Search

The purpose of the chapter is to offer a review of the physiopathology of kidney diseases related to multiple nutritional factors. These include not only protein and phosphate intake, but also dietary fats, excessive energy intake, nutrients related to hypertension, including sodium, alcohol and excess calories, bearing a negative impact and potassium, with a protective action. Metabolic disorders, such as dyslipidemia, obesity and a diabetes mellitus and low physical activity all have a role. Obesity is an independent risk factor for both chronic kidney and diabetic kidney diseases (obesity related glomerulopathy, ORG). Predialysis medical nutrition therapy has a role in delaying progression to stage 5 of kidney failure and in decreasing mortality after initiation of renal replacement therapy. Protein energy malnutrition and the inflammatory processes are frequent before and during dialysis. Kidney transplant is associated with metabolic complications. In the chapter current recommendations for screening, diagnosis, and treatment of clinically relevant nutritional problems are critically reviewed for application in clinical practice.

There is scientific evidence that nutritional treatment can prevent or delay the progression of CKD, control symptoms and prevent or reduce the development of complications such as protein energy malnutrition (PEM) and cardiovascular disease (CVD). PEM is a common clinical finding in renal disease and has a negative bearing on quality of life, morbidity and mortality and therefore it should be adequately prevented, diagnosed and treated. Nutritional prescriptions in renal patients are complex because nutritional goals are multiple, and at time conflicting, yet the prescribed diets should be as realistic and practical as possible. Nutritional support is needed when spontaneous food intake is inadequate to cover nutrient requirements. The main topics of the chapter are: the physiopathology of acute and chronic renal failure, a review of the literature on the role of different nutrients on progression of kidney disease, diagnosis and classification of protein energy malnutrition, which is steel controversial, dietary treatment according to the most recent guidelines, nutritional practical tips, nutrition in dialysis and transplant patients.

Il capitolo prende in esame i diversi aspetti delle vitamine e ha l’obiettivo di rivedere, alla luce della più recente letteratura, le modalità di classificazione, il metabolismo, le funzioni, i fabbisogni, in condizioni fisiologiche , nelle diverse età e nei due sessi, e nelle situazioni di disvitaminosi, oggi spesso subcliniche, ma comunque presenti e talora di difficile definizione, i quadri clinici di carenza, le più aggiornate indagini diagnostiche, le principali sorgenti alimentari e le interazioni tra farmaci e nutrienti. Le funzioni svolte delle vitamine si sono rivelate più complesse rispetto al passato, intervenendo nella regolazione della crescita dei tessuti, nella differenziazione cellulare, nella regolazione epigenetica dell’espressione genica, come antiossidanti, antiinfiammatori e regolatori del sistema immunitario, e nella patogenesi di diverse patologie. Il testo comprende anche una descrizione della tossicità di vitamine assunte in sovradosaggio, sostenuta da un diffuso e frequente ricorso a supplementi e integratori alimentari di vario tipo, assunti talora in modo indiscriminato o per funzioni non ancora confermate sul piano sperimentale.

The chapter reviews the options for the currently available - or under study - antiobesity drugs, including those which have been removed from the market, being considered unsafe. The efficacy of different kinds of products is evaluated. Short term weight loss with drug treatment seems to be generally modest while maintenance in the long term is even more disappointing. Furthermore drug treatment cannot be prescribed without an associated reduction in energy intake, increased physical activity and lifestyle changes, otherwise weight loss will not be achieved and weight regain will annihilate the treatment effects. Drugs have shown wide ranging side effects and contraindication from a prolongued use. Orlistat, which reduces the absorption of fat from the gastrointestinal tract by lipase inhibition, is the most used drug in the present day context, while sibutramine or the endocannabinoids are not more available in most countries. Newer concepts in weight management are mainly hormonal and receptor based, in the effort to reduce adverse effects. Weight loss drugs in development, many of which are in phase II/III trials, include compounds which act at the central level to limit food intake such as neuropeptide Y, Agouty related protein, MCH1 receptor or Serotonin (5-HT) Receptor Ligands. Other compounds act as Gut Hormone Signaling, including Amylin Analogues or Cholecystokinin-1 or as (CCK) Agonists. Drugs such as metformin, topiramate, bupropion or naltrexone alone or as combination therapy are also used. Some pharmacological agents try to induce weight reduction by increasing energy expenditure or by reducing or redistributing adipose tissue

Nutrition has a fundamental role in the management of kidney patients, acute and chronic, on conservative or on substitutive dialysis treatment or after kidney transplantation. In chronic kidney disease (CKD), independently from the cause of the original renal damage there is a progressive and irreversible loss of nephrons and organ function leading to the final stages of kidney failure (ESRD) when dialysis treatment needs to be started. Some nutritional intervention may be useful to prevent or delay the development of kidney disease associated with some chronic conditions such as overweight (leading to Obesity-related glomerulopathy, ORG), diabetes mellitus. or hypertension or to delay the progression toward the end stages of kidney disease. In later stages of CKD, dietary modifications (protein, phosphate, calcium, potassium and sodium) are part of the management of some uremic complications. Since protein-energy malnutrition (PEM) is a common finding in CRF and its presence at the beginning of dialysis caries a bad prognosis, with higher mortality and complication rates, the nutritional status of the patient needs to be constantly monitored and every effort should be taken be prevented or to control malnutrition. In patients with CRF the rationale, the goals and the modalities of nutritional prescriptions change with the degree of loss of renal function, the etiology of kidney disease, the nutritional status of the subjects, the presence and the severity of clinical complications or co-morbidities and the need for dialysis treatment. When CRF patients start substitutive treatment the nutritional requirements change considerably. The big challenge for the nutritionist is to preserve the nutritional status, threatened by chronic nutrient losses and catabolism induced by dialysis, while at the same time controlling some of the symptoms not corrected by the dialysis sesions. Acute kidney failure(ARF) is associated with an acute type of PEM and nutritional interventions are generally similar to those for the acute hypercatabolic patients, with normal renal function.. In acute kidney patients however special substrates may be useful. Finally kidney transplant subjects require special care to counteract the effects on the nutritional status and nutrient requirements at first from the surgery and later from the post-transplant drug treatment.

Dietary therapy has a role in renal disease to control the symptoms and the metabolic consequences of renal dysfunction. Protein and phosphate intake modification may decrease the rate of kidney failure patients. Protein-energy malnutrition is a common clinical finding in kidney patients from a number of cause, including iatrogenic factors from inadequate diets. Malnutrition may with a negative bearing in morbidity, mortality, quality of life and costs and also in the rate of progression of renal disease The indices to evaluate may be influenced by renal failure and may therefore not be as reliable as in subjects with normal renal function. The nutritional status of the patient needs to be monitored to prevent or treat malnutrition and regular follow up procedure are relevant. Acute and chronic kidney disease require specific nutritional treatments according the stage or the severity of renal failure, associated clinical conditions and the need of renal replacement therapy. In chronic patients personalized modified diets are prescribed after a careful assessment of the nutrient requirements. The compliance may be low and patient need to be educated and adequately informed. In some patients special substrates may be required . Finally kidney transplant subjects require special dietary treatment according to the different clinical stages and the type of medical treatment required by patients.

Diet plays a pivotal role in shaping the trajectory of chronic diseases. In this regard, the Mediterranean diet has been widely shown to exert beneficial effects on cardiometabolic health. On the contrary, the Western diet, which has also been reported to be an acidogenic dietary pattern, elicits detrimental effects on both metabolic and cardiovascular (CV) health. However, the role of dietary acid load (DAL) as a predictor of cardiometabolic prognosis remains to be elucidated. Thus, this study aims to compare Mediterranean diet adherence (MDA) and DAL focusing on their relationship with metabolic and CV prognosis. A total of 448 individuals aged 55–80 years were grouped depending on their MDA, assessed using food frequency questionnaires, or DAL, evaluated using potential renal load acid (PRAL) and net-endogenous acid production (NEAP). Study participants underwent anthropometric and biochemical measurements. The metabolic syndrome (MetS) prevalence was evaluated according to the National Cholesterol Education Program-Adult Treatment Panel III. Finally, the CV risk was evaluated using three independent algorithms: atherosclerotic cardiovascular disease (ASCVD), European Systematic COronary Risk Evaluation (SCORE), and Cuore risk scores. Mediterranean diet adherence was negatively associated with PRAL and NEAP. Individuals in the higher MDA tertile group had higher HDL cholesterol as well as lower homeostasis model assessment index (HOMA-IR) and fat mass relative to the lowest MDA tertile. However, in the high-MDA tertile group, there was neither a significantly lower MetS prevalence nor CV risk. Instead, both the MetS prevalence and CV risk were higher in individuals in the higher acid PRAL quartile relative to the lower alkaline PRAL quartile. Dietary acid load, especially assessed using PRAL but not MDA, was associated with indices of metabolic and CV prognosis. Thus, DAL assessed by 24-h dietary recalls may represent a better predictor of cardiometabolic health if compared to MDA evaluated using food frequency questionnaires.

Objective This study aimed to evaluate the relationship between physical activity habits, physical performance and cognitive capacity in older adults' population of Italy and Slovenia. Methods Anthropometric characteristics and body composition bioelectrical impedance analysis (BIA) were evaluated in 892 older adults (60-80 y). Aerobic capacity was measured using the 2km walking test and handgrip and flexibility tests were performed. Physical activity habits and cognitive functions were evaluated by the Global-Physical-Activity-Questionnaires (GPAQ) and by Montreal-Cognitive-Assessment (MoCA) questionnaires, respectively. Results GPAQ scores were associated with lower BMI (r=-0.096; p=0.005), lower percentage of fat-mass (r=-0.138; p=0.001), better results in the 2km-walk test (r=-0.175; p=0.001) and a higher percentage of fat-free mass (r=0.138; p=0.001). We also evaluated that, a higher MoCA score correlates with age (r=-0.208; p=0.001), 2km-walk test (r=-0.166; p=0.001), waist-hip ratio (r=-0.200; p=0.001), resting heart-rate (r=-0.087; p=0.025) and heart-rate at the end of 2km-walk test (r=0.189; p=0.001). Conclusions Older adults with a higher level of daily physical activity showed reduction in fat mass and BMI, and higher aerobic fitness; these characteristics have a protection effect on cognitive function.

BACKGROUND & AIMS: Physical inactivity is associated with lean body mass wasting, oxidative stress and pro-inflammatory changes of cell membrane lipids. Alkalinization may potentially counteract these alterations. We evaluated the effects of potassium bicarbonate supplementation on protein kinetics, glutathione status and pro- and anti-inflammatory polyunsaturated fatty acids (PUFA) in erythrocyte membranes in humans, during experimental bed rest. METHODS: Healthy, young, male volunteers were investigated at the end of two 21-day bed rest periods, one with, and the other without, daily potassium bicarbonate supplementation (90 mmol × d-1), according to a cross-over design. Oxidative stress in erythrocytes was evaluated by determining the ratio between reduced (GSH) and oxidized glutathione (GSSG). Glutathione turnover and phenylalanine kinetics, a marker of whole body protein metabolism, were determined by stable isotope infusions. Erythrocyte membranes PUFA composition was analyzed by gas-chromatography. RESULTS: At the end of the two study periods, urinary pH was 10 ± 3% greater in subjects receiving potassium bicarbonate supplementation (7.23 ± 0.15 vs. 6.68 ± 0.11, p < 0.001). Alkalinization increased total glutathione concentrations by 5 ± 2% (p < 0.05) and decreased its rate of clearance by 38 ± 13% (p < 0.05), without significantly changing GSH-to-GSSG ratio. After alkalinization, net protein balance in the postabsorptive state improved significantly by 17 ± 5% (p < 0.05) as well as the sum of n-3 PUFA and the n-3-to-n-6 PUFA ratio in erythrocyte membranes (p < 0.05). CONCLUSIONS: Alkalinization during long-term inactivity is associated with improved glutathione status, anti-inflammatory lipid pattern in cell membranes and reduction in protein catabolism at whole body level. This study suggests that, in clinical conditions characterized by inactivity, oxidative stress and inflammation, alkalinization could be a useful adjuvant therapeutic strategy.

PURPOSE OF REVIEW: Cachexia is a disease-related multifactorial syndrome characterized by inflammation, massive muscle protein catabolism and carbohydrate and lipid metabolism disorder.Several studies tried to define the impact of either nutrition or physical exercise (single approach strategy) or their combination (multimodal approach strategy) on prevention and/or treatment of muscle wasting in cachectic patients. RECENT FINDINGS: Single approach strategies (i.e. nutrition or physical exercise) have the potential of preventing and improving features of the cachexia syndrome possibly with a differential impact according to the underlying disease. Limited information is available on the beneficial effect of multimodal approach strategies. SUMMARY: Multimodal approaches appear to be more effective than those based on single interventions in physiological condition and in cachectic patients with COPD or chronic kidney disease. Further studies, however, are required in cachexia induced by heart failure, cancer and critical illness.

In chronic diseases, hypoxia and physical inactivity are associated with atherosclerosis progression. In contrast, a lower mortality from coronary artery disease and stroke is observed in healthy humans residing at high altitude in hypoxic environments. Eleven young, male volunteers completed the following 10-day campaigns in a randomized order: hypoxic ambulatory, hypoxic bed rest and normoxic bed rest. Before intervention, subjects were evaluated in normoxic ambulatory condition. Normobaric hypoxia was achieved in a hypoxic facility simulating 4000 m of altitude. Following hypoxia, either in bed rest or ambulatory condition, markers of cardiometabolic risk shifted toward a more atherogenic pattern consisting of: (a) lower levels of total HDL cholesterol and HDL2 sub-fraction and decreased hepatic lipase; (b) activation of systemic inflammation, as determined by C-reactive protein and serum amyloid A; (c) increased plasma homocysteine; (d) decreased delta-5 desaturase index in cell membrane fatty acids, a marker of insulin sensitivity. Bed rest and hypoxia additively decreased total HDL and delta-5 desaturase index. In parallel to the pro-atherogenic effects, hypoxia activated selected anti-atherogenic pathways, consisting of increased circulating TNF-related apoptosis-inducing ligand (TRAIL), a protective factor against atherosclerosis, membrane omega-3 index and erythrocyte glutathione availability. Hypoxia mediated changes in TRAIL concentrations and redox glutathione capacity (i.e., GSH/GSSG ratio) were greater in ambulatory conditions (+34 ± 6% and +87 ± 31%, respectively) than in bed rest (+17 ± 7% and +2 ± 27% respectively). Hypoxia-induced cardiometabolic risk is blunted by moderate level of physical activity as compared to bed rest. TRAIL and glutathione redox capacity may contribute to the positive interaction between physical activity and hypoxia. Highlights: - Hypoxia and bed rest activate metabolic and inflammatory markers of atherogenesis. - Hypoxia and physical activity activate selected anti-atherogenic pathways. - Hypoxia and physical activity positive interaction involves TRAIL and glutathione.

Impulsivity, conceptualized as impulsive personality trait, poor inhibitory control and enhanced reward sensitivity, has been strongly linked to obesity. In particular, a disequilibrium between cognitive control and reward sensitivity has been observed in obese individuals in both behavioural and imaging studies. While this issue has been widely investigated in children and adults, it has received little attention in older adults. Here, obese and non-obese participants aged between 40 and 70 years completed the Barratt Impulsiveness scale (assessing motor, non-planning and attentional impulsiveness), a Go/no-go task with foods and non-foods (assessing inhibitory control) and a reward sensitivity battery with high and low caloric foods (assessing liking, wanting, tastiness and frequency of consumption). We observed that participants with higher BMI reported increased wanting for high calorie foods, but did not show poorer inhibitory control. Interestingly, participants who scored lower on the MMSE reported to consume high calorie more than low calorie foods. Finally, those who presented low scores on non-planning and motor impulsiveness subscales reported higher tastiness ratings for low calorie foods. These results show that increased reward sensitivity but not reduced inhibitory control may characterize higher BMI during aging. Importantly, they also highlight new findings concerning food preferences among older adults.

Purpose of review In clinical management of acutely ill adults and children, continuous enteral feeding (CEF), being considered the most tolerable approach, in comparison to other temporal patterns of nutrient administration (i.e. intermittent, cyclic and bolus), is the most frequently applied method. However, uncertainties remain about the most efficient approach to counteract protein catabolism. Recent findings In critically ill adults, protein loss is mainly driven by increased protein breakdown whereas, in pediatric patients, acute illness is mainly characterized by blunted regulation of protein synthesis and stunted growth. Kinetic studies in fed adult volunteers indicate that protein synthesis can be stimulated for a limited period only. However, continuous feeding persistently improves protein balance through a sustained suppression of protein breakdown. This leads to the hypothesis that CEF could be more anticatabolic than intermittent enteral feeding (IEF) in these patients. Differently from adults, experimental models of acute disease in growing animals have consistently indicated that IEF can improve protein anabolism more efficiently than CEF, mainly through protein synthesis stimulation. The scarce number of clinical studies in acutely ill adults or pediatric patients, mostly performed with inadequate methodology, could not define the best approach to maintain protein balance. Summary There is a need for pragmatic studies to directly compare the protein anabolic action of CEF and IEF using accurate methodologies, such as stable isotopes of amino acids, in both adult and pediatric patients with acute illness.

Purpose of review The optimal approach to improve protein metabolism in critical illness is not yet fully defined. Here, we have summarized recent literature dealing with the main catabolic and anabolic factors influencing protein kinetics in acute hypercatabolic patients. Recent findings Protein/amino acid intake levels should be adapted to type and severity of illness, keeping in mind that energy overfeeding is associated with poor outcome. A number of anticatabolic nutraceuticals and drugs have been tested in acute patients. The encouraging results have been obtained with β-hydroxy-β-methylbutyrate, omega-3 fatty acids, oxandrolone, propranolol, and metformin. Their efficacy and lack of side-effects need to be confirmed. Physical therapy, including muscle electro-stimulation, appears a very promising intervention, both effective and safe. Summary Protein catabolism can be minimized in acute patients by adequate nutritional support, early mobilization, and, possibly, pharmacological and nutraceutical interventions. A combination of these strategies should be tested in randomized controlled trials.

Summary Background & aims Arachidonic (AA) and eicosapentaenoic (EPA) polyunsaturated fatty acids can play respectively a pro- and an anti-inflammatory role. We hypothesized that, at the end of 5-week experimental bed rest, baseline AA/EPA in red blood cells (RBC) membranes, considered the result of dietary fat intake over the previous month, could influence lean body mass wasting in twenty-six healthy volunteers (age: 23.5 ± 0.5 years; body mass index: 22.9 ± 0.5 kg/m2). Methods We measured AA and EPA content in RBC membranes at baseline ambulatory conditions and at the end of the study protocol, to verify the PUFA concentrations stability. We assessed changes, between beginning and end of bed, in lean body mass (bioimpedance), insulin resistance (homeostasis model assessment), systemic inflammation (C-reactive protein) and oxidative stress (thiobarbituric acid reactive substances). Volunteers were divided in two groups according to the AA/EPA ratio median value (i.e. AA/EPA = 44): High AA/EPA group (60 ± 3; n = 13) and Low AA/EPA group (37 ± 1; n = 13). Results At baseline, all analyzed anthropometrical and biochemical indices were similar in the two groups. Bed rest induced a major decrease in lean body mass in High AA/EPA group (−5.2 ± 0.5%), when compared to Low AA/EPA group (−3.7 ± 0.5%; p = 0.03; ANOVA). Bed rest mediated-changes of insulin resistance, fat mass, systemic inflammation and oxidative stress, failed to show significant interaction with baseline AA/EPA (ANOVA). In pooled data, baseline AA/EPA ratio and percent lean body mass delta changes showed a significant inverse correlation (n = 26; R = −0.50; p < 0.01). Conclusions Results suggest that baseline AA/EPA, in RBC membranes, can independently predict lean body mass wasting in immobilized subjects during long term disuse.

Background & aims Aging and experimental bed rest are associated with muscle atrophy and resistance to post-prandial stimulation of protein synthesis or anabolic resistance (AR). We have used in young and older adult volunteers, during short-term bed rest, a quick and non-invasive method, based on a single oral bolus of the stable isotope L[ring-2H5]phenylalanine (D5Phe), to determine post-prandial AR, defined as ratio between irreversible hydroxylation and incorporation into body protein of ingested phenylalanine. Methods We compared in older (O, 59 ± 1 y) and young (Y, 23 ± 1 y) healthy male volunteers the effects of two-week bed rest on post-prandial protein kinetics, assessed during absorption of a standard ready-to-use oral nutritional supplement, through stable-labeled isotope amino acid D5Phe, diluted in water, given as single oral load. The metabolic fate of D5Phe is either utilization for protein synthesis or irreversible hydroxylation to L[ring-2H4]tyrosine (D4Tyr). AR was defined as ratio between the areas under the curves of D4Tyr-to-D5Phe plasma concentrations over 6 h meal absorption. To determine the relationships between AR and muscle changes following bed rest, quadriceps muscle volume (QMV) was determined by magnetic resonance imaging (MRI). Results At baseline, in pooled Y and O subjects, values of AR were inversely correlated with QMV (R = −0.75; p < 0.03). Following 2-weeks of inactivity, there were significant bed rest effects on AR (p < 0.01) and QMV (p < 0.03), as well as significant bed rest × group interaction for AR (p < 0.03; +9.2% in Y; +21.9% in O) and QMV (p < 0.05; −5.7% in Y; −%7.3 in O). In pooled subjects, the percentage delta changes in AR and QMV, induced by bed rest, were inversely correlated (R = −0.57; p < 0.05). Conclusion Bed rest-induced AR is much greater in the older than in younger adults. We have developed a new, simple, non-invasive method for the assessment of AR. The results indicate that this metabolic abnormality is a key mechanism for sarcopenia of aging and inactivity.

Coffee consumption is negatively associated with risk of type 2 diabetes and cardiovascular mortality. Coffee roasting can greatly modify the quality-quantitative characteristics of bioactive compounds. We compared the effects of two different roasting intensities of the same naturally low-caffeine Arabica coffee variety (Laurina) on glucose and lipid metabolism as well as oxidative stress.We performed a double-blind, crossover intervention study. Fourteen healthy male volunteers consumed four cups daily of light roasted coffee (LRC) and dark roasted coffee (DRC), each for 1 wk (intervention period 1 and 2 respectively). One wk washout, with total abstinence from coffee and other possible caffeine sources, preceded each intervention. Data were collected at the end of washout and intervention periods.Changes between washout and intervention periods in glucose concentrations at 2 h post-oral glucose tolerance test, were significantly lower after DRC than LRC intake (-0.6 ± 0.3 and 0.4 ± 0.3 mmol/L, P 0.03). Changes in β-cell function, assessed as insulin secretion-sensitivity index-2, were significantly greater after DRC than LRC (34.7 ± 25.0 and -18.8 ± 21.0, P = 0.03). The initial (30 min) post-oral glucose tolerance test area under the curve of glucagon-like peptide-1 was 24± 9% greater (P = 0.03) after DRC than LRC. LRC or DRC did not affect insulin sensitivity. Changes from basal of reduced-to-oxidized glutathione ratio (GSH/GSSG) in erythrocytes were significantly greater after DRC than LRC (+1437 ± 371 and -152 ± 30, P 0.05). The omega-3 index in erythrocyte membranes was 16± 4% greater (P 0.001) after DRC than LRC.DRC consumption improved postload glucose metabolism by increasing incretin and insulin secretions. DRC compared to LRC improved redox balance and increased omega-3 fatty acids. Thus, we suggest greater metabolic benefits related to DRC.

The aim of the study was to assess the relationship between sweet taste genes and dental caries prevalence in a large sample of adults. In addition, the association between sweet liking and sugar intake with dental caries was investigated. Caries was measured by the decayed, missing, filled teeth (DMFT) index in 647 Caucasian subjects (285 males and 362 females, aged 18–65 years), coming from six villages in northeastern Italy. Sweet liking was assessed using a 9-point scale, and the mean of the liking given by each individual to specific sweet food and beverages was used to create a sweet liking score. Simple sugar consumption was estimated by a dietary history interview, considering both added sugars and sugar present naturally in foods. Our study confirmed that polymorphisms in TAS1R2 and GLUT2 genes are related to DMFT index. In particular, GG homozygous individuals for rs3935570 in TAS1R2 gene (p value = 0.0117) and GG homozygous individuals for rs1499821 in GLUT2 gene (p value = 0.0273) showed higher DMFT levels compared to both heterozygous and homozygous for the alternative allele. Furthermore, while the relationship sugar intake–DMFT did not achieve statistical significance (p value = 0.075), a significant association was identified between sweet liking and DMFT (p value = 0.004), independent of other variables. Our study showed that sweet taste genetic factors contribute to caries prevalence and highlighted the role of sweet liking as a predictor of caries risk. Therefore, these results may open new perspectives for individual risk identification and implementation of target preventive strategies, such as identifying high-risk patients before caries development.