Serum calcium concentration and carotid artery plaque: a population-based study.

OBJECTIVE

Serum calcium level may be associated with the morbidity and mortality of cerebrovascular and cardiovascular diseases. However, only a few large-scale population studies have been performed to investigate the association between serum calcium and carotid plaque.

METHODS

A retrospective cross-sectional study was performed on the subjects who underwent general health screening tests including ultrasonographic evaluation of the carotid artery between 1994 and 2000 at our institute. Before the statistical analysis, all serum calcium values were adjusted for the serum albumin concentration.

RESULTS

Of 5,732 subjects enrolled in the present study, 3,785 were male and 1,947 were female, and were aged 22-88 years (median 57 years). Carotid plaque was identified in 1,313 (23%) subjects. Serum calcium concentration was slightly greater in the subjects with plaque than in those without (2.28 +/- 0.8 vs 2.27 +/- 0.7 mmol/l, p < 0.001; unpaired t-test). Multivariate logistic regression analysis including confounding risk factors revealed that serum calcium is an independent positive predictor for carotid plaque with an odds ratio of 1.70 [95% confidence interval (CI): 1.50-1.92] for each increase of 1 mg/dl. Male and female subjects in the highest quartiles of serum calcium concentrations had a greater risk of carotid plaque with odds ratios of 1.52 (95% CI 1.35-1.71, p < 0.01) and 1.57 (95% CI 1.27-1.92, p < 0.05), respectively, compared to the subjects in the lowest quartiles of calcium concentrations.

CONCLUSIONS

These findings indicate that serum calcium is an independent risk factor for carotid plaque.