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Trial registered on ANZCTR


Registration number
ACTRN12609000840280
Ethics application status
Approved
Date submitted
15/04/2009
Date registered
28/09/2009
Date last updated
9/07/2012
Type of registration
Retrospectively registered

Titles & IDs
Public title
Vitamin D deficiency in diabetic patients with obesity
Scientific title
To assess the effects of vitamin D supplementation in improving endothelial function in patients with diabetes and obesity
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Vitamin D deficiency 4598 0
Diabetes 236987 0
Obesity 236988 0
Condition category
Condition code
Cardiovascular 4894 4894 0 0
Other cardiovascular diseases
Metabolic and Endocrine 237326 237326 0 0
Diabetes
Diet and Nutrition 237327 237327 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Identify patients with diabetes and obesity who have vitamin D deficiency by screening from cardiology outpatient settings (n=200). Vitamin D supplementation at 3000 international units (IU)/day or placebo orally for 3 months will be given to these patients (n=20). Cross-over between active treatment and placebo will be done for a further 3 months after a 3 month wash-out period.
Intervention code [1] 4361 0
Treatment: Drugs
Intervention code [2] 236751 0
Treatment: Other
Comparator / control treatment
Vitamin D vs placebo (sugar pill) orally
Control group
Placebo

Outcomes
Primary outcome [1] 5745 0
Endothelial function: plasma asymmetric dimethylarginine (assessed by a blood test), flow mediated dilatation (An ultrasound of the upper arm's artery will be conducted. This will involve lying down in a comfortable position for 15 to 20 minutes while the ultrasound is performed. The change in diameter of the upper arm's artery will be assessed after release of a tight blood pressure cuff and drug administration (glyceryl trinitrate, 25 mcg), high-sensitivity C-reactive protein (blood test)
Timepoint [1] 5745 0
3 months of treatment, 3 months of wash-out period, and a further 3 months of cross-over study. The outcome will be measured 4 times, at 3 monthly intervals: at entry, after 3 months of treatment, after 3 months of wash-out, and after 3 months of the second phase of the study.
Secondary outcome [1] 241694 0
platelet responsiveness to nitric oxide (NO). A blood sample will be taken, and platelet aggregation will be measured using a platelet aggregometer,. Platelet aggregation will be measured upon addition to a nitric oxide (NO)donor using the platelet aggregometer.
Timepoint [1] 241694 0
The outcome will be measured 4 times, at 3 monthly intervals: at entry, 3 after 3 months of treatment, after 3 months of wash-out, and after 3 months of the second phase of the study.

Eligibility
Key inclusion criteria
Patients with previous diagnosis of diabetes and body mass index (BMI) >=30kg/m2 with vitamin D levels <=50nmol/mL and are ambulant are enrolled
Minimum age
40 Years
Maximum age
100 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Patients will be excluded if they are:
1. Have had treatment initiated with Angiotensin-converting enzme (ACE) inhibitors or statins in the previous 3 months
2. Have had previous adverse reaction to vitamin D supplements.
3. Previous intolerance of glyceryl trinitrate
4. Patients with severe renal impairment (calculated glomerular filtration rate (GFR) < 30mls/min)
5. Patient is pregnant

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 4783 0
Hospital
Name [1] 4783 0
The Queen Elizabeth Hospital, Department of Cardiology
Address [1] 4783 0
28 Woodville Rd, Woodville South, SA 5011
Country [1] 4783 0
Australia
Primary sponsor type
Hospital
Name
The Queen Elizabeth Hospital, Department of Cardiology
Address
28 Woodville Rd, Woodville South, SA 5011
Country
Australia
Secondary sponsor category [1] 4318 0
None
Name [1] 4318 0
Address [1] 4318 0
Country [1] 4318 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 243934 0
The Queen Elizabeth Hospital Human Ethics Committee
Ethics committee address [1] 243934 0
Ethics committee country [1] 243934 0
Date submitted for ethics approval [1] 243934 0
Approval date [1] 243934 0
Ethics approval number [1] 243934 0

Summary
Brief summary
We invite you to participate in a research project which we believe is of potential importance in identifying the significance of vitamin D deficiency in patients with obesity and diabetes. Vitamin D deficiency has been shown to poorly affect cardiovascular health, and we hope to investigate whether vitamin D supplementation will improve markers associated with cardiovascular health. We hope that the findings of this study will help us better manage this condition in future.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 29489 0
Address 29489 0
Country 29489 0
Phone 29489 0
Fax 29489 0
Email 29489 0
Contact person for public queries
Name 12736 0
Professor John Horowitz
Address 12736 0
The Queen Elizabeth Hospital
Department of Cardiology
28 Woodville Rd, Woodville South
South Australia, 5011
Country 12736 0
Australia
Phone 12736 0
+61 8 8222 6000
Fax 12736 0
Email 12736 0
john.horowitz@adelaide.edu.au
Contact person for scientific queries
Name 3664 0
Professor John Horowitz
Address 3664 0
The Queen Elizabeth Hospital
Department of Cardiology
28 Woodville Rd,
Woodville South,
South Australia 5011
Country 3664 0
Australia
Phone 3664 0
+61 8 8222 6000
Fax 3664 0
Email 3664 0
john.horowitz@adelaide.edu.au

No information has been provided regarding IPD availability
Summary results
No Results