In order to obtain multiple regression models, the relationship between overhydration and mortality was studied after controlling for variables that had a p value <0.20 (age, BMI, Charlson Index, hypertension, diabetes, arrhythmias, coronary disease, congestive heart failure, cerebrovascular disease, peripheral vascular disease, DBP, iron therapy and EPO resistance). The gene discussed is EPO; the disease is Arrhythmia.