(P01-047-20) Dietary Iron Intake and Incident Type 2 Diabetes in Chinese Middle-Aged and Elderly Population: A Prospective Cohort Study

Objectives: Excessive dietary iron intake may lead to iron overload and further induce pancreatic islet damage to increase risk of diabetes, which has a higher prevalence in middle-aged and elderly population. We aimed to explore the association between dietary iron intake and incident type 2 diabetes (T2D) in Chinese middle-aged and elderly population.

Methods: This study was based on the Guangzhou Nutrition and Health Study (GNHS), an on-going, community-based prospective cohort study that recruited participants aged 40-75 years from 2008. All participants were followed up every three years. 2765 participants free of diabetes were included in data analysis. Dietary iron intake was obtained by a validated food-frequency questionnaire at baseline. T2D was ascertained by self-reported diabetes medications, fasting glucose ≥7.0 mmol/L or glycosylated hemoglobin ≥6.5%. Cox proportional hazards models were used to estimate HRs and 95%CIs.

Results: We ascertained 209 incident diabetes cases during 13634 person-years of observation. The mean ± SD intakes of dietary total iron, heme iron and nonheme iron among all participants were 20.40 ± 2.73 mg/d, 1.26 ± 0.62 mg/d and 19.14 ± 2.66mg/d, respectively. The multivariate-adjusted HR and 95%CI for T2D for the highest quartile of heme iron intake compared with the lowest quartile was 2.11 (95%CI: 1.14-3.89, P-trend =0.014). However, the association between total iron intake or a nonheme iron intake with T2D risk was no significant difference. The adjusted HR for T2D risk was 1.79 (95%CI:1.05-3.08, P-trend =0.037) for heme iron intake from red meat, while no association was found for heme iron intake from poultry or fish.

Conclusions: Greater intake of heme iron, especially heme iron from red meat, was associated with higher risk of incident T2D in Chinese middle-aged and elderly population, while intakes of total iron and nonheme were not related to diabetes. Controlling heme iron intake, especially red meat intake, may be a target to prevent T2D in middle-aged and elderly population.

Funding Sources: The National Science Foundation of China; the National Science Foundation of Guangdong Province, China