CUHK’s nearly 20-year studies highlight long-term risks of gestational diabetes and elevated glucose during pregnancy
In three studies published recently by The Chinese University of Hong Kong (CUHK)’s Faculty of Medicine (CU Medicine), researchers have provided important new insights on the long-term impact of maternal hyperglycaemia on mothers and offspring.
In almost 20 years of follow-up on over 500 mother-child pairs, CUHK researchers found that children born to mothers with gestational diabetes mellitus (GDM) face increased risks of abnormal glucose and obesity in early adulthood. Maternal hyperglycaemia was linked to a 50% higher risk of being overweight. When the mother was also overweight, the effect was amplified. The team also identified DNA methylation markers that could explain these long-term effects. These findings underscore the lasting impact of maternal metabolic health on offspring and highlight the importance of early intervention and follow-up care.
CU Medicine’s 20-year follow-up on over 500 mother-child pairs has provided important new insights into the long-term impact of maternal hyperglycaemia on mothers and offspring. The research team has also identified DNA methylation markers that could explain these long-term effects.
Research team members include (from left) Professor Ronald Wang Chi-chiu in the Department of Obstetrics and Gynaecology; Professor Ronald MaChing-wan, S.H. Ho Professor of Diabetes and Head of the Division of Endocrinology and Diabetes (Academic Affairs) in the Department of Medicine and Therapeutics; and Dr Tam Wing-hung, Clinical Professor (Honorary) from the Department of Obstetrics and Gynaecology at CU Medicine.
One in six pregnancies comes with elevated blood sugar levels
Hyperglycaemia in pregnancy describes pregnancies complicated by abnormally high blood glucose levels. About 80% of cases of hyperglycaemia in pregnancy are due to GDM, a form of transient hyperglycaemia precipitated by the state of pregnancy, complicating approximately one out of every six pregnancies in Hong Kong. While mothers with gestational diabetes are well known to be at about seven to 10 times higher risk of diabetes later in life, the long-term impact on their children has been less clear.
GDM has persistent effects on the metabolic health of offspring into early adulthood
In a study that followed 506 mother-child pairs from birth up to early adulthood, the researchers noted that children born to mothers with gestational diabetes have a higher frequency of abnormal glucose levels in early adulthood. The researchers noted the close relationship between glucose levels during pregnancy and the later risk of abnormal glucose in the offspring during early adulthood, and that this relationship extends beyond just mothers with a diagnosis of GDM. Furthermore, high maternal glucose levels during pregnancy were associated with a 50% increased risk of the offspring being overweight or obese as a young adult, highlighting the link between maternal condition and the long-term metabolic health of their children. The findings have been published in the international journal Diabetologia.
In the same issue of Diabetologia, the research team also reported that gestational diabetes and excessive maternal weight can have additive effects and contribute to the risk of childhood obesity. They evaluated the amount of body fat in children from birth to age seven and then ages 11-14, and noted that children born to mothers who both had gestational diabetes and were overweight during pregnancy were seven times more likely to have increased body fat accumulation during childhood, compared to children born to mothers with neither metabolic problem. The study highlights the potential adverse long-term effects of maternal over-nutrition on the future development of those mothers’ offspring.
Dr Tam Wing-hung, Clinical Professor (Honorary) from the Department of Obstetrics and Gynaecology at CU Medicine, said: “When we first embarked on the follow-up study of children born to mothers with gestational diabetes more than 10 years ago, we did not have much idea what the long-term consequences of gestational diabetes would be. Over the last two decades, we have discovered that GDM is associated with an increased risk of childhood obesity and abnormal glucose levels. However, we were surprised in this study to observe that after 18 years, we could still observe this link between maternal glycaemia and the children’s metabolic status, highlighting the powerful and potentially long-lasting effect of maternal hyperglycaemia.”
DNA methylation markers in cord blood found to be potential biomarkers that could predict future metabolic risk in offspring
Professor Ronald Wang Chi-chiu in the Department of Obstetrics and Gynaecology at CU Medicine, said: “The Hyperglycaemia and Adverse Pregnancy Outcome Study is a unique study and an opportunity to examine the relationship between maternal glucose levels and health in mothers and children. The detailed assessment we have undertaken in this study has allowed us to gain new insights into the impact of abnormal glucose during pregnancy on long-term health. The mechanisms whereby exposure to abnormal glucose during pregnancy for several months can be linked to persistent effects are of much interest and warrant further study to identify potential biological mechanisms.”
To dissect the biological mechanisms linking maternal hyperglycaemia with metabolic health in those mothers’ offspring, the research team collaborated with researchers from the Baker Heart and Diabetes Institute in Melbourne, Australia to identify several new methylation markers as a potential link between elevated glucose in pregnancy and the risk of glucose abnormalities and beta-cell function in offspring. These DNA methylation markers in cord blood show promise as potential biomarkers and an underlying mechanism to predict and explain future metabolic risk in offspring. These findings have been published in the international journal Diabetes.
Professor Ronald Ma Ching-wan, S.H. Ho Professor of Diabetes and Head of the Division of Endocrinology and Diabetes (Academic Affairs) in the Department of Medicine and Therapeutics at CU Medicine, remarked: “Gestational diabetes is a very common problem now, complicating approximately one out of every six pregnancies. Work from our project has provided important new insights into the long-term effects of gestational diabetes and elevated glucose during pregnancy. We are pleased to have identified better ways to predict this risk and would like to take this opportunity to thank all the mothers and their children who took part in our study spanning almost two decades. Our work highlights that the effects of GDM do not disappear after pregnancy and emphasises the importance of follow-up for mothers with GDM and their babies to promote healthy habits before, during and after pregnancy, and reduce risk of diabetes and obesity in the future.”
The research team, through support from the Area of Excellence Scheme of the Research Grants Council (RGC) of Hong Kong, has launched a new initiative to improve the health of mothers with gestational diabetes and their children. Further details can be obtained from the research team’s hotline +852 6743 9107 (WhatsApp only).
The works were supported by grants from the RGC’s General Research Fund. The team also acknowledges support from the RGC’s University Grants Matching Scheme and the Hong Kong PhD Fellowship Scheme.
Ms. Tse (left) and Ms. Pang (middle) participated in the CU Medicine follow-up study and both were diagnosed with gestational diabetes during pregnancy. They were found to have a lasting impact on metabolic health, including high cholesterol and elevated blood sugar levels, nearly 20 years after giving birth. They say that upon learning about the long-term impact of maternal hyperglycaemia on their offspring, they have been extra cautious about their children’s diet and sugar intake, also to remind them of the importance of regular exercise in lowering metabolic health risks.
