ObjectiveIn adults, skeletal muscle insulin sensitivity (SI) and fatty acid oxidation (FAO) are linked with a predisposition to obesity. The current study aimed to determine the effects of maternal exercise on a model of infant skeletal muscle tissue (differentiated umbilical cord mesenchymal stem cells [MSCs]) SI and FAO and analyzed for associations with infant body composition.MethodsFemales <16 weeks' gestation were randomized to either 150 min/wk of moderate‐intensity aerobic, resistance, or combination exercise or a nonexercising control. At delivery, MSCs were isolated from umbilical cords and myogenically differentiated, and SI and FAO were measured using radiolabeled substrates. Infant body fat percentage (BF%) and fat‐free mass were calculated using standard equations at 1 and 6 months of age.ResultsMSCs from infants of all exercisers had significantly (p < 0.05) higher SI. MSC SI was inversely associated with infant BF% at 1 (r = −0.38, p < 0.05) and 6 (r = −0.65, p < 0.01) months of age. Infants with high SI had lower BF% at 1 (p = 0.06) and 6 (p < 0.01) months of age. MSCs in the high SI group had higher (p < 0.05) FAO.ConclusionsExposure to any type of exercise in utero improves offspring SI and could reduce adiposity in early infancy.

Type 2 diabetes is more prevalent in African American (AA) than Caucasian (C) adults. Further, differential substrate utilization has been observed between AA and C adults, but data regarding metabolic differences between races at birth remains scarce. The purpose of the present study was to determine if there are racial differences in substrate metabolism evident at birth utilizing mesenchymal stem cells (MSCs) collected from offspring umbilical cords. Using radio-labeled tracers, MSCs from offspring of AA and C mothers were tested for glucose and fatty acid metabolism in the undifferentiated state and while undergoing myogenesis in vitro. Undifferentiated MSCs from AA exhibited greater partitioning of glucose towards non-oxidized glucose metabolites. In the myogenic state, AA displayed higher glucose oxidation, but similar fatty acid oxidation rates. In the presence of both glucose and palmitate, but not palmitate only, AA exhibit a higher rate of incomplete fatty acid oxidation evident by a greater production of acid soluble metabolites. Myogenic differentiation of MSCs elicited an increase in glucose oxidation in AA, but not in C. Together, these data suggest that metabolic differences between AA and C races may exist at birth.

Purpose: The objective of this study is to assess the effects of supervised, recommended levels of prenatal aerobic exercise on 1-month-old infant cardiac function. Methods: Eligible pregnant women were randomly assigned to either an aerobic exercise group that participated in 150 min of supervised, moderate-intensity (40% to 59% VO 2peak , 12 to 14 on Borg rating of perceived exertion) aerobic exercise per week for 24 wk or more or a nonexercising group that consisted of 150 min•wk −1 of relaxation techniques. One-month-old infant echocardiogram was performed to assess infant cardiac function, including heart rate (HR), left-ventricular stroke volume, cardiac output, cardiac index, ejection fraction, fractional shortening, and velocity time integral at the aortic valve. Pearson correlation analyses and linear regression models were performed. Results: Prenatal aerobic exercise was negatively correlated with infant resting HR (r = −0.311, P = 0.02). Similarly, when controlling for infant sex and activity state, exercise level/volume (β = −0.316; 95% CI, −0.029 to −0.002; P = 0.02) predicted resting infant HR (R 2 = 0.18, P = 0.02). In infants of overweight/obese women, infants of aerobic exercisers had increased fractional shortening (P = 0.03). In addition, infant ventricular ejection fraction was correlated with maternal exercise attendance (r = 0.418, P = 0.03) as well as a trend for exercise level (r = 0.351, P = 0.08). Similarly, the only significant regression model for infants of overweight/obese women controls infant activity state ( β = −0.444; 95% CI, −0.05 to −0.01; P = 0.006) and maternal exercise level (β = 0.492; 95% CI, 5.46-28.74; P = 0.01) predicting infant resting HR (F = 5.79, R 2 = 0.40, P = 0.003). Conclusions: The findings of this study demonstrate that women participating in exercise in the second and third trimesters of their pregnancy may have infants with increased cardiac function at 1 month of age. Importantly, the cardiac function effects were further augmented for infants born to overweight/obese women.

Heart rate (HR) and heart rate variability (HRV) reflect autonomic development in infants. To better understand the autonomic response in infants, reliable HRV recordings are vital, yet no protocol exists. The purpose of this paper is to present reliability of a common procedure for analysis from two different file types. In the procedure, continuous electrocardiograph recordings of 5-10 min are obtained at rest in infants at 1 month of age by using a Hexoskin Shirt-Junior's (Carre Technologies Inc., Montreal, QC, Canada). Electrocardiograph (ECG; .wav) and R-R interval (RRi; .csv) files are extracted. The RRi of the ECG signal is generated by VivoSense (Great Lakes NeuroTechnologies, Independence, OH). Two MATLAB (The MathWorks, Inc., Natick, MA) scripts converted files for analysis with Kubios HRV Premium (Kubios Oy, Kuopio, Finland). A comparison was made between RRi and ECG files for HR and HRV parameters, and then tested with t tests and correlations via SPSS. There are significant differences in root mean squared successive differences between recording types, with only HR and low-frequency measures significantly correlated together. Recording with Hexoskin and analysis with MATLAB and Kubios enable infant HRV analysis. Differences in outcomes exist between procedures, and standard methodology for infant HR analysis is needed.