Dietary Phosphorus, Its Sources, and Mortality in Adults on Haemodialysis: The DIET-HD Study.

Dietary phosphorus restrictions are usually recommended for people on haemodialysis, although its impact on patient-relevant outcomes is uncertain. We aimed to evaluate the association between total phosphorus intake and its sources with mortality in haemodialysis. Phosphorus intake was ascertained within the DIET-HD study in 8110 adults on haemodialysis. Adjusted Cox regression analyses were conducted to evaluate the association between the total and source-specific phosphorus (plant-, animal-, or processed and other sources) with mortality. During a median 3.8 years of follow-up, there were 2953 deaths, 1160 cardiovascular-related. The median phosphorus intake was 1388 mg/day. Every standard deviation (SD) (896 mg/day) increase in total phosphorus was associated with higher all-cause mortality [hazard ratio (HR), 1.16; 95% confidence intervals (CI), 1.06-1.26] and cardiovascular mortality (HR, 1.18; 95% CI, 1.03-1.36). Every SD (17%) increase in the proportion of phosphorus from plant sources was associated with lower all-cause mortality (HR, 0.95; 95% CI, 0.90-0.99). Every SD (9%) increase in the proportion of phosphorus from the processed and other sources was associated with higher all-cause mortality (HR, 1.06; 95% CI, 1.02-1.10). A higher total phosphorus intake was associated with increased all-cause and cardiovascular death. This association is driven largely by the phosphorus intake from processed food. Plant based phosphorus was associated with lower all-cause mortality.

Using Structural Equation Modeling to Untangle Pathways of Risk Factors Associated with Incident Type 2 Diabetes: the Lifelines Cohort Study.

Risk factors for type 2 diabetes are multifaceted and interrelated. Unraveling the complex pathways of modifiable risk factors related to incident type 2 diabetes will help prioritize prevention targets. The current analysis extended a previously proposed conceptual model by Bardenheier et al. (Diabetes Care, 36(9), 2655-2662, 2013) on prediabetes with a cross-sectional design. The model described the pathways of four aspects of modifiable risk factors in relation to incident type 2 diabetes, including socioeconomic status (income and education); lifestyle behaviors (diet quality, physical activity, TV watching, smoking, risk drinking, and unhealthy sleep duration); clinical markers (HDL-cholesterol, triglycerides, BMI, and waist circumference); and blood pressure. We performed structural equation modeling to test this conceptual model using a prospective population-based sample of 68,649 participants (35-80 years) from the Lifelines cohort study. During a median follow-up of 41 months, 1124 new cases of type 2 diabetes were identified (incidence 1.6%). The best-fitting model indicated that among all modifiable risk factors included, waist circumference had the biggest direct effect on type 2 diabetes (standardized ß-coefficient 0.214), followed by HDL-cholesterol (standardized ß-coefficient - 0.134). Less TV watching and more physical activity were found to play an important role in improving clinical markers that were directly associated with type 2 diabetes. Education had the biggest positive effects on all lifestyle behaviors except for unhealthy sleep duration. Our analysis provides evidence to support that structural equation modeling enables a holistic assessment of the interplay of type 2 diabetes risk factors, which not only allows the estimation of their total effects but also prioritization of prevention targets. Regarding the current guideline for diabetes prevention, waist management in addition to BMI control (clinical level), as well as less TV watching in addition to more physical activity (behavioral level), may provide additional public health benefits. Better education would be the main societal goal for the prevention of type 2 diabetes.

Does dietary potassium intake associate with hyperkalemia in patients with chronic kidney disease?

BACKGROUND: Dietary potassium restriction is a strategy to control hyperkalemia in chronic kidney disease (CKD). However, hyperkalemia may result from a combination of clinical conditions. This study aimed to investigate whether dietary potassium or the intake of certain food groups associate with serum potassium in the face of other risk factors. METHODS: We performed a cross-sectional analysis including a nondialysis-dependent CKD (NDD-CKD) cohort and a hemodialysis (HD) cohort. Dietary potassium intake was assessed by 3-day food records. Underreporters with energy intake lower than resting energy expenditure were excluded. Hyperkalemia was defined as serum potassium >5.0 mEq/L. RESULTS: The NDD-CKD cohort included 95 patients {median age 67 [interquartile range (IQR) 55-73] years, 32% with diabetes mellitus (DM), median estimated glomerular filtration rate 23 [IQR 18-29] mL/min/1.73 m2} and the HD cohort included 117 patients [median age 39 (IQR 18-67) years, 50% with DM]. In NDD-CKD, patients with hyperkalemia (36.8%) exhibited lower serum bicarbonate and a tendency for higher serum creatinine, a higher proportion of DM and the use of renin-angiotensin-aldosterone system blockers, but lower use of sodium bicarbonate supplements. No association was found between serum and dietary potassium (r = 0.01; P = 0.98) or selected food groups. Conditions associated with hyperkalemia in multivariable analysis were DM {odds ratio [OR] 3.55 [95% confidence interval (CI) 1.07-11.72]} and metabolic acidosis [OR 4.35 (95% CI 1.37-13.78)]. In HD, patients with hyperkalemia (50.5%) exhibited higher serum creatinine and blood urea nitrogen and lower malnutrition inflammation score and a tendency for higher dialysis vintage and body mass index. No association was found between serum and potassium intake (r = -0.06, P = 0.46) or food groups. DM [OR 4.22 (95% CI 1.31-13.6)] and serum creatinine [OR 1.50 (95% CI 1.24-1.81)] were predictors of hyperkalemia in multivariable analyses. CONCLUSIONS: Dietary potassium was not associated with serum potassium or hyperkalemia in either NDD-CKD or HD patients. Before restricting dietary potassium, the patient's intake of potassium should be carefully evaluated and other potential clinical factors related to serum potassium balance should be considered in the management of hyperkalemia in CKD.

Medical Nutritional Therapy for Patients with Chronic Kidney Disease not on Dialysis: The Low Protein Diet as a Medication.

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.

KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for nutrition in kidney diseases since 1999. Since the publication of the first KDOQI nutrition guideline, there has been a great accumulation of new evidence regarding the management of nutritional aspects of kidney disease and sophistication in the guidelines process. The 2020 update to the KDOQI Clinical Practice Guideline for Nutrition in CKD was developed as a joint effort with the Academy of Nutrition and Dietetics (Academy). It provides comprehensive up-to-date information on the understanding and care of patients with chronic kidney disease (CKD), especially in terms of their metabolic and nutritional milieu for the practicing clinician and allied health care workers. The guideline was expanded to include not only patients with end-stage kidney disease or advanced CKD, but also patients with stages 1-5 CKD who are not receiving dialysis and patients with a functional kidney transplant. The updated guideline statements focus on 6 primary areas: nutritional assessment, medical nutrition therapy (MNT), dietary protein and energy intake, nutritional supplementation, micronutrients, and electrolytes. The guidelines primarily cover dietary management rather than all possible nutritional interventions. The evidence data and guideline statements were evaluated using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update.

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for nutrition in kidney diseases since 1999. Since the publication of the first KDOQI nutrition guideline, there has been a great accumulation of new evidence regarding the management of nutritional aspects of kidney disease and sophistication in the guidelines process. The 2020 update to the KDOQI Clinical Practice Guideline for Nutrition in CKD was developed as a joint effort with the Academy of Nutrition and Dietetics (Academy). It provides comprehensive up-to-date information on the understanding and care of patients with chronic kidney disease (CKD), especially in terms of their metabolic and nutritional milieu for the practicing clinician and allied health care workers. The guideline was expanded to include not only patients with end-stage kidney disease or advanced CKD, but also patients with stages 1-5 CKD who are not receiving dialysis and patients with a functional kidney transplant. The updated guideline statements focus on 6 primary areas: nutritional assessment, medical nutrition therapy (MNT), dietary protein and energy intake, nutritional supplementation, micronutrients, and electrolytes. The guidelines primarily cover dietary management rather than all possible nutritional interventions. The evidence data and guideline statements were evaluated using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Sex Differences in Kidney Replacement Therapy Initiation and Maintenance.

BACKGROUND AND OBJECTIVES: More men than women undergo kidney replacement therapy (KRT) despite a larger number of women being affected by CKD. The aim of this multinational European study was to explore whether there might be historic and geographic trends in sex-specific incidence and prevalence of various KRT modalities. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We assessed sex-specific differences in KRT incidence and prevalence using data from nine countries reporting to the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry for at least 40 years, during the period 1965-2015. Sex distribution data were compared with the European general population (Eurostat). Statistical methodology included basic descriptive statistics, incidence and prevalence calculations per million population (pmp), as well as their male-to-female ratios. Analyses were stratified by age group and diabetic status. RESULTS: We analyzed data from 230,378 patients receiving KRT (38% women). For all KRT modalities, the incidence and prevalence rates were consistently higher in men than women. For example, the KRT incidence increased from 8 pmp in 1965-1974 to 98 pmp in 2005-2015 in women, whereas it rose from 12 to 173 pmp in men during the same period. Male-to-female ratios, calculated for incident and prevalent KRT patients, increased with age (range 1.2-2.4), showing consistency over decades and for individual countries, despite marked changes in primary kidney disease (diabetes more prevalent than glomerulonephritis in recent decades). The proportion of kidney transplants decreased less with age in incident and prevalent men compared with women on KRT. Stratified analysis of patients who were diabetic versus nondiabetic revealed that the male-to-female ratio was markedly higher for kidney transplantation in patients with diabetes. CONCLUSIONS: Since the beginning of KRT programs reporting to the ERA-EDTA Registry since the 1960s, fewer women than men have received KRT. The relative difference between men and women initiating and undergoing KRT has remained consistent over the last five decades and in all studied countries.

Dietary n-3 polyunsaturated fatty acid intake and all-cause and cardiovascular mortality in adults on hemodialysis: The DIET-HD multinational cohort study.

BACKGROUND & AIMS: Patients on hemodialysis suffer from high risk of premature death, which is largely attributed to cardiovascular disease, but interventions targeting traditional cardiovascular risk factors have made little or no difference. Long chain n-3 polyunsaturated fatty acids (n-3 PUFA) are putative candidates to reduce cardiovascular disease. Diets rich in n-3 PUFA are recommended in the general population, although their role in the hemodialysis setting is uncertain. We evaluated the association between the dietary intake of n-3 PUFA and mortality for hemodialysis patients. METHODS: The DIET-HD study is a prospective cohort study (January 2014-June 2017) in 9757 adults treated with hemodialysis in Europe and South America. Dietary n-3 PUFA intake was measured at baseline using the GA2LEN Food Frequency Questionnaire. Adjusted Cox regression analyses clustered by country were conducted to evaluate the association of dietary n-3 PUFA intake with cardiovascular and all-cause mortality. RESULTS: During a median follow up of 2.7 years (18,666 person-years), 2087 deaths were recorded, including 829 attributable to cardiovascular causes. One third of the study participants consumed sufficient (at least 1.75 g/week) n-3 PUFA recommended for primary cardiovascular prevention, and less than 10% recommended for secondary prevention (7-14 g/week). Compared to patients with the lowest tertile of dietary n-3 PUFA intake (<0.37 g/week), the adjusted hazard ratios (95% confidence interval) for cardiovascular mortality for patients in the middle (0.37 to <1.8 g/week) and highest (≥1.8 g/week) tertiles of n-3 PUFA were 0.82 (0.69-0.98) and 1.03 (0.84-1.26), respectively. Corresponding adjusted hazard ratios for all-cause mortality were 0.96 (0.86-1.08) and 1.00 (0.88-1.13), respectively. CONCLUSIONS: Dietary n-3 PUFA intake was not associated with cardiovascular or all-cause mortality in patients on hemodialysis. As dietary n-3 PUFA intake was low, the possibility that n-3 PUFA supplementation might mitigate cardiovascular risk has not been excluded.

Vitamin D deficiency and treatment versus risk of infection in end-stage renal disease patients under dialysis: a systematic review and meta-analysis.

Background: Infections are common and can be fatal in patients undergoing long-term dialysis. Recent studies have shown conflicting evidence associating infection with vitamin D status or use of vitamin D and have not been systematically reviewed in this population. Methods: We searched PubMed, Web of Science, Cochrane Library, Embase and three Chinese databases from inception until December 2017 for interventional [non-randomized or randomized controlled trials (RCTs)], cohort and case-control studies on levels of serum 25-hydroxyvitamin D [25(OH)D] or use of vitamin D [supplemental nutritional vitamin D or vitamin D receptor activator (VDRA)] and infection (any infection, infection-required hospitalization or infection-related death or composite) in long-term dialysis patients. We conducted a meta-analysis on the relative risk (RR) of infection and level of 25(OH)D or use of vitamin D. Results: Of 2440 reports identified, 17 studies met inclusion criteria, all with moderate quality, with 6 cohort studies evaluating 25(OH)D serum concentrations (n = 5714) and 11 (2 RCTs and 9 observational studies) evaluating the use of vitamin D (n = 92 309). The risk of composite infection was 39% lower {relative risk [RR] 0.61 [95% confidence interval (CI) 0.41-0.89]} in the subjects with high or normal levels of 25(OH)D than in those with low levels. When compared with those who did not use vitamin D, the pooled adjusted risk for composite infection was 41% lower in those who used vitamin D [RR 0.59 (95% CI 0.43-0.81)]. Conclusions: High or normal serum levels of 25(OH)D and the use of vitamin D, particularly VDRA, were each associated with a lower risk of composite infection in long-term dialysis patients.

Lower serum calcium is independently associated with CKD progression.

Disturbances in calcium metabolism are common in individuals with chronic kidney disease (CKD), but whether they are associated with subsequent kidney function decline is less clear. In a CKD 3-5 cohort of 15,755 adult citizens of Stockholm with creatinine tests taken during 2006-2011 and concurrent calcium testing at cohort entry, we investigated the association between baseline serum calcium and the subsequent change in estimated glomerular filtration rate (eGFR, by CKD-EPI) decline using linear mixed models. Mean (SD) baseline corrected serum calcium was 9.6 (0.5) mg/dL. Mean (95%-confidence interval [CI]) eGFR decline was -0.82 (-0.90; -0.74) mL/min/1.73 m2/year. In advanced CKD stages, higher baseline serum calcium was associated with less rapid kidney function decline. The adjusted change (95%-CI) in eGFR decline associated with each mg/dL increase in baseline serum calcium was -0.10 (-0.28; 0.26), 0.39 (0.07; 0.71), 0.34 (-0.02; 0.70) and 0.68 (0.36; 1.00) mL/min/1.73 m2/year for individuals in CKD stage 3a, 3b, 4, and 5, respectively. In a subgroup of patients using vitamin D supplements, the association between baseline serum calcium and CKD progression was eliminated, especially in CKD stage 3b and 4. To conclude, in individuals with CKD stage 3b to 5, lower baseline corrected serum calcium, rather than higher baseline serum calcium, associated with a more rapid CKD progression. Lower serum corrected calcium seems to be indicative for vitamin D deficiency.

Circulating Alpha-Tocopherol and Insulin Sensitivity Among Older Men With Chronic Kidney Disease.

OBJECTIVE: Insulin resistance is common in individuals with chronic kidney disease (CKD) and may be partly explained by modifiable risk factors. In the general population, vitamin E supplementation has been suggested to improve both insulin sensitivity and secretion. We here explore the potential role of vitamin E as a modifiable risk factor for insulin resistance among individuals with CKD. DESIGN: Observational study. SETTING: A total of 273 nondiabetic men aged 70 to 71 years with CKD defined as either cystatin C estimated glomerular filtration rate < 60 mL/minute/1.73 m(2) or urinary albumin excretion rate ≥ 20 mg/minute from the third examination cycle of Uppsala Longitudinal Study of Adult Men. SUBJECTS: A total of 273 nondiabetic men aged 70 to 71 years with CKD defined as either cystatin C estimated glomerular filtration rate < 60 mL/minute/1.73 m(2) or urinary albumin excretion rate ≥ 20 µg/minute. METHODS: Serum α-, ß-, and γ-tocopherol concentrations were measured by high-performance liquid chromatography and expressed as µmol/total serum cholesterol and triglycerides (in mmol). Dietary vitamin E intake was estimated from 7-day food records. MAIN OUTCOME MEASURE: Insulin sensitivity index (M/I ratio) was measured by hyperinsulinemic-euglycemic glucose clamps. Univariate and multivariate regression models were fitted to assess the association between M/I and circulating concentrations of tocopherols. RESULTS: The mean serum concentration of α-, ß-, and γ- was 37.4 ± 6.58, 0.89 ± 0.23, and 4.32 ± 1.69 µmol/mmol, respectively. Median dietary vitamin E intake was 6.14 (interquartile range, 5.48-6.82) mg/day. In crude and fully-adjusted multivariate regression analyses, serum α-tocopherol levels were directly and strongly associated with M/I (standard ß = 0.17, P = .003). No such association was observed for dietary vitamin E, serum ß-, and γ-tocopherol concentrations. CONCLUSIONS: Serum α-tocopherol concentration associates with insulin sensitivity in nondiabetic older men with CKD.

EFFECT OF SELENIUM SUPPLEMENTATION VIA BRAZIL NUT (BERTHOLLETIA EXCELSA, HBK) ON THYROID HORMONES LEVELS IN HEMODIALYSIS PATIENTS: A PILOT STUDY.

BACKGROUND: thyroid function depends on trace mineral selenium (Se), being at the active center of the iodothyronine deiodinase that catalyzes the conversion of the thyroxine (T4) to the active form of thyroid hormone, triiodothyronine (T3). Hemodialysis (HD) patients have reduced T3 levels partly due to impaired hormonal conversion that can be related to Se deficiency, a common feature in these patients. This study evaluated the effect of Brazil nuts (richest Se source) on thyroid hormone levels in HD patients. METHODS: we performed an uncontrolled intervention with 40 HD patients (53.3 ± 16.1 yrs, dialysis vintage 62.0 (8.0 - 207.0) months) that received one nut (≈5g, average 58.1 µg Se/g) per day for three months. Se plasma levels were determined by atomic absorption spectrophotometry with hydride generation and, serum T3, free T4 (FT4), TSH as well as glutathione peroxidase (GPx) activity were measured by ELISA. RESULTS: all patients were Se deficient and presented low T3 levels at baseline. After intervention, Se plasma levels (from 17.6 ± 11.6 to 153.4 ± 86.1 µg/L), GPx activity (from 33.7 ± 5.9 to 41.4 ± 11.2 nmol/min/mL), T3 (from 27.3 ± 8.8 to 50.2 ± 4.8ng/dL) and FT4 levels (0.87 ± 0.2 to 0.98 ± 0.4 ng/dL) were significantly increased (p < 0.05), while TSH levels were reduced (from 2.17 ± 1.3 to 1.96 ± 1.1 uUI/mL), but not significantly. CONCLUSION: in conclusion, increasing Se levels via Brazil nut supplementation was associated with improvement in thyroid hormone levels in HD patients, although the amount of Se given was not able to restore T3 to normal levels.

Introducción: la funcion tiroidea depende de minerales traza de selenio (Se), que esta en el centro activo de la deiodinasa yodotironina, que cataliza la conversion de la tiroxina (T4) a la forma activa de la hormona tiroidea, triyodotironina (T3). Hemodialisis (HD) de los pacientes ha reducido los niveles de T3 de los pacientes, debido en parte a la conversion hormonal alterada que puede estar relacionada con la deficiencia de Se, una caracteristica comun en estos pacientes. Este estudio evaluo el efecto de las nueces de Brasil (la mas rica fuente de Se) en los niveles de hormonas tiroideas en pacientes en HD. Métodos: se realizo una intervencion no controlada con 40 pacientes en HD (53,3 } 16,1 anos, dialisis vendimia 62,0 (8,0 - 207,0 meses)), que recibieron una nuez (≈ 5, promedio 58,1 mg Se/g) por dia durante tres meses. Determinaron los niveles plasmaticos de Se por espectrofotometria de absorcion atomica con generacion de hidruros y los niveles de T3, T4 libre (FT4), TSH en suero, asi como la actividad de la glutation peroxidasa (GPx) por ELISA. Resultados: todos los pacientes tenian niveles bajos de Se y T3 al inicio del estudio. Despues de la intervencion, los niveles plasmaticos de Se (de 17,6 } 11,6 a 153,4 } 86,1 mg/L), actividad GPx (de 33,7 } 5,9 a 41,4 } 11,2 nmol/min/ml), T3 (de 27,3 } 8,8 a 50,2 } 4,8 ng/dL) y T4L (0,87 } 0,2 a 0,98 } 0,4 ng/dL) se incrementaron significativamente (p < 0,05), mientras que los niveles de TSH se redujeron (de 2,17 } 1,3 a 1,96 } 1,1 IUU/ml), pero no de forma significativa. Conclusión: en conclusion, el aumento de los niveles de Se via suplementacion con nuez brasilena se asocia con una mejoria en los niveles de hormonas tiroideas en pacientes en HD, aunque la cantidad de Se dada no fue capaz de restablecer la T3 a los niveles normales.

Effect of selenium supplementation via Brazil nut (Bertholletia excelsa, HBK) on thyroid hormones levels in hemodialysis patients: a pilot study / Efecto de la suplementación de selenio a través de la nuez de Brasil (bertholletia excelsa, HBK) en los niveles de hormonas tiroideas en pacientes de hemodiálisis: un estudio piloto

Background: thyroid function depends on trace mineral selenium (Se), being at the active center of the iodothyronine deiodinase that catalyzes the conversion of the thyroxine (T4) to the active form of thyroid hormone, triiodothyronine (T3). Hemodialysis (HD) patients have reduced T3 levels partly due to impaired hormonal conversion that can be related to Se deficiency, a common feature in these patients. This study evaluated the effect of Brazil nuts (richest Se source) on thyroid hormone levels in HD patients. Methods: we performed an uncontrolled intervention with 40 HD patients (53.3 ± 16.1 yrs, dialysis vintage 62.0 (8.0 - 207.0) months) that received one nut (≈5g, average 58.1 mg Se/g) per day for three months. Se plasma levels were determined by atomic absorption spectrophotometry with hydride generation and, serum T3, free T4 (FT4), TSH as well as glutathione peroxidase (GPx) activity were measured by ELISA. Results: all patients were Se deficient and presented low T3 levels at baseline. After intervention, Se plasma levels (from 17.6 ± 11.6 to 153.4 ± 86.1 μg/L), GPx activity (from 33.7 ± 5.9 to 41.4 ± 11.2 nmol/min/mL), T3 (from 27.3 ± 8.8 to 50.2 ± 4.8ng/dL) and FT4 levels (0.87 ± 0.2 to 0.98 ± 0.4 ng/dL) were significantly increased (p < 0.05), while TSH levels were reduced (from 2.17 ± 1.3 to 1.96 ± 1.1 uUI/mL), but not significantly. Conclusion: in conclusion, increasing Se levels via Brazil nut supplementation was associated with improvement in thyroid hormone levels in HD patients, although the amount of Se given was not able to restore T3 to normal levels (AU)

Introducción: la función tiroidea depende de minerales traza de selenio (Se), que está en el centro activo de la deiodinasa yodotironina, que cataliza la conversión de la tiroxina (T4) a la forma activa de la hormona tiroidea, triyodotironina (T3). Hemodiálisis (HD) de los pacientes ha reducido los niveles de T3 de los pacientes, debido en parte a la conversión hormonal alterada que puede estar relacionada con la deficiencia de Se, una característica común en estos pacientes. Este estudio evaluó el efecto de las nueces de Brasil (la más rica fuente de Se) en los niveles de hormonas tiroideas en pacientes en HD. Métodos: se realizó una intervención no controlada con 40 pacientes en HD (53,3 ± 16,1 años, diálisis vendimia 62,0 (8,0 - 207,0 meses)), que recibieron una nuez (≈ 5, promedio 58,1 mg Se/g) por día durante tres meses. Determinaron los niveles plasmáticos de Se por espectrofotometría de absorción atómica con generación de hidruros y los niveles de T3, T4 libre (FT4), TSH en suero, así como la actividad de la glutatión peroxidasa (GPx) por ELISA. Resultados: todos los pacientes tenían niveles bajos de Se y T3 al inicio del estudio. Después de la intervención, los niveles plasmáticos de Se (de 17,6 ± 11,6 a 153,4 ± 86,1 mg/L), actividad GPx (de 33,7 ± 5,9 a 41,4 ± 11,2 nmol/min/ml), T3 (de 27,3 ± 8,8 a 50,2 ± 4,8 ng/dL) y T4L (0,87 ± 0,2 a 0,98 ± 0,4 ng/dL) se incrementaron significativamente (p <0,05), mientras que los niveles de TSH se redujeron (de 2,17 ± 1,3 a 1,96 ± 1,1 IUU/ml), pero no de forma significativa. Conclusión: en conclusión, el aumento de los niveles de Se vía suplementación con nuez brasileña se asocia con una mejoría en los niveles de hormonas tiroideas en pacientes en HD, aunque la cantidad de Se dada no fue capaz de restablecer la T3 a los niveles normales (AU)

The relationship between thyroid function and estimated glomerular filtration rate in patients with chronic kidney disease.

BACKGROUND: Recent studies have shown an increasing risk of hypothyroidism with incrementally lower estimated glomerular filtration rate (eGFR) in cohorts comprised of patients with normal to mildly impaired kidney function. We sought to confirm these findings in a nationally representative cohort of Veterans Affairs patients with moderate-to-severe chronic kidney disease (CKD). METHODS: This study examined the association between kidney function and hypothyroidism among 461 607 veterans with Stage 3 to 5 CKD who underwent repeated measurements of serum creatinine and thyrotropin (TSH) at identical time points between October 2004 and September 2006. Kidney function was defined by eGFR using the Chronic Kidney Disease Epidemiology Collaboration formula. In primary analyses, the association between eGFR and hypothyroidism (defined as serum TSH > 5 mIU/L and/or receipt of thyroid hormone supplementation) was estimated using multivariable random effects logistic regression. In secondary analyses, the association between eGFR and serum TSH level was estimated using multivariable random effects linear regression. RESULTS: At baseline, 68.9, 25.5, 5.3 and 0.3% of patients had Stage 3A, 3B, 4 and 5 CKD, respectively. For every 10 mL/min/1.73 m(2) lower eGFR, there was an 18% higher risk of hypothyroidism: adjusted odds ratio 1.18 [95% confidence interval (CI) 1.17-1.20, P < 0.001]. In secondary analyses, we observed that a 10 mL/min/1.73 m(2) lower eGFR was associated with a 0.11 mIU/L higher serum TSH (95% CI 0.10-0.11 mIU/L higher serum TSH, P < 0.001). CONCLUSIONS: In a nationally representative cohort of patients with moderate-to-severe CKD, there is an inverse association between eGFR and risk of hypothyroidism.

Nutritional therapy, phosphate control and renal protection.

Dietary management of chronic kidney disease (CKD) focusses on limiting the intake of substances that might accumulate to toxic levels (such as potassium, phosphorus or salt) and, although still a matter of debate for some, restricting dietary protein to retard kidney damage. Recent evidence brings the opportunity to revisit the role of a healthy diet on disease progression and on some of the cardiometabolic complications of moderate/advanced CKD, such as inflammation or oxidative stress control. This review provides a brief overview of dietary strategies that delay CKD progression and CKD complications, and discusses currently limited data addressing the development of malnutrition and protein-energy wasting before dialysis initiation.

Dietary fat modification in patients with chronic kidney disease: n-3 fatty acids and beyond.

Replacement of dietary saturated fat with unsaturated fat has been recommended for prevention of cardiovascular disease (CVD) in the general population. Less is known of the health risks in individuals with chronic kidney disease (CKD), of a diet with an unhealthy fat profile, in general characterized by insufficient polyunsaturated fatty acids (PUFA) and excess satu-rated fatty acids (SFA). The dietary intake of PUFA, both the n-3 and n-6 subfamilies, is increasingly gaining attention in CKD, owing to its broad cardioprotective effects. Conversely, dietary SFA may promote CVD in this vulnerable population. This review discusses the potential benefits of dietary fat modification in CKD patients, including plausible effects on renal function, albuminuria, lipoproteins, nutritional status, inflammation, thrombosis and clinical outcomes. Increasing evidence supports the concept that n-3 PUFA might have therapeutic potential in reducing proteinuria in CKD and reducing triglycerides and inflammation in dialysis patients. In addition, emerging evidence suggests that linoleic acid, a major n-6 PUFA derived from vegetable oils, may be beneficial for a number of CVD risk factors. Increased consumption of oily fish as part of plant-based diets with low content of SFA is likely to benefit patients who have CKD, or are at risk of developing CKD. Such recommendations are in line with the concept of a healthy "Mediterranean diet" and are in line with current dietary recommendations for CVD prevention in the community.

Intake of fish oil, oleic acid, folic acid, and vitamins B-6 and E for 1 year decreases plasma C-reactive protein and reduces coronary heart disease risk factors in male patients in a cardiac rehabilitation program.

Certain nutrients have been shown to be effective in preventing coronary heart disease. We hypothesized that a daily intake of low amounts of a number of these nutrients would exert beneficial effects on risk factors and clinical variables in patients that suffered from myocardial infarction (MI) and were following a cardiac rehabilitation program. Forty male MI patients were randomly allocated into 2 groups. The supplemented group consumed 500 mL/d of a fortified dairy product containing eicosapentaenoic acid, docosahexaenoic acid, oleic acid, folic acid, and vitamins A, B-6, D, and E. The control group consumed 500 mL/d of semi-skimmed milk with added vitamins A and D. The patients received supervised exercise training, lifestyle and dietary recommendations, and they were instructed to consume the products in addition to their regular diet. Blood extractions and clinical examinations were performed after 0, 3, 6, 9, and 12 mo. Plasma concentrations of eicosapentaenoic acid, docosahexaenoic acid, oleic acid, folic acid, vitamin B-6, and vitamin E increased after supplementation (P<0.05). Plasma total and LDL-cholesterol, apolipoprotein B, and high-sensitivity C-reactive protein concentrations decreased in the supplemented group (P<0.05), and plasma total homocysteine decreased in both groups. There were no changes in heart rate, blood pressure, or cardiac electrocardiographic parameters in either group. Therapeutic lifestyle changes, effected through a CR program comprising regular exercise and the intake of a combination of dietary nutrients, reduced a variety of risk factors in MI patients, which supports the rationale for nutritional programs in the secondary prevention of coronary heart disease.