• Research objectives: Evaluate and compare the clinical and paraclinical characteristics, complications, as well as the changes in beta cell function and HbA1C levels between two patient groups over a one-year follow-up period.

  +Research design: This is a prospective cohort study, monitoring patients at 3, 6, 9, and 12 months.

• Study Population and Sample Size: The study is planned to be conducted on 296 Vietnamese patients (accounting for a 20% dropout rate) who are being examined at the University of Medicine and Pharmacy Hospital in Ho Chi Minh City.

• Key Evaluation Indicators: The function of beta cells and insulin resistance status are measured through the indices of HOMA-B, HOMA-IR, fasting C-peptide levels, and HbA1C levels.

• Time and location: The study will be conducted from February 2025 to February 2028 at the Endocrinology Clinic, University Medical Center Ho Chi Minh City.

1. Research Objectives

   • Objective 1: Comparison of clinical characteristics, paraclinical findings, and complications in two groups of patients with early-onset and typical-onset Type 2 Diabetes Mellitus at the University of Medicine and Pharmacy Hospital in Ho Chi Minh City.
   • Objective 2: Comparison of changes in beta cell function and related factors in patients with early-onset and typical-onset Type 2 Diabetes Mellitus during a one-year follow-up at the University of Medicine and Pharmacy in Ho Chi Minh City.
   • Objective 3: Comparison of HbA1C levels and related factors in patients with early-onset and typical-onset Type 2 Diabetes Mellitus during a one-year follow-up at the University of Medicine and Pharmacy Hospital in Ho Chi Minh City.

2. Study Population and Research Methods

   • Research design: Prospective observational cohort study.

   • Time and location: Implementation from February 2025 to February 2028 at the Endocrinology Clinic - University Medical Center Ho Chi Minh City.

   • Sample size: A minimum of 246 patients is required (equally divided into 2 groups). To account for a 20% dropout rate, the study plans to initially enroll 296 patients.

   • Sampling criteria:

     • Early Onset Group:
     • Patient with early-onset Type 2 Diabetes Mellitus (onset age ≥ 40 years).
     • Duration of Type 2 Diabetes Mellitus diagnosis 10 years.
     • Common onset group: Diagnosed with Type 2 Diabetes Mellitus from the age of 40 and above.
     • Patient with type 2 diabetes mellitus typically onset (onset age ≥ 40 years).
     • Duration of Type 2 Diabetes Mellitus 10 years.
     • To control for confounding factors, the study employed a 1:1 matching based on disease duration ( 1 year, 1-5 years, 5- 10 years).

   • Exclusion criteria: Excluding cases of type 1 diabetes (based on antibodies and C-peptide), secondary diabetes (due to medication, pancreatic pathology, etc.), pregnant women, or patients with severe renal impairment (eGFR < 30).

3. Data Collection Process and Research Variables

   • The patient was monitored over a 12-month period with assessment milestones at T0 (baseline), T3, T6, T9, and T12.
   • Clinical variables: Age, sex, BMI, waist-to-hip ratio, blood pressure, family history, smoking/alcohol consumption habits.
   • Complication variables: Coronary artery disease, cerebrovascular disease, peripheral artery disease, retinopathy, and renal parameters (urinary albumin, eGFR).
   • Treatment variables: Oral medication regimen (Metformin, Sulfonylureas, DPP-4 inhibitors, SGLT2 inhibitors...), dosage and insulin regimen.
   • Clinical variables: HbA1C, beta cell function (fasting C-peptide, HOMA-B, HOMA-IR).

4. Data analysis methods

   • The study utilized R version 4.1.2 software for data analysis.
   • Utilize t-tests, ANOVA, or Wilcoxon tests to compare means among groups.
   • The study applies the Bayesian Model Average (BMA) multivariate linear regression model to identify the optimal models for predicting the decline in beta cell function, HbA1C levels, and the exclusion of confounding factors.

5. Ethics and Security

   • The patient participates voluntarily and has signed the Informed Consent Form for participation in the study.
   • All personal information is encrypted and kept completely confidential, utilized solely for scientific purposes.
   • Approval from the Ethics Committee in Biomedical Research of the University of Medicine and Pharmacy in Ho Chi Minh City, number 936/ĐHYD-HĐĐĐ, dated February 24, 2025.

Inclusion Criteria:

• The patient is diagnosed with Type 2 Diabetes Mellitus according to the ADA 2024 criteria (Fasting Glucose ≥ 126 mg/dl, or Glucose after 2 hours of an Oral Glucose Tolerance Test ≥ 200 mg/dl, or HbA1C ≥ 6.5%, or with typical symptoms accompanied by any Glucose ≥ 200 mg/dl).
• The duration of Type 2 Diabetes Mellitus does not exceed 10 years.
• Classification by age of onset: Early onset group (< 40 years) and typical onset group (≥ 40 years).
• At least 6 months without the need for insulin and no recorded episodes of diabetic ketoacidosis since the time of diagnosis.
• For the early-onset group: Autoantibodies (Anti-GAD, ICA) are negative and fasting C-peptide levels are > 0.6 nmol/L.
• The patient consents to participate in the study and signs the informed consent document.

Exclusion Criteria:

• Pregnant women or patients with acute illnesses at the time of assessment.
• The patient has been diagnosed with or exhibits characteristics suggestive of Type 1 Diabetes Mellitus (such as a history of ketoacidosis, C-peptide < 0.2 nmol/L).
• Secondary diabetes mellitus due to pancreatic disorders (pancreatitis, pancreatic tumors, pancreatic resection), due to medications (glucocorticoids), or due to other endocrine disorders (Cushing's syndrome, hyperthyroidism, acromegaly).
• Severe renal failure with an estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m².
• Use of medications that affect beta cell function or complications such as prolonged high-dose corticosteroids, immunosuppressive agents, or chemotherapy.
• Not of Vietnamese ethnicity.
• Non-compliance with treatment guidelines or failure to attend scheduled follow-up appointments.

A patient with type 2 diabetes mellitus presents for evaluation at the Endocrinology clinic of the University Medical Center of Ho Chi Minh City.