RESUMO
Maintaining an appropriate acid-base equilibrium is crucial for human health. A primary influencer of this equilibrium is diet, as foods are metabolized into non-volatile acids or bases. Dietary acid load (DAL) is a measure of the acid load derived from diet, taking into account both the potential renal acid load (PRAL) from food components like protein, potassium, phosphorus, calcium, and magnesium, and the organic acids from foods, which are metabolized to bicarbonate and thus have an alkalinizing effect. Current Western diets are characterized by a high DAL, due to large amounts of animal protein and processed foods. A chronic low-grade metabolic acidosis can occur following a Western diet and is associated with increased morbidity and mortality. Nutritional advice focusing on DAL, rather than macronutrients, is gaining rapid attention as it provides a more holistic approach to managing health. However, current evidence for the role of DAL is mainly associative, and underlying mechanisms are poorly understood. This review focusses on the role of DAL in multiple conditions such as obesity, cardiovascular health, impaired kidney function, and cancer.
Assuntos
Acidose , Dieta , Animais , Humanos , Equilíbrio Ácido-Base , Rim/metabolismo , Acidose/metabolismo , Obesidade/metabolismoRESUMO
Delayed graft function (DGF) after kidney transplantation heralds a worse prognosis. In patients with hyperoxaluria, the incidence of DGF is high. Oxalic acid is a waste product that accumulates when kidney function decreases. We hypothesize that residual diuresis and accumulated waste products influence the DGF incidence. Patients transplanted between 2018-2022 participated in the prospective cohort study. Pre-transplant concentrations of oxalic acid and its precursors were determined. Data on residual diuresis and other recipient, donor or transplant related variables were collected. 496 patients were included, 154 were not on dialysis. Oxalic acid, and glyoxylic acid, were above upper normal concentrations in 98.8%, and 100% of patients. Residual diuresis was ≤150 mL/min in 24% of patients. DGF occurred in 157 patients. Multivariable binary logistic regression analysis demonstrated a significant influence of dialysis type, recipient BMI, donor type, age, and serum creatinine on the DGF risk. Residual diuresis and glycolic acid concentration were inversely proportionally related to this risk, glyoxylic acid directly proportionally. Results in the dialysis population showed the same results, but glyoxylic acid lacked significance. In conclusion, low residual diuresis is associated with increased DGF incidence. Possibly accumulated waste products also play a role. Pre-emptive transplantation may decrease the incidence of DGF.
Assuntos
Função Retardada do Enxerto , Diurese , Glioxilatos , Transplante de Rim , Ácido Oxálico , Humanos , Transplante de Rim/efeitos adversos , Feminino , Masculino , Pessoa de Meia-Idade , Função Retardada do Enxerto/etiologia , Função Retardada do Enxerto/epidemiologia , Adulto , Estudos Prospectivos , Idoso , Diálise Renal , Glicolatos , Hiperoxalúria/etiologia , Fatores de Risco , IncidênciaRESUMO
OBJECTIVE: Malnutrition is highly prevalent in patients with kidney failure. Since body weight does not reflect body composition, other methods are needed to determine muscle mass, often estimated by fat-free mass (FFM). Bioimpedance spectroscopy (BIS) is frequently used for monitoring body composition in patients with kidney failure. Unfortunately, BIS-derived lean tissue mass (LTMBIS) is not suitable for comparison with FFM cutoff values for the diagnosis of malnutrition, or for calculating dietary protein requirements. Hypothetically, FFM could be derived from BIS (FFMBIS). This study aims to compare FFMBIS and LTMBIS with computed tomography (CT) derived FFM (FFMCT). Secondarily, we aimed to explore the impact of different methods on calculated protein requirements. METHODS: CT scans of 60 patients with kidney failure stages 4-5 were analyzed at the L3 level for muscle cross-sectional area, which was converted to FFMCT. Spearman rank correlation coefficient and 95% limits of agreement were calculated to compare FFMBIS and LTMBIS with FFMCT. Protein requirements were determined based on FFMCT, FFMBIS, and adjusted body weight. Deviations over 10% were considered clinically relevant. RESULTS: FFMCT correlated most strongly with FFMBIS (r = 0.78, P < .001), in males (r = 0.72, P < .001) and in females (r = 0.60, P < .001). A mean difference of -0.54 kg was found between FFMBIS and FFMCT (limits of agreement: -14.88 to 13.7 kg, P = .544). Between LTMBIS and FFMCT a mean difference of -12.2 kg was apparent (limits of agreement: -28.7 to 4.2 kg, P < .001). Using FFMCT as a reference, FFMBIS best predicted protein requirements. The mean difference between protein requirements according to FFMBIS and FFMCT was -0.7 ± 9.9 g in males and -0.9 ± 10.9 g in females. CONCLUSION: FFMBIS correlates well with FFMCT at a group level, but shows large variation within individuals. As expected, large clinically relevant differences were observed in calculated protein requirements.
RESUMO
BACKGROUND: Vascular endothelial growth factor inhibitors (VEGFIs) are effective anticancer agents which often induce hypertension. VEGFI-induced hypertension is sodium-sensitive in animal studies. Therefore, the efficacy of dietary sodium restriction (DSR) to prevent VEGFI-induced hypertension in cancer patients was studied. METHODS: Cancer patients with VEGFI-induced hypertension (day mean >135/85 mmHg or a rise in systolic and/or diastolic BP ≥ 20 mmHg) were treated with DSR (aiming at <4 g salt/day). The primary endpoint was the difference in daytime mean arterial blood pressure (MAP) increase between the treatment cycle with and without DSR. RESULTS: During the first VEGFI treatment cycle without DSR, mean daytime MAP increased from 95 to 110 mmHg. During the subsequent treatment cycle with DSR, mean daytime MAP increased from 94 to 102 mmHg. Therefore, DSR attenuated the increase in mean daytime MAP by 7 mmHg (95% CI 1.3-12.0, P = 0.009). DSR prevented the rise in the endothelin-1/renin ratio that normally accompanies VEGFI-induced hypertension (P = 0.020) and prevented the onset of proteinuria: 0.15 (0.10-0.25) g/24 h with DSR versus 0.19 (0.11-0.32) g/24 h without DSR; P = 0.005. DISCUSSION: DSR significantly attenuated VEGFI induced BP rise and proteinuria and thus is an effective non-pharmacological intervention.
Assuntos
Hipertensão , Neoplasias , Sódio na Dieta , Animais , Sódio na Dieta/efeitos adversos , Sódio/efeitos adversos , Fator A de Crescimento do Endotélio Vascular , Hipertensão/induzido quimicamente , Hipertensão/prevenção & controle , Hipertensão/tratamento farmacológico , Pressão Sanguínea/fisiologia , Inibidores da Angiogênese/farmacologia , Neoplasias/tratamento farmacológico , ProteinúriaRESUMO
BACKGROUND: Distal diuretics are considered less effective than loop diuretics in CKD. However, data to support this perception are limited. METHODS: To investigate whether distal diuretics are noninferior to dietary sodium restriction in reducing BP in patients with CKD stage G3 or G4 and hypertension, we conducted a 6-week, randomized, open-label crossover trial comparing amiloride/hydrochlorothiazide (5 mg/50 mg daily) with dietary sodium restriction (60 mmol per day). Antihypertension medication was discontinued for a 2-week period before randomization. We analyzed effects on BP, kidney function, and fluid balance and related this to renal clearance of diuretics. RESULTS: A total of 26 patients (with a mean eGFR of 39 ml/min per 1.73 m2) completed both treatments. Dietary sodium restriction reduced sodium excretion from 160 to 64 mmol per day. Diuretics produced a greater reduction in 24-hour systolic BP (SBP; from 138 to 124 mm Hg) compared with sodium restriction (from 134 to 129 mm Hg), as well as a significantly greater effect on extracellular water, eGFR, plasma renin, and aldosterone. Both interventions resulted in a similar decrease in body weight and NT-proBNP. Neither approaches decreased albuminuria significantly, whereas diuretics did significantly reduce urinary angiotensinogen and ß2-microglobulin excretion. Although lower eGFR and higher plasma indoxyl sulfate correlated with lower diuretic clearance, the diuretic effects on body weight and BP at lower eGFR were maintained. During diuretic treatment, higher PGE2 excretion correlated with lower free water clearance, and four patients developed mild hyponatremia. CONCLUSIONS: Distal diuretics are noninferior to dietary sodium restriction in reducing BP and extracellular volume in CKD. Diuretic sensitivity in CKD is maintained despite lower diuretic clearance. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: DD-study: Diet or Diuretics for Salt-sensitivity in Chronic Kidney Disease (DD), NCT02875886.
Assuntos
Dieta Hipossódica/métodos , Diuréticos/administração & dosagem , Taxa de Filtração Glomerular/efeitos dos fármacos , Hipertensão/dietoterapia , Hipertensão/tratamento farmacológico , Insuficiência Renal Crônica/terapia , Adulto , Idoso , Amilorida/administração & dosagem , Determinação da Pressão Arterial , Estudos Cross-Over , Diuréticos/farmacologia , Feminino , Seguimentos , Humanos , Hidroclorotiazida/administração & dosagem , Hipertensão/diagnóstico , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/diagnóstico , Medição de Risco , Sódio na Dieta/efeitos adversos , Fatores de Tempo , Resultado do TratamentoRESUMO
Combined nutrition and exercise interventions potentially improve protein-energy wasting/malnutrition-related outcomes in patients with chronic kidney disease (CKD). The aim was to systematically review the effect of combined interventions on nutritional status, muscle strength, physical performance and QoL. MEDLINE, Cochrane, Embase, Web of Science and Google Scholar were searched for studies up to the date of July 2023. Methodological quality was appraised with the Cochrane risk-of-bias tool. Ten randomized controlled trials (nine publications) were included (334 patients). No differences were observed in body mass index, lean body mass or leg strength. An improvement was found in the six-minute walk test (6-MWT) (n = 3, MD 27.2, 95%CI [7 to 48], p = 0.008), but not in the timed up-and-go test. No effect was found on QoL. A positive impact on 6-MWT was observed, but no improvements were detected in nutritional status, muscle strength or QoL. Concerns about reliability and generalizability arise due to limited statistical power and study heterogeneity of the studies included.
Assuntos
Desnutrição Proteico-Calórica , Insuficiência Renal Crônica , Humanos , Estado Nutricional , Qualidade de Vida , Reprodutibilidade dos Testes , Insuficiência Renal Crônica/terapia , Terapia por ExercícioRESUMO
Metabolic acidosis unfavourably influences the nutritional status of patients with non-dialysis dependent chronic kidney disease (CKD) including the loss of muscle mass and functionality, but the benefits of correction are uncertain. We investigated the effects of correcting metabolic acidosis on nutritional status in patients with CKD in a systematic review and meta-analysis. A search was conducted in MEDLINE and the Cochrane Library from inception to June 2023. Study selection, bias assessment, and data extraction were independently performed by two reviewers. The Cochrane risk of bias tool was used to assess the quality of individual studies. We applied random effects meta-analysis to obtain pooled standardized mean difference (SMD) and 95% confidence intervals (CIs). We retrieved data from 12 intervention studies including 1995 patients, with a mean age of 63.7 ± 11.7 years, a mean estimated glomerular filtration rate of 29.8 ± 8.8 mL/min per 1.73 m2 , and 58% were male. Eleven studies performed an intervention with oral sodium bicarbonate compared with either placebo or with standard care and one study compared veverimer, an oral HCl-binding polymer, with placebo. The mean change in serum bicarbonate was +3.6 mEq/L in the intervention group and +0.4 mEq/L in the control group. Correcting metabolic acidosis significantly improved muscle mass assessed by mid-arm muscle circumference (SMD 0.35 [95% CI 0.16 to 0.54], P < 0.001) and functionality assessed with the sit-to-stand test (SMD -0.31 [95% CI -0.52 to 0.11], P = 0.003). We found no statistically significant effects on dietary protein intake, handgrip strength, serum albumin and prealbumin concentrations, and blood urea nitrogen. Correcting metabolic acidosis in patients with CKD improves muscle mass and physical function. Correction of metabolic acidosis should be considered as part of the nutritional care for patients with CKD.
Assuntos
Acidose , Insuficiência Renal Crônica , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Feminino , Proteínas Alimentares/uso terapêutico , Força da Mão , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/tratamento farmacológico , Acidose/etiologia , Acidose/tratamento farmacológico , MúsculosRESUMO
With expanding kidney transplantation programs, remaining hemodialysis patients are more likely to have a high comorbidity burden and may therefore be more prone to lose muscle mass. Our aim was to analyze risk factors for muscle loss in hemodialysis patients with high comorbidity. Fifty-four chronic hemodialysis patients (Charlson Comorbidity Index 9.0 ± 3.4) were followed for 20 weeks using 4-weekly measurements of lean tissue mass, intracellular water, and body cell mass (proxies for muscle mass), handgrip strength (HGS), and biochemical parameters. Mixed models were used to analyze covariate effects on LTM. LTM (-6.4 kg, interquartile range [IQR] -8.1 to -4.8), HGS (-1.9 kg, IQR -3.1 to -0.7), intracellular water (-2.11 L, IQR -2.9 to -1.4) and body cell mass (-4.30 kg, IQR -5.9 to -2.9) decreased in all patients. Conversely, adipose tissue mass increased (4.5 kg, IQR 2.7 to 6.2), resulting in no significant change in body weight (-0.5 kg, IQR -1.0 to 0.1). Independent risk factors for LTM loss over time were male sex (-0.26 kg/week, 95% CI -0.33 to -0.19), C-reactive protein above median (-0.1 kg/week, 95% CI -0.2 to -0.001), and baseline lean tissue index ³10th percentile (-1.6 kg/week, 95% CI -2.1 to -1.0). Age, dialysis vintage, serum albumin, comorbidity index, and diabetes did not significantly affect LTM loss over time. In this cohort with high comorbidity, we found universal and prominent muscle loss, which was further accelerated by male sex and inflammation. Stable body weight may mask muscle loss because of concurrent fat gain. Our data emphasize the need to assess body composition in all hemodialysis patients and call for studies to analyze whether intervention with nutrition or exercise may curtail muscle loss in the most vulnerable hemodialysis patients.
Assuntos
Diálise Renal/efeitos adversos , Sarcopenia/etiologia , Sarcopenia/metabolismo , Tecido Adiposo/metabolismo , Fatores Etários , Composição Corporal , Índice de Massa Corporal , Estudos de Coortes , Comorbidade , Feminino , Força da Mão , Humanos , Masculino , Fatores de Risco , Sarcopenia/prevenção & controle , Albumina Sérica/metabolismo , Fatores SexuaisRESUMO
BACKGROUND: Enteric hyperoxaluria due to malabsorption may cause chronic oxalate nephropathy and lead to end-stage renal disease. Kidney transplantation is challenging given the risk of recurrent calcium-oxalate deposition and nephrolithiasis. METHODS: We established a protocol to reduce plasma oxalic acid levels peritransplantation based on reduced intake and increased removal of oxalate. The outcomes of 10 kidney transplantation patients using this protocol are reported. RESULTS: Five patients received a living donor kidney and had immediate graft function. Five received a deceased donor kidney and had immediate (n = 1) or delayed graft function (n = 4). In patients with delayed graft function, the protocol was prolonged after transplantation. In 3 patients, our protocol was reinstituted because of late complications affecting graft function. One patient with high-output stoma and relatively low oxalate levels had lost her first kidney transplant because of recurrent oxalate depositions but now receives intravenous fluid at home on a routine basis 3 times per week to prevent dehydration. Patients are currently between 3 and 32 months after transplantation and all have a stable estimated glomerular filtration rate (mean, 51 ± 21 mL/min per 1.73 m2). In 4 of 8 patients who underwent for cause biopsies after transplantation oxalate depositions were found. CONCLUSIONS: This is the first systematic description of kidney transplantation in a cohort of patients with enteric hyperoxaluria. Common complications after kidney transplantation impact long-term transplant function in these patients. With our protocol, kidney transplantation outcomes were favorable in this population with unfavorable transplantation prospects and even previous unsuccessful transplants.