Clinical trial NCT00686192: Calcium and Lipid Metabolism
Official title: The Effects of Calcium Supplementation on Adipocyte Metabolism in Overweight Women
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Keywords: Obesity
Calcium carbonate
Dietary Supplements
Lipolysis
Lead sponsor: USDA, Western Human Nutrition Research Center
Sponsor class: FED
Collaborators: name: University of California, Davis
name: San Francisco General Hospital
First posted: 2008-05-29
Enrollment: 15
Sex: FEMALE
Minimum age (years): 20
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: PREVENTION

Brief summary: 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: 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.

Eligibility criteria: 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

Primary outcomes:
measure: Lipolysis by infusion of stable isotopes of 1,1,2,3,3-[2H5] glycerol
timeFrame: 0 and 3 months
Secondary outcomes:
measure: Hepatic glucose production by infusion of stable isotopes of 6,6-[2H2] glucose
timeFrame: 0 and 3 months
measure: Lipogenesis by measurement of fatty acid synthase activity (14C radiochemical assay) , mRNA expression ( Real Time Polymerase Chain Reaction) and protein content (ELISA)
timeFrame: 0 and 3 months
measure: Indirect calorimetry measurement of non-protein respiratory quotient (NPRQ), energy expenditure, fat and carbohydrate oxidation
timeFrame: 0 and 3 months
measure: Serum calcium, glucose, cholesterol, triglycerides, LDL, HDL, parathyroid hormone, leptin, free fatty acids, adiponectin, 1,25(OH)2D, 25(OH)D
timeFrame: 0 and 3 months
measure: urinary calcium and sodium excretion
timeFrame: 0 and 3 months
Other outcomes:
Locations:
city: San Francisco
country: United States
facility: San Francisco General Hospital
state: California
Study officials:
affiliation: UCSF Benioff Children's Hospital Oakland
name: Janet C King, PhD
role: PRINCIPAL_INVESTIGATOR
References: