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

Phase 2

Completed

• Conditions: Diabetes Mellitus, Type 1
• Interventions: Dietary Supplement: Vitamin D

• Registration Number: NCT01103817
• Lead Sponsor: The Hospital for Sick Children

Brief Summary

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.

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 Timeline

• Study Start: 2010-03
• Study First Submitted: 2010-04-13
• Study First Submitted QC: 2010-04-14
• Study First Posted: 2010-04-15
• Primary Completion: 2011-01
• Study Completion: 2011-01
• Status Verified: 2016-05
• Last Update Submitted: 2016-05-30
• Last Update Posted: 2016-06-01

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 33

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Vitamin D Deficient	Vitamin D	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.

Primary Outcome Measures

Name	Time	Method
Change in Endothelial Function after Treatment with Vitamin D	Baseline, 3 or 6 months	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.
Comparison of Endothelial Function	Baseline	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.

Secondary Outcome Measures

Name	Time	Method
Comparison of Urinary Albumin/Creatinine Ratio	Baseline	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).
Monitoring of Vitamin D Levels in Vitamin D deficient subjects	2-3 months	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.
Comparison of Systemic Blood Pressure	Baseline	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).
Monitoring of Calcium Creatine Ratio in Vitamin D deficient subjects	2-3 months	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.

Trial Locations

Locations (1)

The Hospital for Sick Children; 🇨🇦 Toronto, Ontario, Canada