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

N/ANot Yet RecruitingNCT06936657

Shanghai 6th People's Hospital150 enrolled

Overview

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).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

150

Conditions

Type 2 Diabetes Mellitus (T2DM)

Interventions

Eligibility

Sex: ALLMin age: 35 YearsMax age: 70 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Change in the average incremental area under the curve (iAUC) of postprandial blood glucose over 3 hours

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.

Time frame: -2, 0, 10, 16, 18 and 28 weeks

Secondary Outcomes

Change in other parameters of Continuous Glucose Monitoring

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.

Time frame: -2, 0, 10, 16, 18 and 28 weeks

Change in HbA1c

HbA1c will be measured at baseline, 12, 18 and 30 weeks. HbA1c will be expressed in mmol/mol.

Time frame: Baseline, 12, 18 and 30 weeks

Change in insulin sensitivity

Insulin sensitivity will be assessed at baseline, 12, 18 and 30 weeks.

Time frame: Baseline, 12, 18 and 30 weeks

Change in other clinical biochemical indicators

Other clinical biochemical indicators will be measured at baseline, 4, 8, 12, 18, 22, 26 and 30 weeks.

Time frame: Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks

Change in blood glucose

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

Time frame: Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks

Change in insulin and C peptide secretion

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.

Time frame: Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks

Change in anthropometry and body composition parameters

Anthropometry and body composition parameters will be measured at baseline, 4, 8, 12, 18, 22, 26 and 30 weeks.

Time frame: Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks

Change in cognitive function and behavioral performance

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.

Time frame: Baseline, 12, 18 and 30 weeks

Change in appetite

Appetite will be measured by visual analog scales (VAS) and other relevant scales, and will be assessed at baseline, 12, 18, and 30 weeks.

Time frame: Baseline, 12, 18 and 30 weeks

Change in emotion

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.

Time frame: Baseline, 12, 18 and 30 weeks

Change in sleep quality

Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire and other methods at baseline, 12, 18, and 30 weeks.

Time frame: Baseline, 12, 18 and 30 weeks

Change in bowel habits

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.

Time frame: Baseline, 12, 18 and 30 weeks

Change in cardiopulmonary exercise testing performance

Cardiopulmonary exercise testing performance will be conducted at baseline, 12, 18 and 30 weeks.

Time frame: Baseline, 12, 18 and 30 weeks

Change in blood lipid profiles

Blood lipid profiles will be measured at baseline, 4, 8, 12, 18, 22, 26 and 30 weeks.

Time frame: Baseline, 4, 8, 12, 18, 22, 26 and 30 weeks