Abstract Background: Low thyroid hormone (TH) levels and myocardial damage are common in dialysis patients and are associated with mortality. However, little is known about the role of THs on myocardial damage as has been described in primary thyroid diseases. The aim of this study was to explore the potential relationship between low total triiodothyronine (total T3) and biomarkers of myocardial damage and the effect of their interaction on mortality, to ascertain if cardiovascular damage is the link between low THs and the risk of death in dialysis patients with CKD. Material and methods: TH plasma levels, nutritional markers, inflammation and myocardial damage were studied in 296 patients undergoing peritoneal dialysis or haemodialysis, who were followed up for 16 months to ascertain the association between biochemical variables and mortality. Results: Low total T3 levels were found in 45% of patients, which was inversely correlated with C-reactive protein (CRP) and NT-proBNP, and directly correlated with albumin and transferrin. Diabetes, CRP and total T3 were risk factors for all-cause mortality, and CRP, NT-proBNP and total T3 for cardiovascular mortality. Conclusions: Low total T3 levels are common in dialysis patients and are associated with inflammation, malnutrition and myocardial damage. The latter may be the link between low THs and all-cause and cardiovascular mortality.

Resumen Antecedentes: La disminución de hormonas tiroideas (HT) y el daño miocárdico son frecuentes en pacientes en diálisis y están asociados con la mortalidad. Sin embargo, poco se conoce de la importancia de las HT como factor de daño miocárdico, como se ha descrito en las enfermedades tiroideas primarias. El objetivo de este estudio fue explorar si existe interacción entre la disminución de triyodotironina total (tT3) y los marcadores de daño miocárdico y la relación de esta interacción entre ambos con la mortalidad, para establecer si el daño cardiovascular es el vínculo entre la disminución de HT y el riesgo de muerte en pacientes con ERC en diálisis. Material y métodos: Se estudiaron los niveles plasmáticos de HT, de marcadores de nutrición, inflamación y de daño al miocardio en 296 pacientes en diálisis peritoneal o en hemodiálisis, a los que se vigiló por 16 meses para conocer la asociación de las variables bioquímicas con la mortalidad. Resultados: En el 45% de los pacientes se encontró tT3 disminuida, lo cual tuvo correlación inversa con la proteína C reactiva (PCR) y con el NT-proBNP y directa con la albúmina y la transferrina. La diabetes, la PCR y la tT3 fueron factores de riesgo para la mortalidad por cualquier causa y la PCR, el NT-proBNP y la tT3 para mortalidad cardiovascular. Conclusiones: Los niveles bajos de tT3 son frecuentes en pacientes en diálisis, se asocian con inflamación, desnutrición y daño miocárdico: este último puede ser el vínculo entre la disminución de HT y la mortalidad por cualquier causa y la mortalidad cardiovascular.

Abstract Background: Testosterone deficiency (hypogonadism) is common among men undergoing haemodialysis, but its clinical implications are not well characterized. Testosterone is an anabolic hormone that induces erythrocytosis and muscle synthesis. We hypothesized that testosterone deficiency would be associated with low muscle mass, physical inactivity and higher dosages of erythropoietin-stimulating agents (ESA). Methods: Single-center cross-sectional study of 57 male haemodialysis patients. None of the patients was undergoing testosterone replacement therapy. Total testosterone was measured in serum. Body composition (by bioelectrical impedance analysis) and physical activity (by the use of pedometers) were assessed. Patients with testosterone levels below the normal range were considered hypogonadal. Results: Mean testosterone level was 321 ± 146 ng/dL; 20 patients (35%) were hypogonadal. Hypogonadal patients were older and had lower mean arterial blood pressure, higher interleukin-6 levels, lower lean body mass and higher fat body mass. A negative association between testosterone and normalized ESA dose was found in uni- and multivariate regression analyses. Testosterone levels directly correlated with lean body mass regardless of confounders. Hypogonadal patients had lower physical activity than their counterparts [2753 ± 1784 vs. 4291 ± 3225 steps/day (p = 0.04)]. The relationship between testosterone and physical activity was independent of age, comorbidities and inflammatory markers, but dependent on the proportion of muscle mass. Conclusion: Hypogonadism is common in our male haemodialysis population and is associated with higher ESA doses, reduced muscle mass and lower physical activity. The link between low testosterone levels and physical inactivity may conceivably relate to reduced muscle mass due to inadequate muscle protein synthesis.

Resumen Antecedentes: La deficiencia de testosterona (hipogonadismo) es frecuente en varones en hemodiálisis, pero sus consecuencias clínicas no se han caracterizado satisfactoriamente. La testosterona es una hormona anabólica que provoca eritrocitosis y síntesis muscular. Nos planteamos la hipótesis de que la deficiencia de testosterona pudiera estar asociada a una masa muscular baja, a la inactividad física y a dosis más altas de fármacos estimulantes de la eritropoyesis (FEE). Métodos: Estudio transversal de un solo centro de 57 pacientes varones en hemodiálisis. Ninguno de ellos estaba recibiendo tratamiento sustitutivo con testosterona. La cantidad total de testosterona se midió en el suero. Se evaluaron la composición corporal (mediante un análisis de impedancia bioeléctrica) y la actividad física (mediante el uso de podómetros). Los pacientes con concentraciones séricas de testosterona por debajo de los límites de normalidad se consideraron hipogonadales. Resultados: La concentración media de testosterona fue de 321 ± 146 ng/dl; 20 pacientes (35%) se consideraron hipogonadales. Los pacientes hipogonadales eran de edad avanzada y presentaban una presión arterial media más baja, concentraciones más altas de interleucina 6, masa corporal magra más baja y masa corporal grasa más alta. Se observó una asociación negativa entre la dosis de testosterona y de FEE normalizada en análisis de regresión univariante y multivariante. Las concentraciones de testosterona estaban directamente correlacionadas con la masa corporal magra, independientemente de los factores de confusión. Los pacientes hipogonadales presentaban una actividad física más baja que sus homólogos (2.753 ± 1.784 frente a 4.291 ± 3.225 pasos/día; p = 0,04). La relación entre la actividad física y la testosterona fue independiente de la edad, las comorbilidades y los marcadores de inflamación, pero dependían de la proporción de masa muscular. Conclusión: El hipogonadismo es frecuente en la población de varones en hemodiálisis y está asociado a dosis más altas de FEE, masa muscular reducida y actividad física baja. El vínculo entre las concentraciones bajas de testosterona y la inactividad física está posiblemente relacionado con la masa muscular reducida debido a una síntesis de proteínas musculares insuficiente.

OBJECTIVES: Chronic kidney disease is a major public health problem worldwide. In Brazil, approximately 100,000 patients (January 2012) receive renal replacement therapy. Nevertheless, data on dialysis incidence in the Brazilian population are scarce. This study aims to analyze the incidence of patients starting dialysis therapy in São Paulo City, the largest Brazilian metropolis. METHOD: This cohort study analyzed data from 9,994 patients starting hemodialysis or peritoneal dialysis funded by the Brazilian Public Health System during a 5-year period (2007-2011). Patient data for this study (recorded as electronic files) were obtained from the São Paulo City's Dialysis Regulatory Bureau, which regulates the allocation of patients requiring dialytic therapy. RESULTS: The dialysis incidence rates were 178, 174, 170, 185 and 188 per million population for the years 2007, 2008, 2009, 2010 and 2011, respectively. The incidence rates increased with age. Hypertension and diabetes were the main etiologies diagnosed. Hemodialysis was the chosen dialysis modality in the majority of patients (92.6%), whereas the percentage of patients referred for peritoneal dialysis decreased from 10.1% to 5.5%. CONCLUSION: The incidence of patients starting renal replacement therapy from 2007-2011 in São Paulo was stable but higher than the projected incidence for the entire country. The authors emphasize the need for further studies of the incidence of dialysis in the Brazilian population and for the creation of a Brazilian registry of dialysis patients, which would be a valuable tool for developing healthcare policies and renal replacement therapy strategies.

INTRODUÇÃO: A presença de desnutrição tem sido associada a inflamação e estresse oxidativo (EO) em pacientes em hemodiálise (HD) crônica. OBJETIVO: Verificar a associação entre marcadores do estado nutricional, incluindo a gordura corporal (GC), marcadores inflamatórios e de EO em pacientes em HD. MÉTODOS: Estudo transversal, realizado em 40 pacientes em HD. O estado nutricional foi avaliado por avaliação subjetiva global modificada (SGAm), equivalente protéico do aparecimento de nitrogênio total normalizado (PNAn), albumina sérica (Alb-s), índice de massa corporal (IMC), GC e massa corporal magra (MCM). Inflamação e EO foram avaliadas através da proteína C-reativa de alta sensibilidade (PCRas), interleucina-6 (IL-6), produtos protéicos de oxidação avançada (PPOA), 8-hidroxideoxiguanosina (8OHdG) e pentosidina, respectivamente. RESULTADOS: Trinta e sete por cento dos pacientes apresentavam algum grau de desnutrição avaliada pela SGAm. A mediana e variação da GC (kg) foram de 16,2 (5,3 - 36,7). Com relação aos marcadores inflamatórios e de EO, houve uma correlação positiva e significativa entre IMC e PCRas (R = 0,37; p = 0,02), GC e PCRas (R = 0,32; p = 0,04) e entre PCRas e IL-6 (R = 0,51; p = 0,0007). Correlação negativa foi encontrada entre Alb-s e PCRas (R = -0,31; p = 0,05). Apenas no sexo masculino, a PCRas apresentou relação com IMC (R = 0,54; p = 0,01) e com a GC (R = 0,52; p = 0,01). Nenhuma associação foi encontrada entre marcadores inflamatórios e de EO. CONCLUSÃO: Marcadores de desnutrição e de excesso de peso não foram correlacionados com EO. A associação da PCRas com IMC e GC somente no sexo masculino pode sugerir diferenças na resposta inflamatória entre os sexos.

INTRODUCTION: The presence of malnutrition has been associated with inflammation and oxidative stress (OS) in patients on chronic hemodialysis (HD). OBJECTIVE: To assess the association between nutritional status markers, such as body fat (BF), markers of inflammation and of OS in patients on HD. METHODS: Cross-sectional study performed with 40 patients on HD. The nutritional status was evaluated by use of the modified subjective global assessment (SGAm), normalized total protein equivalent of nitrogen appearance (PNAn), serum albumin (Alb-s), body mass index (BMI), BF, and lean body mass (LBM). Inflammation and OS were assessed by use of highsensitivity protein C-reactive (HS-PCR), interleukin-6 (IL-6), advanced oxidation protein products (AOPP), 8-hydroxydeoxyguanosine (8OHdG), and pentosidine. RESULTS: Some degree of malnutrition was observed in 37% of the patients assessed through SGAm. Median and variation of BF (kg) were 16.2 and 5.3-36.7, respectively. Regarding the markers of inflammation and of OS, a positive and significant correlation was observed between BMI and HS-PCR (R = 0.37; p = 0.02), BF and HS-PCR (R = 0.32; p = 0.04), and between HS-PCR and IL-6 (R = 0.51; p = 0.0007). A negative correlation was found between Alb-s and HS-PCR (R = -0.31; p = 0.05). Only in males HS-PCR related to BMI (R = 0.54; p = 0.01) and to BF (R = 0.52; p = 0.01). No association was found between markers of inflammation and of OS. CONCLUSION: Markers of malnutrition and of overweight did not correlate with OS. The association of HS-PCR with BMI and BF only in the male sex may suggest differences in the inflammatory response between the sexes.