Maternal Exercise and Infant Skeletal Muscle

The American Heart Association suggests that heart disease prevention should target pregnancy and the first year of life; however, there is a fundamental gap in knowledge regarding the effects of prenatal exercise on the prevention of heart disease.[1, 2] Insulin resistance in skeletal muscle is believed to be a critical contributor to the metabolic syndrome which increases the risk for cardiovascular disease (CVD). Conversely, exercise improves insulin sensitivity and many other facets of skeletal muscle function and metabolism; however, it is unclear if this positive effect can be "imprinted" in the skeletal muscle of the fetus with maternal exercise and accordingly diminish CVD risk in offspring. Our previous studies found that exercise during pregnancy leads to improved heart measures and reduced adiposity.[3-6] These studies demonstrated the potential for maternal exercise to reduce risk for CVD, but the cellular mechanisms involved, however, are not clearly evident. The proposed project will fill this critical gap and assess the influence of maternal exercise intervention to "imprint" progenitor stem cells in the fetus (umbilical cord tissue) to develop into insulin sensitive skeletal muscle and also improve indices of infant morphometry and movement. Using a randomized design, 160 women will perform either exercise intervention (aerobic training, resistance training, or both) or usual care (controls). Infant cord tissue and blood will be sampled at birth while blood will be sampled at 1 month of age. Similarly, infant neuromotor and morphometric examinations will be performed at 1 month. and at 1-month of age via blood sample, neuromotor, and morphometric examinations. The rationale for the project is to elucidate the effects of maternal exercise on offspring health outcomes and determine specific metabolic targets predictive of offspring long-term disease risk. The investigators will test the central hypothesis that exercise during pregnancy alters skeletal muscle in a manner which decreases the risk of heart disease in offspring. To test this central hypothesis, the investigators will pursue two specific aims: Aim 1- Determine the ability of regular maternal exercise to imprint key myocellular metabolic (insulin sensitivity) properties of offspring mesenchymal stem cells (MSC), neuromotor function, and morphometry. Aim 2- Determine the distinct abilities of regular maternal exercise to imprint the metabolome of offspring MSC.