Abstract 15459: Calcium Intake and Source Effects on Soft Tissue Calcification in Ossabaw Miniature Swine
Concern over calcium supplementation for elevating risk of cardiovascular disease has led to a calcium controversy because calcium is a shortfall essential nutrient. Understanding cardiovascular risk of calcium intake and source (diet or supplements) has been hampered by lack of an appropriate animal model and sensitive outcome measures to monitor early soft tissue calcification. The aim of this study was to compare calcium intake (2% vs 0.5% by weight) and source (calcium carbonate or dairy) on soft tissue calcification using an innovative technology in the Ossabaw miniature swine, a model that mimics human metabolic syndrome and coronary artery disease when fed a high fat/cholesterol atherogenic diet. Pigs (n=24) were fed the high fat diet that varied in calcium for 6 months. The pigs were dosed with the rare isotope, 41Ca, which can be measured at a sensitivity of 10-18 M by Accelerator Mass Spectrometry. Kinetic modeling of 41Ca based on serial samples of blood taken over 27 days post dose and proximal arterial tissues (circumflex, left anterior descending, and right coronary arteries) taken at sacrifice was performed to assess soft tissue calcification. Traditional outcome measures including blood pressure, plaque wall coverage of coronary arteries assessed by intravascular ultrasound, stroke volume and ejection fraction from 18 F-NaF PET-CT analysis, and endothelial-dependent and independent relaxation of coronary arteries by in vitro wire myography were not significantly (p>0.05) affected by diet as determined by general linear mixed model analysis. Preliminary results of 41Ca support the traditional outcome measures. Thus, high calcium intake up to the Upper Tolerable Level recommended by the Institute of Medicine is unlikely to exacerbate soft tissue calcification.
- © 2013 by American Heart Association, Inc.