Loss of muscle strength in patients under hemodialysis evaluated by dynamometry in the Mexican population

espanolIntroduccion: la enfermedad renal cronica contribuye a disminuir la fuerza muscular y la funcion fisica a traves de una disminucion de la masa muscular. De acuerdo con la evidencia, la hemodialisis puede acentuar esta complicacion, asi como llevar al paciente a un deterioro del estado general de salud. El objetivo de la investigacion fue comparar la fuerza muscular de pacientes con hemodialisis, evaluada mediante dinamometria en una poblacion mexicana, con los valores de referencia. Material y metodos: se realizo un estudio transversal en pacientes masculinos y femeninos de 20 a 81 anos, con enfermedad renal cronica en estadio 5, del area de consulta externa del Hospital General Regional No 46 del Instituto Mexicano del Seguro Social. La fuerza muscular se evaluo por medio de un dinamometro mecanico. El valor promedio clasificado por rango de edad y genero se comparo con el percentil 50 de un estudio de referencia. Las diferencias intergrupales se calcularon con la prueba no parametrica de la U de Mann-Whitney y la correlacion mediante la prueba de Pearson. Todos los pacientes firmaron la carta de consentimiento informado. Resultados: la muestra del estudio fue de 150 pacientes, 97 (64,7 %) hombres y 53 (35,3 %) mujeres. De acuerdo con la dinamometria, la media fue de 21,5 ± 10,1 kg; se demostro una correlacion significativa entre la edad, el peso y la hemoglobina. Conclusion: se encontro que los pacientes con enfermedad renal cronica sometidos a hemodialisis se encontraban en el percentil 10 de fuerza muscular, medido por dinamometria, lo que demuestra una disminucion marcada de dicha fuerza muscular. Sin embargo, este resultado tambien podria verse afectado por diferentes variables, como la edad del paciente, la altura, el peso, la tasa de filtracion glomerular (TFG), la concentracion de hemoglobina, la creatinina serica, la glucosa serica y la evaluacion global subjetiva, dado que se encontro una asociacion significativa entre estos factores y la fuerza muscular. EnglishIntroduction: chronic kidney disease contributes to decreased muscle strength and physical function through a decrease in muscle mass. Current evidence suggests that hemodialysis can accentuate this complication, as well as lead to deterioration of the patient’s overall health. The aim of this study is to compare muscle strength in a group of Mexican patients undergoing hemodialysis, evaluated by dynamometry, with available reference values. Materials and methods: a cross-sectional study was conducted in male and female patients between 20 and 81 years of age, with stage-5 chronic kidney disease, from the outpatient Hospital General Regional No 46 of the Mexican Social Security Institute. Muscle strength was assessed by means of a mechanical dynamometer. The average value classified by age and gender was compared with the 50th percentile of a reference study. Inter-group differences were calculated with the nonparametric Mann-Whitney U-test, and correlation using Pearson’s test, logistic regression, and chi-squared test. All patients signed an informed consent form. Results: a total of 150 patients, 97 (64.7 %) men and 53 (35.3 %) women, were included in the study. The mean dynamometric value for muscle strength was 21.5 ± 10.1 kg, and a significant correlation was found with age, weight, and hemoglobin concentration. Conclusion: patients undergoing hemodialysis treatment for chronic kidney disease were found to be at the 10th percentile for muscle strength, as measured by dynamometry, thus demonstrating a marked decrease in muscle strength. This result could, however, also have been affected by different variables such as patient age, height, weight, glomerular filtration rate (GFR), hemoglobin concentration, serum creatinine, serum glucose, and the subjective global assessment, given that a significant association was also found between these and muscle strength.