Circulating calcium concentrations, vascular disease and mortality: a systematic review

Area of Science:

• Cardiovascular Medicine
• Clinical Biochemistry
• Epidemiology

Background:

• Previous studies suggest a link between serum calcium and vascular disease, but findings are inconsistent.
• The association between circulating calcium concentrations and health risks in normocalcaemic populations requires further investigation.

Purpose of the Study:

• To systematically review and meta-analyze evidence on the association between serum calcium levels and risks of cardiovascular disease and death in normocalcaemic individuals.

Main Methods:

• Systematic literature search of PubMed and reference lists up to December 2014.
• Inclusion of longitudinal studies with at least one-year follow-up, excluding populations with renal disease or abnormal serum calcium.
• Data extraction by two independent investigators, with meta-analysis where possible.

Main Results:

• Meta-analysis of eight studies revealed a hazard ratio of 1.13 (1.09-1.18) for death per standard deviation increase in serum calcium.
• Meta-analysis of eight studies showed a hazard ratio of 1.08 (1.04-1.13) for cardiovascular disease per standard deviation increase in serum calcium.
• Adjusted analyses indicated a pooled hazard ratio of 1.04 (1.01-1.08) for cardiovascular risk factors.

Conclusions:

• Observational data indicate a significant association between serum calcium and increased risks of vascular disease and mortality.
• While causality cannot be determined, these findings highlight serum calcium as a potential marker for vascular risk.