Chinese Cohort Study of Chronic Kidney Disease

The study is a multicenter prospective cohort study, aimed to explore underlying mechanisms of chronic kidney disease progression and its association with adverse consequences. The study will establish a baseline cohort of 5000 Chinese pre-dialysis chronic kidney disease patients, who will be followed up until death or dropout or starting renal replacement therapy. The follow-up will be conducted for at least 5 years. Their clinical information and biomaterials will be collected at baseline and then annually during follow-up.

The baseline visit includes the following items: detailed demographics; socioeconomic and health care services information; medical and family history; medication history; and questionnaires concerning quality of life, health behaviors, depressive and anxiety symptoms, cognitive function, and physical activity. Anthropometric measures (height, weight, waist circumference, hip circumference, resting blood pressure, heart rate, grip strength, and 15-feet measured walk) will also be collected. The laboratory parameters of chemistry test, intact parathyroid hormone, 24-hour urine electrolytes, protein creatinine ratio, and albumin creatinine ratio should also be collected for each participant and measured in the central laboratory. After the baseline visit, participants will return annually for follow-up visits and evaluation. The evaluating items of follow-up visits are similar to the baseline visit, and sample collection.

The principal clinical outcomes of the study can be broadly categorized as renal disease events, cardiovascular events, and death. Renal disease events include the incident end stage renal disease or significant loss of renal function.Cardiovascular events include acute myocardial infarction, unstable angina, hospitalization for congestive heart failure, incident serious cardiac arrhythmia, cerebrovascular events, and peripheral vascular diseases. Death is further clarified as cardiac, cerebrovascular, renal, others, or unknown.

Inclusion criteria

Participants should meet the following criteria of enrollment according to their etiology of nephrology.

• For glomerular nephrology patients, the estimated glomerular filtration rate (eGFR) should be ≥15 ml/minute per 1.73m(2).
• For diabetic nephrology patients, the defining eligibility was 15 ml/minute per 1.73m(2) ≤eGFR<60 ml/minute per 1.73m(2) or eGFR≥ 60 ml/minute per 1.73m(2) with "nephrotic range" proteinuria, which is defined as 24-hour urinary protein ≥3.5 g or urinary albumin creatinine ratio (ACR) ≥2 000 mg/g or corresponding values of urine dipstick test or urinary protein creatinine ratio (PCR).
• For non-glomerular nephrology and non-diabetic nephrology patients, 15 ml/minute per 1.73m(2)≤eGFR<60 ml/minute per 1.73m(2) is set for enrollment.

Exclusion criteria

Participants meeting even one of the listed items should be excluded.

• NYHA Class III or IV heart failure.
• Chronic kidney disease caused by systemic inflammatory illness or autoimmune disease, such as lupus erythematosus.
• Treated with immunosuppressive agents in the preceding 6 months to treat renal or immune disease.
• Self-reported or known diagnosis of HIV infection and/or AIDS.
• Isolated hematuria.
• Self-reported or known diagnosis of cirrhosis.
• Pregnant or breast-feeding women.
• Malignancy treated with chemotherapy within last 2 years.
• Renal or other transplantation.
• Hereditary kidney disease.
• Participation in interventional clinical trial.