Association Between Body Iron Stores and Risk of Type 2 Diabetes in the Chinese Population: A Prospective Study

AbstractionAims/hypothesisThe aim of this study was to examine the association between baseline body iron stores factors and incident type 2 diabetes mellitus. We hypothesized that elevated serum ferritin levels have a positive association with the incidence of type 2 diabetes, and soluble transferrin receptor levels and the ratio of soluble transferrin receptor to ferritin have negative associations with new-onset type 2 diabetes. Subjects and methodsA prospective cohort study explored associations between baseline iron stores factors and incident type 2 diabetes in 3198 adults who participated in both the waves of 2009 and 2015 China Health and Nutrition Survey. Three iron stores factors were categorized into quintiles, and the outcome measure was the incident cases of type 2 diabetes. ResultsThe mean baseline serum ferritin level for participants who developed type 2 diabetes during follow-up 6 years was significantly higher than those who did not have the disease. (169.4 ± 205.3 ng/mL vs 124.6 ± 170.0 ng/mL; P-difference<0.001). For multivariate logistic regression analysis, models were adjusted by known risk factors (age, gender, central obesity condition, blood pressure, smoking status, and physical activity); to minimize the effect of inflammation on iron stores factors, models were further adjusted by the inflammation factor (high-sensitivity CRP). After adjustment, the risk ratios (RRs) of incident type 2 diabetes across increasing quintiles of serum ferritin were 1.00, 1.51 (95% CI 0.85-2.67), 1.34 (95% CI 0.75-2.39), 1.70 (95% CI 0.96-3.00), 2.03 (95% CI 1.15-3.58) (P-trend=0.018); the RRs of incident type 2 diabetes across decreasing quintiles of the ratio of soluble transferrin receptor to ferritin were 1.00, 1.10 (95% 0.63-1.94), 1.12 (95% CI 0.64 1.97), 1.86 (95% CI 1.10-3.15), 1.51 (95% CI 0.93-2.78) (P-trend=0.049); there was not a significant association found between soluble transferrin receptor and new-onset type 2 diabetes. ConclusionElevated ferritin levels and a lower ratio of transferrin receptor to ferritin were independently associated with increased incident type 2 diabetes in Chinese populations.Bachelor of Science in Public Healt