Blood treatment device, designed as a dialysis device for the treatment by dialysis of a patient (3), having a side substituent and / or dialysate, and a dialyzer (9), a device configured to determine the least one characteristic indicator relating to glucose metabolism of the patient (3) during an extracorporeal dialysis treatment of the patient (3) by means of the dialysis machine, wherein the device further comprises: a device for measuring a glucose concentration and an adder (31), is appropriate and is expected for extracorporeal addition of glucose by the dialysate side (7) and / or substituent (17a, 17v) for the purpose of analysis of glucose metabolism, characterized in that the addition device is equipped with a control or regulation, which is configured to cause the addition of glucose as a glucose addition at least increased over time, for the purpose of analyzing the glucose tolerance and in that the device for determining at least one characteristic indicator is configured to calculate at least one characteristic indicator for assessment of glucose tolerance in time from changing glucose concentration.Dispositivo de tratamiento sanguíneo, diseñado como un dispositivo de diálisis para el tratamiento por diálisis de un paciente (3), que presenta un lado del sustituyente y/o del dializado, así como un dializador (9), con un dispositivo configurado para determinar al menos un indicador característico relativo al metabolismo de la glucosa del paciente (3) durante un tratamiento extracorporal por diálisis del paciente (3) por medio del dispositivo de diálisis, donde el dispositivo presenta además: un dispositivo para medir una concentración de glucosa y un dispositivo de adición (31), que resulta apropiado y se prevé para la adición extracorporal de glucosa por el lado del dializado (7) y/o del sustituyente (17a, 17v) para el propósito del análisis del metabolismo de la glucosa, caracterizado porque el dispositivo de adición está equipado de un dispositivo de
