To investigate and quantify the potential dose-response association between egg consumption and risk of coronary heart disease and stroke.
Dose-response meta-analysis of prospective cohort studies.
PubMed and Embase prior to June 2012 and references of relevant original papers and review articles.
Eligibility criteria for selecting studies
Prospective cohort studies with relative risks and 95% confidence intervals of coronary heart disease or stroke for three or more categories of egg consumption.
Eight articles with 17 reports (nine for coronary heart disease, eight for stroke) were eligible for inclusion in the meta-analysis (3 081 269 person years and 5847 incident cases for coronary heart disease, and 4 148 095 person years and 7579 incident cases for stroke). No evidence of a curve linear association was seen between egg consumption and risk of coronary heart disease or stroke (P=0.67 and P=0.27 for non-linearity, respectively). The summary relative risk of coronary heart disease for an increase of one egg consumed per day was 0.99 (95% confidence interval 0.85 to 1.15; P=0.88 for linear trend) without heterogeneity among studies (P=0.97, I2=0%). For stroke, the combined relative risk for an increase of one egg consumed per day was 0.91 (0.81 to 1.02; P=0.10 for linear trend) without heterogeneity among studies (P=0.46, I2=0%). In a subgroup analysis of diabetic populations, the relative risk of coronary heart disease comparing the highest with the lowest egg consumption was 1.54 (1.14 to 2.09; P=0.01). In addition, people with higher egg consumption had a 25% (0.57 to 0.99; P=0.04) lower risk of developing hemorrhagic stroke.
8篇研究及17项报告（冠心病9项，卒中8项）符合荟萃分析的纳入标准（通过3081269人年的追踪调查有冠心病新发病例5847例，通过4148095人年的追踪调查有卒中新发病例7579例）。没有证据显示鸡蛋摄入量与冠心病或卒中的风险之间存在线性关联（P = 0.67和P = 0.27非线性）。增加至每天摄入一枚鸡蛋，冠心病总的相对危险度为0.99（95％可信区间0.85-1.15，P = 0.88线性趋势），且研究间无异质性（P = 0.97，I2 = 0％）。对于卒中而言，增加至每天一枚鸡蛋，其合并的相对危险度为0.91（0.81-1.02，P = 0.10线性趋势），且各研究之间无异质性（P = 0.46，I2 = 0％）。在糖尿病人群的亚组分析中，最高和最低鸡蛋的摄入量的冠心病的相对危险比为1.54（1.14-2.09，P = 0.01）。此外，鸡蛋摄入量增加与出血性卒中的发病风险降低25%（0.57-0.99，P = 0.04）有关。
Higher consumption of eggs (up to one egg per day) is not associated with increased risk of coronary heart disease or stroke. The increased risk of coronary heart disease among diabetic patients and reduced risk of hemorrhagic stroke associated with higher egg consumption in subgroup analyses warrant further studies.