The Hong Kong Diabetes Biobank

The Hong Kong Diabetes Biobank leverages on the existing infrastructure of clinical assessment for people with diabetes. Subjects undergoing routine diabetes complications screen at different diabetes centres across Hong Kong will be invited for recruitment into the Hong Kong Diabetes Biobank. Subjects will receive detailed information and explanation of the study, and written informed consent will be obtained from each subject interested in participating in the study. As part of the routine diabetes complications assessment, all subjects will undergo a structured assessment based on the same protocol, including collection of background clinical information including demographics, diabetes duration, family history, medications and other relevant medical information. Anthropometric measurements including body weight, height, BMI will be collected. Clinical assessment include blood pressure, as well as fundus photography for assessment of diabetic retinopathy, and examination of peripheral pulses for peripheral vascular disease. Urine microalbumin will be measured using spot urine albumin/creatinine ratio. Other biochemical assessment include renal function, liver function, estimated GFR, fasting lipid profile, fasting glucose and HbA1c. An additional 20ml blood will be obtained from each participating patient for extraction of genomic DNA, storage of serum, plasma, and for subsequent biomarker studies. Samples will be transported and processed for secure centralized storage at -80°C in dedicated facilities fitted with alarms. Samples will be identified by a unique assigned sample code. Selection and use of the samples for replication studies will be governed by the Steering Committee. All recruited subjects will be prospectively followed up for development of diabetes complications and other clinical endpoints. Other clinical information and prescription records would be obtained from the electronic medical records. Initial analyses would include identification of biomarkers associated with cardio-renal complications in diabetes. Subjects from the registry who have developed renal complications (diabetic kidney disease (DKD) defined as stage 3 chronic kidney disease or worse i.e. eGFR ≤60ml/min/1.73m2 and/or micro/macroalbuminuria) on prospective follow-up, will be compared to subjects free of kidney complications. Subjects who developed cardiovascular complications (defined as new-onset acute coronary events, coronary revascularization, stroke and congestive cardiac failure) will be identified for a case: control analysis to replicate genetic predictors and other biomarkers associated with development of cardiovascular complications. Control subjects will be identified as subjects with type 2 diabetes who are free of cardiovascular events described above despite long duration of disease. Other clinical outcomes of interest include diabetes progression and need for treatment intensification (including initiation of insulin treatment), as well as other clinical events.