Diabetes mellitus is recognized as a metabolic disease that causes global economic and health burdens with an estimated number of patients 135 million in 1995 to 300 million in 2025. Moreover, the Asia-Pacific region is considered to be on the verge of an emerging diabetes epidemic. Diabetes is associated with numerous comorbidities due to a wide range of complications, such as retinopathy, nephropathy, neuropathy, and cardiovascular disease, which could lead to premature mortality. Management of diabetes under standard treatment protocol improves quality of life and prevents complications and premature mortality. Pathogenesis of these detrimental complications caused by diabetes is not yet discovered and it is important to reveal epidemiology and mechanisms of diabetes and its complications in order to successfully manage and control diabetes. According to the Committee of the Korean Diabetes Association on the Epidemiology of Diabetes Mellitus, only about one third of patients with diabetes was found to reach target glycemic control (<7% of HbA1c) and 30.3%, 38.3% and 44.6% of patients found to have microalbuminuria, retinopathy and nephropathy, respectively in tertiary hospitals of Korea in 2006. Also, prevalence of coronary artery disease, cerebrovascular disease and peripheral artery disease was 8.7%, 6.75 and 3.0%, respectively in tertiary hospitals. Due to inadequate achievement of glycemic control and improper prevention tactics to prevent diabetic complication for patients in tertiary hospitals in Korea, it is pivotal to determine and analyze the current status of patients with diabetes and prediabetes for efficient management of diabetes/prediabetes and its complications. Annual visits of newly diagnosed diabetes or prediabetes to Endocrinology department of Severance hospital in Korea are increasing, about 5,000 patients per year since 2017. However, there is no current systemic clinical registry involving patients with diabetes or prediabetes in Severance hospital. Therefore, in this prospective cohort study, we will establish registry for patients with diabetes or prediabetes who would perform standard blood/urine tests and follow treatment protocols in Endocrinology department of Severance hospital.

Inclusion Criteria:

• Drug naive patients who are newly diagnosed type 1 diabetes/type 2 diabetes or prediabetes since March, 2022 in Severance hospital ② Male or female who are older than 20 years ③ Patients who consented and underwent recommended regular blood and urinary tests according to the current guidelines.

Exclusion Criteria:

① Patients who are considered to be unable to participate in the study by the judgement of researchers

② Patients who are unable to read the consent forms (E.g Foreigner, illiteracy)

Patients who visited Severance hospital from March, 2022 with newly diagnosed type 1 diabetes/type 2 diabetes or prediabetes and consented and underwent regular blood and urinary tests acccording to the current guidelines Inclusion criteria

• Drug naive patients who are newly diagnosed type 1 diabetes/type 2 diabetes or prediabetes since March, 2022 in Severance hospital ② Male or female who are older than 20 years ③ Patients who consented and underwent recommended regular blood and urinary tests according to the current guidelines.

Exclusion criteria ① Patients who are considered to be unable to participate in the study by the judgement of researchers

② Patients who are unable to read the consent forms (E.g Foreigner, illiteracy)