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

NCT01779908 | Completed

• 2 other identifiers: CDA grant no OG-3-12-3681-CGB12-12-1095
• Study Type: interventional
• Target: 96
• Locations: 1 country
• Sites: 1

Brief Summary

Prospective, randomized and placebo-controlled 6-month trial of vitamin D supplementation in 130 Caucasian and vitamin D-deficient men and women aged 25 years and over. Participants will have abdominal obesity and at least one factor associated with insulin resistance. Participants will be randomized by sex, BMI and age. 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.

Conditions

Vitamin D-deficient; Insulin-resistant

Keywords

Vitamin D supplementation; Insulin resistance

Outcome Measures

Primary Outcomes (2)

• Change in peripheral insulin sensitivity assessed by the euglycemic-hyperinsulinemic clamp between placebo and vitamin D groups

  M-value

  0 and 6 months

• Change in peripheral insulin sensitivity assessed by the euglycemic-hyperinsulinemic clamp between placebo and vitamin D groups

  M/I ratio

  0 and 6 months

Secondary Outcomes (15)

• Change in insulin sensitivity indice assessed by fasting- and oral glucose tolerance test between placebo and vitamin D groups

  0 and 6 months

• Change in insulin sensitivity indice assessed by fasting- and oral glucose tolerance test between placebo and vitamin D groups

  0 and 6 months

• Change in insulin secretion indice between placebo and vitamin D groups

  0 and 6 months

• Change in insulin secretion indice between placebo and vitamin D groups

  0 and 6 months

• Change in insulin secretion indice between placebo and vitamin D groups

  0 and 6 months

Study Arms (2)

Vitamin D supplementation

EXPERIMENTAL

5000 IU of vitamin D3 for 6 months

Dietary Supplement: Vitamin D

Placebo

PLACEBO COMPARATOR

Placebo pill for 6 months

Other: Placebo

Interventions

Vitamin D DIETARY_SUPPLEMENT

Vitamin D supplementation

Placebo OTHER

Placebo

Eligibility Criteria

• Age: 25 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Caucasian men and women
• ≥25 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; (4) history of gestational diabetes.

You may not qualify if:

• Type 2 diabetes under drug therapy
• HbA1c \>7%
• BMI \>40 kg/m2
• pregnancy or breast-feeding;
• medication influencing vitamin D or glucose metabolism in the last 3 mo
• regular consumption of supplements containing \>400 IU/d of vitamin D3 over the last 2 mo;
• renal insufficiency (creatinine clearance \<60 ml/min);
• cirrhosis,
• intestinal malabsorption (bypass surgery, celiac disease, etc);
• 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);

Sponsors & Collaborators

• CHU de Quebec-Universite Laval: lead
• Canadian Diabetes Association: collaborator
• Laval University: collaborator
• Fonds de la Recherche en Santé du Québec: collaborator

Study Sites (1)

CHU de Québec, Laval University Research Center

Québec, Quebec, G1V 4G2, Canada

Location

MeSH Terms

Conditions

Insulin Resistance

Interventions

Vitamin D

Condition Hierarchy (Ancestors)

Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases

Intervention Hierarchy (Ancestors)

Secosteroids; Steroids; Fused-Ring Compounds; Polycyclic Compounds

Study Officials

• Claudia Gagnon, Dr.

  CHU de Québec Research Center

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD

Study Record Dates

• First Submitted: January 24, 2013
• First Posted: January 30, 2013
• Study Start: January 1, 2013
• Primary Completion: June 2, 2017
• Study Completion: June 1, 2020
• Last Updated: July 24, 2020

Record last verified: 2020-07

Locations

CA (1)