Association of Red Meat Usual Intake with Serum Ferritin and the Risk of Metabolic Syndrome in Chinese Adults: A Longitudinal Study from the China Health and Nutrition Survey

Objective The present study aimed to investigate the association of red meat usual intake with metabolic syndrome (MetS), and explore the contribution of red meat usual intake to serum ferritin. Methods Based on the data from the longitudinal China Health and Nutrition Survey (CHNS), 2,797 healthy adults aged 18-75 years without hypertension, diabetes, and MetS were selected in 2009 as subjects and follow-up studies were carried out till 2015. We used the National Cancer Institute (NCI) method to estimate the usual intake of foods. Multivariable logistic regressions were performed to evaluate the association between red meat usual intake and the risk of MetS. Quantile regression analysis was used to study the relationship between red meat consumption and serum ferritin levels. Results After adjusting for potential confounders, red meat, and fresh red meat were positively associated with the risk of MetS (RR = 1.41, 95% CI: 1.05-1.90 and RR = 1.37, 95% CI: 1.02-1.85, respectively). These relationships showed increasing trend (P < 0.05). The level of serum ferritin increased significantly with the number of MetS components (P < 0.05). The quantile regression analysis showed that red meat and fresh red meat usual intake had a significant positive association with serum ferritin levels across the entire conditional serum ferritin distribution (P < 0.05). Processed red meat did not exhibit a similar association. Conclusion Higher red meat usual intake was associated with an increased risk of MetS and elevated serum ferritin levels.