Determinants of indoxyl sulfate and p-cresyl sulfate.

*P**P***PPFirst a stepwise regression model not taking into account family relationships was used to select the covariables. Then, a mixed model with family included as a random effect and the covariables selected in the previous step entered as fixed effects was used to calculate parameter estimates. The following variables were offered to the stepwise regression model: sex, age (linear and squared term), systolic and diastolic blood pressure, history of cardiovascular disease, antihypertensive drug intake, current smoking and alcohol intake, body mass index, diabetes mellitus, serum total cholesterol, triglycerides, serum creatinine and calculated creatinine clearance.