Fibroblast growth factor 21 is associated with increased serum total antioxidant capacity and oxidized lipoproteins in humans with different stages of chronic kidney disease.

Background and aims: Oxidative stress (OS) induces the production of fibroblast growth factor 21 (FGF21). Previous data have revealed that FGF21 protects cells from OS injury and death, making it a potential therapeutic option for many diseases with increased OS. However, the association of this growth factor with OS markers in humans with chronic kidney disease (CKD) remains unknown. This study aims to evaluate the association of serum FGF21 with serum total antioxidant capacity (TAC) and oxidized low-density lipoproteins (OxLDL) in subjects in different stages of kidney disease. Methods: This is a cross-sectional study that included 382 subjects with different stages of CKD, irrespective of type 2 diabetes (T2D) diagnosis. Associations of serum FGF21 with OxLDL, TAC, sex, age, body mass index (BMI), fasting plasma glucose, estimated glomerular filtration rate (eGFR), T2D, and smoking, were evaluated through bivariate and partial correlation analyses. Independent associations of these variables with serum FGF21 were evaluated using multiple linear regression analysis. Results: Serum FGF21 was significantly and positively correlated with age (r = 0.236), TAC (lnTAC) (r = 0.217), and negatively correlated with eGFR (r = -0.429) and male sex (r = -0.102). After controlling by age, sex, BMI, T2D, smoking, and eGFR; both TAC and OxLDL were positively correlated with FGF21 (r = 0.117 and 0.158 respectively, p < 0.05). Using multiple linear regression analysis, eGFR, male sex, T2D, OxLDL, and TAC were independently associated with serum FGF21 (STDß = -0.475, 0.162, -0.153, 0.142 and 0.136 respectively; p < 0.05 for all) adjusted for age, BMI, smoking, and fasting plasma glucose. Conclusion: A positive association between serum FGF21 and OS has been found independently of renal function in humans. Results from the present study provide novel information for deeper understanding of the role of FGF21 in OS in humans with CKD and T2D; mechanistic studies to explain the association of serum FGF21 with oxidative stress in CKD are needed.

Frequency of Intradialytic Hypotension Events Do Not Increase with Oral Nutritional Supplementation during Hemodialysis Treatment: A Randomized Controlled Trial.

OBJECTIVE: This study aimed to compare the effect of the use of a renal-specific oral nutritional supplement (RS-ONS) during hemodialysis sessions and the use of RS-ONS at home on the incidence of intradialytic hypotension. METHODS: A single-center, 12-week, open-label, randomized controlled clinical trial was conducted. The intervention was a RN-ONS divided into two portions: 100 and 137 mL. The first portion was given after 1 hour of hemodialysis (HD) treatment, while the second portion was given 45 minutes before the end of HD. The research staff registered the baseline and final nutritional parameters and systolic arterial pressure (SAP) from the screen of the HD device during 36 HD sessions. Hypotension symptoms were also recorded every hour during each HD session. The nutritional and functional status was also assessed. RESULTS: We registered a total of 16 hypotensive events during 1082 HD sessions: 9 were in patients supplemented at home (551 HD sessions) and 7 occurred in patients supplemented during HD P = .668. Incidence of intradialytic hypotension (IH) during 1082 HD sessions was 1.4%. The total malnutrition inflammation score (MIS) decreased in both groups (P < .01), and the percentage of cachexia improved in the supplemented-during-HD group (P < .05). CONCLUSIONS: In this randomized controlled trial, intradialytic hypotension events did not increase with the RS-ONS during HD treatment. This strategy appears to be a safe anabolic nutritional strategy for the prevention of PEW, selecting stable patients and administering a fractioned volume of the supplement after the first hour of HD treatment. More studies with larger samples size are required to confirm these findings.

Association between Serum Uric Acid Levels, Nutritional and Antioxidant Status in Patients on Hemodialysis.

PURPOSE: To determine the relationship between uric acid (UA) and nutritional and antioxidant status in hemodialysis (HD) patients, given that hyperuricemia could be an indicator of good nutritional status possibly because of the antioxidant properties of UA. METHODS: Cross-sectional study with 93 patients on HD. Hyperuricemia was considered as UA ≥6.0 mg/dL in females and ≥7.0 mg/dL in males. Nutritional variables were registered. Blood samples were taken before the dialysis session to determine oxidative damage as plasma malondialdehyde (MDA) content, and antioxidant capacity measuring 2,2-diphenyl-piclrylhidrazil radical (DPPH●) scavenging activity and oxygen radical absorbance capacity (ORAC) value. RESULTS: Patients with hyperuricemia had higher creatinine (11.9 vs. 10.5 mg/dL; p = 0.004), potassium (5.5 vs. 5.0 mg/dL; p = 0.014) levels; phase angle (5.8 vs. 4.9; p = 0.005), protein consumption (normalized protein nitrogen appearance, nPNA, 1.03 vs. 0.83; p = 0.013) than normouricemic patients. DPPH● scavenging activity was higher in hyperuricemic subjects (1.139 vs. 1.049 mM Trolox equivalents; p = 0.007); likewise, hyperuricemic subjects had less oxidant damage measured by MDA (10.6 vs. 12.7 nmol/mL; p = 0.020). Subjects with normouricemia were at higher risk of having a reactance to height (Xc/H) ratio less than 35 (OR 2.79; 95% CI, 1.1-7.017, p = 0.028); nPNA < 1.0 (OR 3.78; 95% CI, 1.4-10.2, p = 0.007), diagnosis of cachexia (OR 2.95; 95% CI, 1156-7.518, p = 0.021), potassium levels <5 (OR 2.97; 95% CI, 1.136-7.772, p = 0.023) and PA < 5.5° (OR 3.38; 95% CI, 1.309-8.749, p = 0.012.) Conclusions: Patients with hyperuricemia had higher antioxidant capacity and better nutritional status. Purines and protein restrictions in HD patients with hyperuricemia need to be reviewed individually for each patient. More studies are needed to stablish a cut point of UA levels in renal population.

Plant-based diets, insulin sensitivity and inflammation in elderly men with chronic kidney disease.

BACKGROUND: In persons with CKD, adherence to plant-based diets is associated with lower risk of CKD progression and death, but underlying mechanisms are poorly characterized. We here explore associations between adherence to plant-based diets and measures of insulin sensitivity and inflammation in men with CKD stages 3-5. METHODS: Cross-sectional study including 418 men free from diabetes, aged 70-71 years and with cystatin-C estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m2 and not receiving kidney-specific dietetic advice. Information from 7-day food records was used to evaluate the adherence to a plant-based diet index (PBDi), which scores positively the intake of plant-foods and negatively animal-foods. Insulin sensitivity and glucose disposal rate were assessed with the gold-standard hyperinsulinemic euglycemic glucose clamp technique. Inflammation was evaluated by serum concentrations of C-reactive protein (CRP) and interleukin (IL)-6. Associations were explored through linear regression and restricted cubic splines. RESULTS: The majority of men had CKD stage 3a. Hypertension and cardiovascular disease were the most common comorbidities. The median PBDi was 38 (range 14-55). Across higher quintiles of PBDi (i.e. higher adherence), participants were less often smokers, consumed less alcohol, had lower BMI and higher eGFR (P for trend <0.05 for all). Across higher PBDi quintiles, patients exhibited higher insulin sensitivity and lower inflammation (P for trend <0.05). After adjustment for eGFR, lifestyle factors, BMI, comorbidities and energy intake, a higher PBDi score remained associated with higher glucose disposal rate and insulin sensitivity as well as with lower levels of IL-6 and CRP. CONCLUSION: In elderly men with non-dialysis CKD stages 3-5, adherence to a plant-based diet was associated with higher insulin sensitivity and lower inflammation, supporting a possible role of plant-based diets in the prevention of metabolic complications of CKD.

Relationship between protein-energy wasting in adults with chronic hemodialysis and the response to treatment with erythropoietin.

BACKGROUND: It is known that one of the leading causes of morbidity in chronic kidney disease (CKD) is the anemic syndrome. Although the pathogenic mechanisms of anemia are multiple, erythropoietin deficiency appears as the dominant factor. Patients in hemodialysis (HD) have a high prevalence of protein energy wasting (PEW) that may explains the poor response to Erythropoietin (EPO). METHODS: Retrospective cohort study of patients on HD from January to December 2014. The participants were classified according to a diagnostic of PEW using the "Malnutrition Inflammation Score" (MIS) and bioimpedance analysis (BIA) measurement of body composition at the start of erythropoietin therapy and after 3 months of follow up. We performed descriptive statistics and analyzed the differences between groups with and without PEW considering their responsiveness. In addition, we calculated the relative risk of EPO resistance, considering p value < 0.05 as statistically significant. RESULTS: Sixty-one patients ended the follow up. Both groups were similar in basal hemoglobin, hematocrit and other hematopoiesis markers (p = NS). Patients without PEW have a decrease risk for poor response to treatment with EPO (RR = 0.562 [95% CI, 0.329-0.961-]) than those with PEW. Finally, hemoglobin concentrations were evaluated at baseline and every four weeks until week 12, finding a statistically significant improvement only in patients without PEW according MIS (p < 0.05). CONCLUSIONS: PEW is an incremental predictor of poor responsiveness to EPO in HD patients, thus, it is important to consider correcting malnutrition or wasting for a favorable response to treatment with EPO.

Survey on the perception of health professionals on the use of intradialytic oral nutrition in patients under hemodialysis

Abstract Background Intradialytic oral nutrition (ION) has been shown to improve many clinical outcomes, including lowering mortality, in hemodialysis (HD) patients. Despite the benefits, ION is underused in many countries. Objective The objective of our study was to determine the perception of health-care professionals (HCP) in our environment of the use of ION in patients undergoing HD. Methods Survey applied to HCP in Mexico who worked or had worked in an HD unit in their locality. Results From 272 HCP who answered the survey, 74.3% believed that the use of ION has at least one beneficial effect; of these, the most frequently mentioned were an improvement in quality of life (QoL) (54.7%) followed by an improvement in serum albumin (37.9%) and muscle anabolism (31.6%). However, 49% consider that its use involves some risks. Of the respondents, 22% reported that their HD units allowed patients to consume food or supplements during HD sessions; the main reason given to forbid the introduction of food or supplements was the clinic’s policy (41%). Conclusions The personnel surveyed heterogeneous opinions regarding ION, but most believe that it may improve the QoL or the nutritional status of the patients. Nevertheless, the use of ION is uncommon in our country as it is against the internal regulations of most HD units.

[Development of a screening tool for a high sodium intake in an adult Mexican population]. / Desarrollo de una herramienta de tamizaje para consumo elevado de sodio en una población adulta mexicana.

BACKGROUND: twenty-four-hour urinary sodium excretion is the reference method to assess sodium intake; however, tools that can be more easily applied in the clinical and population setting are needed. OBJECTIVES: to develop and evaluate a self-administered high-sodium food frequency questionnaire (abbreviated to CFCA-S in Spanish) as a screening tool for high sodium intake in an adult Mexico City population. METHODS: a CFCA-S including 28 sodium-rich food categories and a scoring system were developed. The 75 percentile for the total score was tested as cut-off point to classify high sodium consumers at two different levels (≥ 2,000 and ≥ 3,000 mg/day) against 24-h urinary sodium excretion as reference method. RESULTS: ninety-five participants were included (median age: 39 [25th-75th percentiles: 26-46] years; men: 39 [41.1%]). A total score of 51.2 in the CFCA-S showed a sensitivity of 31.6% (95% confidence interval [CI]: 19.1-47.5), specificity of 78.9 (95% CI: 66.7-87.5), positive predictive value of 50% (95% CI: 31.4-68.6) and negative predictive value of 63.4% (95% CI: 51.8-73.6) to classify high-sodium consumers at a level of intake ≥ 3,000 mg/day. A total score ≥ 51.2 was significantly associated with a sodium intake ≥ 3,000 mg/day, observing an odds ratio of 3.12 (CI 95%: 1.03-9.44, p = 0.04), after adjusting by sex, age, and body mass index. CONCLUSIONS: the sodium CFCA-S developed in this study is a practical, feasible and useful tool to identify individuals at greater risk of having a high sodium intake.

INTRODUCCIÓN: la excreción de sodio en orina de 24 horas es el método de referencia para evaluar la ingesta de sodio; sin embargo, se  requieren herramientas que puedan aplicarse de manera más práctica tanto en el ámbito clínico como en el poblacional. OBJETIVOS: desarrollar y evaluar un cuestionario autoadministrable de frecuencia de consumo de alimentos ricos en sodio (CFCA-S) como herramienta de tamizaje para consumo elevado de sodio en una población adulta de la Ciudad de México. MÉTODOS: se desarrolló un CFCA-S con 28 categorías de alimentos ricos en sodio y su sistema de puntuación respectivo. El percentil 75 del puntaje total del CFCA-S se probó como punto de corte para clasificar a las personas con alto consumo de sodio a dos niveles (≥ 2.000 y ≥ 3.000 mg/día), considerando la excreción urinaria de sodio en 24 horas como método de referencia. RESULTADOS: se incluyeron 95 participantes (mediana de edad: 39 [percentiles 25-75: 26-46] años; hombres: 39 [41,1%]). Un puntaje total de 51,2 en el CFCA-S mostró una sensibilidad del 31,6% (intervalo de confianza [IC] 95%: 19,1-47,5), una especificidad del 78,9% (IC 95%: 66,7-87,5), valor predictivo positivo del 50% (IC 95%: 31,4-68,6) y valor predictivo negativo del 63,4% (IC 95%: 51,8-73,6), para clasificar a las personas con consumo de sodio ≥ 3.000 mg/día. Un puntaje ≥ 51,2 se asoció significativamente con una ingesta de sodio ≥ 3.000 mg/día, resultando en una razón de momios de 3,12 (IC 95%: 1,03-9,44, p = 0,04), después de ajustar por sexo, edad e índice de masa corporal (IMC). CONCLUSIONES: el CFCA-S es una herramienta práctica, factible de aplicarse y útil para identificar a personas en riesgo de tener un consumo elevado de sodio.

Low phase angle is associated with the development of hepatic encephalopathy in patients with cirrhosis.

AIM: Evaluate the association between phase angle and the development of hepatic encephalopathy in the long-term follow-up of cirrhotic patients. METHODS: This was a prospective cohort study. Clinical, nutritional and biochemical evaluations were performed. Mann-Whitney's U and χ2 tests were used as appropriate. Kaplan-Meier curves and Cox proportional Hazards analysis were used to evaluate the prediction and incidence of hepatic encephalopathy. RESULTS: Two hundred and twenty were included; the most frequent etiology of cirrhosis was hepatitis C infection, 52% of the patients developed hepatic encephalopathy (18.6% covert and 33.3% overt); the main precipitating factors were infections and variceal bleeding. Kaplan-Meier curves showed a higher proportion of HE in the group with low phase angle (39%) compared to the normal phase angle group (13%) (P = 0.012). Furthermore, creatinine and phase angle remained independently associated to hepatic encephalopathy in the Cox regression multivariate analysis [hazard ratio = 1.80 (1.07-3.03)]. CONCLUSION: In our cohort of patients low phase angle was associated with an increased incidence of hepatic encephalopathy. Phase angle is a useful nutritional marker that evaluates cachexia and could be used as a part of the integral assessment in patients with cirrhosis.