Serum Sulfate and Brain Function in Diabetic Encephalopathy

NCT07837258 | Not Yet Recruiting DMC

• 1 other identifier: 2026DZMEC-235-02
• Study Type: observational
• Target: 220
• Locations: 0 countries
• Sites: N/A

Brief Summary

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. 1.Are blood sulfate ion levels related to memory and thinking test scores?
2. 2.Are blood sulfate ion levels related to the severity of brain shrinkage (brain atrophy) seen on MRI?
3. 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.
4. 4.Give a blood sample to measure sulfate ion levels, HbA1c, and neurofilament light chain (NfL), a marker of nerve damage.
5. 5.Complete the Montreal Cognitive Assessment (MoCA), a test of memory and thinking, and questionnaires about daily living skills.
6. 6.Have a brain MRI scan to assess brain shrinkage, unless a recent scan within the past 6 months can be used.
7. 7.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.

Conditions

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

Keywords

Diabetic encephalopathy; type 2 diabetes mellitus

Outcome Measures

Primary Outcomes (11)

• 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.

  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.

  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.

  At enrollment (single cross-sectional assessment)

• Brain atrophy assessed by cranial MRI

  Brain atrophy assessed on cranial MRI (T1WI, T2WI, FLAIR) by experienced radiologists using standardized visual rating scales (e.g., MTA, GCA, and/or Evans index). Severity graded as none, mild, moderate, or severe, or per the selected validated scale; higher grades indicate more severe atrophy (worse outcome).

  At enrollment; baseline MRI, or prior MRI within 6 months if it meets study criteria

• Montreal Cognitive Assessment (MoCA) visuospatial/executive function score

  Visuospatial/executive function domain score on the MoCA. Scores range from 0 to 5, with higher scores indicating better visuospatial/executive function.

  At enrollment (single cross-sectional assessment)

• Montreal Cognitive Assessment (MoCA) naming score

  Naming domain score on the MoCA. Scores range from 0 to 3, with higher scores indicating better naming ability.

  At enrollment (single cross-sectional assessment)

• Montreal Cognitive Assessment (MoCA) attention score

  Attention domain score on the MoCA. Scores range from 0 to 6, with higher scores indicating better attention.

  At enrollment (single cross-sectional assessment)

• Montreal Cognitive Assessment (MoCA) language score

  Language domain score on the MoCA. Scores range from 0 to 3, with higher scores indicating better language function.

  At enrollment (single cross-sectional assessment)

• Montreal Cognitive Assessment (MoCA) abstraction score

  Abstraction domain score on the MoCA. Scores range from 0 to 2, with higher scores indicating better abstract reasoning.

  At enrollment (single cross-sectional assessment)

• Montreal Cognitive Assessment (MoCA) delayed recall score

  Delayed recall domain score on the MoCA. Scores range from 0 to 5, with higher scores indicating better memory.

  At enrollment (single cross-sectional assessment)

• Montreal Cognitive Assessment (MoCA) orientation score

  Orientation domain score on the MoCA. Scores range from 0 to 6, with higher scores indicating better orientation.

  At enrollment (single cross-sectional assessment)

Secondary Outcomes (3)

• Barthel Index total score

  At enrollment (single cross-sectional assessment)

• Instrumental Activities of Daily Living Scale (IADL) score

  At enrollment (single cross-sectional assessment)

• Serum neurofilament light chain (NfL) level

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

Study Arms (1)

Diabetic encephalopathy

Adults aged 45-75 years of either sex with type 2 diabetes mellitus for ≥6 years and diabetic encephalopathy, defined as MoCA \<26 plus MRI evidence of age-inappropriate brain atrophy after excluding other structural causes. Concomitant prior cerebral infarction or small vessel disease changes are allowed. Approximately 220 participants will be enrolled and assessed once at enrollment (cross-sectional), including serum sulfate ion, NfL, HbA1c, MoCA, ADL/IADL, and brain MRI.

Other: This study does not involve any treatment or intervention.

Interventions

This study does not involve any treatment or intervention. OTHER

This study does not involve any treatment or intervention.

Diabetic encephalopathy

Eligibility Criteria

• Age: 45 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adults aged 45-75 years of either sex with T2DM for ≥6 years and diabetic encephalopathy, defined as MoCA \<26 plus MRI evidence of age-inappropriate brain atrophy after excluding other structural causes. Both sexes; primary school education or above; able to complete MoCA/MRI; signed informed consent. Exclusions include type 1/gestational/other diabetes, other causes of cognitive impairment, recent severe illness/trauma/surgery, active malignancy, major psychiatric disorders, severe hepatic/renal insufficiency, and MRI contraindications. Approximately 220 participants will be enrolled.

You may qualify if:

• 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.
• 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.
• Montreal Cognitive Assessment (MoCA) score \< 26.
• Education level of primary school or above; able to communicate well with the investigators and comply with all study requirements.
• Voluntarily participate in this study and provide signed informed consent.

You may not qualify if:

• Patients with type 1 diabetes, gestational diabetes, other specific types of diabetes, or participants with unknown diabetes status.
• 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.).
• 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.
• Major depressive disorder, schizophrenia, or other psychiatric disorders or delirium that may affect the assessment of cognitive function.
• Severe hepatic or renal insufficiency (e.g., ALT or AST \> 3 times the upper limit of normal, eGFR \< 30 mL/min/1.73 m²).
• Severe hearing or visual impairment, MRI contraindications, or any other condition that prevents cooperation with the examinations.

Sponsors & Collaborators

• Dongzhimen Hospital, Beijing: lead

Biospecimen

Retention: SAMPLES WITHOUT DNA

Venous blood samples will be collected from each participant at enrollment. Serum will be separated, aliquoted at 200 µL per tube (5 tubes, total 1 mL), and stored at -80°C until batch analysis. Serum sulfate ion levels will be measured by ion chromatography at the Testing Center of Tongji Medical College, Huazhong University of Science and Technology. Serum neurofilament light chain (NfL) levels will be measured by Hangzhou Jingbai Biotechnology Co., Ltd. HbA1c will be measured from the same blood draw or from routine clinical samples. No DNA extraction or genetic testing is planned. Residual serum samples will be retained in a -80°C biobank and may be used for future research related to diabetic encephalopathy, subject to ethics committee approval and participant consent.

MeSH Terms

Conditions

Diabetes Mellitus, Type 2; Cognitive Dysfunction; Brain Diseases, Metabolic; hypoglycemic encephalopathy

Interventions

Methods

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Cognition Disorders; Neurocognitive Disorders; Mental Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Intervention Hierarchy (Ancestors)

Investigative Techniques

Central Study Contacts

Yifeng Rui

CONTACT

+8617812005760; ruiyifeng@msn.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Profressor

Study Record Dates

• First Submitted: September 12, 2026
• First Posted: September 23, 2026
• Study Start: September 20, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028
• Last Updated: September 23, 2026

Record last verified: 2026-09