Oral Calcium Not Linked to Higher Coronary Atherosclerosis Risk in RA

SAN DIEGO, CA—Calcium supplementation was not associated with a higher risk of coronary atherosclerosis in a study population of patients with rheumatoid arthritis, and may have relevant therapeutic implications in the daily treatment of rheumatoid arthritis, according to study findings presented at the 2013 ACR/ARHP Annual Meeting.

Calcium supplementation has been recently linked to possible cardiovascular adverse effects. However, the association between calcium intake and subclinical markers of atherosclerosis has not been fully explored in patients with rheumatoid arthritis. Patients with rheumatoid arthritis are already at increased risk for coronary artery disease and cardiovascular mortality.

Shanthi Dhaduvai, MD, from Stony Brook University Hospital & Medical Center, Stony Brook, NY, and study investigators assessed the daily supplemental calcium dose from prescription and over-the-counter (OTC) medications at baseline and at the first follow-up visit (median time 20 months) for 145 patients with rheumatoid arthritis participating in a cohort study of subclinical cardiovascular disease. Participants underwent 64-slice cardiac multi-detector row CT scanning at baseline and at Visit 3 (median time 39 months) to assess coronary artery calcium (CAC), a measure of coronary atherosclerosis.

At baseline, 42 patients (28%) were taking ≥1000mg/day of calcium while the remainder took <1000mg/day.  A CAC score ≥100 units was observed in 44 patients (30%) at baseline and 51 patients (35%) at follow-up.

At baseline, CAC scores of ≥100 were significantly less frequent in the higher vs. lower dose calcium supplementation groups [OR 0.30 (95% CI 0.12-0.78)], and this difference remained significant after adjustment for relevant confounders [OR 0.31 (95% CI 0.10-0.95)]. Similarly, at follow-up, CAC scores of ≥100 were also significantly less frequent in the group taking an average calcium supplement dose of ≥1000mg/day vs. those taking <1000mg/day. However, when adjusted for relevant confounders, study researchers found only a trend to significance [OR 0.40 (95% CI 0.14-1.12)].  

Change in CAC score over time between baseline and follow-up was not statistically significant different between the two calcium groups, noted researchers. “Calcium supplementation was not associated with a higher risk of coronary atherosclerosis in this RA population, and may have been protective, a finding with relevant therapeutic implications in the daily treatment of RA patients,” concluded Dr. Dhaduvai.