CKD-MBD (Chronic Kidney Disease - Mineral and Bone Disorder) is an extensive disease and includes dysfunction of the mineral metabolism, the bone metabolism and cardiovascular diseases in the context of renal insufficiency. Clinical pictures of peripheral artery occlusive disease (PAOD), Coronary artery disease (CAD) and arterial hypertension favours among other main risk factors (smoking, obesity, etc.) additional cardiovascular complications. For this reason it makes sense to monitor these patients regularly. For this purpose the determination of different biomarkers would be appropriate for control of the course of disease.

During various studies the biomarkers FGF23, s-klotho, sclerostin, DKK1, BMP2, YKL-40 und MGP were established as indicators for the disease activity, as diagnostic criteria for the existence of CKD-MBD or as risk markers for the incidence of adverse events (incl. death) within the scope of CKD-MBD. For the clinical routine care application of these parameters standard operating procedures (SOP) are missing for the determination method relating to optimal pre-analytic and analytic procedures. These analyses are necessary to ensure the reproducibility of study results and to transfer these parameters in the clinical daily routine for risk stratification.

Inclusion Criteria:

• Patients who are regularly (3 times a week) on dialysis in the Maria-Hilf-Clinic or healthy subjects
• Male or Female at the age of at least 18 years
• Patients who will be admitted to the clinics of the University Hospital RWTH Aachen or of the Maria-Hilf-Clinic Mönchengladbach or healthy subjects
• written informed consent form
• Subjects who are contractually capable and mentally able to understand and follow the instructions of the study personnel

Exclusion Criteria:

• age < 18 years
• subjects who are unwilling or not able to consent
• pregnant or lactating women
• subject has been committed to an institution by legal or regulatory order
• dependency or working relationship with the investigator
• participation in a parallel interventional clinical study
• Hb-value < 10 g/dl

Patients who are regularly on dialysis in the clinics will be selected . Healthy Subjects will be recruited over notices in clinic.