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    ABSTRACT: Concern that calcium use may increase cardiovascular risk was previously the domain of nephrologists. By contrast, calcium supplementation has been promoted within the general community as beneficial to the maintenance of bone mineral density, as an adjunct to osteoporosis therapies and as potentially useful for cardiovascular health. Studies of patients with normal serum creatinine levels have reported that combined calcium and vitamin D supplementation reduced fracture risk, and osteoporosis trials have generally included calcium and vitamin D in placebo and active arms. However, an increased risk of myocardial infarction and other cardiovascular events has now been reported in secondary analysis of a fracture study of patients taking calcium or placebo, in subsequent meta-analysis of 15 similar studies, and most recently in re-analysis of the Women's Health Initiative calcium, vitamin D dataset. These reports have been criticized regarding event ascertainment, adjudication and the use of composite outcomes. Patients with chronic kidney disease (CKD) have impaired renal calcium regulation, abnormal bone turnover and are predisposed to positive calcium balance. If these general population data are proven, they should heighten our unease regarding the use of calcium salts in all stages of CKD, and particularly for patients with prevalent vascular calcification, suspected adynamic bone and high bone turnover.
    Current opinion in nephrology and hypertension 07/2011; 20(4):369-75. DOI:10.1097/MNH.0b013e328347486a · 3.96 Impact Factor
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    Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 04/2012; 27(4):960-1. DOI:10.1002/jbmr.1569 · 6.83 Impact Factor
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    ABSTRACT: We sought to evaluate the association of urine calcium excretion (UCaE), which reflects systemic calcium absorption, with cardiovascular (CV) events and mortality in outpatients with prevalent coronary heart disease (CHD). Calcium supplementation is associated with vascular calcification and adverse CV outcomes in patients with end-stage renal disease. Recent studies have raised concern that this phenomenon may also extend to the general population. However, previous studies have assessed oral calcium intake, which correlates poorly with systemic calcium absorption. We measured UCaE from 24-hour urine collections provided by 903 outpatients who were recruited from 2000 to 2002. We used Cox proportional hazard models to evaluate the association of baseline UCaE with a primary end point of any CV event (myocardial infarction [MI], heart failure, stroke, or CV mortality). During a mean follow-up of 6 ± 3 years, 287 subjects (32%) had a CV event. After multivariate adjustment for demographics, traditional CV risk factors, and kidney function, there was no association between UCaE and the primary end point of any CV event (per 10-mg/day greater UCaE, hazard ratio 1.00, 95% confidence interval 0.98 to 1.02). Evaluation of individual CV outcomes revealed a lower rate of MI with higher UCaE (hazard ratio 0.97, 95% confidence interval 0.94 to 1.00). In conclusion, greater UCaE is not associated with higher overall CV event rates or mortality in outpatients with stable CHD. On the contrary, greater UCaE is associated with a modestly lower rate of MI. These findings suggest that greater systemic calcium absorption does not confer CV harm in outpatients with prevalent CHD.
    The American journal of cardiology 09/2012; 110(12). DOI:10.1016/j.amjcard.2012.08.007 · 3.28 Impact Factor
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