Researchers at the University of Cambridge have discovered how exercising before and during pregnancy, reduces the risk of long-term health issues for both mother and baby.
In a study of obese pregnant mice, exercise restored key tissues and improved management of blood glucose, thereby reducing the risk of metabolic problems such as type 2 diabetes.
Research fellow Amanda Sferruzzi-Perri and colleagues say the findings reinforce the importance of being active when planning to conceive.
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Obesity affects many women in the UK
In the UK, more than half of women who are of reproductive age and almost one-third of pregnant women are obese or overweight.
Being overweight or obese whilst pregnant increases the risk for maternal metabolic diseases such as gestational diabetes, as well as the risk of the baby developing conditions such as type 2 diabetes in the years following birth.
It is well known that exercise can improve the body’s ability to manage blood glucose and reduce the risk for type 2 diabetes and metabolic syndrome among women who are not pregnant. Exercise is also known to have beneficial health effects prior to and during pregnancy on the health of both mother and baby.
It helps to prevent excessive gestational weight gain and the development of gestational diabetes, as well as reducing the need for insulin use among women who already have gestational diabetes. However, little is known about the changes that exercise causes in the tissues of obese pregnant mothers.
Investigating the benefits of exercise during pregnancy
To investigate the benefits of exercise during pregnancy, researchers fed female mice a sugary, high-fat diet so that they became obese and then exercised them on a treadmill. The mice were exercised for 20 minutes per day for at least one week before they became pregnant and then for 12.5 minutes per day until day 17 of their pregnancy. In mice, pregnancy lasts for around 20 days.
Mice serve as a useful animal model for investigating human disease. Their biology and physiology share important characteristics in common with humans, including the metabolic changes that occur in obesity and obesity-causing diets and the changes seen in the female during pregnancy.
Benefits were related to changes in cell signaling
As reported in the journal Physiological Reports, the team found that metabolic health benefits among the obese mice were related to changes in how cells and molecules communicated in tissues.
A moderate level of exercise immediately before and then during pregnancy leads to important changes in different tissues of the obese mother, effectively making the tissues more like those seen in non-obese mothers.
We believe these changes may explain how exercise improves the metabolism of the obese mother during pregnancy and, in turn, may prevent her babies from developing early signs of type 2 diabetes after birth."
Amanda Sferruzzi-Perri, Senior Author
The main tissues that benefited were the white adipose tissue, the skeletal muscle and the liver. Key signaling pathways that were affected included those involved in the body’s response to insulin, the storage and breakdown of lipids and the synthesis of proteins.
White adipose tissue showed the biggest change
The greatest number of changes occurred in white adipose tissue, which was restored to a similar state to that seen in mothers who are not obese. This suggests that insulin resistance in the white adipose tissue may be the cause of poorly managed insulin and glucose levels in obese pregnancies.
The findings are different from those seen among non-pregnant animals, in which case exercise generally affects insulin signaling in skeletal muscle.
The researchers have also previously shown that exercise increases insulin sensitivity and glucose management throughout the whole body in obese mothers.
In addition, it prevents insulin resistance among the offspring of obese mothers following birth. Low insulin sensitivity and insulin resistance make the body need more insulin to control blood sugar levels.
Our findings reinforce the importance of having an active lifestyle and eating a healthy balanced diet when planning pregnancy and throughout for both the mother and her developing child. This can be important in helping to reduce the risk of adverse health problems in the mother and of later health problems for her child."
Susan Ozanne, Co-Author
The findings also highlight potential metabolic targets for therapeutic intervention, as well as how important a healthy lifestyle is in terms of reducing the burden of the current obesity epidemic on healthcare systems.
Musial, B., et al. (2019). Exercise alters the molecular pathways of insulin signaling and lipid handling in maternal tissues of obese pregnant mice. Physiological Reports. https://physoc.onlinelibrary.wiley.com/doi/full/10.14814/phy2.14202