Clinical trial NCT01019642: Vitamin D, C-reactive Protein and Insulin Resistance
Official title: Effect of Vitamin D Supplementation on C-reactive Protein and Insulin Resistance in Postmenopausal Women With Type 2 Diabetes Mellitus
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE3
Conditions: Diabetes
Low-intensity Chronic Inflammation
Insulin Resistance
Keywords: vitamin D
diabetes
C-reactive protein
insulin resistance
Lead sponsor: Instituto Nacional de Salud Publica, Mexico
Sponsor class: OTHER
Collaborators: name: Instituto Mexicano del Seguro Social
name: Ellison Medical / International Nutrition Foundation
name: Tufts University
First posted: 2009-11-25
Enrollment: 104
Sex: FEMALE
Minimum age (years): 45
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

Eligibility criteria: 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

Primary outcomes:
measure: Serum C-reactive protein concentrations, measured by a high-sensitivity assay -nephelometry-.
timeFrame: 3 and 6 months
measure: Insulin resistance, measured by HOMA-IR index
timeFrame: 3 and 6 months
Secondary outcomes:
measure: Serum 25-OH-vitamin D3 levels
timeFrame: 3 and 6 months
Other outcomes:
Locations:
city: Cuernavaca
country: Mexico
facility: Instituto Mexicano del Seguro Social
state: Morelos
Study officials:
affiliation: Instituto Nacional de Salud Publica, Mexico
name: Mario E Flores, MD, MSc
role: PRINCIPAL_INVESTIGATOR
References:
citation: Flores M. A role of vitamin D in low-intensity chronic inflammation and insulin resistance in type 2 diabetes mellitus? Nutr Res Rev. 2005 Dec;18(2):175-82. doi: 10.1079/NRR2005104.
citation: Munoz-Aguirre P, Flores M, Macias N, Quezada AD, Denova-Gutierrez E, Salmeron J. The effect of vitamin D supplementation on serum lipids in postmenopausal women with diabetes: A randomized controlled trial. Clin Nutr. 2015 Oct;34(5):799-804. doi: 10.1016/j.clnu.2014.10.002. Epub 2014 Oct 13.