Department of Epidemiology.
Department of Internal Medicine, Erasmus MC, Rotterdam.
Eur J Cancer Prev. 2021 Sep 1;30(5):364-372. doi: 10.1097/CEJ.0000000000000650.
Previous studies showed that high calcium intake may be associated with the reduced colorectal cancer (CRC) risk, but results were inconclusive. In this study, we evaluated whether calcium intake from diet and supplements, as well as the calcium levels itself, were associated with the CRC risk in middle-aged and older individuals. Also, we evaluated whether these associations were modified by genetic variation of calcium homeostasis.
This study was embedded in the Rotterdam study, a prospective cohort study among adults aged 55 years and older without CRC at baseline, from the Ommoord district of Rotterdam, The Netherlands (N = 10 941). Effect modification by a predefined polygenetic risk score (PRS) from seven loci known to be associated with calcium concentrations, was evaluated.
The incidence rate of CRC in the study population was 2.9 per 1000 person-years. Relative to the recommended dietary calcium intake, only higher than the recommended dietary calcium intake (≥1485 mg/day) was associated with a reduced risk of CRC [hazard ratio (HR), 0.66; 95% confidence interval (CI), 0.44-1.00]. No significant associations were found for calcium supplementation and only in the subgroup analysis, albumin-adjusted calcium levels were associated with an increased risk of CRC (HR = 1.11; 95% CI, 1.00-1.23). PRS showed effect modification in the association between calcium intake and CRC (P for interaction = 0.08). After stratification of PRS into low, intermediate and high, we found a lower CRC risk for low-weighted PRS per increase in calcium intake.
There is no consistent association between calcium indices on CRC. However, the association between calcium intake and CRC may be modified by genetic variation associated with serum calcium concentrations that deserves further replication in other studies with different population.
先前的研究表明，高钙摄入可能与降低结直肠癌（CRC）风险有关，但结果尚无定论。在这项研究中，我们评估了饮食和补充剂中的钙摄入量以及钙水平本身是否与中年及以上人群的 CRC 风险相关。此外，我们还评估了这些关联是否受到钙稳态遗传变异的影响。
本研究嵌入了 Rotterdam 研究，这是一项针对荷兰鹿特丹 Ommoord 区年龄在 55 岁及以上且基线时无 CRC 的成年人的前瞻性队列研究（N=10941）。评估了来自七个与钙浓度相关的已知位点的预先确定的多基因风险评分（PRS）的效应修饰。
研究人群中 CRC 的发病率为 2.9/1000 人年。与推荐的膳食钙摄入量相比，仅高于推荐的膳食钙摄入量（≥1485mg/天）与 CRC 风险降低相关[风险比（HR），0.66；95%置信区间（CI），0.44-1.00]。钙补充剂与 CRC 之间未发现显著关联，仅在亚组分析中，白蛋白校正的钙水平与 CRC 风险增加相关（HR=1.11；95%CI，1.00-1.23）。PRS 显示钙摄入量与 CRC 之间的关联存在效应修饰（P 交互=0.08）。在将 PRS 分层为低、中和高后，我们发现随着钙摄入量的增加，低加权 PRS 与较低的 CRC 风险相关。
钙指数与 CRC 之间没有一致的关联。然而，钙摄入量与 CRC 之间的关联可能受到与血清钙浓度相关的遗传变异的影响，值得在其他具有不同人群的研究中进一步复制。
