banning plant derived food may limit consumption of "vascular healthy" food in a vulnerable population. Tailored approaches and agreed practices are needed so that we can identify attainable goals and pursue them in our fragile haemodialysis populations.

Background & Aims: Vitamin K acts as a coenzyme in the γ-carboxylation of vitamin K-dependent proteins, including coagulation factors, osteocalcin, matrix Gla protein (MGP), and the growth arrest-specific 6 (GAS6) protein. Osteocalcin is a key factor for bone matrix formation. MGP is a local inhibitor of soft tissue calcification. GAS6 activity prevents the apoptosis of vascular smooth muscle cells. Few data on vitamin K intake in chronic kidney disease patients and no data in patients on a Mediterranean diet are available. In the present study, we evaluate the dietary intake of vitamin K1 in a cohort of patients undergoing haemodialysis., Methods: In this multi-centre controlled observational study, data were collected from 91 patients aged >18 years on dialysis treatment for at least 12 months and from 85 age-matched control subjects with normal renal function. Participants completed a food journal of seven consecutive days for the estimation of dietary intakes of macro- and micro-nutrients (minerals and vitamins)., Results: Compared to controls, dialysis patients had a significant lower total energy intake, along with a lower dietary intake of proteins, fats, carbohydrates, fibres, and of all the examined minerals (Ca, P, Fe, Na, K, Zn, Cu, and Mg). With the exception of vitamin B12, vitamins intake followed a similar pattern, with a lower intake in vitamin A, B1, B2, C, D, E, folates, K1 and PP. These finding were confirmed also when normalized for total energy intake or for body weight. In respect to the adequate intakes recommended in the literature, the prevalence of a deficient vitamin K intake was very high (70-90%) and roughly double than in controls. Multivariate logistic model identified vitamin A and iron intake as predictors of vitamin K deficiency., Conclusions: Haemodialysis patients had a significantly low intake in vitamin K1, which could contribute to increase the risk of bone fractures and vascular calcifications. Since the deficiency of vitamin K intake seems to be remarkable, dietary counselling to HD patients should also address the adequacy of vitamin K dietary intake and bioavailability. Whether diets with higher amounts of vitamin K1 or vitamin K supplementation can improve clinical outcomes in dialysis patients remains to be demonstrated., (Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Background and Aims: Reduction of intestinal load of phosphorus is important for the prevention and treatment of chronic kidney disease (CKD)-mineral and bone disorder (MBD). However, this strategy is limited by patients' poor adherence to dietary prescription and by the existence of hidden sources of phosphorus. In addition to food containing phosphate-based additives, it was recently claimed that medications may contribute to increase the load of phosphate (P), mainly present as an excipient. To identify medications containing P as an excipient, we performed a systematic screening of medications which could potentially be prescribed for chronic oral therapies in CKD patients., Methods: We examined 311 active pharmaceutical ingredients (APIs) and 3763 branded or generic medications, identified by the anatomical therapeutic chemical (ATC) international classification system., Results: Sixty APIs (19.3 %) included at least one medication containing P as an excipient. In total, 472 medications (12.5 %) listed P as an excipient. The prevalence of medications containing phosphate as an excipient was highest for oral antidiabetic medications (23.8 %), followed by antidepressant (19.2 %), antihypertensive (17.5 %) and gastro-intestinal tract (16.4 %) medications. All other classes showed a prevalence <10 %. Within each ATC class, the APIs at risk of containing phosphate were identified as well as the prevalence of both branded and generic medications. Calcium hydrogen phosphate was the most prevalent form (77.7 %) of phosphate as an excipient., Conclusions: Our results suggest that the prevalence of phosphate-containing medications is quite low and it is possible to identify, within each drug category, the medications containing P as an excipient. Calcium phosphate, the most prevalent form, has a lower rate of intestinal absorption than sodium phosphate salts. We did not measure the actual P content, but existing data (measured or estimated) show that it is generally low, except for a few medications that can be easily identified. Thus, the extra-phosphate load from medications may be of concern only in special cases, which could be further limited when correct information and prescriptions are given. The extra-phosphate load from P-containing food and beverages remains the main concern of hidden phosphorus sources in CKD patients.

Background: Dietary treatment is helpful in CKD patients, but nutritional interventions are scarcely implemented. The main concern of the renal diets is its feasibility with regards to daily clinical practice especially in the elderly and co-morbid patients. This study aimed to evaluate the effects of a pragmatic, step-wise, personalized nutritional support in the management of CKD patients on tertiary care., Methods: This is a case-control study. It included 823 prevalent out-patients affected by CKD stage 3b to 5 not-in-dialysis, followed by tertiary care in nephrology clinics; 305 patients (190 males, aged 70 ± 12 years) received nutritional support (nutritional treatment Group, NTG); 518 patients (281 males, aged 73 ± 13 years) who did not receive any dietary therapy, formed the control group (CG). In the NTG patients the dietary interventions were assigned in order to prevent or correct abnormalities and to maintain a good nutritional status. They included manipulation of sodium, phosphate, energy and protein dietary intakes while paying special attention to each patient's dietary habits., Results: Phosphate and BUN levels were lower in the NTG than in the CG, especially in stage 4 and 5. The prevalence of hyperphosphatemia was lower in the NTG than in CG in stage 5 (13.3 % vs 53.3 %, p < 001, respectively), in stage 4 (4.1 % vs 18.3 % vs, p < 0.001) and stage 3b (2.8 % vs 9.5 % p < 0.05). Serum albumin was higher in NTG than in CG especially in stage 5 . The use of calcium-free intestinal phosphate binders was significantly lower in NTG than in CG (11 % vs 19 % p < 0.01), as well as that of Erythropoiesis stimulating agents (11 % vs 19 %, p < 0.01), and active Vitamin D preparations (13 % vs 21 %, p < 0.01)., Conclusions: This case-control study shows the usefulness of a nutritional support in addition to the pharmacological good practice in CKD patients on tertiary care. Lower phosphate and BUN levels are obtained together with maintenance of serum albumin levels. In addition, a lower need of erythropoiesis stimulating agents, phosphate binders and active Vitamin D preparations was detected in NTG. This study suggests that a nutritional support may be useful in the management of the world-wide growing CKD burden.

Dietary therapy represents an important tool in the management of chronic kidney disease (CKD), mainly through a balanced reduction of protein intake aimed at giving the remnant nephrons in damaged kidneys a "functional rest". While dialysis, transplantation, and pharmacological therapies are usually seen as "high tech" medicine, non pharmacological interventions, including diets, are frequently considered lifestyle-complementary treatments. Diet is one of the oldest CKD treatments, and it is usually considered a part of "mainstream" management. In this narrative review we discuss how the lessons of complementary alternative medicines (CAMs) can be useful for the implementation and study of low-protein diets in CKD. While high tech medicine is mainly prescriptive, prescribing a "good" life-style change is usually not enough and comprehensive counselling is required; the empathic educational approach, on which CAMs are mainly, though not exclusively based, may support a successful personalized nutritional intervention.There is no gold-standard, low-protein diet for all CKD patients: from among a relatively vast choice, the best compliance is probably obtained by personalization. This approach interferes with the traditional RCT-based analyses which are grounded upon an assumption of equal preference of treatments (ideally blinded). Whole system approaches and narrative medicine, that are widely used in the study of CAMs, may offer ways to integrate EBM and personalised medicine in the search for innovative solutions respecting individualization, but gaining sound data, such as with partially-randomised patient preference trials.

Nutritional abnormalities and physical inactivity are risk factors of increased morbidity and mortality in patients with ESRD. Identify and define malnutrition, in particular protein-energy depletion (PEW), is an important task in the management of renal patients. The aim of this multicenter observational study was to implement the assessment of nutritional status and functional capacity in patients on peritoneal dialysis, including tests and validated methods which are relatively easy to apply in daily clinical practice. The study includes all the 133 prevalent patients (80 m, 53 f, age 65 14 years), in peritoneal dialysis treatment (vintage 26 19 months) in 9 centers in Tuscany. We performed anthropometry, bioimpedance (BIA), clinical biochemistry, evaluation of habitual physical activity (RAPA tests) and performance (Sit-To-Stand test), appetite-evaluation questionnaire, and indices including the Malnutrition Inflammation Score (MIS), Geriatric Nutrition Risk Index (GNRI), Charlson comorbidity index, Barthel and Karnowsky index. The latter showed a condition of dependence in 7.2% and 19.7% of cases, respectively. Poor appetite was recorded in 48.2%. The majority of patients fell within the overweight / obesity range (51%) with waist circumference values associated with increased cardiovascular risk in 51% of males and 60% of females. At the BIA analysis, a BCMI <8 kg/m2 was detected in 39% of patients; an estimated protein intake <1.0 g / kg/d was found in 59% of cases; 34% of patients had serum albumin <3.5 g / dl; control of acidosis was good (bicarbonate 25.4 3.8 mM) but hyperphosphatemia was present in 64.6% of patients. A condition of sedentary or light physical activity was reported by 65.1% of patients, vigorous activity only by 11.9%. The 86.5% of patients able to perform the Sit-to-stand test reported a lower than the reference values for age and sex. A diagnosis of PEW was possible in 8% of our series, while a MIS score> 11, indicative of PEW, took place in 12.7% of cases. The values of the MIS correlated directly with age and the degree of comorbidity and inversely with the sit-to-stand test, RAPA tests and appetite level. The data in this study show that single tests indicative of malnutrition disorders are frequent to be found in our series of peritoneal dialysis patients. However, a diagnosis of PEW is quite infrequent. A large percentage of patients are overweight with increased abdominal adiposity, and reduced cell mass and protein intake below recommended levels; the level of habitual physical activity is low, and the level of physical capability is scarce. Therefore it is conceivable a nutritional counseling intervention to increase the intake of proteins, limiting the phosphorus and (when indicated) energy intake and to stimulating spontaneous physical activity or arranging assisted programs for functional rehabilitation. Close monitoring of the nutritional status and implementation of programs of adapted physical activity should have a prominent role in the clinical management of patients on peritoneal dialysis.

This study investigated the factors associated with hypovitaminosis D, in a cohort of 405 prevalent patients with chronic kidney disease (CKD) stages 2-4, living in Italy and followed-up in tertiary care. The effect of cholecalciferol 10,000 IU once-a-week for 12 months was evaluated in a subgroup of 100 consecutive patients with hypovitaminosis D. Vitamin D deficiency was observed in 269 patients (66.4%) whereas vitamin D insufficiency was found in 67 patients (16.5%). In diabetic patients, 25-hydroxyvitamin D deficiency was detected in 80% of cases. In patients older than 65 years, the prevalence of hypovitaminosis D was 89%. In the univariate analysis, 25-hydroxyvitamin D was negatively related to age, parathyroid hormone (PTH), proteinuria, and Charlson index, while a positive relationship has emerged with hemoglobin level. On multiple regression analysis, only age and PTH levels were independently associated with 25-hydroxyvitamin D levels. No relationship emerged between vitamin D deficiency and renal function. Serum levels of 25-hydroxyvitamin D or prevalence of hypovitaminosis D did not differ between patients on a free-choice diet and on a renal diet, including low-protein, low-phosphorus regimens. Twelve-month oral cholecalciferol administration increased 25-hydroxyvitamin D and reduced PTH serum levels. In summary, hypovitaminosis D is very prevalent in CKD patients (83%) in Italy, and it is similar to other locations. PTH serum levels and age, but not renal function, are the major correlates of hypovitaminosis D. Implementation of renal diets is not associated with higher risk of vitamin D depletion. Oral cholecalciferol administration increased 25-hydroxyvitamin D and mildly reduced PTH serum levels. Oral cholecalciferol supplementation should be recommended as a regular practice in CKD patients, also when serum 25-hydroxyvitamin D determination is not available or feasible.

Phosphorus retention plays a pivotal role in the onset of mineral and bone disorders (MBD) in chronic kidney disease (CKD). Phosphorus retention commonly occurs as a result of net intestinal absorption exceeding renal excretion or dialysis removal. The dietary phosphorus load is crucial since the early stages of CKD, throughout the whole course of the disease, up to dialysis-dependent end-stage renal disease.Agreement exits regarding the need for dietary phosphate control, but it is quite challenging in the real-life setting. Effective strategies to control dietary phosphorus intake include restricting phosphorus-rich foods, preferring phosphorus sourced from plant origin, boiling as the preferred cooking procedure and avoiding foods with phosphorus-containing additives. Nutritional education is crucial in this regard.Based on the existing literature, we developed the "phosphorus pyramid", namely a novel, visual, user-friendly tool for the nutritional education of patients and health-care professionals. The pyramid consists of six levels in which foods are arranged on the basis of their phosphorus content, phosphorus to protein ratio and phosphorus bioavailability. Each has a colored edge (from green to red) that corresponds to recommended intake frequency, ranging from "unrestricted" to "avoid as much as possible".The aim of the phosphorus pyramid is to support dietary counseling in order to reduce the phosphorus load, a crucial aspect of integrated CKD-MBD management.

A definite epidemiological association exists between kidney stone disease and arterial hypertension, but the pathophysiological mechanisms are still not fully understood. Hypercalciuria or inflammation and oxidative stress have been proposed as possible links. However, there is more convincing evidence that the association between nephrolithiasis and hypertension may be considered as a part of the association between kidney stone disease, metabolic syndrome and atherosclerosis. From a clinical point of view, this association represents a crucial aspect of the clinical management of patients affected by kidney stone disease. In order to implement early prevention and treatment of cardiovascular and/or renal damage physicians should be encouraged to assess individual cardiovascular risk factors in any adult with kidney stones. Consequently, patients with kidney stones need a comprehensive approach rather than an intervention limited to the urinary tract and focused on stone resolution and recurrence prevention. It is time to view kidney stone disease as a systemic disorder, associated to or predictive of hypertension, chronic kidney disease, bone and cardiovascular damage. All these conditions negatively affect patient prognosis. This multi-systemic approach could increase the clinical impact of the kidney stone clinic.