Umesawa Mitsumasa, Iso Hiroyasu, Ishihara Junko, Saito Isao, Kokubo Yoshihiro, Inoue Manami, Tsugane Shoichiro
Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
Stroke. 2008 Sep;39(9):2449-56. doi: 10.1161/STROKEAHA.107.512236. Epub 2008 Jul 17.
Although it has been hypothesized that a high intake of dietary calcium may reduce the risk of cardiovascular disease (CVD), no prospective studies have been conducted to examine the specific association between calcium intake and incidence of stroke or coronary heart disease among Japanese with a low average calcium intake.
To investigate the association between calcium intake and risk of CVD, a total of 41 526 Japanese men and women age 40 to 59 years without a history of CVD or cancer and who had completed a food consumption frequency questionnaire were enrolled in this study. The subjects were followed up from 1990 to 1992 to 2003, and after 533 692 person-years of follow-up, 1321 incident cases of stroke (664 ischemic, 425 intraparenchymal hemorrhage, and 217 subarachnoid hemorrhage) and 322 of coronary heart disease were documented.
Total calcium intake showed an inverse association with the risk of total stroke; the multivariable hazard ratio and 95% CIs for the highest versus the lowest quintile were 0.70 (95% CI, 0.56 to 0.88; P for trend=0.02). Dairy calcium intake was inversely associated with risks of total and ischemic stroke with respective multivariable hazard ratios (95% CIs) of 0.69 (0.56 to 0.85; P for trend=0.007) and 0.69 (0.52 to 0.93; P for trend=0.05). Dietary calcium intake was not significantly associated with risk of coronary heart disease.
Dietary calcium intake, especially calcium from dairy products, was found to be associated with a reduced incidence of stroke among middle-aged Japanese.
尽管有假说认为高膳食钙摄入量可能降低心血管疾病（CVD）风险，但尚未有前瞻性研究考察平均钙摄入量较低的日本人中钙摄入量与中风或冠心病发病率之间的具体关联。
为研究钙摄入量与CVD风险之间的关联，本研究纳入了41526名年龄在40至59岁之间、无CVD或癌症病史且完成了食物消费频率问卷调查的日本男性和女性。对这些受试者从1990年至1992年随访至2003年，经过533692人年的随访后，记录了1321例中风事件（664例缺血性中风、425例脑实质内出血和217例蛛网膜下腔出血）以及322例冠心病事件。
总钙摄入量与总中风风险呈负相关；最高五分位数与最低五分位数相比的多变量风险比及95%置信区间为0.70（95%置信区间，0.56至0.88；趋势P值=0.02）。乳制品钙摄入量与总中风和缺血性中风风险呈负相关，多变量风险比（95%置信区间）分别为0.69（0.56至0.85；趋势P值=0.007）和0.69（0.52至0.93；趋势P值=0.05）。膳食钙摄入量与冠心病风险无显著关联。
发现膳食钙摄入量，尤其是来自乳制品的钙，与中年日本人中风发病率降低有关。
