Serum Sulfate and Brain Function in Diabetic Encephalopathy

N/ANot Yet RecruitingNCT07837258

Dongzhimen Hospital, Beijing220 enrolled

Overview

The goal of this observational study is to learn about the relationship between sulfate ion levels in the blood and brain function in people with diabetic encephalopathy, a diabetes-related brain condition that can affect thinking and memory. The main questions it aims to answer are: 1. Are blood sulfate ion levels related to memory and thinking test scores? 2. Are blood sulfate ion levels related to the severity of brain shrinkage (brain atrophy) seen on MRI? 3. Do sulfate ion levels and their relationship with thinking and memory differ among people with different levels of long-term blood sugar control? Researchers will compare participants grouped by long-term blood sugar control (based on HbA1c, a blood test that reflects average blood sugar over the past 2-3 months) to see whether sulfate ion levels and their associations with brain function differ. Participants will: 1. Give a blood sample to measure sulfate ion levels, HbA1c, and neurofilament light chain (NfL), a marker of nerve damage. 2. Complete the Montreal Cognitive Assessment (MoCA), a test of memory and thinking, and questionnaires about daily living skills. 3. Have a brain MRI scan to assess brain shrinkage, unless a recent scan within the past 6 months can be used. 4. Provide information about their diabetes and medical history. This is a cross-sectional study, so participants will be assessed once at enrollment. No treatment or intervention is given. About 220 adults aged 45-75 years with type 2 diabetes and diabetic encephalopathy will take part.

Study Type

OBSERVATIONAL

Enrollment

220

Conditions

Diabetes Mellitus, Type 2 Cognitive Dysfunction, Cognitive Disorder Brain Diseases, Metabolic

Eligibility

Sex: ALLMin age: 45 YearsMax age: 75 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Age 45-75 years, no restriction on sex; patients with type 2 diabetes mellitus who meet the current American Diabetes Association (ADA) Standards of Care in Diabetes or the World Health Organization (WHO) diagnostic criteria for diabetes, with a confirmed disease duration ≥ 6 years. 2. Cranial plain magnetic resonance imaging (MRI; sequences including at least T1WI, T2WI, and FLAIR) with a radiological report indicating age-inappropriate brain atrophy (e.g., ventricular enlargement, widened sulci). Concomitant prior cerebral infarction or cerebral small vessel disease changes (e.g., lacunar infarction, white matter hyperintensities, etc.) are allowed. Other major structural causes that may lead to cognitive impairment, such as cerebral hemorrhage and space-occupying lesions, are excluded. Patients with acute cerebral infarction at least 2 weeks after onset, with stable vital signs and metabolic status, who are able to complete the MoCA assessment and MRI examination, are allowed. 3. Montreal Cognitive Assessment (MoCA) score \< 26. 4. Education level of primary school or above; able to communicate well with the investigators and comply with all study requirements. 5. Voluntarily participate in this study and provide signed informed consent. Exclusion Criteria: 1. Patients with type 1 diabetes, gestational diabetes, other specific types of diabetes, or participants with unknown diabetes status. 2. Cognitive impairment caused by other definite etiologies (e.g., Alzheimer's disease, Lewy body dementia, frontotemporal dementia, central nervous system infection, severe traumatic brain injury, poisoning, etc.). 3. Severe infection, major trauma, or surgery within 3 months; active malignancy (except localized skin cancer); or acute or severe systemic diseases that may significantly affect metabolic status or cognitive function. 4. Major depressive disorder, schizophrenia, or other psychiatric disorders or delirium that may affect the assessment of cognitive function. 5. Severe hepatic or renal insufficiency (e.g., ALT or AST \> 3 times the upper limit of normal, eGFR \< 30 mL/min/1.73 m²). 6. Severe hearing or visual impairment, MRI contraindications, or any other condition that prevents cooperation with the examinations.

Outcomes

Primary Outcomes

Serum sulfate ion levels

Serum sulfate ion concentration, measured in mmol/L by ion chromatography. Analyzed as a continuous variable; no predefined minimum or maximum. Higher values indicate higher serum sulfate ion levels.

Time frame: At enrollment (single blood draw; cross-sectional assessment)

Long-term glycemic control (HbA1c)

Glycated hemoglobin (HbA1c) level, measured as a percentage (%) by a standardized assay. Reflects average blood glucose over the preceding 2-3 months. Analyzed as a continuous variable; higher values indicate poorer long-term glycemic control.

Time frame: At enrollment (reflecting glycemic control over the preceding 2-3 months)

Brain function: MoCA total score

Total score on the Montreal Cognitive Assessment (MoCA). Scores range from 0 to 30, with higher scores indicating better cognitive function.