Epidemiology Branch, Division of Epidemiology, Statistics and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA.
Diabetes Care. 2011 Jul;34(7):1557-63. doi: 10.2337/dc11-0134.
It is important to identify modifiable factors that may lower gestational diabetes mellitus (GDM) risk. Dietary iron is of particular interest given that iron is a strong prooxidant, and high body iron levels can damage pancreatic β-cell function and impair glucose metabolism. The current study is to determine if prepregnancy dietary and supplemental iron intakes are associated with the risk of GDM.
A prospective study was conducted among 13,475 women who reported a singleton pregnancy between 1991 and 2001 in the Nurses' Health Study II. A total of 867 incident GDM cases were reported. Pooled logistic regression was used to estimate the relative risk (RR) of GDM by quintiles of iron intake controlling for dietary and nondietary risk factors.
Dietary heme iron intake was positively and significantly associated with GDM risk. After adjusting for age, BMI, and other risk factors, RRs (95% CIs) across increasing quintiles of heme iron were 1.0 (reference), 1.11 (0.87-1.43), 1.31 (1.03-1.68), 1.51 (1.17-1.93), and 1.58 (1.21-2.08), respectively (P for linear trend 0.0001). The multivariate adjusted RR for GDM associated with every 0.5-mg per day of increase in intake was 1.22 (1.10-1.36). No significant associations were observed between total dietary, nonheme, or supplemental iron intake and GDM risk.
These findings suggest that higher prepregnancy intake of dietary heme iron is associated with an increased GDM risk.
确定可能降低妊娠糖尿病（GDM）风险的可改变因素非常重要。鉴于铁是一种很强的促氧化剂，体内铁含量高会损害胰岛β细胞功能并损害葡萄糖代谢，因此膳食铁尤其值得关注。本研究旨在确定孕前膳食和补充铁摄入量是否与 GDM 风险相关。
1991 年至 2001 年期间，护士健康研究 II 中报告了单胎妊娠的 13475 名女性参与了一项前瞻性研究。共报告了 867 例 GDM 病例。采用汇总逻辑回归模型，在控制饮食和非饮食危险因素的情况下，按铁摄入量五分位数估计 GDM 的相对风险（RR）。
膳食血红素铁摄入量与 GDM 风险呈正相关且有统计学意义。在调整年龄、BMI 和其他危险因素后，血红素铁摄入量五分位数递增的 RR（95%CI）分别为 1.0（参考）、1.11（0.87-1.43）、1.31（1.03-1.68）、1.51（1.17-1.93）和 1.58（1.21-2.08）（P 趋势=0.0001）。与每日摄入增加 0.5mg 相关的 GDM 多变量校正 RR 为 1.22（1.10-1.36）。总膳食、非血红素或补充铁摄入量与 GDM 风险之间无显著关联。
这些发现表明，孕前膳食血红素铁摄入量较高与 GDM 风险增加有关。
