Prepregnancy Heme Iron Intake Linked to Diabetes Risk
Dose-response relationship between heme iron intake and risk of gestational diabetes mellitus
THURSDAY, July 7 (HealthDay News) -- The intake of dietary heme iron before pregnancy is associated with an increased risk of developing gestational diabetes mellitus (GDM), according to a study published in the July issue of Diabetes Care.
Katherine Bowers, Ph.D., from the Eunice Kennedy Shriver National Institute of Child Health and Human Development in Bethesda, Md., and colleagues investigated the impact of prepregnancy dietary iron intake on GDM in 13,475 U.S. nurses with singleton pregnancies confirmed between 1991 and 2001. A total of 867 cases of incident GDM were identified in the cohort. The relative risk (RR) of incident GDM by quintiles of iron intake for each iron category was assessed using pooled logistic regression, after adjusting for dietary and nondietary risk factors.
The investigators found a significant and positive association between the intake of dietary heme iron and the risk of GDM. The RR of GDM increased significantly across increasing quintiles of heme iron (RR, 1.0, 1.11, 1.31, 1.51, and 1.58, respectively), after adjustment for age, body mass index, and other risk factors. An increase of 0.5-mg per day in intake was associated with an increase of 1.22 in the multivariate RR. There was no significant correlation between total dietary, nonheme, or supplemental iron intake and the risk of GDM.
"These findings suggest that higher prepregnancy intake of dietary heme iron is associated with an increased GDM risk," the authors write.