RNLS and chronic kidney disease: Multivariate analysis performed in CKD group with logarithm of urinary renalase concentration as dependent variable and logarithm of serum renalase concentration and six covariates (sex, age, GFR, presence of hypertension, diabetes, and proteinuria) as independent variables, showed that serum renalase was the only significant independent factor strongly positively associated with urinary renalase concentration (standardized β = + 0.67, p < 0.001; R2 = 0.47, p < 0.001 for the whole model) (Table 3).