Randomized Controlled Trial of Calcium in Healthy Older Women

Reid, Ian R.; Mason, Barbara; Horne, Anne; Ames, Ruth; Reid, Helen; Bava, Usha; Bolland, Mark J; Gamble, Gregory D.

doi:10.1016/j.amjmed.2006.02.038

Cited by 248 publications

(228 citation statements)

References 14 publications

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“…The study design and results of both trials have been published previously. (10,14,15) The women were over 55 years of age, were not taking agents for osteoporosis (including hormone-replacement therapy or vitamin D supplements in doses > 1000 IU/day), and were free from major ongoing illnesses, including hepatic, renal, or thyroid dysfunction, malignancy, metabolic bone disease, or serum 25-hydroxyvitamin D concentration of less than 25 nmol/L and had normal spine BMD for their age (Z-score > -2). The men were over 40 years of age, free from major ongoing illness (including coronary heart disease, hypertension, diabetes, renal or thyroid dysfunction, liver disease, malignancy, or metabolic bone disease), had an estimated 5-year cardiovascular risk of greater than 15% and a serum 25-hydroxyvitamin D concentration of less than 25 nmol/L, had normal spine and hip BMD for their age (Z-score > -2), and were not using lipid-lowering therapy or agents that might have an impact on calcium metabolism.…”

Section: Participantsmentioning

confidence: 99%

“…(11) The mechanism of the association between calcium metabolism and vascular disease is unknown. The process of vascular calcification is thought to be similar to bone formation, (12,13) and since calcium supplements increase bone mineral density (BMD), (14,15) they also may increase vascular calcification.…”

Section: Introductionmentioning

confidence: 99%

“…(36,37) We have recently completed randomized, controlled trials of calcium supplements in a cohort of healthy elderly women and a cohort of healthy middle-aged or older men. (14,15) We set out to investigate whether indices of calcium metabolism, dietary calcium intake, or use of calcium supplements were associated with AAC or CAC in these trials. We also investigated whether there was any association between AAC and BMD or fractures or between CAC and BMD.…”

Section: Introductionmentioning

confidence: 99%

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Relationships between vascular calcification, calcium metabolism, bone density, and fractures

Wang

Bolland

Pelt

et al. 2010

Journal of Bone and Mineral Research

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Factors involved with calcium metabolism, such as serum calcium and phosphate and calcium intake, have been associated with vascular disease in different populations. We investigated whether this association is mediated via increased vascular calcification by assessing relationships between these factors and abdominal aortic calcification (AAC) and coronary artery calcification (CAC). A total of 1471 healthy postmenopausal women participated in a 5-year randomized, placebo-controlled trial of calcium 1 g/day, and 323 healthy middle-aged and older men participated in a 2-year randomized, placebo-controlled trial of calcium 600 or 1200 mg/day. AAC was assessed on vertebral morphometric images at baseline and follow-up. Based on computed tomography, 163 men had CAC assessed, on average, 1.5 years after study completion. In elderly women, AAC was positively related to serum calcium (p < .001), phosphate (p ¼ .04), and the calcium-phosphate product (p ¼ .003), but changes in AAC over time and incidence of cardiovascular events were not related to these variables. In middle-aged men, AAC and CAC were not consistently related to these variables. Neither dietary calcium intake nor calcium supplementation was associated with changes in the prevalence of AAC over time, and calcium supplementation also was not related to CAC scores in men. After adjusting for age, AAC was not associated with low bone mineral density (BMD) at baseline, changes in BMD over time, or fracture incidence. CAC also was not related to baseline BMD. In summary, serum calcium and phosphate are associated with AAC in older women, but dietary calcium intake and calcium supplementation were not associated with changes in AAC over 2 to 5 years. ß

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Section: Participantsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Relationships between vascular calcification, calcium metabolism, bone density, and fractures

Wang

Bolland

Pelt

et al. 2010

Journal of Bone and Mineral Research

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“…Surprisingly, the authors also did not seek data for their primary endpoint from our previous trial, which would have increased the size of their data set of calcium monotherapy trials by about 40%. (8) In addition, a group that previously supplied individual patient data for our meta-analysis did not agree to participate in the Lewis meta-analysis.In their analyses of calcium monotherapy and MI, the authors identified only one trial (with four MIs) published after our metaanalysis, (2) In their analyses of calcium plus vitamin D, the authors included two trials not in our meta-analysis, (3) one trial with one MI, and the second a trial by Larsen and colleagues. (9) The latter was an open-label study of multifactorial interventions, one of which included calcium and vitamin D, administered to people living in different regions of the city.…”

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confidence: 99%

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Calcium Supplements Increase Risk of Myocardial Infarction

Bolland

Grey

Avenell

et al. 2014

Journal of Bone and Mineral Research

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The cardiovascular safety of calcium supplements has been revisited with a further meta-analysis, (1) which concludes that calcium supplementation does not increase coronary heart disease in women, without providing data for men. Their conclusion is at odds with that of our meta-analyses, which reported that calcium increased the risk of myocardial infarction (MI) and possibly stroke in men and women together. (2,3) There are important differences between approaches to the meta-analyses. In the current article and previously, the authors suggest that including men and self-reported events may have explained the increased risk of MI from calcium. However, in sensitivity analyses, we reported that sex did not interact with the effect of calcium supplements on cardiovascular risk (4) and that the risk of MI from calcium is increased after men or self-reported events are excluded. (4,5) The major effect of restricting the analyses to the subgroup of women is a reduction in the power of the analyses, and, for trials that included men and women, potentially introducing bias through loss of the balancing effects of randomization on possible confounders. These, and other major limitations of subgroup analyses, have been well described. (6) Additionally, even though they state the question is whether calcium has an impact on MI, the authors chose to use a composite endpoint of a much broader cluster of cardiovascular diagnoses of different clinical significance for their primary endpoint, which is not recommended practice and does not provide a better measure of safety when there is an increased risk of a clearly defined single endpoint. (7) The composite endpoint included angina pectoris and chronic coronary heart disease, although there is no evidence that these conditions are influenced by calcium supplementation, and they lack a standardized objective definition, which precludes reliable ascertainment of these events. Including such conditions in the composite endpoint might obscure the elevated risk of MI from calcium. Surprisingly, the authors also did not seek data for their primary endpoint from our previous trial, which would have increased the size of their data set of calcium monotherapy trials by about 40%. (8) In addition, a group that previously supplied individual patient data for our meta-analysis did not agree to participate in the Lewis meta-analysis.In their analyses of calcium monotherapy and MI, the authors identified only one trial (with four MIs) published after our metaanalysis, (2) In their analyses of calcium plus vitamin D, the authors included two trials not in our meta-analysis, (3) one trial with one MI, and the second a trial by Larsen and colleagues. (9) The latter was an open-label study of multifactorial interventions, one of which included calcium and vitamin D, administered to people living in different regions of the city. Although described as a cluster randomized trial, there was only one cluster per treatment group, meaning it is better described as quasi-randomized by location of...

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Randomized Controlled Trial of Calcium Supplementation in Healthy, Nonosteoporotic, Older Men

Reid¹,

Ames²,

Mason³

et al. 2008

Arch Intern Med

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Background: There is no consistent evidence, to our knowledge, that calcium supplementation affects bone mineral density (BMD) in men, despite male osteoporosis being a common clinical problem.Methods: To determine the effects of calcium supplementation (600 mg/d, 1200 mg/d, or placebo) on BMD in men, we conducted a double-blind, randomized controlled trial for a 2-year period at an academic clinical research center. A total of 323 healthy men at least 40 years old (mean age, 57 years) were recruited by newspaper advertisement. Complete follow-up was achieved in 96% of subjects. Results:The BMD increased at all sites in the group receiving calcium, 1200 mg/d, by 1% to 1.5% more than those receiving placebo. The results for the group receiving calcium, 600 mg/d, were not different from the placebo group at any BMD site. There was no interaction between the BMD treatment effect and either age or dietary calcium intake.

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Randomized Controlled Trial of Calcium in Healthy Older Women

Cited by 248 publications

References 14 publications

Relationships between vascular calcification, calcium metabolism, bone density, and fractures

Relationships between vascular calcification, calcium metabolism, bone density, and fractures

Calcium Supplements Increase Risk of Myocardial Infarction

Randomized Controlled Trial of Calcium Supplementation in Healthy, Nonosteoporotic, Older Men

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