Vitamin D, C-reactive Protein and Insulin Resistance

Phase 3

Completed

• Conditions: Diabetes; Low-intensity Chronic Inflammation; Insulin Resistance
• Interventions: Drug: placebo; Drug: cholecalciferol

• Registration Number: NCT01019642
• Lead Sponsor: Instituto Nacional de Salud Publica, Mexico

Brief Summary

Randomized, double blind, placebo-controlled clinical trial of vitamin D supplementation (cholecalciferol, 4,000 IU/day for 6 months, in 104 postmenopausal women with type 2 diabetes mellitus.

The objective was to evaluate the effect of vitamin D supplementation on C-reactive protein (CRP) and insulin resistance in women with type 2 diabetes mellitus (T2DM).

The trial was conducted from March to October 2008 at the Hospital of the Mexican Social Security in Cuernavaca, Mexico.

Detailed Description

Methods. Randomized, double blind, placebo-controlled clinical trial. We selected 104 postmenopausal women, ages 45 to 65, with uncomplicated T2DM and BMI ≥25. Women with history of kidney or liver disease, BMI\>40, autoimmune disease or cancer were not included in the study.

Participants were randomly assigned to receive either a capsule containing 4,000 IU of vitamin D3 (cholecalciferol, n=52) or placebo (n=52), once a day during 6 months.

Outcome variables were serum CRP, measured with a high-sensitivity assay (nephelometry), and HOMA-IR. Serum vitamin D (25-OH-D) was measured by HPLC. Outcome variables were measured at baseline, and 3 and 6 months thereafter. All participants received diet and physical activity counseling, and visited the clinic for medical check-up once a month.

Baseline Results. Mean age was 56.8 ± 5.1 y. Baseline BMI was 30.7 ± 3.9. Median CRP concentration was 5.0 mg/L (Interquartile range: 1.0, 8.5). HOMA index at baseline was 7.13 ± 3.8. Serum 25-OH-D concentration at baseline was 54.5 ± 15.7 nmol/L (\~22 ng/mL). Almost 94% of patients had baseline serum 25-OH-D levels \<80 nmol/L, and 25% were below 40 nmol/L. No one had levels \<20 nmol/L. There were no statistical differences on important variables by treatment group at the onset of study.

Study Timeline

• Study Start: 2008-03
• Primary Completion: 2008-10
• Study Completion: 2008-10
• Status Verified: 2009-11
• Study First Submitted: 2009-11-23
• Study First Submitted QC: 2009-11-23
• Last Update Submitted: 2009-11-23
• Study First Posted: 2009-11-25
• Last Update Posted: 2009-11-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 104

Inclusion Criteria

• Type 2 diabetes mellitus w/ < 10 yrs of diagnosis
• Postmenopausal
• Overweight or obesity (BMI >=25)
• Treated with metformin

Exclusion Criteria

• BMI >=40
• Liver or kidney disease
• Other important chronic disease: i.e. cancer, autoimmune.
• Receiving insulin

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	placebo	placebo
Vitamin D	cholecalciferol	Cholecalciferol, 4,000 IU/d for 6 months

Primary Outcome Measures

Name	Time	Method
Serum C-reactive protein concentrations, measured by a high-sensitivity assay -nephelometry-.	3 and 6 months
Insulin resistance, measured by HOMA-IR index	3 and 6 months

Secondary Outcome Measures

Name	Time	Method
Serum 25-OH-vitamin D3 levels	3 and 6 months

Trial Locations

Locations (1)

Instituto Mexicano del Seguro Social; 🇲🇽 Cuernavaca, Morelos, Mexico