Role of Vitamin D in the Prevention and Treatment of Diseases Associated With Insulin Resistance (VIDIR)

This study is currently recruiting participants. (see Contacts and Locations)
Verified June 2014 by Centre Hospitalier Universitaire de Québec, CHU de Québec
Sponsor:
Collaborators:
Canadian Diabetes Association
CHU de Québec Research Centre
Laval University
Fonds de recherche du Québec - Santé
Information provided by (Responsible Party):
Claudia Gagnon, Centre Hospitalier Universitaire de Québec, CHU de Québec
ClinicalTrials.gov Identifier:
NCT01779908
First received: January 24, 2013
Last updated: June 24, 2014
Last verified: June 2014
  Purpose

Prospective, randomized and placebo-controlled 6-month trial of vitamin D supplementation in 130 Caucasian and vitamin D-deficient men and postmenopausal women aged 50 years and over. Participants will have abdominal obesity and at least one factor associated with insulin resistance. Participants will be randomized by sex and BMI The primary aim is to compare the effect of daily vitamin D3 (cholecalciferol, 5000 IU) vs. placebo for 6 mo on insulin sensitivity (M-value by the gold standard method, the euglycemic hyperinsulinemic clamp). Secondary aims are to evaluate the effects of vitamin D3 vs. placebo on other indices of glucose metabolism, the lipid profile, blood pressure and anthropometric measurements. Questionnaires on physical activity and sunlight exposure, and a food frequency questionnaire will be administered at 0 and 6 mo to adjust for confounding factors. At 0 and 6 mo, changes in serum 25(OH)D will be correlated with changes in blood markers associated with insulin sensitivity [hs-CRP, inflammatory cytokines (IL-6 and TNF-alpha), adiponectin, leptin, total and undercarboxylated osteocalcin].

This research project intends to test 2 major hypotheses: (1) that vitamin D deficiency plays a causal role in the pathogenesis of insulin resistance in humans; and (2) that vitamin D increases insulin sensitivity.


Condition Intervention
Vitamin D-deficient
Insulin-resistant
Dietary Supplement: Vitamin D
Other: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Prevention
Official Title: Role of Vitamin D in the Prevention and Treatment of Diseases Associated With Insulin Resistance

Resource links provided by NLM:


Further study details as provided by Centre Hospitalier Universitaire de Québec, CHU de Québec:

Primary Outcome Measures:
  • Change from baseline in peripheral insulin sensitivity assessed by the euglycemic-hyperinsulinemic clamp at 6 months between placebo and vitamin D groups [ Time Frame: 0 and 6 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Change from baseline in glucose homeostasis (fasting glucose, 2h glucose post OGTT, HbA1c, HOMA-IS, HOMA-B, insulinogenic index, disposition index) at 6 months between placebo and vitamin D groups [ Time Frame: 0 and 6 months ] [ Designated as safety issue: No ]
  • Change from baseline in blood pressure [ Time Frame: 0 and 6 months ] [ Designated as safety issue: No ]
  • Change from baseline in lipid profile [ Time Frame: 0 and 6 months ] [ Designated as safety issue: No ]
  • Change from baseline in anthropometry (weight, waist circumference and fat mass by bioimpedance analysis) [ Time Frame: 0 and 6 months ] [ Designated as safety issue: No ]

Other Outcome Measures:
  • Changes from baseline in cytokines/adipokines at 6 months between placebo and vitamin D groups [ Time Frame: 0 and 6 months ] [ Designated as safety issue: No ]

Estimated Enrollment: 130
Study Start Date: January 2013
Estimated Study Completion Date: January 2016
Estimated Primary Completion Date: September 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Vitamin D supplementation
5000 IU of vitamin D3 for 6 months
Dietary Supplement: Vitamin D
Placebo Comparator: Placebo
Placebo pill for 6 months
Other: Placebo

Detailed Description:

Part 1: Prospective, randomized and placebo-controlled 6-month trial of vitamin D supplementation in 130 Caucasian and vitamin D-deficient [serum 25(OH)D ≤55 nM] men and postmenopausal women aged 50 years and over with a BMI ≤40 kg/m2. Participants will have abdominal obesity (increased waist circumference of at least 102 cm for men and 88 cm for women) and at least one factor associated with insulin resistance, namely: (1) serum triglyceride levels of at least 1.7 mmol/L or treated dyslipidemia; (2) prediabetes or untreated type 2 diabetes (HbA1c >=5.6% or fasting glucose >=5.6 mmol/L or glucose 2h post OGTT >=7.8 mmol/L); (3) first degree relative with type 2 diabetes. Participants will be randomized according to sex and BMI (<30 kg/m2 vs. 30 kg/m2 and over). The primary aim is to compare the effect of daily vitamin D3 (cholecalciferol, 5000 IU) vs. placebo for 6 mo on insulin sensitivity (M-value by the gold standard method, the euglycemic hyperinsulinemic clamp). Secondary aims are to evaluate the effects of vitamin D3 vs. placebo on other indices of glucose metabolism (fasting glucose, 2-h plasma glucose post OGTT, HbA1c, insulin sensitivity index (HOMA-IS using fasting glucose and insulin), insulin secretion index (HOMA-B using fasting glucose and C-peptide), insulinogenic index [(C-peptide at 30 min post OGTT - C-peptide at 0 min)/(glucose at 30 min post OGTT - glucose at 0 min)] and disposition index (insulinogenic index x M-value)), the lipid profile, blood pressure and anthropometric measurements (weight, waist and hip circumference, bioimpedance analysis). Questionnaires on physical activity and sunlight exposure, and a food frequency questionnaire will be administered at 0 and 6 mo to adjust for confounding factors. At 0 and 6 mo, biochemical markers associated with insulin sensitivity will be measured (point 2).

Part 2: Mechanistic studies comparing, before and after vitamin D3 supplementation, changes in serum 25(OH)D with changes in blood markers associated with insulin sensitivity [hs-CRP, inflammatory cytokines (IL-6 and TNF-alpha), adiponectin, leptin, total and undercarboxylated osteocalcin].

  Eligibility

Ages Eligible for Study:   50 Years to 75 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Caucasian men and postmenopausal women (absence of menstrual cycles for ≥12 mo)
  • ≥50 yrs
  • vitamin D deficiency [serum 25(OH)D concentration ≤55 nM]
  • Abdominal obesity (waist circumference >=102 cm for men and >=88 cm for women) AND at least one factor associated with insulin resistance: (1) fasting serum triglycerides >=1.7 mmol/L or treated dyslipidemia; (2) prediabetes or untreated type 2 diabetes (HbA1c >=5.6% or fasting glucose >=5.6 mmol/L or 2h glucose post OGTT >=7.8 mmol/L); (3) first degree relative with type 2 diabetes.

Exclusion Criteria:

  • Type 2 diabetes under drug therapy
  • HbA1c >7%
  • BMI >40 kg/m2
  • medication influencing vitamin D or glucose metabolism in the last 3 mo (including estrogen replacement)
  • regular consumption of supplements containing >400 IU/d of vitamin D3 over the last 2 mo; renal insufficiency
  • cirrhosis, intestinal malabsorption (bypass surgery, celiac disease, etc) or osteoporosis
  • history of nephrolithiasis
  • hypercalcemia (>2.6 mM)
  • hypercalciuria (>0.6 fasting urine Ca/creatinine ratio)
  • >5% change in weight in the last 3 mo
  • diseases affecting glucose metabolism (e.g. hyperthyroidism)
  • pacemaker (for bioimpedance only)
  • inability to provide informed consent and complete questionnaires due to physical or mental problems
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01779908

Contacts
Contact: Sarah Chouinard-Castonguay, MSc 1-418-525-4444 ext 48729 Sarah.Chouinard-Castonguay@crchudequebec.ulaval.ca
Contact: Claudia Gagnon, Dr 1-418-525-4444 ext 48535 claudia.gagnon@crchuq.ulaval.ca

Locations
Canada, Quebec
CHU de Québec, Laval University Research Center Recruiting
Quebec city, Quebec, Canada, G1V 4G2
Contact: Verson Barbara    1-418-525-4414    barbara.verson@crchuq.ulaval.ca   
Principal Investigator: Claudia Gagnon, Dr         
Sponsors and Collaborators
Centre Hospitalier Universitaire de Québec, CHU de Québec
Canadian Diabetes Association
CHU de Québec Research Centre
Laval University
Fonds de recherche du Québec - Santé
Investigators
Principal Investigator: Claudia Gagnon, Dr. CHU de Québec Research Center
  More Information

Additional Information:
No publications provided

Responsible Party: Claudia Gagnon, MD, Centre Hospitalier Universitaire de Québec, CHU de Québec
ClinicalTrials.gov Identifier: NCT01779908     History of Changes
Other Study ID Numbers: CDA grant no OG-3-12-3681-CG, B12-12-1095
Study First Received: January 24, 2013
Last Updated: June 24, 2014
Health Authority: Canada: Health Canada

Keywords provided by Centre Hospitalier Universitaire de Québec, CHU de Québec:
Vitamin D supplementation
Insulin resistance

Additional relevant MeSH terms:
Insulin Resistance
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases
Insulin
Vitamins
Vitamin D
Ergocalciferols
Hypoglycemic Agents
Physiological Effects of Drugs
Pharmacologic Actions
Micronutrients
Growth Substances
Bone Density Conservation Agents

ClinicalTrials.gov processed this record on October 01, 2014