Nav: Home

Higher iron levels are associated with an increased risk of gestational diabetes in pregnant women, raising questions about iron supplementation recommendations

November 10, 2016

New research published in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]) shows that high levels of iron biomarkers in the body are associated with an increased risk of gestational diabetes (GDM) in pregnant women, raising questions about routine recommendations on iron supplementation in pregnancy. The study is by Dr Cuilin Zhang and Dr Shristi Rawal, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), US National Institutes of Health (NIH), Bethesda, MD, USA and colleagues.

Iron is regarded as a double-edged sword in living systems, as both iron deficiency andexcess can be harmful. Pregnant women are particularly vulnerable to iron deficiency and related adverse pregnancy outcomes. While a few guidelines, including those from the American Congress of Obstetricians and Gynecologists, recommend screening and treatment only as necessary for iron deficiency, several other groups such as the World Health Organization (WHO) and the Centers for Disease Control and Prevention recommend routine iron supplementation among pregnant women. Emerging evidence has pointed to a possible link between higher iron stores and abnormal blood sugar control (including type 2 diabetes) in non-pregnant individuals.

In this new research, the authors did a case-control study of 107 GDM cases and 214 controls (matched on age, race/ethnicity, and gestational week of blood collection) within the prospective, multiracial NICHD Fetal Growth Studies-Singleton Cohort (2009-2013). The authors looked at several biomarkers of iron status, including plasma hepcidin, ferritin, and soluble transferrin receptor (sTfR), and these data were used to calculate the sTfR:ferritin ratio, which captures both cellular iron need and availability of body iron stores. These markers were longitudinally measured or calculated four times during pregnancy, twice before GDM diagnosis (gestational weeks 10-14 and 15-26), and twice afterwards (gestational weeks 23-31 and 33-39). GDM diagnosis was ascertained from medical records based on oral glucose tolerance test results. Statistical modelling was then used to calculate the odds ratio of GDM with iron status, accounting for factors such as demographics, pre-pregnancy body mass index (BMI), and other major risk factors.

The authors found that for both hepcidin and ferritin, in the second trimester of pregnancy, those in the top 25% of levels of these markers had around a 2.5 times increased subsequent risk of developing GDM compared with those in the bottom 25%. Similar findings were observed for ferritin levels in the first trimester.

Describing the findings as biologically plausible, the authors offer various potential explanations. Iron may play a role in the development of GDM through several potential mechanisms. As a strong pro-oxidant, free iron can promote several cellular reactions that generate reactive oxygen species and increase the level of oxidative stress. Oxidative stress induced from excess iron accumulation can cause damage to and death of pancreatic beta cells which produce insulin, and consequently, contribute to impaired insulin synthesis and secretion. In the liver, high iron stores may induce insulin resistance via impaired insulin signalling as well as by limiting the capacity of the liver to extract insulin.

The authors conclude: "In summary, findings from this longitudinal and prospective study among multiracial, relatively healthy pregnant women without major pre-pregnancy chronic diseases, suggest that higher maternal iron stores may play a role in the development of GDM starting as early as the first trimester. These findings are of clinical and public health importance as they extend the observation of an association between high body iron stores and elevated risk of glucose intolerance among non-pregnant individuals to pregnancy, and raise potential concerns about the recommendation of routine iron supplementation among pregnant women who already have sufficient iron."
-end-


Diabetologia

Related Diabetes Articles:

Maternal gestational diabetes linked to diabetes in children
Children and youth of mothers who had gestational diabetes during pregnancy are at increased risk of diabetes themselves, according to new research published in CMAJ (Canadian Medical Association Journal).
Two diabetes medications don't slow progression of type 2 diabetes in youth
In youth with impaired glucose tolerance or recent-onset type 2 diabetes, neither initial treatment with long-acting insulin followed by the drug metformin, nor metformin alone preserved the body's ability to make insulin, according to results published online June 25 in Diabetes Care.
People with diabetes visit the dentist less frequently despite link between diabetes, oral health
Adults with diabetes are less likely to visit the dentist than people with prediabetes or without diabetes, finds a new study led by researchers at NYU Rory Meyers College of Nursing and East Carolina University's Brody School of Medicine.
Diabetes, but not diabetes drug, linked to poor pregnancy outcomes
New research indicates that pregnant women with pre-gestational diabetes who take metformin are at a higher risk for adverse pregnancy outcomes -- such as major birth defects and pregnancy loss -- than the general population, but their increased risk is not due to metformin but diabetes.
New oral diabetes drug shows promise in phase 3 trial for patients with type 1 diabetes
A University of Colorado Anschutz Medical Campus study finds sotagliflozin helps control glucose and reduces the need for insulin in patients with type 1 diabetes.
Can continuous glucose monitoring improve diabetes control in patients with type 1 diabetes who inject insulin
Two studies in the Jan. 24/31 issue of JAMA find that use of a sensor implanted under the skin that continuously monitors glucose levels resulted in improved levels in patients with type 1 diabetes who inject insulin multiple times a day, compared to conventional treatment.
Complications of type 2 diabetes affect quality of life, care can lead to diabetes burnout
T2D Lifestyle, a national survey by Health Union of more than 400 individuals experiencing type 2 diabetes (T2D), reveals that patients not only struggle with commonly understood complications, but also numerous lesser known ones that people do not associate with diabetes.
A better way to predict diabetes
An international team of researchers has discovered a simple, accurate new way to predict which women with gestational diabetes will develop type 2 diabetes after delivery.
The Lancet Diabetes & Endocrinology: Older Americans with diabetes living longer without disability, US study shows
Older Americans with diabetes born in the 1940s are living longer and with less disability performing day to day tasks than those born 10 years earlier, according to new research published in The Lancet Diabetes & Endocrinology journal.
Reverse your diabetes -- and you can stay diabetes-free long-term
A new study from Newcastle University, UK, has shown that people who reverse their diabetes and then keep their weight down remain free of diabetes.
More Diabetes News and Diabetes Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#540 Specialize? Or Generalize?
Ever been called a "jack of all trades, master of none"? The world loves to elevate specialists, people who drill deep into a single topic. Those people are great. But there's a place for generalists too, argues David Epstein. Jacks of all trades are often more successful than specialists. And he's got science to back it up. We talk with Epstein about his latest book, "Range: Why Generalists Triumph in a Specialized World".
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.