This clinical trial was conducted at the National Diabetes Center for Treatment and Research, Mustansiriyah University, Baghdad (Sept 2024-May 2025).

It evaluated the effect of mangosteen supplementation (500 mg twice daily) as an adjunct to sitagliptin/metformin (50/1000 mg twice daily) in newly diagnosed Type 2 Diabetes Mellitus (T2DM) patients over a period of 12 weeks.

• Sample: 47 patients completed the study (22 in sitagliptin/metformin group; 25 in sitagliptin/metformin + mangosteen group).
• Design: Prospective, randomized, controlled, open-label trial.
• Intervention: Both groups also received lifestyle modification (diet, exercise, diabetes education).
• Endpoints: Anthropometric measures, glycemic control (FBG, HbA1c, insulin, HOMA-IR, HOMA-B), lipid profile, oxidative stress (SOD1), inflammatory marker (IL-6), liver & kidney function, and safety monitoring.
• Statistical Analysis: Parametric/non-parametric tests, correlations, regression, and ANCOVA to assess changes and adjust for confounders.

1. Patients

   • Inclusion: Adults (>30 years) with T2DM (AACE criteria), HbA1c 7.5-9%.
   • Exclusion: T1DM, insulin users, patients with complications, liver/kidney disease, other metabolic/endocrine disorders, patients on steroids/contraceptives/thyroid meds/supplements, pregnant/lactating women.
   • Ethics: Approved by Mustansiriyah University Ethics Committee. Written informed consent obtained.

2. Study Design

   • Type: Interventional, prospective, randomized, controlled, open-label.
   • Groups:
   • Group 1 (n=22): Sitagliptin/metformin 50/1000 mg twice daily + lifestyle modification.
   • Group 2 (n=25): Sitagliptin/metformin 50/1000 mg twice daily + Mangosteen 500 mg twice daily + lifestyle modification.
   • Duration: 12 weeks.
   • Compliance: Monitored via pill counts, phone follow-ups, monthly clinic visits.

3. Interventions & Protocol

   • All patients received standardized diabetes education and counseling.
   • Two-week washout for lipid-lowering drugs before enrollment to avoid confounding.
   • Data collected: demographics, socioeconomic, comorbidities, medication use, family history.

4. Measurements

   • Anthropometry: Weight, height, BMI, waist circumference, index of central obesity (ICO).
   • Samples:
   • Blood: Collected after 12-hour fasting (baseline & after 12 weeks). Serum separated for immediate and stored analysis.
   • Urine: Albumin/creatinine ratio to exclude nephropathy.
   • Biochemical tests:
   • Glycemic control: HbA1c (immunoassay), fasting blood glucose (hexokinase method), fasting serum insulin (ECLIA).
   • Insulin resistance & β-cell function: HOMA-IR, HOMA-B formulas.
   • Lipid profile: TC, HDL-C, TG, LDL-C, VLDL-C.
   • Inflammatory marker: Interleukin-6 (ELISA).
   • Oxidative stress marker: Superoxide dismutase-1 (ELISA).
   • Kidney function: Serum urea, creatinine, urinary ACR.
   • Liver function: AST, ALT, ALP.

5. Statistical Analysis

   • Software: SPSS v25.
   • Tests Used:
   • Normality: Shapiro-Wilk test.
   • Between-group: Independent t-test or Mann-Whitney U.
   • Within-group: Paired t-test or Wilcoxon signed-rank.
   • Categorical: Chi-square or Fisher's exact.
   • Correlations: Pearson test.
   • Regression: Linear regression for predictors of HbA1c change.
   • ANCOVA: Adjusted analysis for differences between groups (e.g., baseline HOMA-IR).
   • Significance: p < 0.05.

Inclusion Criteria:

• Adults aged ≥30 years.
• Diagnosed with Type 2 Diabetes Mellitus according to American Association of Clinical Endocrinologists (AACE) criteria.
• HbA1c between 7.5% and 9%.

Exclusion Criteria:

• T1DM patients were excluded from study.
• T2DM patients receiving any anti-diabetic treatment other than the study intervention or T2DM patients receiving insulin therapy.
• Patients with T2DM complications or having liver disease, kidney disease.
• Patients with other metabolic diseases (thyroid disorders, adrenal disorders, growth hormone disorders and pituitary disorders) that may affect glycemic and metabolic status.
• Patients receiving drugs (steroids, contraceptives, anticoagulants and thyroid medications) or using other nutritional supplements or herbal remedies that may interfere with lab results.
• Pregnant or lactating women.

Individual participant data (IPD) will not be shared. Only aggregated results and statistical analyses will be published in scientific journals or presented at conferences.

This is open-label study, no parties were masked.