Am J Clin Nutr：钙摄入并不增加冠脉钙化风险

　　众所周知，充足的钙摄入可保护骨骼，但既往多项研究发现，补充钙有发生血管事件的不良反应。而近期的一项研究并不支持上述结论。该研究发现，高钙摄入不增加冠状动脉钙化风险。但是，修改当前有关钙摄入的推荐证据尚不足。相关论文发表于《美国临床营养学杂志》[Am J Clin Nutr 2012，96（6）:1274]。

　　研究旨在评估钙摄入（饮食摄入和补充剂摄入）与冠脉钙化的关系。该观察性、前瞻性队列研究共纳入了690例女性和588例男性受试者（平均年龄为60岁）。这些受试者分别在1998—2001年间进行门诊诊疗并完成食物—频率调查问卷，且在2002—2005年间进行了计算机体层摄影扫描。

　　结果显示，随着总体钙摄入的增加，年龄校正后的冠脉钙化Agatston评分降低，校正年龄、体质指数（BMI）、吸烟、酒精摄入、应用维生素D补充剂、能量摄入以及女性绝经状态和应用雌激素后，上述关系也不显著。饮食钙和应用钙补充剂的结果相似。

Calcium intake is not associated with increased coronary artery calcification: the Framingham Study

Background: Adequate calcium intake is known to protect the skeleton. However, studies that have reported adverse effects of calcium supplementation on vascular events have raised widespread concern.

Objective: We assessed the association between calcium intake (from diet and supplements) and coronary artery calcification, which is a measure of atherosclerosis that predicts risk of ischemic heart disease independent of other risk factors.

Design: This was an observational, prospective cohort study. Participants included 690 women and 588 men in the Framingham Offspring Study (mean age: 60 y; range: 36–83 y) who attended clinic visits and completed food-frequency questionnaires in 1998–2001 and underwent computed tomography scans 4 y later in 2002–2005.

Results: The mean age-adjusted coronary artery–calcification Agatston score decreased with increasing total calcium intake, and the trend was not significant after adjustment for age, BMI, smoking, alcohol consumption, vitamin D–supplement use, energy intake, and, for women, menopause status and estrogen use. Multivariable-adjusted mean Agatston scores were 2.36, 2.52, 2.16, and 2.39 (P-trend = 0.74) with an increasing quartile of total calcium intake in women and 4.32, 4.39, 4.19, and 4.37 (P-trend = 0.94) in men, respectively. Results were similar for dietary calcium and calcium supplement use.

Conclusions: Our study does not support the hypothesis that high calcium intake increases coronary artery calcification, which is an important measure of atherosclerosis burden. The evidence is not sufficient to modify current recommendations for calcium intake to protect skeletal health with respect to vascular calcification risk.