Acute Exercise Effects in Obese Pregnancy

Maternal obesity prevalence is at a historic high with over 1 in 3 women entering pregnancy
obese and 1 in 10 extremely obese. Obesity before and during pregnancy is associated with a
higher risk for a number of obstetric and metabolic complications in women and their
offspring. Of particular importance, obese women have a higher risk of developing gestational
diabetes and preeclampsia. In addition, obese women have larger offspring who have a higher
risk for the development of obesity and diabetes; both largely attributed to higher maternal
glycemia and glucose intolerance during pregnancy. Thus, identifying rehabilitative
interventions that improve maternal and offspring metabolic and cardiovascular health in
obese pregnancy are critical and have immediate and generational impact.

Resistance and aerobic exercise training is a clinical staple for improving musculoskeletal,
metabolic and cardiovascular health in non-gravid adolescents and adults with obesity.
Observational studies suggest that exercise in pregnancy is safe and higher levels of
physical activity before and during pregnancy in normal weight (i.e. lean) women reduces the
risk of gestational diabetes and gestational hypertensive disorders; however, little is known
regarding the effects of exercise training during obese pregnancy and several important
questions still exist. These include: 1) "What are the acute and chronic effects of maternal
exercise on glucose metabolism and vascular function?", 2) "Are there different effects of
aerobic and resistance type exercise on glucose metabolism and vascular function?" and 3)
"What are the physiologic and molecular transducers of maternal aerobic and resistance
exercise for changes in maternal glucose metabolism and vascular function during pregnancy?"
This pilot project aims to collect preliminary data on these questions.

This proposal would be the first study to collect preliminary data on the independent effects
of acute aerobic and resistance rehabilitative exercise in pregnancy, and further, in obese
women; a population with a high morbidity during gestation. In addition, this proposal would
inform a large, multisite clinical trial examining the acute and chronic effects of aerobic
and resistance exercise on glucose metabolism and vascular function in normal weight,
overweight and obese women during pregnancy. Moreover, this proposal would provide initial
evidence of molecular transducers of acute physical activity/rehabilitative exercise
necessary for a large, comprehensive clinical trial examining the molecular transducers of
rehabilitative exercise in normal weight, overweight and obese women during different stages
of pregnancy.

Specific Aim #1: To characterize the acute effects of aerobic and resistance exercise on
glucose metabolism (tolerance, insulin sensitivity and β-cell function) in obese women during
mid-pregnancy.

Specific Aim #2: To characterize the acute effects of aerobic and resistance exercise on
vascular function in obese women during mid-pregnancy.

Specific Aim #3: To explore the molecular transducers of physiologic responses in glucose
metabolism and vascular function following acute aerobic and resistance exercise in obese
women during mid-pregnancy.

The hypothesis is that acute aerobic and resistance rehabilitative exercise will improve
post-exercise glucose metabolism and vascular function in obese women during mid-pregnancy.
In a subsequent multi-site clinical trial, this study will examine differences in physiologic
effects and molecular transducers of aerobic and resistance exercise on glucose metabolism
and vascular function during different stages of pregnancy in overweight and obese women.

Inclusion Criteria:

1. First trimester BMI ≥ 30.0 and <45.0 kg/m2 (calculated from clinical weight and
height)

2. Singleton gestation, between 23 weeks and 0/7 days and 28 weeks and 0/7 days

3. Normal fetal anatomy (no major structural abnormalities identified on standard of care
survey before enrollment)

4. Established prenatal care at Women's Health Clinic before 18 weeks of gestation, plans
to deliver at Barnes-Jewish Hospital

5. Permission from Obstetrics physician provider to participate in study.

Exclusion Criteria:

1. Gestational or pre-gestational diabetes diagnosis

2. Inability to provide voluntary consent

3. Currently using illegal drugs (e.g., cocaine, methamphetamine, opiates) (safety risk
and potential confounding)

4. Current smoker who does not agree to stop (confounding)

5. Participation in routine (>1x/week) exercise program (may improve glucose
metabolism/vascular function)

6. History of heart disease, orthopedic, metabolic or neurological condition that would
contraindicate exercise (safety risk)