Influence of Vitamin D on Vascular Function in Adolescents and Young Adults With Type 1 Diabetes

The purpose of this study is to study the role of low vitamin D levels on the health of blood vessels or vascular function in adolescents and young adults with type 1 diabetes.

Study Overview

• Status: Completed
• Conditions: Diabetes Mellitus, Type 1
• Intervention / Treatment: Dietary supplement: Vitamin D

Detailed Description

Vitamin D deficiency is known to be common in patients with type 1 diabetes. Studies in adults have shown that vitamin D deficiency is associated with cardiovascular events such as stroke, myocardial infarction and peripheral arterial disease. However, the impact of this deficiency on vascular health in adolescents with diabetes has not been examined. Furthermore given that endothelial dysfunction is reversible, early detection of this process may have therapeutic and prognostic implications in this population.

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada
      • The Hospital for Sick Children

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 12 years to 18 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Diagnosed with type 1 diabetes, according to Canadian Diabetes Association guidelines
2. Diagnosed with type 1 diabetes for at least 2 years
3. Between the ages of 12 and 18 years

Exclusion Criteria:

1. Previous organ transplantation
2. Diagnosed with familial hypercholesterolemia
3. Active smoker
4. Receiving lipid lowering medications
5. Receiving anti hypertensive medication
6. Significant chronic medical illness, including granulomatous disease
7. History of hypertension
8. BMI >95%tile
9. Known renal failure
10. HbA1c greater than 12% on two successive occasions
11. Known peripheral vascular disease
12. Known hypercalcemia

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Vitamin D Sufficient; Sufficient is defined as a 25 OH vitamin D level >50 nmol/l measured at baseline. No clinical intervention will be assigned to this group. Subjects will have fasting bloodwork done. Other study measurements to be taken include: height and weight, stage of puberty, blood pressure, vitamin D and calcium intake information, diabetes risk information, demographic information and spot urine sample. We will also do a non-invasive test called a "PAT" or 'peripheral arterial tonometry' to look at the health of your blood vessels.
Experimental: Vitamin D Deficient; Deficient is defined as a 25 OH vitamin D level ≤ 37.5 nmol/l. This group will receive Vitamin D. Subjects will have fasting bloodwork done. Other study measurements to be taken include: height and weight, stage of puberty, blood pressure, vitamin D and calcium intake information, diabetes risk information, demographic information and spot urine sample. We will also do a non-invasive test called a "PAT" or 'peripheral arterial tonometry' to look at the health of your blood vessels.	Dietary supplement: Vitamin D; Dosing If the 25 OH Vitamin D level at Baseline/Screening is less than 20 nmol/L then the subject will receive 2000 IU daily. If the 25 OH Vitamin D level at Baseline/Screening is between 20 and 37.5 nmol/L then the subject will receive 1000 IU daily.; Other Names: Ddrops®

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison of Endothelial Function	We will compare endothelial function in adolescents with type 1 diabetes divided into 2 groups on the basis of vitamin D status (deficient and sufficient). Endothelial function will be assessed by peripheral arterial tonometry (PAT) which measures the elasticity of the arteries.	Baseline
Change in Endothelial Function after Treatment with Vitamin D	We will measure the change in endothelial function from baseline in the children that were vitamin D deficient. This measurement will be done once the child has become vitamin D sufficient. Vitamin D status will be assessed at 3 months. If the levels remain deficient treatment would continue for another 3 months, with repeat testing at 6 months. Endothelial function will be assessed by peripheral arterial tonometry (PAT) which measures the elasticity of the arteries.	Baseline, 3 or 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Monitoring of Vitamin D Levels in Vitamin D deficient subjects	At a vist to take place at 2-3 months, the Vitamin D deficient sujects will undergo blood sampling for 25 hydroxyvitamin D levels to ensure appropriate treatment with D Drops to normalize 25 OH vitamin D levels greater than 50 nmol/L.	2-3 months
Monitoring of Calcium Creatine Ratio in Vitamin D deficient subjects	At a vist to take place at 2-3 months, the Vitamin D deficient sujects will have a urine assessment of spot calcium creatinine ratio to ensure that hypercalcemia (calcium/ creatinine ratio greater than 0.7) is not present.	2-3 months
Comparison of Systemic Blood Pressure	We will compare endothelial function in adolescents with type 1 diabetes divided into 2 groups on the basis of vitamin D status (deficient and sufficient).	Baseline
Comparison of Urinary Albumin/Creatinine Ratio	We will compare the urinary albumin/creatinine ratio in adolescents with type 1 diabetes divided into 2 groups on the basis of vitamin D status (deficient and sufficient).	Baseline

Collaborators and Investigators

• Sponsor: The Hospital for Sick Children
• Investigators: Principal Investigator: Farid Mahmud, MD, The Hospital for Sick Children

Study record dates

Study Major Dates

• Study Start: March 1, 2010
• Primary Completion (Actual): January 1, 2011
• Study Completion (Actual): January 1, 2011

Study Registration Dates

• First Submitted: April 13, 2010
• First Submitted That Met QC Criteria: April 14, 2010
• First Posted (Estimate): April 15, 2010

Study Record Updates

• Last Update Posted (Estimate): June 1, 2016
• Last Update Submitted That Met QC Criteria: May 30, 2016
• Last Verified: May 1, 2016

More Information

Terms related to this study

• Keywords: Vitamin D; Cardiovascular Disease; Type 1 Diabetes; Adolescents and Young Adults
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Immune System Diseases; Autoimmune Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 1; Physiological Effects of Drugs; Micronutrients; Vitamins; Bone Density Conservation Agents; Vitamin D
• Other Study ID Numbers: 1000014567