Transcript Calcium/Vitamin D-related CV Events

Calcium/Vitamin D-related CV Events
Based on Poster 1163
“Risk of Cardiovascular Events with Calcium/Vitamin D –
a Re-Analysis of the Women’s Health Initiative”
Mark Bolland, Andrew Grey, Gregory Gamble, Ian Reid
Monday, October 18, 2010
ASBMR 2010
Toronto, Ontario
Background
• A consistent pattern of increased myocardial infarction (MI) risk from calcium
supplementation vs. placebo was demonstrated in a meta-analysis of 11,900
subjects (Bolland et al. IOF 2010, Abstract OC25)
• Reid et al. re-analyzed the interaction between BMI and the calcium/vitamin D
intervention in the Women’s Health Initiative (WHI)
• As part of the WHI, postmenopausal women received 1 g calcium plus
400 IU vitamin D or placebo and were followed for 7 years
• At baseline, 54% (20,000) of the cohort were already taking personal calcium
supplements and approximately 16,000 women were not
• For non-obese women (BMI<30 kg/m2) randomized to calcium/vitamin D,
there was a significant increased risk for:
– A revascularization procedure (28%)
– Total MI, coronary heart disease, death and revascularization (24%)
Results
• In women not taking personal calcium supplements at baseline, a significant
increase in MI and combined stroke/MI was observed
• In women taking personal calcium supplements at baseline, there was no evidence
of altered cardiovascular disease (CVD) events
• The addition of vitamin D therefore did not abrogate the effect of calcium on CVD
end points except in obese women
Other Studies on Calcium/Vitamin D
and Vascular Events
• In a meta-analysis of 3 such studies, the HR was similar to that identified in the
WHI where the combination of calcium/vitamin D increased the risk of MI by
21% and stroke by 20%
• Given the similarity of the CVD risk between calcium alone and calcium + vitamin D,
it is reasonable to hypothesize that the addition of vitamin D to calcium does not
make a substantive difference to CVD risk
Meta-analysis of Calcium ± Vitamin D Effect on Stroke
Based on the meta-analysis, a 15% increase in the combination of MI and stroke is associated with
calcium supplementation with or without vitamin D
Summary
According to these data, if 1000 people were treated with calcium for 5 years
(± Vitamin D), this would result in an estimated increase of:
MIs = 4x
Stroke = 4x
Deaths = 2x
At the same time, 3 fractures would be prevented.
Findings suggest that reassessment of the role of calcium supplementation
± vitamin D in osteoporosis prevention and treatment is warranted