El síndrome de apneas-hipoapneas del sueño (SAHS) grave incrementa la excreción urinaria de eritropoyetina. Efecto del tratamiento con CPAP / Increased Urinary Erythropoietin Excretion in Severe Sleep Apnea-Hipoapnea Syndrome: The Effect of CPAP

Introducción: La hipoxia tisular estimula la producción de eritropoyetina (EPO) que tiene como principal función estimular la eritropoyesis. El SAHS es una entidad caracterizada por la presencia de episodios repetidos de hipoxemia durante el sueño. Objetivo: Analizar si dicha hipoxemia es un estímulo suficiente para incrementar la excreción urinaria de EPO. Si la respuesta fuera positiva, valorar si el tratamiento con presión continua positiva de la vía aérea (CPAP) la inhibiría. Métodos: Se han estudiado 25 sujetos con sospecha de SAHS, a los que se les realizó un estudio polisomnográfico. En todos ellos se determinaron los niveles de EPO en la primera orina de la mañana (uEPO), así como los niveles de creatinina y hemoglobina en sangre. En los pacientes con SAHS grave se repitieron las mismas determinaciones tras el tratamiento con CPAP. Resultados: Doce sujetos fueron diagnosticados de SAHS grave (media ± SD, IAH de 53,1 ± 22,7). La creatinina y la hemoglobina fueron normales en todos los sujetos. La uEPO fue cuatro veces superior en el grupo SAHS respecto a los controles (1,32 ± 0,83 vs. 0,32 ± 0,35 IU/l, p < 0,002). El tratamiento con CPAP descendió la uEPO hasta 0,61 ± 0,49 IU/l (p < 0,02), acercándose al valor de los sujetos sanos. No se observó una relación dosis-respuesta entre la gravedad de las alteraciones de la PSG y los valores de uEPO. Conclusiones: Los pacientes con SAHS grave muestran un incremento en su excreción de uEPO, que se normaliza tras el tratamiento con CPAP

Introduction: Tissue hypoxia stimulates the production of erythropoietin (EPO), the main effect of which is, in turn, to stimulate erythropoiesis. Sleep apnea-hypopnea syndrome (SAHS) is an entity characterized by repeated episodes of hypoxemia during sleep. Objective: To analyze whether hypoxemia stimulated increased urinary excretion of EPO, and if so, to evaluate if treatment with continuous positive airway pressure (CPAP) can inhibit this phenomenon. Methods: We studied 25 subjects with suspected SAHS who underwent a polysomnography study (PSG). EPO levels in first morning urine (uEPO) and blood creatinine and hemoglobin were determined in all patients. Patients with severe SAHS repeated the same determinations after CPAP treatment. Results: Twelve subjects were diagnosed with severe SAHS (mean ± SD, AHI 53.1 ± 22.7). Creatinine and hemoglobin levels were normal in all subjects. uEPO was 4 times higher in the SAHS group than in the control group (1.32 ± 0.83 vs. 0.32 ± 0.35 UI/l, p <.002). CPAP treatment reduced uEPO to 0.61 ± 0.9 UI/l (p <.02), levels close to those observed in healthy subjects. No dose-response relationship was observed between severity of PSG changes and uEPO values. Conclusions: Patients with severe SAHS show increased uEPO excretion, but this normalizes after treatment with CPAP

Increased Urinary Erythropoietin Excretion in Severe Sleep Apnea-Hipoapnea Syndrome: The Effect of CPAP. / El síndrome de apneas-hipoapneas del sueño (SAHS) grave incrementa la excreción urinaria de eritropoyetina. Efecto del tratamiento con CPAP.

INTRODUCTION: Tissue hypoxia stimulates the production of erythropoietin (EPO), the main effect of which is, in turn, to stimulate erythropoiesis. Sleep apnea-hypopnea syndrome (SAHS) is an entity characterized by repeated episodes of hypoxemia during sleep. OBJECTIVE: To analyze whether hypoxemia stimulated increased urinary excretion of EPO, and if so, to evaluate if treatment with continuous positive airway pressure (CPAP) can inhibit this phenomenon. METHODS: We studied 25 subjects with suspected SAHS who underwent a polysomnography study (PSG). EPO levels in first morning urine (uEPO) and blood creatinine and hemoglobin were determined in all patients. Patients with severe SAHS repeated the same determinations after CPAP treatment. RESULTS: Twelve subjects were diagnosed with severe SAHS (mean ± SD, AHI 53.1 ± 22.7). Creatinine and hemoglobin levels were normal in all subjects. uEPO was 4 times higher in the SAHS group than in the control group (1.32 ± 0.83 vs. 0.32 ± 0.35 UI/l, p <.002). CPAP treatment reduced uEPO to 0.61 ± 0.9 UI/l (p <.02), levels close to those observed in healthy subjects. No dose-response relationship was observed between severity of PSG changes and uEPO values. CONCLUSIONS: Patients with severe SAHS show increased uEPO excretion, but this normalizes after treatment with CPAP.