View clinical trials related to Calcium Metabolism Disorders.
Filter by:The investigators aim to recruit 60 women who have agreed to participate in an existing randomized, double-blind, placebo-controlled trial (Treatment of Vitamin D Insufficiency, HSC 2009-0055). In this trial, the investigators propose to evaluate the associations between magnesium intake, magnesium stores, fractional magnesium absorption and calcium homeostasis. The investigators will stratify 60 subjects in the sub-study, ensuring that approximately 20 subjects are randomized into each treatment arm (placebo, low-dose and high-dose vitamin D). The investigators already assess calcium homeostasis throughout the study by measuring bone mineral density, fractional calcium absorption, serum and urine calcium levels, among other tests. In the sub-study of 60 women, the investigators will evaluate whether habitually higher magnesium intake increases or decreases fractional calcium absorption. The investigators will evaluate the interplay between magnesium stores, vitamin D levels and serum parathyroid hormone levels. The investigators will directly assess magnesium stores using serum magnesium and 24-hour urine magnesium levels, and will measure magnesium absorption using the dual stable isotope approach.
The prospective EUTrigTreat multi-center study is an observational, advanced diagnostics and genetic risk stratification trial in patients with standard indications for ICD treatment, with and without myocardial infarction in their history. Its aims are fourfold: 1) To accurately risk stratify a large cohort of implantable cardioverter-defibrillator (ICD) patients for ICD shock risk and mortality using traditional risk markers as well as genetic markers 2) To find a link between repolarization biomarkers and genetic markers of calcium metabolism. 3) To compare invasive and noninvasive electrophysiologic (EP) testing systematically 4) To assess temporal changes of typical noninvasive risk stratifiers and their prognostic implication. In five European academic clinical centers, 700 ICD patients are prospectively enrolled (optionally the number of enrolled patients may be expanded to 1000 patients). Comprehensive non-invasive risk stratifying ECG diagnostics including beat-to-beat variability of repolarization (BVR) are applied, and candidate genes associated with malignant arrhythmias are analyzed. Programmed electrical stimulation is performed to test for inducibility of malignant ventricular arrhythmias and BVR. In a subset of patients, electrophysiologic studies include recording of monophasic action potentials (MAP) from the right ventricle for assessment of restitution properties. Non-invasive risk stratifying ECG methods are repeated annually. Outcome (mortality, ICD shocks) will be assessed until September 2014.
This prospective, single-blind, matched controlled study aims to evaluate the effect of proton pump inhibitors on biochemical markers of calcium and bone metabolism in an effort to establish additional biological plausibility for the apparent association between proton pump inhibitors (PPIs) and osteoporosis-related fractures. Young males (age 18-45 years), who are either healthy volunteers, or who complain of daily or frequent heartburn but are otherwise healthy, will be recruited and enrolled in the study. Patients with heartburn will be assigned to the intervention group and will be assigned to take a PPI for three months. Healthy volunteers will be matched by age to patients in the intervention group and will act as the control group. 70 patients will be enrolled in total. Blood studies for all subjects will be taken at 0, 1 and 3 months to test for various biochemical markers of calcium and bone metabolism, which act as surrogate markers of calcium absorption and bone remodeling. Levels of biochemical markers in the two groups will be compared using two-way analysis of variance (ANOVA). Changes in biochemical parameters within a group will be assessed using repeated measures ANOVA.