Relationship between calcium supplements and cardiovascular disease

Acute effect of calcium supplementation on arterial stiffness and endothelial function in healthy volunteers aged 50 years and over

Status

Completed

Phases

Phase 4

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12612000232831

Enrollment

Registered

2012-02-23

Start date

2011-05-17

Completion date

2012-04-23

Last updated

2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Calcium supplements increase bone density and are frequently prescribed to patients with osteoporosis. However, it is not certain whether they reduce the risk of fracture. A recent study from Auckland, New Zealand raised the possibility that calcium supplements might increase the risk of a heart attack (1). Therefore the medical community is reassessing the pros and cons of taking calcium supplements. After taking calcium tablets, the concentration of calcium in blood increases slightly for a few hours. The flow of calcium from blood into the muscle cells that line blood vessels causes them to contract. We hypothesize that the increase in blood calcium after taking calcium tablets makes the blood vessels contract and become stiffer, putting pressure on the heart. This study will assess the stiffness of blood vessels in 20 subjects before and after a single dose of calcium. We hope to determine whether arterial stiffening is a mechanism that could explain a relationship between calcium supplements and an increased risk of heart disease. Reference 1. Bolland MJ, Barber PA, Doughty RN et al. BMJ 2008; 336:262-266

Interventions

Subjects will be studied immediately before (i.e on the same day) and 3 hours after 1000 mg calcium citrate orally (one dose)

Study design

Allocation

Non-randomised trial

Intervention model

Single group

Primary purpose

Diagnosis

Masking

Open (masking not used)

Eligibility

Sex/Gender

All

Age

50 Years to 100 Years

Healthy volunteers

Yes

Inclusion criteria

Age > 50 years

Exclusion criteria

Taking calcium or vitamin D (>300 IU/day) in the last 3 months Taking proton pump inhibitors in last 3 months Taking calcium channel blockers in the last 3 months Primary hyperparathyroidism Diabetes mellitus Atrial fibrillation Raynaud’s phenomenon

Outcome results