Mazdutide in Type 2 Diabetes With Early-Stage Cognitive Impairment (LIGHT-COG Study)

Inclusion Criteria: 1. Diagnosis of type 2 diabetes according to the American Diabetes Association criteria; 2. Aged 50-75 years (inclusive), male or female. 3. Early-stage cognitive impairment (defined as mild cognitive impairment or mild dementia), with all of the following: 1. MMSE score \>20 and \<27, 2. CDR global score 0.5-1.0 (inclusive), with a CDR memory subscore ≥0.5, 3. A history of gradual and progressive cognitive decline for at least 6 months, reported by the participant or an informant. 4. Stable glycemic control regimen for ≥3 months prior to screening, meeting one of the following: 1. Lifestyle/dietary intervention alone (no glucose-lowering drugs), 2. Oral antidiabetic drugs (OADs), with or without once-daily basal insulin. 5. HbA1c 7.0-9.0% (inclusive) at screening. 6. BMI ≥20 kg/m², with stable weight (fluctuation \<5%) for ≥3 months. 7. Stable treatment regimen for cognitive impairment for at least 3 months prior to screening and commit to its continuation throughout the study period, meeting one of the following criteria: 1. No treatment: Not receiving any pharmacological or non-pharmacological interventions for cognitive impairment; 2. Non-pharmacological therapy only: Engaged exclusively in non-drug interventions (e.g., cognitive training); 3. Pharmacological therapy: Using approved symptomatic cognitive-enhancing medications (e.g., cholinesterase inhibitors, NMDA receptor antagonists), excluding disease-modifying therapies for Alzheimer's disease (AD). 8. Ability to comply with systematic cognitive and functional assessments. 9. Fully understands the trial protocol, voluntarily signs the informed consent form (ICF), and agrees to adhere to all study requirements and restrictions. Exclusion Criteria: 1. Known or suspected neurodegenerative disorders other than AD that are likely to be a major cause of cognitive impairment or to interfere with cognitive assessment, including but not limited to frontotemporal dementia and related syndromes, dementia with Lewy bodies, Parkinson's disease with cognitive impairment or dementia, progressive supranuclear palsy, corticobasal degeneration, multiple system atrophy, and Huntington's disease; 2. Current diagnosis of a poorly controlled or unstable psychiatric disorder (including but not limited to schizophrenia, bipolar disorder, major depressive disorder, generalized anxiety disorder, personality disorders, etc.), which, in the investigator's judgment, may interfere with study assessments, affect treatment compliance, or increase participant risk. 3. With a Patient Health Questionnaire-9 (PHQ-9) score ≥10 at screening, or a Generalized Anxiety Disorder Scale-7 (GAD-7) score ≥10 at screening. 4. Ischaemic or haemorrhagic stroke, transient ischaemic attack, or epileptic seizure within 3 months before screening; or other current or clinically significant central nervous system disorders or injuries likely to impair cognitive function or interfere with cognitive assessment, including but not limited to central nervous system infection, intracranial tumour, multiple sclerosis, metabolic encephalopathy, neurological disorders related to malnutrition, or severe traumatic brain injury; 5. Acute hyperglycemic/hypoglycemic events within 1 year, including: Diabetic ketoacidosis (DKA), hyperosmolar hyperglycemic state (HHS), and Hypoglycemic coma 6. Use of GLP-1 receptor agonists, dual GIP/GLP-1 receptor agonists, dual GLP-1/glucagon receptor agonists, or triple GIP/GLP-1/glucagon receptor agonists within 3 months before screening; 7. Regular use (\>2 doses/week) of moderate-to-strong anticholinergic drugs within 4 weeks prior to screening; Use within 3 months prior to screening of: Anti-Parkinsonian drugs, Antiepileptic drugs, Antipsychotics, Morphine and opioid analgesics (Exemption: Short-term use \[\<5 days\] for surgery/acute injury, if completed \>4 weeks before screening); Use within 4 weeks prior to screening of: CNS stimulants; Medical/recreational cannabis, cannabinoids, or cannabidiol (CBD).a. Moderate/high anticholinergics, antiparkinsonian/antiepileptic drugs. 8. Alcohol abuse (defined as \>21 units/week for men or \>14 units/week for women; 1 unit = 360 mL beer, 150 mL wine, or 45 mL spirits). 9. Medical history of: 1. Medullary thyroid carcinoma (MTC), pancreatitis 2. Multiple endocrine neoplasia type 2 (MEN2) 3. Gallbladder/biliary disease, severe gastrointestinal disorders, or bowel resection 4. Active malignancy 10. Uncontrolled or potentially unstable diabetic retinopathy/maculopathy. 11. Severe organ dysfunction, including: 1. ALT/AST \>3× upper limit of normal (ULN); 2. eGFR \<45 mL/min/1.73m² (CKD-EPI equation); 3. History of unstable angina or myocardial infarction within 3 months before screening, or current heart failure of NYHA class II or higher. 12. Known/suspected hypersensitivity to the investigational product or related compounds 13. Pregnancy, lactation, or women of childbearing potential not using highly effective contraception. 14. MRI contraindications (e.g., metal implants, claustrophobia). 15. Participation in other clinical trials within 3 months, involving an investigational medicinal product or enrollment in any other type of medical research judged not to be scientifically or medically compatible with this study. 16. Any other condition deemed by the investigator to compromise safety or interfere with study assessments.