A Prospective Study of Plasma Ferritin and Incident Type 2 Diabetes: The Atherosclerosis Risk in Communities (ARIC) Study
Abstract Number: 1008-P
Authors: MEGAN L. JEHN, ELISEO GUALLAR, ZENA L. HARRIS, JAMES PANKOW
Institutions: Baltimore, MD; Minneapolis, MN
Results: Elevated iron stores may contribute to insulin resistance and to the development of type 2 diabetes. The objective of this study was to determine the prospective association between plasma ferritin and risk of incident type 2 diabetes. We conducted a case-cohort study nested within the Atherosclerosis Risk in Communities (ARIC) study, a large community-based cohort study (aged 45-64 years at baseline). Incident cases of type 2 diabetes (n = 599) were compared to a random sample of the cohort (n = 690). Incident type 2 diabetes was assessed every 3 years over 9 years of follow-up. Ferritin was measured in frozen baseline plasma samples. At baseline, geometric mean ferritin levels were significantly higher in cases compared to participants in the cohort random sample (120.9 mg/L vs. 88.5 mg/L; P < 0.001). After adjusting for age, gender, race and study center, BMI, waist circumference, inflammation markers, hypertension, and parental history of diabetes, the relative risk of diabetes comparing the fifth vs. the first quintile of ferritin was 1.82 (95% CI 1.06 - 3.12; P trend 0.007). After further adjustment for fasting glucose and insulin, the relative risk was 0.95 (95% CI 0.51 - 1.78; P-trend 0.47). Ferritin levels were positively associated with the risk of diabetes, however; this association did not persist after adjusting for baseline fasting glucose and insulin levels.