Exercise in pregnancy improves health of obese mothers by restoring their tissues
August 29, 2019
Science Daily/University of Cambridge
Exercise immediately prior to and during pregnancy restores key tissues in the body, making them better able to manage blood sugar levels and lowering the risk of long term health problems, suggests new research carried out in mice.
Researchers at the University of Cambridge, who led the study published today in the journal Physiological Reports, say the findings reinforce the importance of an active lifestyle when planning pregnancy.
In the UK, more than a half of all women of reproductive age and almost a third of pregnant women are overweight or obese. This is particularly concerning, as being overweight or obese during pregnancy increases the risk of complications in the mother, such as gestational diabetes, and predisposes both her and her infant to develop metabolic diseases such as type 2 diabetes in the years after pregnancy.
Exercise is known to improve how the body manages blood sugar levels and thereby reduce the risk of type-2 diabetes and metabolic syndrome in non-pregnant women. It also has positive effects prior to and during pregnancy, with beneficial outcomes for both mother and her child, preventing excessive gestational weight gain and the development of gestational diabetes, and the need for insulin use in women who have already developed gestational diabetes. However, little is known about the changes that exercise causes to the tissues of obese pregnant mother.
To answer this questions, researchers at the University of Cambridge fed mice a sugary, high fat diet such that they become obese and then the obese mice were exercised. The mice exercised on a treadmill for 20 minutes a day for at least a week before their pregnancy and then for 12.5 minutes a day until day 17 of the pregnancy (pregnancy lasts for around 20 days in mice).
Mice are a useful model for studying human disease as their biology and physiology have a number of important characteristics in common with those of humans, including showing metabolic changes with obesity/obesity-causing diets and in the female body during pregnancy.
The researchers found that the beneficial effects on metabolic health in obese mothers related to changes in how molecules and cells communicate in maternal tissues during pregnancy.
"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," says Dr Amanda Sferruzzi-Perri, a Royal Society Dorothy Hodgkin Research Fellow from the Centre for Trophoblast Research in the Department of Physiology, Development and Neuroscience at the University of Cambridge, who co-led the study.
"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."
The key organs of the mother that were affected by exercise were:
· white adipose tissue -- the fatty tissue that stores lipids and can be found in different parts around the body, including beneath the skin and around internal organs;
· skeletal muscle -- muscle tissue that uses glucose and fats for contraction and movement;
· the liver -- the organ that stores, as well as syntheses lipids and glucose.
Exercise affected key signalling pathways -- the ways that molecules and cells within tissue communicate -- involved in responding to insulin (the hormone that stimulates glucose uptake by white adipose tissue and skeletal muscle), in storage and breakdown of lipids (fats found in the blood and tissue) and in growth and the synthesis of proteins.
White adipose tissue showed the greatest number of changes in response to exercise in the obese pregnant mouse, being restored to a state similar to that seen in the tissue of non-obese mothers. This suggests that insulin resistance of the mother's white adipose tissue may be the cause of poor glucose-insulin handling in obese pregnancies. The findings are different to that seen in non-pregnant animals, whereby exercise typically affects insulin signalling in the skeletal muscle.
In addition, the team's previous work showed that exercise improves sensitivity to insulin and glucose handling throughout the whole body in the obese mother. It also prevents the development of insulin resistance in the offspring of obese mothers after birth. Low insulin sensitivity/insulin resistance requires larger amounts of insulin to control blood glucose 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," says co-lead Professor Susan Ozanne from the Wellcome Trust-Medical Research Council Institute of Metabolic Science at the University of Cambridge.
"This is can be important in helping to reduce the risk of adverse health problems in the mother and of later health problems for her child."
https://www.sciencedaily.com/releases/2019/08/190829214754.htm
Overweight pregnant women can safely cut calories, restrict weight gain
Healthier for mom and baby to control mom's weight gain during pregnancy
September 24, 2018
Science Daily/Northwestern University
With proper nutrition guidance, it is safe and feasible to restrict weight gain in obese and overweight pregnant women, a new study shows.
Being obese or overweight during pregnancy can result in serious health problems for the mother and child. Obstetricians are often reluctant to recommend restricted weight gain for pregnant women due to safety concerns for the baby and lack of time and tools to safely guide women in their weight control efforts.
A new Northwestern Medicine study shows with proper nutrition guidance it is safe and feasible to restrict weight gain in obese and overweight pregnant women. The obese and overweight women in the study gained five pounds less during their pregnancy than those in the control group. Their babies were born in the normal weight range.
The approach included nutritional counseling on a healthy diet and lifestyle as supported by a commercially available smartphone diet app, with ongoing coaching via the phone and online.
"We need to help these women, who make up the majority of pregnancies in the U.S, leverage this unique opportunity during their pregnancy to adopt a healthier diet and lifestyle plan that they can follow throughout pregnancy and, hopefully, post-partum," said lead study author Linda Van Horn, professor of preventive medicine at Northwestern University Feinberg School of Medicine. "These results show promise in harnessing modern technology to help a mom achieve those goals."
The majority of U.S. women of reproductive age are overweight or obese, and the risk of excess gestational weight gain is higher for them than women of healthy weight. Among the risks for women and their babies: diabetes, preeclampsia, hypertension and birth defects.
Van Horn, along with obstetrician colleague Dr. Alan Peaceman, developed and led the study, called MOMFIT (Maternal Offspring Metabolics: Family Intervention Trial). It was part of the Lifestyle Interventions for Expectant Moms (LIFE-Moms) Consortium, a National Institutes of Health (NIH)-supported research project, with each study implementing separate interventions.
The Northwestern study was novel because it concentrated on improving diet quality and healthy lifestyle in the moms using modern tools and focused on potential maternal fetal nutrition advantages that could have lifelong benefits, Van Horn said.
The study will be published Sept. 24 in the American Journal of Preventive Medicine.
This is believed to be the first study of obese and overweight pregnant women using a technologically advanced, commercially available weight-loss smartphone app to test the effects of a specially tailored diet combined with modest physical activity.
Existing commercial weight control technologies target non-pregnant women and don't address prenatal energy and nutrient needs, the authors said. Most commercial apps are designed to support weight loss. During pregnancy, weight gain is anticipated and appropriate, but it should be curtailed in overweight and obese women.
"MOMFIT demonstrates the feasibility of counseling pregnant women in healthy diet and lifestyle behaviors through nutrition coaching using modern technology," Van Horn said. "Applying this approach in a clinical setting could help women achieve recommended weight-gain goals during pregnancy and improve postpartum lifestyle behaviors for the whole family."
One unusual outcome of the trial was a higher rate of cesarean sections for the women in the intervention group. Researchers are investigating possible contributors to this finding.
Will MOMFIT kids have less risk of developing obesity?
"The next big question is whether the children born to moms who restricted their weight gain will have a reduced risk of becoming obese themselves compared to children whose moms were in the control group," Van Horn said.
Children born to overweight and obese moms have more than a 50 percent chance of becoming overweight themselves. If both parents are overweight or obese, this risk can increase to more than 70 percent, according to epidemiological data.
The difference in the children's obesity risk won't be evident until they are three, four and five years old, which is when weight trajectories start to separate. Van Horn and colleagues have recently launched a new study -- KIDFIT -- to monitor the children of the women in her MOMFIT study and determine whether prenatal and/or postpartum diet and lifestyle counseling can help these children lower their risk of obesity.
Rebooting the whole family's diet
The study's goal was not weight loss. "Weight loss during pregnancy is not encouraged. Rather, we aimed for controlled weight gain by developing healthy diet habits and increasing physical activity that could be sustained long term.
"The overarching goal of MOMFIT was to help the mom make these changes while she was still pregnant, a time when many women are more motivated to do what is right for their babies, and then maintain these new behaviors and become a role model for the family and better informed about how to feed them," Van Horn said.
"The perpetuation of obesity is a never-ending cycle. We're attempting to interrupt that cycle and successfully influence the risk for developing pediatric obesity starting in utero and -- with additional follow up -- protect that child from adopting that parental heritage in the family home."
Fewer participants in the intervention group, 68.6 percent versus 85 percent, exceeded the National Academy of Medicine recommendations for pregnancy weight gain for obese and overweight women, which is limited to 11 to 25 pounds compared to 25 to 35 pounds for women of healthy weight. This is important evidence demonstrating the challenges of encouraging pregnant women to adhere to recommended diet and activity levels at a time when emotional-eating and reluctance to exercise tend to increase.
How the study worked
MOMFIT studied 281 ethnically diverse overweight or obese women ages 18 to 45, who were divided into the intervention or control group. Women in the intervention group met with a nutritionist who calculated the appropriate amount of calories for each participant and counseled her on a DASH-type diet -- higher in fruits, vegetables, whole grains, nuts, fish and lean protein. It was modified to the restricted weight gain recommendations for each participant.
The DASH (Diet Approach to Stopping Hypertension) eating pattern is ideally suited to pregnancy, providing a pregnant woman with the calcium, potassium and protein she needs without the salt, sugar and saturated fat that she does not need, Van Horn said.
The women were also encouraged to walk at least 30 minutes or take 10,000 steps per day. The nutrition coach tracked each woman's weight gain, food intake and exercise. Telephone, text message prompts and e-mail reminders encouraged women to adhere to the program.
"It was technologically convenient yet strategic and nutritionally individualized," Van Horn said. "MOMFIT took a precision medicine approach to healthy eating utilizing a commercially available product."
Women tracked their food intake with the Lose It! app. Participants were also encouraged to sleep seven to nine hours daily, because sleep deprivation hampers metabolism and contributes to weight gain.
https://www.sciencedaily.com/releases/2018/09/180924084332.htm