Intervention Effects of Optimized Carbohydrate Diet in Patients With Type 2 Diabetes

Not Applicable

Not yet recruiting

• Conditions: Type 2 Diabetes Mellitus (T2DM)

• Registration Number: NCT06936657
• Lead Sponsor: Shanghai 6th People's Hospital

Brief Summary

This study is a multi-center, randomized, crossover investigator-initiated trial conducted at Shanghai Sixth People's Hospital and other centers. Each participant will undergo two 12-week dietary intervention phases, separated by a 6-week washout, for a total study duration of 30 weeks. Participants will be randomly assigned in a 1:1 ratio to one of two intervention order: (1) optimized carbohydrate diet-washout-conventional diabetes diet, or (2) conventional diabetes diet-washout-optimized carbohydrate diet. The optimized carbohydrate diet is a modified diet with adjusted carbohydrate composition and proportions, while the conventional diabetes diet adheres to an energy-matched protocol in accordance with diabetes dietary guidelines. The study aims to explore the effects of the optimized carbohydrate diet on blood glucose control and glucose metabolism in patients with type 2 diabetes, and to systematically assess its impact on cognitive function and a range of physiological and psychological indicators (such as depression, anxiety, appetite, sleep, bowel habits and others).

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-03
• Study First Submitted: 2025-04-10
• Study First Submitted QC: 2025-04-14
• Study Start: 2025-04-20
• Study First Posted: 2025-04-20
• Last Update Submitted: 2025-04-21
• Last Update Posted: 2025-04-24
• Primary Completion: 2026-12-30
• Study Completion: 2027-03-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 150

Inclusion Criteria

1. Patients diagnosed with type 2 diabetes according to the ADA diagnostic criteria
2. HbA1c ≥ 7% and < 9%
3. Antidiabetic medication has been stable for at least 3 months before recruitment
4. Aged 35-70 years
5. Signed the informed consent form

Exclusion Criteria

1. Treatment with insulin
2. Treatment with GLP-1 receptor agonists or DPP-4 inhibitors
3. Occurrence of diabetic ketoacidosis, lactic acidosis, hyperosmolar coma, or recurrent severe hypoglycemia within the past year
4. Having one or more severe chronic diabetic complications, including advanced diabetic retinopathy, macroalbuminuria (urine albumin-to-creatinine ratio ≥300 mg/g), or impaired renal function (eGFR ≤60 ml/min/1.73 m²)
5. Presence of cardiovascular events (e.g., myocardial infarction, stent placement, unstable angina, heart failure, cardiac dysfunction) or cerebrovascular diseases (e.g., intracerebral hemorrhage, ischemic stroke) within the past 6 months
6. Diagnosis of acute or chronic gastrointestinal diseases (e.g., ulcers), hyperthyroidism or hypothyroidism, uncontrolled hypertension, active malignancy not in remission, or other life-threatening diseases
7. Recent use of antibiotics, probiotics, or prebiotics within the past 3 weeks or need for long-term use
8. Unstable medication regimen or use of prescription medications affecting metabolism (e.g., thyroid hormones, glucocorticoids)
9. Pregnancy, breastfeeding, or planning pregnancy
10. Presence of a pacemaker or metal implants, claustrophobia, or other contraindications to fMRI
11. Psychiatric disorders impairing cooperation
12. Expected poor compliance
13. Current or recent (within 4 weeks prior to study initiation) participation in other clinical trials

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Change in the average incremental area under the curve (iAUC) of postprandial blood glucose over 3 hours	-2, 0, 10, 16, 18 and 28 weeks	Average incremental area under the curve (iAUC) of postprandial blood glucose over 3 hours will be measured at -2, 0, 10, 16, 18, and 28 weeks using the continuous glucose monitoring system.

Secondary Outcome Measures

Name	Time	Method
Change in HbA1c	Baseline, 12, 18 and 30 weeks	HbA1c will be measured at baseline, 12, 18 and 30 weeks. HbA1c will be expressed in mmol/mol.
Change in insulin sensitivity	Baseline, 12, 18 and 30 weeks	Insulin sensitivity will be assessed at baseline, 12, 18 and 30 weeks.
Change in other clinical biochemical indicators	Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks	Other clinical biochemical indicators will be measured at baseline, 4, 8, 12, 18, 22, 26 and 30 weeks.
Change in appetite	Baseline, 12, 18 and 30 weeks	Appetite will be measured by visual analog scales (VAS) and other relevant scales, and will be assessed at baseline, 12, 18, and 30 weeks.
Change in emotion	Baseline, 12, 18 and 30 weeks	Emotion will be measured using the PHQ-9 depression screening scale, the Problem Areas in Diabetes (PAID) questionnaire, and other relevant scales at baseline, 12, 18, and 30 weeks.
Change in sleep quality	Baseline, 12, 18 and 30 weeks	Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire and other methods at baseline, 12, 18, and 30 weeks.
Change in bowel habits	Baseline, 12, 18 and 30 weeks	Bowel habits will be assessed using the Bristol Stool Form Scale (BSFS; range: 1-7, with higher scores indicating looser stools) and other relevant scales at baseline, 12, 18, and 30 weeks.
Change in cardiopulmonary exercise testing performance	Baseline, 12, 18 and 30 weeks	Cardiopulmonary exercise testing performance will be conducted at baseline, 12, 18 and 30 weeks.
Change in blood lipid profiles	Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks	Blood lipid profiles will be measured at baseline, 4, 8, 12, 18, 22, 26 and 30 weeks.
Change in other parameters of Continuous Glucose Monitoring	-2, 0, 10, 16, 18 and 28 weeks	Other parameters of Continuous Glucose Monitoring, including Time in Range (TIR), Time Above Range (TAR), Time Below Range (TBR), Mean Glucose, Glucose Variability, Glycemic Excursions, Area Under the Curve (AUC), and other relevant metrics, will be assessed at -2, 0, 10, 16, 18, and 28 weeks.
Change in blood glucose	Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks	Fasting blood glucose will be measured at baseline, 4, 8, 12, 18, 22, 26 and 30 weeks. During meal tolerance test (MTT) at baseline, 12, 18 and 30 weeks, blood glucose at 0, 30, 60, 90, 120 minutes will be measured. Glucose concentration will be expressed in mmol/L
Change in insulin and C peptide secretion	Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks	Fasting insulin and C peptide concentration will be assessed at baseline, 4, 8, 12, 18, 22, 26 and 30 weeks. During meal tolerance test (MTT) at baseline, 12, 18 and 30 weeks, insulin and C peptide concentration at 0, 30, 60, 90, 120 minutes will be measured. Insulin concentration will be expressed in uU/ml. C peptide concentration will be expressed in ng/ml.
Change in anthropometry and body composition parameters	Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks	Anthropometry and body composition parameters will be measured at baseline, 4, 8, 12, 18, 22, 26 and 30 weeks.
Change in cognitive function and behavioral performance	Baseline, 12, 18 and 30 weeks	Cognitive function changes will be assessed using questionnaires (including the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA, Beijing version), Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Trail Making Test, Stroop Color and Word Test, and others) at baseline, 12 18, and 30 weeks. Behavioral performance will be assessed using N-back and other paradigms at baseline, 12, 18, and 30 weeks.; In addition, subgroups within the two arms will undergo fMRI to assess cognitive function at baseline, 12 18, and 30 weeks.