Calcium and Lipid Metabolism

Study Overview
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Brief Summary
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We hope to determine if supplementing the diet of women who habitually consume low levels of calcium, with 1500 mg of calcium a day for three months will increase fat oxidation and decrease fat storage. We will also measure concentrations of lipids, glucose, hormones and enzymes associated with fat and carbohydrate metabolism to determine alterations and mechanism of the metabolic changes.

Detailed Description
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The incidence of obesity has rapidly increased in recent years and reached epidemic proportions in the United States. Recent epidemiological data has shown an inverse relationship between calcium intake and body fat and emerging research suggests that inadequate dietary calcium consumption may increase obesity. Studies in mice have shown that an increase in dietary calcium consumption creates a shift in the utilization of energy stores from carbohydrates to fat and a shift in the partitioning of energy from storage (as fat) to expenditure (as heat). We will give 1500 mg of calcium a day for three months to women who habitually consume low levels of dietary calcium. The following measurements will be made before and after calcium supplementation: body fat by DEXA, lipolysis by infusion of stable isotopes of 1,1,2,3,3-[2H5] glycerol , hepatic glucose production by infusion of stable isotopes of 6,6-[2H2] glucose, lipogenesis by measurement of fatty acid synthase activity (14C radiochemical assay) , mRNA expression ( Real Time Polymerase Chain Reaction) and protein content (ELISA), indirect calorimetry measurement of non-protein respiratory quotient (NPRQ), energy expenditure, fat and carbohydrate oxidation. Serum calcium, glucose, cholesterol, triglycerides, LDL, HDL, parathyroid hormone, leptin, free fatty acids, adiponectin, 1,25(OH)2D, 25(OH)D and urinary calcium excretion will also be measured.

Official Title
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The Effects of Calcium Supplementation on Adipocyte Metabolism in Overweight Women

Conditions
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Obesity

Intervention / Treatment
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* Dietary Supplement: Calcium Carbonate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI between 25 and 30 kg/m2 Taking oral contraceptives Having regular menses Exclusion Criteria: Pregnant History of metabolic bone, renal or thyroid disease, History of diabetes mellitus, or gestational diabetes mellitus Cigarette smoking Self-administration of calcium supplements Regular aerobic activity, i.e. jogging > 1 mile/day

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Dietary Supplement: Calcium Carbonate|1500 mg per day|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lipolysis by infusion of stable isotopes of 1,1,2,3,3-[2H5] glycerol |  | 0 and 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hepatic glucose production by infusion of stable isotopes of 6,6-[2H2] glucose |  | 0 and 3 months | 
| Lipogenesis by measurement of fatty acid synthase activity (14C radiochemical assay) , mRNA expression ( Real Time Polymerase Chain Reaction) and protein content (ELISA) |  | 0 and 3 months | 
| Indirect calorimetry measurement of non-protein respiratory quotient (NPRQ), energy expenditure, fat and carbohydrate oxidation |  | 0 and 3 months | 
| Serum calcium, glucose, cholesterol, triglycerides, LDL, HDL, parathyroid hormone, leptin, free fatty acids, adiponectin, 1,25(OH)2D, 25(OH)D |  | 0 and 3 months | 
| urinary calcium and sodium excretion |  | 0 and 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Calcium carbonate, Dietary Supplements, Lipolysis