A prospective study of plasma ferritin level and incident diabetes: the Atherosclerosis Risk in Communities (ARIC) Study.
The authors performed a case-cohort study nested within the Atherosclerosis Risk in Communities (ARIC) Study to determine the association between plasma ferritin level and risk of type 2 diabetes mellitus. Persons with incident cases of type 2 diabetes diagnosed over an average follow-up period of 7.9 years (n = 599) were compared with a random sample of the cohort (n = 690). After adjustment for age, gender, menopausal status, ethnicity, center, smoking, and alcohol intake, the hazard ratio for diabetes, comparing the fifth quintile of ferritin with the first quintile, was 1.74 (95% confidence interval: 1.14, 2.65; p-trend < 0.001). After further adjustment for body mass index and components of the metabolic syndrome, the hazard ratio was 0.81 (95% confidence interval: 0.49, 1.34; p-trend = 0.87). From a causal perspective, there are two alternative interpretations of these findings. Elevated iron stores, reflected in elevated plasma ferritin levels, may induce baseline metabolic abnormalities that ultimately result in diabetes. Alternatively, elevated ferritin may be just one of several metabolic abnormalities related to the underlying process that ultimately results in diabetes, rather than a causal factor for diabetes. Longitudinal studies with repeated measurements of glucose and iron metabolism parameters are needed to establish the role of iron stores and plasma ferritin in diabetes development.
Jehn
Megan L
ML
Department of Epidemiology, Welch Center for Prevention, Epidemiology, and Clinical Research, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
Guallar
Eliseo
E
Clark
Jeanne M
JM
Couper
David
D
Duncan
Bruce B
BB
Ballantyne
Christie M
CM
Hoogeveen
Ron C
RC
Harris
Z Leah
ZL
Pankow
James S
JS
D001161:Arteriosclerosis; D015992:Body Mass Index; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D015994:Incidence; D019190:Iron Overload / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
D005293:Ferritins