The Therapeutic Effects of Ceylon Cinnamon Supplementation and a Self-Efficacy Educational Program on Glycemic Control, Lipid Profiles, and Pain in Type 2 Diabetes Mellitus With Painful Diabetic Peripheral Neuropathy

Type 2 diabetes mellitus (T2DM) is a major global health challenge often complicated by diabetic peripheral neuropathy (DPN), which frequently manifests as painful diabetic peripheral neuropathy (PDPN) and severely compromises patients' quality of life. Conventional pharmacological treatments for PDPN often produce limited efficacy and adverse side effects, necessitating safe and effective complementary interventions.

This study is a prospective, three-group, parallel-arm, randomized controlled trial (RCT) designed to investigate the synergistic therapeutic impact of botanical supplementation and behavioral education. A total of 900 eligible adult participants diagnosed with T2DM and PDPN attending clinical healthcare centers will be enrolled and randomly allocated in a 1:1:1 ratio into one of three trial arms:

Control Group (Standard Care, n = 300): Participants receive routine diabetic medical care, standard counseling, and matching placebo capsules administered twice daily for 6 months, without structured educational interventions.

Cinnamon Supplementation Group (n = 300): Participants receive standard routine care alongside pure Ceylon cinnamon (Cinnamomum verum) extract capsules (500 mg orally twice daily with meals, total daily dose: 1,000 mg) for 6 months, combined with a double-blind placebo control for the educational component.

Combined Intervention Group (n = 300): Participants receive the identical daily regimen of 1,000 mg Ceylon cinnamon supplementation for 6 months, integrated with a structured, theory-driven Self-Efficacy-Based Educational Program grounded in Bandura's social cognitive theory. The educational program focuses on self-monitoring of blood glucose (SMBG), medication and supplement adherence, dietary modifications, foot care, and psychological coping strategies for chronic pain.

Primary and Secondary Endpoints:

Evaluations will be conducted at baseline and 6 months post-intervention. Primary outcomes include changes in glycated hemoglobin (HbA1c), fasting blood glucose (FBG), insulin resistance (HOMA-IR), and neuropathic pain severity assessed via the Numeric Rating Scale (NRS). Secondary outcomes include lipid profile biomarkers (Total Cholesterol, Triglycerides, LDL-C, and HDL-C), patient adherence, and safety/adverse event tracking. Statistical analyses will utilize repeated measures ANOVA and mixed-model frameworks to evaluate longitudinal and between-group differences.

Inclusion criteria

• Diagnosed with Type 2 Diabetes Mellitus (T2DM) for at least 6 months.
• Confirmed diagnosis of painful diabetic peripheral neuropathy (PDPN).
• Age between 18 and 65 years.
• Able to provide written informed consent and willing to comply with the study protocol, supplement intake, and educational sessions.

Exclusion criteria

• Type 1 diabetes mellitus or gestational diabetes.
• Severe renal or hepatic impairment.
• Known allergy, hypersensitivity, or contraindication to cinnamon or related botanical products.
• Pregnancy or lactation.
• Concurrent participation in another clinical trial or severe psychiatric/cognitive disorders that hinder study participation.