Calcium Over Postprandial Effects of Fatty Meal on Metabolism, Blood Pressure, Oxidative Stress, Endothelial Function.

Influence of Dietary and Supplementary Calcium Over the Postprandial Effects of a Fatty Meal on Metabolism Profile, Blood Pressure, Oxidative Stress, and Endothelial Function of Obese Women.

The purpose of the study is to investigate calcium acute influence over the postprandial effects of a fatty meal on serum calcium, plasma glucose and triglycerides, blood pressure, oxidative stress, and endothelial function in obese women.

Studies suggest that dietary calcium intake is inversely associated with cardiovascular disease, but supplementary calcium appears to be associated with raised risk of cardiovascular events. Fatty meals lead to oxidative and inflammation which seems to interfere in postprandial dismetabolism, a predictor of cardiovascular events. To investigate calcium acute influence over the postprandial effects of a fatty meal a crossover, controlled, and randomized clinical trial will be conducted with obese adult women who will be randomized into one of the three interventions, characterized by a fatty meal with different contents of calcium: low calcium (40 mg), high dietary calcium (540 mg from non-fat milk), and high supplementary calcium (540 mg from calcium carbonate). Each participant will receive all three meals and one of them every week. Before meals' intake blood sample will be collected and endothelial function assess will be performed. Participants will eat the specific meal and endothelial function will be assessed again after 120 minutes. Blood sample collections will be repeated every 60 minutes after meal's intake to perform latter biochemical analyzes to determine: 8-isoprostane levels, to assess oxidative stress status; triglycerides; glucose; insulin; and serum calcium. Blood pressure will be continuously assessed during 25 minutes before meals' intake and during 2 hours after it.

Inclusion Criteria:

• body mass index (BMI) greater than or equal to 30 kg/m2 and below 40 kg/m2
• habitual dietary calcium intake below 500 mg per day

Exclusion Criteria:

• smoking
• dietary supplements or drugs that could interfere with body weight, metabolic profile and blood pressure
• diabetes
• thyroid dysfunction
• hypertension
• angina pectoris
• heart kidney or liver failure
• intestinal malabsorption
• acute or chronic inflammation
• HIV infection
• autoimmune diseases
• cancer
• chronic obstructive pulmonary disease
• dyslipidemia with indication for drug treatment
• history of myocardial infarction or stroke
• pregnancy and lactation
• menopause