Minghui Han1, Li Guan2, Yongcheng Ren1,3, Yang Zhao1,3, Dechen Liu1,3, Dongdong Zhang4, Leilei Liu1, Feiyan Liu3, Xu Chen1, Cheng Cheng1, Quanman Li1, Chunmei Guo1, Qionggui Zhou3, Gang Tian1, Ranran Qie1, Shengbing Huang1, Xiaoyan Wu3, Yu Liu2, Honghui Li2, Xizhuo Sun2, Ming Zhang3, Dongsheng Hu1, Jie Lu5. 1. Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China. 2. The Affiliated Luohu Hospital of Shenzhen University Health Science Center, Shenzhen, Guangdong, People's Republic of China. 3. Department of Preventive Medicine, Shenzhen University School of Medicine, Shenzhen, Guangdong, People's Republic of China. 4. Department of Nutrition and Food Hygiene, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China. 5. Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China. Email: hanyaa800@zzu.edu.cn.
Abstract
BACKGROUND AND OBJECTIVES: Many studies have investigated the association between dietary iron intake and death due to cardiovascular disease (CVD), but the results were inconsistent. We performed a dose-response meta- analysis to quantitatively assess the risk of CVD mortality with dietary intake of iron (total iron, heme iron, and non-heme iron). METHODS AND STUDY DESIGN: PubMed and Embase databases were searched for articles published up to February 21, 2019. Prospective cohort studies were included if reporting relative risks (RRs) and 95% confidence intervals (CIs) for risk of CVD mortality associated with dietary iron intake. Restricted cubic splines were used to model the dose-response association. RESULTS: We included eight articles (19 studies including 720,427 participants [46,045 deaths due to CVD]) in the meta-analysis. When comparing the highest versus lowest level of dietary heme iron intake, the pooled RR for CVD mortality was 1.19 (95% CI, 1.01-1.39). With a 1-mg/day increase in dietary heme iron intake, the pooled RR for death due to CVD, stroke, coronary heart disease, and myocardial infarction were 1.25 (95% CI, 1.17-1.33), 1.17 (1.04-1.32), 1.25 (0.70-2.22), and 1.17 (0.55-2.50) respectively. The association between dietary iron intake and CVD mortality was linear (pnonlinearity> 0.05). CONCLUSIONS: Higher dietary intake of heme iron was associated with a greater risk of CVD mortality. Reducing consumption of heme iron may help to prevent premature death due to CVD.
BACKGROUND AND OBJECTIVES: Many studies have investigated the association between dietary iron intake and death due to cardiovascular disease (CVD), but the results were inconsistent. We performed a dose-response meta- analysis to quantitatively assess the risk of CVDmortality with dietary intake of iron (total iron, heme iron, and non-heme iron). METHODS AND STUDY DESIGN: PubMed and Embase databases were searched for articles published up to February 21, 2019. Prospective cohort studies were included if reporting relative risks (RRs) and 95% confidence intervals (CIs) for risk of CVDmortality associated with dietary iron intake. Restricted cubic splines were used to model the dose-response association. RESULTS: We included eight articles (19 studies including 720,427 participants [46,045 deaths due to CVD]) in the meta-analysis. When comparing the highest versus lowest level of dietary heme iron intake, the pooled RR for CVDmortality was 1.19 (95% CI, 1.01-1.39). With a 1-mg/day increase in dietary heme iron intake, the pooled RR for death due to CVD, stroke, coronary heart disease, and myocardial infarction were 1.25 (95% CI, 1.17-1.33), 1.17 (1.04-1.32), 1.25 (0.70-2.22), and 1.17 (0.55-2.50) respectively. The association between dietary iron intake and CVDmortality was linear (pnonlinearity> 0.05). CONCLUSIONS: Higher dietary intake of heme iron was associated with a greater risk of CVDmortality. Reducing consumption of heme iron may help to prevent premature death due to CVD.