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Can Vitamin D3 Improve Cognitive Function in Individuals With Type 2 Diabetes? (THINK-D) (THINK-D)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT02416193
Recruitment Status : Terminated (the study was halted prematurely due to slow recruitment and expiration of funding)
First Posted : April 14, 2015
Results First Posted : October 23, 2020
Last Update Posted : October 23, 2020
Sponsor:
Collaborator:
University of Chicago
Information provided by (Responsible Party):
Mary A Byrn, Loyola University

Brief Summary:
Diabetes increases the risk of cognitive dysfunction. The incidence of dementia is 1.5 to 2.5 times higher in persons with diabetes than the general population. There is evidence that cognitive decline significantly impacts the ability to self-manage diabetes. Strategies to prevent cognitive decline in persons with diabetes has not been well studied. A recent study reported that in persons who had vitamin D deficiency, the risk for all-cause dementia and Alzheimer's was doubled. Vitamin D receptors are located in the brain and deficiency of vitamin D has been reported to negatively affect the development of brain. Therefore, providing vitamin D supplementation to improve cognitive function is worthy of study. The investigators propose a small, randomized controlled trial to determine the effects of vitamin D3 supplementation in persons with type 2 diabetes who have symptoms of cognitive impairment. Persons will be randomized to receive either weekly vitamin D3 supplementation (50,000 IUs) or a matching comparator (5000 IUs) for a period of three months. The study aims are to determine (1) the effect of vitamin D3 supplementation on cognitive function and (2) the effect of vitamin D3 supplementation on diabetes self-management. A sample of persons with type 2 diabetes (n=62), who have a subjective complaint of a cognitive dysfunction or scoring at least one standard deviation below normal on a cognitive functioning screening test, have vitamin D levels less 30 ng/ml, are not depressed (as this impacts cognitive function), and do not have severe diabetes complication will be recruited. Participants will be phone screened and complete two baseline visits prior to randomization. They will then have phone call and follow-up visits to assess (1) cognitive function using standardized tests to assess for executive function (2) serum measurements (HBA1c, fasting glucose, vitamin D levels, and cardiometabolic profile) and (3) surveys to assess cognitive function as well as self-management behaviors.

Condition or disease Intervention/treatment Phase
Diabetes Executive Dysfunction Drug: Cholecalciferol Phase 2

Detailed Description:

Study Aims Diabetes increases the risk of cognitive dysfunction. The incidence of dementia is 1.5 to 2.5 times higher in persons with diabetes than the general population (1). There is evidence that cognitive decline significantly impacts the ability to self-manage diabetes (2). Strategies to prevent cognitive decline in persons with diabetes has not been well studied. A recent study reported that in persons who had vitamin D deficiency, the risk for all-cause dementia and Alzheimer's was doubled (3). Vitamin D receptors are located in the brain, and deficiency of vitamin D has been reported to negatively affect the development of brain and impact both growth factor signaling and neural activity (4, 5). Therefore, providing vitamin D supplementation to improve cognitive function in persons with diabetes who are at great risk for this comorbid condition is important. The investigators propose a small, randomized controlled trial to determine the effects of vitamin D3 supplementation in persons with type 2 diabetes who have symptoms of cognitive impairment. Persons will be randomized to receive either weekly vitamin D3 supplementation (50,000 IUs) or a matching comparator (5000 IUs) for a period of three months.

Primary Aim: To determine the effect of vitamin D3 supplementation on cognitive function for persons with type 2 diabetes.

Primary Hypothesis: Persons receiving weekly vitamin D3 supplementation (50,000 IUs) will have improved cognitive function compared to those receiving the comparator (5000 IUs) at three months.

Secondary Aim: To determine the effect of vitamin D3 supplementation on diabetes self-management.

Secondary Hypothesis: Persons receiving weekly vitamin D3 supplementation (50,000 IUs) will have improved self-management compared to those receiving the comparator (5000 IUs) at three months.

The importance of this study is several fold. Vitamin D supplementation is a low cost intervention (6), it has minimal side effects (7), and it could have high impact for persons with type 2 diabetes who suffer from cognitive impairment which can significantly affect their diabetes self-management.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 56 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Can Vitamin D3 Improve Cognitive Function in Individuals With Type 2 Diabetes? (THINK-D)
Actual Study Start Date : September 23, 2015
Actual Primary Completion Date : July 12, 2018
Actual Study Completion Date : July 12, 2018

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin D

Arm Intervention/treatment
Experimental: High Dose
50,000 IU cholecalciferol once weekly for three months
Drug: Cholecalciferol
Participants will take randomly assigned high dose cholecalciferol once weekly for three months
Other Name: Vitamin D3

Active Comparator: Low Dose
5,000 IU cholecalciferol once weekly for three months
Drug: Cholecalciferol
Participants will take randomly assigned active comparator cholecalciferol once weekly for three months
Other Name: Vitamin D3




Primary Outcome Measures :
  1. Letter-Number Sequencing [ Time Frame: 13 weeks ]
    The the Letter-Number Sequencing Test (from the Wechsler Adult Intelligence Scale-III assessment) is an assessment of working memory. Scores on the assessment are standardized as scaled scores with a mean of 10 and standard deviation of 3 (μ = 10, SD = 3) using age adjusted normative data provided by Pearson assessments (https://www.pearsonassessments.com/). A scaled score indicates the number of standard deviations away from the mean. A scaled score of 10 is equal to the mean. Scaled scores below 10 indicate performance is lower than average, and scaled scores higher than 10 indicate performance is higher than average. Higher scaled scores indicate better performance.

  2. Controlled Oral Word Association Test [ Time Frame: 13 Weeks ]
    The Controlled Oral Word Association Test is a measure of verbal fluency. Scores are standardized as z-scores (μ = 0, SD = 1) using age adjusted normative data provided by Tombaugh and Kozak (1996). A z-score indicates the number of standard deviations away from the mean. A z-score of 0 is equal to the mean. Negative z-scores indicate performance is lower than average, and positive z-scores indicate performance is higher than average. Positive z-scores indicate better performance.

  3. Stroop Interference Test [ Time Frame: 13 Weeks ]
    The Stroop Interference Test is a measure of executive functioning. Scores are standardized as z-scores (μ = 0, SD = 1) using age adjusted normative data provided by PAR Incorporated (https://www.parinc.com/). A z-score indicates the number of standard deviations away from the mean. A z-score of 0 is equal to the mean. Negative z-scores indicate performance is lower than average, and positive z-scores indicate performance is higher than average. Positive z-scores indicate better performance.

  4. Symbol-Digit Modality Test [ Time Frame: 13 Weeks ]
    The Symbol-Digit Modality Test is a measure of executive functioning. Scores are standardized as z-scores (μ = 0, SD = 1) using age adjusted normative data provided by WPS Publishers (https://www.wpspublish.com/). A z-score indicates the number of standard deviations away from the mean. A z-score of 0 is equal to the mean. Negative z-scores indicate performance is lower than average, and positive z-scores indicate performance is higher than average. Positive z-scores indicate better performance.

  5. Trail Making Test Part B [ Time Frame: 13 Weeks ]
    The Trail Making Test Part B is a measure of executive functioning. Scores are standardized as z-scores (μ = 0, SD = 1) using age adjusted normative data provided by WPS Publishers (https://www.wpspublish.com/). A z-score indicates the number of standard deviations away from the mean. A z-score of 0 is equal to the mean. Negative z-scores indicate performance is lower than average, and positive z-scores indicate performance is higher than average. Positive z-scores indicate better performance.


Secondary Outcome Measures :
  1. Hopkins Verbal Learning Total Recall Test [ Time Frame: 13 weeks ]
    The Hopkins Verbal Learning Total Recall Test is an assessment of memory. Scores are standardized as T-scores (μ = 50, SD = 10) using age adjusted normative data provided by PAR Incorporated (https://www.parinc.com/). A T-score indicates the number of standard deviations away from the mean. A T-score of 50 is equal to the mean. T-scores below 50 indicate performance is lower than average, and T-scores above 50 indicate performance is higher than average. Higher T-scores indicate better performance.

  2. Semantic Fluency Test [ Time Frame: 13 Weeks ]
    The Semantic Fluency Test is a measure of verbal fluency. Scores are standardized as z-scores (μ = 0, SD = 1) using age adjusted normative data provided by Tombaugh and Kozak (1996). A z-score indicates the number of standard deviations away from the mean. A z-score of 0 is equal to the mean. Negative z-scores indicate performance is lower than average, and positive z-scores indicate performance is higher than average. Positive z-scores indicate better performance.



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Women and men aged 18 to 75 years
  • Have type 2 diabetes
  • Having a subjective complaint of a cognitive dysfunction or scoring at least one standard deviation below normal on a cognitive functioning screening test
  • Vitamin D level as measured by 25-hydroxyvitamin D (25-OH D) < 32 ng/mL
  • Under the care of a healthcare provider
  • Systolic blood pressure ≤160 and diastolic blood pressure ≤100

Exclusion Criteria:

  • Persons with malabsorption problems (e.g., crohn's disease)
  • Hypercalcemia
  • Supplementation other than a daily multivitamin
  • Severe complications of diabetes (i.e., amputation, blindness, and dialysis)
  • Concomitant use of steroids
  • GFR < 60
  • Creatinine > 1.2
  • Significant depressive symptoms
  • Having a history of bipolar depression, psychotic disorders, loss of consciousness greater than 5 minutes, or a current alcohol or substance use disorder
  • Other serious medical conditions deemed significant by the PI or medical monitor
  • Concomitant use of cholinesterase inhibitors
  • Concomitant use of anxiolytics, kava kava, St. John's Wort, or Ginkgo Biloba
  • Pregnancy
  • HbA1c >13%

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02416193


Locations
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United States, Illinois
Loyola University Medical Center
Maywood, Illinois, United States, 60153
Sponsors and Collaborators
Loyola University
University of Chicago
Investigators
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Principal Investigator: Mary A Byrn, Ph.D., R.N. Loyola University
  Study Documents (Full-Text)

Documents provided by Mary A Byrn, Loyola University:
Informed Consent Form  [PDF] February 21, 2018

Publications:

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Responsible Party: Mary A Byrn, Assistant Professor, Loyola University
ClinicalTrials.gov Identifier: NCT02416193    
Other Study ID Numbers: 206988
206988031815 ( Other Identifier: Loyola University Chicago )
First Posted: April 14, 2015    Key Record Dates
Results First Posted: October 23, 2020
Last Update Posted: October 23, 2020
Last Verified: September 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Plan Description: There is no plan to share individual participant data with other researchers

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Mary A Byrn, Loyola University:
Diabetes
Cognition
Functioning
Additional relevant MeSH terms:
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Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Vitamin D
Ergocalciferols
Cholecalciferol
Vitamins
Micronutrients
Nutrients
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents
Calcium-Regulating Hormones and Agents