[Can FT3 levels facilitate the detection of inflammation or catabolism and malnutrition in dialysis patients?]. / ¿Pueden los niveles de T3L facilitar la detección de estados inflamatorios o de catabolismo y desnutrición en enfermos en diálisis?

INTRODUCTION: Low serum free triiodothyronine (FT3) levels have been reported in a high percentage of chronic renal failure (CRF) patients and have been considered as independent predictors of mortality in both hemodialysis (HD) and peritoneal dialysis (PD). A reduction in thyroid function in dialysis patients could be a marker of malnutrition and/or inflammation. OBJECTIVE: Our aim has been to evaluate the incidence of low T3 syndrome in a group of dialysis patients and analyze its relationship with different parameters of malnutrition and inflammation. PATIENTS AND METHODS We included 32 stable dialysis patients (24 HD and 8 DP); mean age +/- SD 71.2 +/- 11.7 years; 46.9% males; 15.6% diabetics; mean time on dialysis 47 +/- 43 months. The following parameters were measured in every patient: thyrothropin (TSH), Free T4 (FT4) and Free T3 (FT3); biochemical data related to nutritional status; anthropometric measurements, bioelectrical impedance vector analysis (BIVA), and dietary survey of three consecutive days. Statistical analysis was performed by using SPSS 11.0. RESULTS: Mean hormonal values of thyroid function were: TSH 2,2 +/- 1.5 U/ml (range: 0,4-5.0); FT4 14.7 +/- 2.3 pmol/l (range: 11.0-23.0) and FT3 4,0 +/- 0.71 pmol/l (range: 3.95-6.80). Only 2 patients (6.3%) showed low FT4 levels and another 2 patients increased TSH levels, whereas 17 patients (53.1%) presented with low FT3 levels. We did not found any correlation between serum FT3, FT4 and TSH levels. We found a correlation between FT3 and inflammation/nutritional parameters: prealbumin (r = 0,36; p = 0,04); transferrin (r = 0,40; p = 0,025); PCR (r = -0.38; p = 0,039); and IGF-I (r = 0,38; p = 0,03); body mass index (BMI) (r = 0,51; p = 0,002); arm circumference (AC) (r = 0,65; p = 0,000), and arm muscle circumference (AMC) (r = 0,72; p = 0,000). FT3 levels were also correlated with BIVA parameters: phase angle (r = 0,54; p = 0,002); muscle mass percentage (r = 0,49; p = 0,005); and cell mass percentage (r = 0,53; p = 0,02), but not with any data of fat mass. AMC was the only variable that independently correlated with FT3 levels in the multivariate regression analysis (r = 0,69; r2: 0,48; p = 0,000) CONCLUSION: Half of our dialysis patients have decreased levels of serum FT3 without alteration on FT4 or TSH. Low FT3 levels are correlated bioquimical and anthropometric parameters indicators of malnutrition and inflammation. Periodical measurement of FT3 levels could be used by clinicians as an accesible and reproducible method to detect such states.

Can FT3 levels facilitate the detection of inflammation or catabolism and malnutrition in dialysis patients?

Introduction: Low serum free triiodothyronine (FT3) levels have been reported in a high percentage of chronic renal failure (CRF) patients and have been considered as independent predictors of mortality in both haemodialysis (HD) and peritoneal dialysis (PD). A reduction in thyroid function in dialysis patients could be a marker of malnutrition and/or inflammation. Objective: Our aim has been to evaluate the incidence of low T3 syndrome in a group of dialysis patients and analyze its relationship with different parameters of malnutrition and inflammation. Patients and Methods: We included 32 stable dialysis patients (24 HD and 8 DP); mean age ± SD 71.2 ± 11.7 years; 46.9% males; 15.6% diabetics; mean time on dialysis 47 ± 43 months. The following parameters were measured in every patient: thyrothropin (TSH), Free T4 (FT4) and Free T3 (FT3); biochemical data related to nutritional status; anthropometric measurements, bioelectrical impedance vector analysis (BIVA), and dietary survey of three consecutive days. Statistical analysis was performed by using SPSS 11.0. Results: Mean hormonal values of thyroid function were: TSH 2,2 ± 1.5 U/ml (range: 0,4-5.0); FT4 14.7 ± 2.3 pmol/l (range: 11.0-23.0) and FT3 4,0±0.71 pmol/l (range: 3.95-6.80). Only 2 patients (6.3%) showed low FT4 levels and another 2 patients increased TSH levels, whereas 17 patients (53.1%) presented with low FT3 levels. We did not found any correlation between serum FT3, FT4 and TSH levels. We found a correlation between FT3 and inflammation/nutritional parameters: prealbumin (r = 0,36; p = 0,04); transferrin (r = 0,40; p = 0,025); PCR (r = -0.38; p = 0,039); and IGF-I (r = 0,38; p = 0,03); body mass index (BMI) (r = 0,51; p = 0,002); arm circumference (AC) (r = 0,65; p = 0,000), and arm muscle circumference (AMC) (r = 0,72; p = 0,000). FT3 levels were also correlated with BIVA parameters: phase angle (r = 0,54; p = 0,002); muscle mass percentage (r = 0,49; p = 0,005); and cell mass percentage (r = 0,53; p = 0,02), but not with any data of fat mass. AMC was the only variable that independently correlated with FT3 levels in the multivariate regression analysis (r = 0,69; r2: 0,48; p = 0,000). Conclusion: Half of our dialysis patientshave decreased levels of serum FT3 without alteration on FT4 or TSH. Low FT3 levels are correlated bioquimical and anthropometric parameters indicators of malnutrition and inflammation. Periodical measurement of FT3 levels could be used by clinicians as an accessible and reproducible method to detect such states (AU)

Introducción: Un alto porcentaje de pacientes en diálisis presenta niveles séricos disminuidos de triiodotironina libre (T3L), y algunos autores han mostrado su relación con marcadores de inflamación. Niveles bajos de T3L también se han mostrado como predictores independientes de mortalidad en diálisis. Objetivo: Evaluar la incidencia de síndrome T3L baja en un grupo de pacientes en diálisis y analizar su relación con diferentes parámetros de malnutrición e inflamación. Pacientes y métodos: Se estudiaron 32 pacientes estables en diálisis (24 hemodiálisis y 8 diálisis peritoneal), edad (media ± DS) 71,2 ± 11,7 años; 46,9% varones; 15,6% diabéticos; media de tiempo en diálisis 47 ± 43 meses. En cada paciente se cuantificó: tirotropina, T4 Libre y T3L; parámetros bioquímicos relacionados con nutrición e inflamación; parámetros antropométricos, composición corporal mediante bioimpedancia eléctrica con análisis vectorial e ingesta de nutrientes. El análisis estadístico se hizo usando un SPSS 11.0. Resultados: La media de los valores de las hormonas tiroideas fue: TSH 2,2 ± 1,5 U/ml (rango 0,4-5,0), T4L 14,7 ± 2,3 pmol/l (rango: 11,0-23,0) y T3L 4,0 ± 0,71 pmol/l (rango: 3,95-6,80). Sólo dos pacientes (6,3%) mostraron niveles de T4L bajos, y otros dos pacientes aumento de TSH, mientras que 17 pacientes (53,1%) presentaron niveles bajos de T3L. No encontramos ninguna correlación entre los niveles de T3L, T4L y TSH. Los niveles de T3L se correlacionaron con parámetros de inflamación/ nutrición: prealbúmina (r = 0,36; p = 0,04); transferrina (r = 0,40; p = 0,025); proteína C reactiva (r = - 0,38; p = 0,039); y factor de crecimiento similar a la insulina (r = 0,38; p = 0,03); índice de masa corporal (r = 0,51; p = 0,002); circunferencia de brazo (r = 0,65; p = 0,000); perímetro muscular de brazo (r = 0,72; p = 0,000), ángulo de fase (r = 0,57; p = 0,001); porcentaje de masa muscular (r = 0,49; p = 0,005) y porcentaje de masa celular (r = 0,54; p = 0,002). En el análisis de regresión lineal múltiple, el perímetro muscular del brazo fue la única variable que mostró asociación independiente con los niveles de T3L (r = 0,69; p = 0,000). Conclusión: Alrededor del 50% de los pacientes en diálisis tienen niveles séricos disminuidos de T3L sin alteración de TSH o T4L. Estos niveles se correlacionan con parámetros de malnutrición e inflamación. Su determinación periódica podría facilitar al clínico un método accesible y reproducible de detección de estos estados (AU)