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NCT Number: NCT00736632

Vitamin D, Insulin Resistance, and Cardiovascular Disease

In recent years, vitamin D has been shown not only to be important for bone and calcium metabolism but also for homeostasis of critical tissues involved in vascular disease in patients with diabetes. Epidemiological studies indicated the high prevalence of vitamin D deficiency among Type 2 DM patients and suggest an increased risk of cardiovascular disease and hypertension with low vitamin D levels. The objective of this proposal is to evaluate the effects of vitamin D replacement on blood pressure control and vascular disease in vitamin D deficient hypertensive patients with diabetes

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Key information

Conditions

Vitamin D Deficiency Avitaminosis Cardiovascular Disease Cardiovascular Diseases Deficiency Diseases Diabetes Mellitus Diabetes Mellitus, Type 2 Endocrine System Diseases Glucose Metabolism Disorders Hyperinsulinism Hypertension Insulin Resistance Malnutrition Metabolic Diseases Nutrition Disorders Nutritional and Metabolic Diseases Type 2 Diabetes Mellitus Vascular Diseases

Age range

25 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Washington Universiy

St Louis, Missouri, 63110, United States

About this study

This is a double blinded, placebo controlled trial. Patients who meet the inclusion criteria will be randomized to placebo or 25(OH)D3, 4,000 IU/d orally for 16 weeks. Enrolled patients will be tested for 24h-blood pressure, brachial arterial blood flow, vascular inflammatory markers and macrophage inflammatory response to modified-lipoproteins at baseline, middle and at the end of the study.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Type 2 diabetes
  • 25 (OH) vitamin D levels < 25 ng/ml
  • Age 25 to 80 years
  • Not on insulin for diabetes treatment
  • HbA1c 5.5% -9.5%
  • Mild/moderately increased blood pressure (systolic 120-160, diastolic 80-100) off BP medications

Exclusion criteria

  • Pregnancy
  • Patients with systolic >160 or diastolic >100 mmHg
  • High urine calcium or history of recurrent kidney stones
  • Cardiovascular disease
  • Stage 3 or worse chronic kidney disease

Treatment and study plan

Vitamin D3

Drug

Cholecalciferol 4000 units orally daily Calcium carbonate 500 mg orally twice daily

Other names: Vitamin D

Placebo

Drug

Placebo pill orally daily Calcium carbonate 500 mg twice daily

Primary outcomes

  1. Hypertension (24h Blood Pressure, Central Blood Pressure, and Office BP)

    Time frame: 0, 2, and 4 months

    24-hour blood pressure collected by ambulatory automated arm cuff, central mean arterial blood pressure (MAP) collected by non-invasive arterial tonometry and pulse wave analysis/pulse wave velocity, office blood pressure collected by manual aneroid sphygmomanometry.

Secondary outcomes

  1. Brachial Artery Reactivity Testing

    Time frame: 0, 2, and 4 months

    Brachial artery response to hyperemia assessed by measuring brachial artery diameter every 30 seconds for 180 seconds after a 5-minute occlusion with arm cuff above systolic blood pressure, with response defined as maximal percentage increase above baseline.

  2. Macrophage Cholesterol Metabolism

    Time frame: 0 and 4 months

    Macrophage uptake of labeled oxidized low density lipoprotein, assessed by the ratio of post-treatment cholesterol uptake to baseline uptake.

  3. Serum Calcium

    Time frame: 0, 2, and 4 Month

    Serum calcium assessed by photometric assessment after calcium reaction with NM-BAPTA, then with EDTA

  4. HbA1C

    Time frame: 0, 2, and 4 month

    HbA1c percentage assessed by turbidimetric inhibition immunoassay for hemolyzed whole blood

  5. Vitamin D

    Time frame: 0, 2, and 4 Month

    25(OH) Vitamin D assess by liquid chromatography with tandem mass spectrometry

  6. hsCRP

    Time frame: 0, 2, and 4 Month

    High sensitivity C-reactive protein assessed by particle-enhanced immunoturbidimetric assay

  7. Fasting Glucose

    Time frame: 0, 2, and 4 Month

    Serum fasting glucose assessed by hexokinase method

  8. Urine Calcium to Creatinine Ratio.

    Time frame: 0, 2 and 4 Months

    Urine calcium to creatinine ratio assessed by spectrophotometry

Sponsors and collaborators

Lead sponsor

Washington University School of Medicine

Other

Collaborators

  • American Diabetes Association
  • National Heart, Lung, and Blood Institute (NHLBI)

Registry information

Important dates

Study start
2006
Primary completion
2019
Study completion
2019
First posted
Aug 18, 2008
Registry last updated
Feb 10, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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