Insulin Resistance, Obesity, Overweight
Conditions
Keywords
Obesity, Insulin resistance, Vitamin D, Cardiovascular risk factors
Brief summary
Hypovitaminosis D is highly prevalent in the general population, particularly in obese individuals. Besides being associated with obesity, vitamin D deficiency seems to be involved in the pathogenesis of insulin resistance and low-grade chronic inflammation. In addition, it has been reported that individuals with low vitamin D levels are at increased risk for cardiovascular diseases. A healthy diet and weight loss are cornerstones in the prevention of cardiovascular diseases. Vitamin D supplementation could increase the beneficial effects of these lifestyle interventions. The purpose of this study is to assess whether vitamin D supplementation in conjunction with a hypocaloric diet improves the cardiometabolic profile of overweight/obese subjects to a greater extent than diet alone.
Interventions
DRUGVitamin D
Sponsors
Fondazione Policlinico Universitario Agostino Gemelli IRCCS
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* BMI≥25 kg/m2
Exclusion criteria
* Diabetes mellitus * Chronic kidney disease * Liver disease * Cholestasis * Cancer * Chronic bowel disease * Primary or secondary hyperparathyroidism * Treatment with drugs that may affect insulin sensitivity, weight or calcium/vitamin D metabolism * Laxative abuse * Changes \>10% of usual body weight in the previous 6 months * Alcohol or illicit drug abuse * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline in insulin sensitivity (M value) | Baseline, 3 months | Insulin sensitivity will be measured with the hyperinsulinemic euglycemic clamp technique and expressed as M value, calculated from the glucose infusion rate during the last 30 min of the clamp. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline in body composition | Baseline, 3 months | Body composition will be determined by using dual energy X-ray absorptiometry (DXA). |
| Change from baseline in anthropometric parameters | Baseline, 3 months | Weight, BMI, waist and hip circumference, waist/hip ratio. |
| Change from baseline in oral glucose tolerance | Baseline, 3 months | Oral glucose tolerance will be assessed with a standard 2-hour oral glucose tolerance test (OGTT). |
| Change from baseline in phosphocalcic metabolism | Baseline, 3 months | Serum vitamin D, PTH and calcium |
| Change from baseline in inflammatory markers | Baseline, 3 months | Interleukin-6 (IL-6), IL-10, adiponectin, TNF-α, C-reactive protein (CRP) and fibrinogen |
| Change form baseline in systolic and diastolic blood pressure | Baseline, 3 months | — |
Countries
Italy
Outcome results
None listed