Vitamin D, C-reactive Protein and Insulin Resistance
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.
Low-intensity Chronic Inflammation
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Effect of Vitamin D Supplementation on C-reactive Protein and Insulin Resistance in Postmenopausal Women With Type 2 Diabetes Mellitus|
- Serum C-reactive protein concentrations, measured by a high-sensitivity assay -nephelometry-. [ Time Frame: 3 and 6 months ] [ Designated as safety issue: No ]
- Insulin resistance, measured by HOMA-IR index [ Time Frame: 3 and 6 months ] [ Designated as safety issue: No ]
- Serum 25-OH-vitamin D3 levels [ Time Frame: 3 and 6 months ] [ Designated as safety issue: Yes ]
|Study Start Date:||March 2008|
|Study Completion Date:||October 2008|
|Primary Completion Date:||October 2008 (Final data collection date for primary outcome measure)|
Experimental: Vitamin D
Cholecalciferol, 4,000 IU/d for 6 months
4,000 IU per day during 6 months. Capsule form.
Placebo Comparator: Placebo
no active principles given.
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.
|Instituto Mexicano del Seguro Social|
|Cuernavaca, Morelos, Mexico, 62450|
|Principal Investigator:||Mario E Flores, MD, MSc||Instituto Nacional de Salud Publica, Mexico|